U.S. Department

of Transpor tation

Federal Aviation

Administration

Charles A. DeJohn

Stephen J.H. Véronneau

Alex M. Wolbrink

Julie G. Larcher

Federal Aviation Administration

Civil Aeromedical Institute

Oklahoma City, Oklahoma 73125

David W. Smith

University of Oklahoma

Norman, Oklahoma 73019

Joan Garrett

MedAire, Inc.

Phoenix, Arizona 85006

May 2000

Final Report

This document is available to the public

through the National Technical Information

Service, Springfield, Virginia 22161.

Office of Aviation Medicine

Washington, D.C. 20591

The Evaluation of In-Flight

Medical Care Aboard Selected

U.S. Air Carriers: 1996 to 1997

DOT/FAA/AM-00/13
NOTICE

This document is disseminated under the sponsorship of

the U.S. Department of Transportation in the interest of

information exchange. The United States Government

assumes no liability for the contents thereof.
iii

Technical Report Documentation Page

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.

DOT/FAA/AM-00/13

4. Title and Subtitle 5. Report Date

The Evaluation of In-Flight Medical Care Aboard Selected U.S. Air

Carriers: 1996 to 1997

May 2000

6. Performing Organization Code

7. Author(s) 8. Performing Organization Report No.

DeJohn, C.A., Véronneau, S.J.H., Wolbrink, A.M., Larcher, J.G.1;

Smith, D.W.2

; and Garrett, J.3

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS)

11. Contract or Grant No.

1

FAA Civil Aeromedical Institute , P.O. Box 25082, Oklahoma City, OK 73125

2

University of Oklahoma, Norman, OK 73019

3

MedAire, Inc., Phoenix, AZ 85006

DTFA 02-97P53665

12. Sponsoring Agency name and Address 13. Type of Report and Period

Covered

Office of Aviation Medicine

Federal Aviation Administration 14. Sponsoring Agency Code

800 Independence Ave., S.W.

Washington, DC 20591

15. Supplemental Notes

This work was performed under task AMB-97-TOX-203

16. Abstract

Medical care in-flight and the FAA-mandated medical kit have been studied for many years. This study

includes a detailed correlation between in-flight medical care, patient response in-flight, and post-flight

follow-up, in an effort to evaluate in-flight medical care delivery on US airlines and re-evaluate the FAAmandated in-flight medical kit. A survey of five US domestic air carriers from October 1, 1996, to

September 30, 1997, showed 1132 in-flight medical incidents. These airlines accounted for

approximately 22% of scheduled US domestic enplanements during the period. There was good overall

agreement between in-flight and post-flight diagnoses (70% of cases), and passenger condition

improved in a majority of cases (60%), suggesting that in-flight diagnoses were generally accurate and

treatment was appropriate. Results indicated that bronchodilator inhalers, oral antihistamines, and nonnarcotic analgesics, all of which were obtained from other passengers, were used frequently enough to

support a suggestion to include them in the medical kit.

17. Key Words 18. Distribution Statement

In-Flight Medical Emergencies, In-Flight Fatalities, InFlight Medical Care, Medical Flight Diversions, InFlight Medical KitDocument is available to the public through

the National Technical Information Service,

Springfield, Virginia 22161

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price

Unclassified Unclassified 26

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

v

TABLE OF CONTENTS

INTRODUCTION-------------------------------------------------------------------------------------------------1

METHODS ----------------------------------------------------------------------------------------------------------1

Sources of Data ------------------------------------------------------------------------------------------------1

Nature of the Data --------------------------------------------------------------------------------------------2

Potential Additions to In-flight Medical Kit-------------------------------------------------------------2

Evaluation of In-flight Medical Care ----------------------------------------------------------------------3

RESULTS -------------------------------------------------------------------------------------------------------------3

Categories of In-flight Medical Events --------------------------------------------------------------------3

Diversions of Flights With In-flight Medical Events ---------------------------------------------------3

Frequency of In-flight Medical Kit Use-------------------------------------------------------------------4

Overall Patient Response In-flight -------------------------------------------------------------------------4

Patient Response Associated With In-flight Medical Kit Use ----------------------------------------5

Medical Personnel Onboard During In-flight Medical Events ---------------------------------------5

Medical Kit Users During In-flight Medical Events----------------------------------------------------5

Diversions and Medical Kit Users During In-flight Medical Events --------------------------------6

Patient Disposition Following In-flight Medical Events-----------------------------------------------6

Fatalities Associated With In-flight Medical Events ----------------------------------------------------7

Potential Additions to the In-flight Medical Kit --------------------------------------------------------7

Comparison of In-flight and Hospital Discharge Diagnostic Categories ------------------------ 11

DISCUSSION ----------------------------------------------------------------------------------------------------- 12

Limitations of the Study ----------------------------------------------------------------------------------- 12

Frequency of In-flight Medical Events ------------------------------------------------------------------ 13

Categories of In-flight Medical Events ------------------------------------------------------------------ 13

Diversions of Flights With In-flight Medical Events ------------------------------------------------- 13

Diversion Categories for In-flight Medical Events---------------------------------------------------- 14

Diversions and Medical Kit Use-------------------------------------------------------------------------- 14

Overall Patient Response In-flight ----------------------------------------------------------------------- 14

Patient Response Associated With In-flight Medical Kit Use -------------------------------------- 14

Medical Personnel Onboard and Medical Kit User--------------------------------------------------- 14

Diversions and Medical Kit User------------------------------------------------------------------------- 15
Patient Disposition Following In-flight Medical Events--------------------------------------------- 15

Fatalities Associated With In-flight Medical Events -------------------------------------------------- 15

Potential Additions to the Medical Kit ----------------------------------------------------------------- 16

Comparison of In-flight and Hospital Discharge Diagnostic Categories ------------------------ 16

Severity of In-flight Medical Incidents------------------------------------------------------------------ 16

CONCLUSIONS ------------------------------------------------------------------------------------------------- 16

RECOMMENDATIONS --------------------------------------------------------------------------------------- 17

REFERENCES----------------------------------------------------------------------------------------------------- 17

APPENDIX A

Table A-1. Frequency of Use of Medical Kit Items -------------------------------------------------A1

Table A-2. Frequency of Use of Items Not Included in the Medical Kit -----------------------A1

List A-1. Information Provided by MedAire -------------------------------------------------------A2

List A-2. Data Coded by CAMI ----------------------------------------------------------------------A2

List A-3. CAMI Diagnostic Code Categories ------------------------------------------------------A2

List A-4. Treatment Code Categories----------------------------------------------------------------A3

List A-5. Discharge Diagnostic Code Categories--------------------------------------------------A3

List A-6. Outcome Code Categories -----------------------------------------------------------------A3

vi
1

THE EVALUATION OF IN-FLIGHT MEDICAL CARE ABOARD

SELECTED U.S. AIR CARRIERS: 1996 TO 1997

INTRODUCTION

On March 3, 1981, the Public Citizen Health

Research Group of the Aviation Consumer Action

Project (ACAP) petitioned to amend the Federal

Aviation Regulations (FARs) to require the carriage

of emergency medical equipment on commercial

flights in addition to the FAA required first aid kit.

The petition urged that US air carriers be required to

have onboard emergency equipment and medication

that would enable crew-members and/or medically

qualified passengers to respond to any in-flight emergency. On March 14, 1985, the Federal Aviation

Administration (FAA) published Notice of Proposed

Rulemaking (NPRM) Number 85-9 on emergency

medical equipment and on January 6, 1986, published a final rule requiring medical kits on commercial aircraft, although airlines have never been

specifically mandated to provide medical attention to

passengers (Federal Aviation Administration, 1986).

The FAA-mandated medical kit has been the topic

of study for many years (Hordinsky & George, 1991a;

Hordinsky & George, 1991b; Thibeault, 1998;

DeJohn, Véronneau, and Hordinsky, 1997). A primary question of interest is whether additional items

should be included by regulation in the FAA required

medical kit. The current medical kit, as mandated

under Title 14 of the Code of Federal Regulations

(CFR) Part 67, §67.121.309(d) and shown in Table

A-1, has a limited number of items. Additional drugs,

or drugs with different routes of administration,

might be useful in specific incidents. Attitudes toward the medical kit have varied widely and several

recent studies have asserted that the FAA mandated

in-flight medical kit is inadequate. Speizer, Rennie &

Breton (1989) found that none of the 260 passengers

arriving at the Los Angeles International airport

during a one year period from 1985 to 1986, who

developed medical complaints in-flight, benefited

from the equipment or drugs available, no deaths

were prevented, and the absence of qualified personnel onboard may have rendered any in-flight medical

kit useless. In contrast, Cottrell et al. (1989) reported

that 26% of 157 health care providers who used the

kit in-flight thought that it was very useful, 55% felt

that it was somewhat useful, and 18% felt that it was

not of any benefit, and Cummins and Schubach

(1989) suggested that though the medical kit contained useful items, it was inadequate to deal with

several problems that may occur in-flight and suggested several medications be added to the kit to

improve it. In addition, Rosenberg and Pak (1997)

listed what they broadly classified as mechanical and

logistical limitations that made kits inadequate for

dealing with emergencies. In their review, they made

the observation that in-flight medical problems often

require the administration of medications not found

in the kit, which frequently may be obtained from

other passengers. Also, Prew (1997) went as far as to

state that some medical experts believe that without

special care, including drugs and a defibrillator, there

is not much chance of long-term survival for an inflight cardiac patient. These studies and significant

technical shifts in the last few years suggest that the

contents of the medical kit might be re-evaluated and

changes considered.

While there have been several studies that have

evaluated in-flight medical care aboard commercial

airlines (Rodenberg, 1987; Cummins et al., 1988;

Speizer, Rennie, & Breton, 1989; Cummins &

Schubach, 1989; Cottrell et al., 1989; Hordinsky &

George, 1991a; Hordinsky & George, 1991b;

Rosenberg & Pak, 1997; DeJohn, Véronneau, &

Hordinsky, 1997), they generally did not include a

detailed correlation between medical care and patient

response in-flight, and post-flight follow-up. The

present study attempts to compare patient response

to in-flight medical treatment with follow-up information in an effort to evaluate in-flight medical

treatment on domestic US air carriers, and the appropriateness of flight diversions for medical reasons.

METHODS

Sources of Data. A survey was undertaken of inflight medical care aboard domestic US air carriers

that contract with MedAire, Inc. for in-flight medical support. MedAire is a private medical service
2

company that provides in-flight assistance to airlines

during medical incidents. Normally this assistance

takes the form of a radio patch between the aircraft

and a ground-based emergency-room physician who

advises the in-flight medical provider on medical

treatment decisions, and the aircrew on diversion

decisions. Only those incidents that involved an airto-ground radio patch with MedAire were included

in the survey. The survey included five US airlines

that contracted with MedAire, and showed there

were 1132 in-flight medical incidents from October

1, 1996 to September 30, 1997. These air carriers

accounted for approximately 22% of the total number of enplanements for US domestic scheduled air

carriers during this period (Austin, 1997).

Nature of the Data. Internal data collection forms

were used by MedAire to collect the data at the time

of each in-flight event. After the event, a record was

completed by the MedAire staff, based on their own

experience and the advice of any medical personnel

onboard at the time of the incident. The MedAire

staff then entered the information from each record

into a Microsoft Access® database designed by the

FAA Civil Aeromedical Institute (CAMI).

Information provided by MedAire included patient demographics, flight information, flight diversion status, details of the in-flight medical event,

outcome, and post-flight discharge diagnosis (List A1). Most of the information supplied by MedAire was

closed-formatted, allowing a specific list of responses;

however, some information was open-ended, permitting a wide variation of the entered data. Six areas of

primary interest included: patient presentation, inflight diagnosis, treatment, medical kit items used,

outcome, and post-flight discharge diagnosis. All

open-ended items were later coded by the CAMI

medical staff into fixed categories more suitable to

data analysis including patient demographics, flight

information, diversion status, in-flight treatment

category, CAMI diagnostic category, outcome category, and post-flight discharge diagnostic category

(List A-5). Patient demographics included age, gender, and medical history. Flight information included the origin, destination, and type of aircraft.

Treatment data, provided in text format, were coded

into several categories, including specific medications, patient monitoring, and supportive therapy

(List A-4). Similarly, outcome data were coded to

reflect what type of post-flight medical treatment

facility the patient was transferred to, or whether

follow-up treatment was refused or canceled (List A6). Also, discharge diagnostic category was coded

using the post-flight discharge diagnosis data (List A5). In addition, the patient’s demographics, presenting symptoms, in-flight diagnosis, in-flight treatment,

response to in-flight treatment, medical kit items

used, diversion status of the flight, outcome, and

post-flight discharge diagnosis when available, were

all considered in coding the CAMI diagnostic category (List A-3).

Data collection was unique in that it involved

radio communication between an aircraft in-flight

with a physician on the ground. This environment

often limits the ability of the ground-based physician

to accurately assess and diagnose the airborne emergency situation. The patient can be interviewed and

observed with the most rudimentary medical equipment, essentially a stethoscope and sphygmomanometer. Additionally, only a limited choice of treatments

are normally available in-flight. Although items used

from the medical kit may be supplemented by medications obtained from other passengers, signs and

symptoms are likely to be the only reliable information available. As a result, onboard medical conclusions are frequently tentative, and often an accurate

diagnosis will not be possible. Consequently, both

the in-flight diagnosis and treatment must be viewed

with caution and accepted as the best possible conclusions and actions that could be made during an inflight medical incident. However, the additional

quality assurance provided by CAMI physician review allowed for accurate post-flight categorization

of cases, which reflected detailed post-flight verification data, including patient outcome, and post-flight

discharge diagnosis.

Potential Additions to In-flight Medical Kit

(IMK). Frequency tables of usage rates for specific

items or categories of items were used to determine

potential additions to the medical kit. Items that

were frequently obtained from other passengers and

used, but not available in the currently mandated

medical kit (Table A-2) were primary candidates for

additions. The criteria for selection of potential additions to the IMK resulted from a review of the data,

which suggested that additional items should be

considered for inclusion in the medical kit if: (1) the

item was used in more than 2% of all cases, or (2) the

item was used in more than 1% of all cases where 1/

3 or more of those cases occurred in a single category.

For example, diphenhydramine is available in injectable
3

form in the medical kit but may also be commonly

obtained as Benadryl, an oral preparation, from another passenger. Oral Benadryl use was therefore

compared to injectable diphenhydramine use to evaluate whether the oral form of the drug should be

included in the medical kit. Although an attempt was

made to collect data on in-flight medical provider

preferences, there were not enough responses from

in-flight medical care providers to that item on the

questionnaire to properly evaluate the question.

Unfortunately, this approach does not address

items that are not included in the medical kit and not

routinely carried by passengers, but could have been

useful if they had been available to the health care

provider in-flight. Such items could not be defined in

this study because of insufficient responses to the

appropriate question on the questionnaire.

Evaluation of In-flight Medical Care. Other specific analyses included examining the quality of inflight medical care delivery; patient response to

in-flight medical care, including final outcome; and

a comparison between in-flight diagnosis and treatment and hospital diagnosis and treatment.

RESULTS

We studied 1132 in-flight medical events which

occurred on five US domestic Part 121 air carriers

from October 1, 1996 to September 30, 1997. Of the

1125 cases that reported gender, 596 were females

and 529 were males. The mean age of the 1057

individuals for whom age was known was 49 years,

and the range was seven weeks to 106 years.

Categories of In-flight Medical Events. Each case

was assigned a category (List A-3) based on the

patient’s presenting symptoms, in-flight diagnosis,

in-flight treatment, response to in-flight treatment,

medical kit items used, the diversion status of the

flight, outcome, post-flight discharge diagnosis, and

medical history (Table 1). Although vasovagal cases

occurred with the greatest frequency, the most common serious categories of in-flight medical events

were cardiac (20%), neurological (12%), and respiratory (8%).

Diversions of Flights With In-flight Medical

Events. A diversion was defined as a flight that landed

at an airport other than the scheduled destination due

to an in-flight medical event involving a passenger.

Of the 1132 in-flight medical incidents (IMIs), 145

Category Frequency Percent

Vasovagal 254 22.4

Cardiac 221 19.5

Neurological 134 11.8

Respiratory 92 8.1

Gastrointestinal 90 7.7

Trauma 60 5.3

Endocrine 53 4.7

Miscellaneous 52 4.6

Psychological 38 3.4

Vascular 35 3.1

OB/GYN 33 2.9

Allergic Reaction 27 2.4

ENT 20 1.8

Urological 18 1.6

Not Reported 3 0.3

Unknown 2 0.2

Total 1132 100

Table 1. Categories of In-flight Medical Incidents.

(13%) resulted in an emergency diversion. This represents a diversion rate of about one passenger per one

million enplanements.

Of the 449 cases where physicians were onboard,

70 (16%) flights were diverted for medical reasons.

In contrast, of the 683 cases where there was no

physician onboard, 75 (11%) flights were diverted. A

chi-square test performed on the data, which is summarized in Table 2, shows that the presence of a

physician was associated with an increase in the

percentage of diversions (χ2 = 4.75, p < 0.03).

Diversion

Yes No Total

Yes 70 379 449

No 75 608 683

Physician

Onboard

Total 145 987 1132

Table 2. Flight Diversions and Physician Presence.
4

Table 3 summarizes flight diversions by category.

There were no diversions reported for the “ENT,”

“Urological,” “Not Reported,” and “Unknown” categories. Cardiac incidents had the greatest percentage

of diversions (30%) followed by obstetrical-gynecological incidents (21.2%), and neurological incidents (19.4%).

Frequency of In-flight Medical Kit (IMK) Use.

The IMK was used in 533 out of 1132 in-flight medical

incidents (47%), it was not used 543 times (48%), and its

use status was not reported in 56 cases (5%).

Table 4 shows the relationship between the number of times the IMK was used and whether or not the

flight was diverted. Unreported cases are not included in the table; therefore, the total of diversions

and non-diversions is not equal to 1132. The kit was

used in 82 out of 127 cases (65%) when the flight

diverted, and in 451 out of 949 flights (48%) that did

not divert. The data, therefore, indicate that there is

a greater likelihood that the IMK was used when

there was a diversion (χ2

 = 12.34, n = 1, p < .001).

Overall Patient Response In-flight. The medical

condition of passengers improved in 60% of cases,

remained the same in 12% of cases, worsened in 2%

of cases, and was not reported by MedAire in 26% of

cases as indicated in Table 5.

Category Category

Total

Category

Percent

Diversions

in Category

Category

Diversion Rate

(%)

Percent of

All

Diversions

(%)

Cardiac 221 19.5 66 30.0 45.5

OB/GYN 33 2.9 7 21.2 4.8

Neurological 134 11.8 26 19.4 18.0

Vascular 35 3.1 5 14.3 3.4

Endocrine 53 4.7 6 11.3 4.1

Respiratory 92 8.1 9 9.8 6.2

Miscellaneous 52 4.6 5 9.6 3.4

Gastrointestinal 90 8.0 7 7.8 4.8

Psychological 38 3.4 2 5.3 1.4

Vasovagal 254 22.4 10 3.9 6.9

Allergic Reaction 27 2.4 1 3.7 0.7

Trauma 60 5.3 1 1.7 0.7

Total* 1089* 96.2* 145* N/A* 100*

*

Total does not equal 100% because “Not Reported” and “Unknown” categories are not included.

Table 3. Flight Diversion Frequency by Category.

IMK Used

Diversion Yes No Total

Yes 82 45 127

No 451 498 949

Total 533 543 1076

Table 4. Flight Diversions by In-flight Medical

Kit Use.

Response Frequency Percent

Improved 675 60

Unchanged 136 12

Worsened 27 2

Not Reported 294 26

Total 1132 100

Table 5. Overall Patient Response In-flight.

Patient Improved

Yes No Total

Yes 291 57 348

No 385 106 491

Physician

Onboard

Total 676 163 839

Table 6. Patient Improvement Associated With

Physician Presence.
5

Of the 348 cases (Table 6) where physicians were

onboard and overall patient response was reported,

patient condition improved 291 times (84%). By

comparison, of the 491 cases where there was no

physician onboard and patient response was reported,

patient condition improved 385 times, (78%). A chisquare test performed on the data, which is summarized in Table 6, showed that the presence or absence

of a physician onboard was unrelated to the number

of patients who improved in-flight.

Patient Response Associated With In-flight Medical Kit Use. Table 7 shows that, in general, use of the

medical kit was associated with patient response (χ2

= 8.74, p = 0.013). While there was no significant

difference in the number of patients who improved

in-flight as a result of medical kit use, more patients’

conditions worsened with kit use compared to those

without kit use (Z = – 0.096, p = 0.011). This

association may have been confounded by differences

in the severity of the cases and, although statistically

significant, may not be of clinical importance.

Medical Personnel Onboard During In-flight

Medical Events. Data provided by MedAire (List A1) indicates physicians were available approximately

40% of the time, nurses 25% of the time, and EMTs

4% of the time as shown in Table 8. “Other” includes

physician’s assistant, nurse practitioner, dentist, and

other individuals who may not have been health care

professionals. “None” implies that the medical kit

was not used.

Medical Kit Users During In-flight Medical

Events. Table 9 shows how frequently each type of

medical care provider used the IMK. Cases where the

medical kit user was not reported are not shown in the

table. It is interesting to note that physicians did not

appear to use the kit proportionately more often than

other groups of health care professionals.

IMK Used

Patient

Response

Yes No Total

Improved 349 314 663

Unchanged 73 60 133

Worsened 22 5 27

Total 444 379 823

Table 7. Patient Response Associated

With In-flight Medical Kit Use.

Medical Personnel Frequency Percent

Physician 449 40

Nurse 278 25

None 249 22

EMT 48 4

Other 47 4

Not Reported 34 3

Paramedic 27 2

Total 1132 100

Table 8. Medical Personnel Onboard.

Medical Kit User Onboard Used Kit

Percent

of Time

Used

Physician 449 275 61

Nurse 278 190 68

Emergency Medical Technician (EMT) 48 28 58

Other 41 25 61

Paramedic 27 11 41

Physician's Assistant 4 2 50

Nurse Practitioner 1 1 100

Dentist 1 1 100

Table 9. Medical Kit Users.
6

Diversions and Medical Kit Users During Inflight Medical Events. Physicians used the IMK

most often during flights that were diverted (30%),

followed by nurses, and EMTs (Table 10). For this

analysis, two paramedics were re-categorized and

included in the “Other” category resulting in a total

of eight flight diversions for that category.

Patient Disposition Following In-flight Medical

Events. Many patients who experienced an in-flight

medical event refused medical advice (RMA), as

shown in Table 11. RMA implies that treatment was

indicated but the patient refused further medical

treatment following the flight. Of those patients who

received medical treatment, most were treated at the

airport, either in an airport clinic or by EMTs or

paramedics. The next largest group of patients were

seen in the emergency room (ER).

Nine out of the 15 fatalities were not transported

to a treatment facility and are tabulated separately in

Table 11 as “Un-transported Fatalities.” The remaining

six fatalities were transported to treatment facilities

but eventually expired, and they are categorized according to the type of treatment facility involved.

In those cases where further medical assistance at

a ground facility was canceled, it was not possible to

determine if cancellations were made because the

situation changed and the patient no longer required

medical attention, or the patient refused further

medical support. Of the 102 cancellations for further

medical assistance shown in Table 11, 60% were

made by the MedAire physician, 33% by the aircrew

(usually the captain), 3% by the patient, and 4% of

the time it was not known who canceled the response.

Of the 179 patients transported to the hospital,

173 were admitted with an average stay of 2.8 days,

although the type of floor or service was known in

only ten cases. Of those ten cases, three were admitted

to the medical floor, two to the neurological service,

two to the obstetrical/gynecological floor, and one to

orthopedics.

IMK User Frequency

of

Diversions

Percent

of

Diversions

Physician 43 30

Nurse 28 19

EMT 3 2

Other 8 6

None 45 31

Not Reported 18 12

Total 145 100

Table 10. Flight Diversions and Medical Kit Users.

Patient

Disposition RMA Airport ER Hospital Canceled

Not

Reported

Un-transported

Fatalities Total

Number of

Patients 340 289 196 179 102 17 9 1132

Percent of

Patients 30 26 17 15 9 2 1 100

Table 11. Patient Post-flight Disposition.
7

As shown in Table 12, of the 173 patients admitted to the hospital, 40 were admitted to an intensive/

critical care unit (ICU/CCU) with an average length

of stay of 3.1 days, while 30 patients were admitted

to a telemetry unit for an average of 2.7 days, and 5

patients were sent to an intermediate care unit staying

an average of 2.2 days.

Of the 40 patients admitted to an ICU/CCU, 38

were admitted to a medical unit with an average

length of stay of three days; one patient was admitted

to a cardiac unit for a day, and another was admitted

to a surgical unit for a day. Although only one patient

was sent to a cardiac intensive care unit, this does not

imply that there was only one cardiac intensive care

case. Many hospitals do not have separate cardiac or

surgical intensive care units; therefore, all serious

cases go to a general medical CCU or ICU. When the

categories of the 38 patients who were admitted to

general ICUs/CCUs were checked, it was discovered

that 27 of the patients were diagnosed as cardiac cases in

flight. In addition, the one case admitted to the surgical

intensive care unit was also diagnosed as a cardiac

patient. Consequently, 27 of the 40 patients who were

admitted to critical care units were cardiac cases.

Five of the 173 patients admitted to the hospital

were sent to intermediate care units with an average

length of stay of 2.2 days. Two patients were sent to

a general medical intermediate care unit, one patient

was sent to a cardiac unit, another to a surgical unit,

and one patient was sent to an intermediate care unit

where the type of unit was not specified. The average

length of stay for the two medical patients was 2.5

days, while the length of stay for the cardiac, surgical,

and unknown patients was four days, one day, and

one day respectively. While this implies that only one

cardiac patient was sent to an intermediate care unit,

many hospitals do not have separate cardiac intermediate care units and patients are simply sent to a

medical intermediate care unit. When the categories

of the two patients admitted to general intermediate

care units were checked, it was discovered that one of

them was a cardiac case while one was a neurological

case; consequently, two of the five patients who were

admitted to intermediate care units were actually

cardiac cases.

Fatalities Associated With In-flight Medical

Events. A fatality was defined as a passenger death

that occurred at any time in-flight, during transport

to a treatment facility, or at a treatment facility.

Fifteen of 1132 cases were fatalities for a case fatality

rate of 13.3 per 1000 patients. A summary of the

post-flight diagnostic categories for fatalities (CAMI

diagnostic categories) is shown in Table 13.

In this, study two fatalities that were initially misclassified as “Respiratory” cases (as shown in parentheses) were later determined to be “Cardiac” deaths

when additional information became available from

the hospital. In other cases, the status of the patient

was unknown at the end of the flight; however,

details were subsequently available from the admitting hospital or emergency room.

Potential Additions to the In-flight Medical Kit.

A review and analysis of the data suggested criteria for

inclusion of additional items in the medical kit: (1) if

the item was used in more than 2% of all cases, or (2)

if the item was used in more than 1% of all cases

where 1/3 or more of those cases occurred in a single

category. Table 14 summarizes the items that met

either of these criteria.

Oxygen, supportive care (i.e., orange juice, recline, cover with blanket, etc.), close patient monitoring, and analgesics met the first criterion (> 2% of

all cases) by wide margins. Nitroglycerin, other than

from the medical kit, met both criteria (> 2% of all

cases and more than 1/3 of cases in a single category).

Specialty Care

Unit

Number of

Patients

Average Length of

Stay (Days)

ICU/CCU 40 3.1

Telemetry 30 2.7

Intermediate 5 2.2

Total 75 2.7

Table 12. Distribution of Patients in Specialty Care Units.
8

Age Sex Presentation Category Kit User Diversion Outcome

61 F Short of breath and

vomiting.

Cardiac

(Respiratory)

Nurse No Pronounced dead

at hospital.

79 F Passenger expired

according to the nurse on

board. Pulseless, apneic,

pupils fixed and dilated.*

Cardiac Nurse No Pronounced dead

at gate.

75 M Problems breathing, and

unconscious.

Cardiac Physician No Pronounced dead

at gate.

27 F Not breathing. CPR was

initiated. In cardiac arrest.

Cardiac Not Reported Yes Expired at

hospital.

65 M Pale, not breathing, not

moving, cold to the touch.*

Cardiac Not Reported No Pronounced dead

at gate.

67 F Unconscious, unresponsive,

unable to find pulse.

Cardiac None Yes Expired at

hospital.

71 M Short of breath. Cardiac

(Respiratory)

None No Admitted to

hospital; ICU for 3

days & telemetry

for 6 days before

expiring.

71 M Difficulty breathing. Cardiac None No Pronounced dead

at gate.

68 M Difficulty breathing.

Respiratory arrest.

Cardiac Nurse No Pronounced dead

at gate.

70 F Respiratory arrest. Cardiac None No Pronounced dead

at gate.

80 M Syncopal episode in

lavatory; vomited and

unconscious.

Cardiac None No Expired at

unreported time.

32 F Abdominal pain. OB/GYN Other No Admitted to

hospital where

patient later

expired.

36 F Unconscious and not

breathing.

Drug Overdose Paramedic Yes Patient expired at

hospital.

48 M Cardiac arrest.* Cardiac Physician No Patient was later

pronounced dead.

40 M Non-responsive. Cancer None Yes Transported to

hospital where he

later expired.

* Indicates cases where information suggests patient may have died on the airplane.

Table 13. Summary of Fatalities
9

A bronchodilator inhaler and an oral antihistamine

met the second criterion (> 1% of all cases and more

than 1/3 of cases in a single category).

After identifying items that might be considered

for inclusion in the medical kit, the impact of these

items on patient response to in-flight medical care

was investigated. In Table 15, frequencies are shown

above, while percentages associated with changes in

patient condition are shown below in parentheses.

On average, a passenger’s condition improved approximately 84% of the time when these measures

were employed. Interestingly, close patient monitoring was associated with improvement about 90% of

the time. Of those items that could be added to the kit,

a bronchodilator inhaler and an oral antihistamine

appeared to have the greatest effect on positive patient response to treatment; however, analgesic therapy

also showed good results.

Table 16 summarizes cases where bronchodilator

therapy was used in-flight, while reflecting whether

oxygen was used, and the passenger’s response to the

treatment.

Item

Percent

of Total

Cases Category

Category

Frequency

Total

Frequency

Oxygen 58.2 N/A N/A N/A

Supportive care 40.8 N/A N/A N/A

Monitor patient 36.1 N/A N/A N/A

Analgesic 4.1 N/A N/A N/A

Nitroglycerin (not from kit) 3.4 Cardiac 35 38

Bronchodilator inhaler 1.6 Respiratory 14 18

Oral antihistamine 1.0 Allergic

reaction

8 11

Table 14. Summary of Response Frequencies for Potential Additions to the Medical Kit.

Item Worse Unchanged Improved

Monitor patient 9

(3.0%)

21

(7.0%)

271

(90.0%)

Nitroglycerin

(not from kit)

1

(3.1%)

3

(9.4%)

28

(87.5%)

Bronchodilator

Inhaler

1

(6.3%)

1

(6.3%)

14

(87.5%)

Oral

Antihistamine

0

(0.0%)

1

(12.5%)

7

(87.5%)

Supportive Care 13

(3.6%)

51

(14.2%)

296

(82.2%)

Oxygen 25

(4.6%)

79

(14.5%)

442

(81.0%)

Analgesic 0

(0.0%)

8

(29.6%)

19

(70.4%)

Mean 2.9 13.4 83.7

Table 15. Effect on Patient Response of Treatments/Potential Additions

to the Medical Kit.

Bronchodilator Therapy Cases

Oxygen

Used Worsened Unchanged Improved

Yes 1 1 12

No - - 2

Table 16. Oxygen Use in Bronchodilator Therapy.
10

In-flight Diagnostic Category

Cardiac (70)

Trauma (22)

Vasovagal (32)

Respiratory (20)

Misc. (15)

GI (15)

Neurological (22)

Vascular (12)

OB/GYN (8)

Endocrine (8)

ENT (5)

Allergic

Reaction (4)

Psychological (3)

Urological (3)

Cardiac (62) 57 0 4 0 0 0 0 0 0 1 0 0 0 0

Trauma (22) 0 22 0 0 0 0 0 0 0 0 0 0 0 0

Vasovagal (29) 5 0 22 1 0 0 1 0 0 0 0 0 0 0

Respiratory (20) 0 0 1 18 1 0 0 0 0 0 0 0 0 0

Misc. (22) 2 0 1 1 12 3 3 0 0 0 0 0 0 0

GI (14) 1 0 0 0 0 11 1 0 1 0 0 0 0 0

Neurological (10) 0 0 0 0 0 0 9 1 0 0 0 0 0 0

Vascular (23) 3 0 3 0 1159 0 1 0 0 0 0

OB/GYN (8) 0 0 0 0 1 0 0 0 7 0 0 0 0 0

Endocrine (10) 0 0 1 0 0 0 2 1 0 6 0 0 0 0

ENT (5) 0 0 0 0 0 0 0 0 0 0 5 0 0 0

Allergic (4)

Reaction

0 0 0 0 0 0 0 0 0 0 0 4 0 0

Psychological (6) 2 0 0 0 0 0 1 0 0 0 0 0 3 0

Post-flight Diagnostic Category

Urological (4) 0 0 0 0 0 0 0 1 0 0 0 0 0 3

Table 17. Comparison of In-flight and Post-flight Diagnostic Categories.
11

The overwhelming majority of patients who received both bronchodilator and oxygen therapy improved; however, there were not enough cases that

did not receive oxygen therapy in conjunction with

bronchodilator therapy to allow a proper comparative analysis. In fact, the two cases that did not receive

oxygen with a bronchodilator improved.

Comparison of In-flight and Hospital Discharge

Diagnostic Categories. Post-flight diagnostic categories were obtained from patients who were seen in

the emergency room, airport clinic, or hospital. Postflight diagnostic categories were known in 239 out of

1132 cases, or approximately 21% of the time. Those

cases where in-flight diagnostic category and postflight discharge diagnostic category were known are

compared in Table 17. Cases classified as “Unknown”

were not included in the comparison. In-flight diagnostic categories are shown as columns, while postflight diagnostic categories are shown as rows. The

figure in parentheses next to each category indicates

the number of cases in that category. All cases where

in-flight diagnostic category agrees with post-flight

diagnostic category appear on the diagonal in the

table. In-flight and post-flight diagnostic categories

agreed in 188 out of 239 cases (79%). Accepting

post-flight diagnoses as accurate, further comparisons are possible. For example, while 70 patients were

assigned a cardiac diagnostic category in-flight, only

62 were similarly classified on discharge from the

hospital, with agreement in 57 cases. There are two

ways that the in-flight category can disagree with the

post-flight category: (1) a cardiac category could be

assigned in-flight and a non-cardiac category can be

assigned post-flight (i.e., over-diagnosis in-flight), or

(2) a non-cardiac category could be assigned in-flight

where a cardiac category is assigned post-flight (i.e.,

under-diagnosis in-flight). Examination of the cardiac column (in-flight diagnostic category) in Table

17 reveals that 16 patients were assigned a cardiac

diagnosis in-flight, and were later assigned a noncardiac diagnosis at hospital discharge, implying that

these patients might have been over-diagnosed as

cardiac patients in-flight. Looking at the cardiac row

(post-flight diagnostic category) in Table 17 shows

that five patients who were diagnosed as non-cardiac

in-flight, were eventually classified as cardiac cases

post-flight, suggesting that these patients might have

been under-diagnosed as cardiac patients in-flight.

A comparison of in-flight and post-flight diagnoses for cardiac cases is shown in Table 18. A Chisquare analysis of these data shows that there was

general agreement between in-flight diagnostic categories and post-flight discharge diagnostic categories (χ2 = 154.6, n = 1, p < .001).

Next, a post-hoc analysis was performed using a

McNemar test on the data to determine if cardiac

patients were over-diagnosed or under-diagnosed inflight. The results suggests that cardiac patients were

neither under- nor over-identified in-flight.

Similarly it can be demonstrated that non-neurological cases were over-identified as neurological inflight (χ2 = 8.6, n = 1, p < .003) while vascular

incidents were under-diagnosed in-flight and attributed to other causes (χ2 = 5.9, n = 1, p < .01). Of the

14 vascular cases, five were diagnosed in-flight as

neurological cases, three as cardiac, three as vasovagal, one as gastrointestinal, one as endocrine, and one

as miscellaneous. Of the 13 non-neurological cases

that were diagnosed as neurological cases in-flight,

two were later determined to be endocrine, one was

later diagnosed as gastrointestinal, one as psychological, five as vascular, one as vasovagal, and three as

miscellaneous.

Post-flight Discharge Category

In-flight Category Cardiac Non-cardiac Total

Cardiac 57 13 70

Non-cardiac 5 157 162

Total 62 170 232

Table 18. Comparison of In-flight and Post-Flight Diagnoses for Cardiac Cases.
12

An agreement rate of 92.2% was calculated for

cardiac cases by summing the total cases where inflight and post-flight diagnoses agreed (57 cardiac

plus 157 non-cardiac) and dividing by the total

number of cases (232). Agreement rates for the other

categories are summarized in Table 19.

DISCUSSION

Limitations of the Study. The experience of airlines that contract with MedAire for support during

in-flight medical emergencies may not be representative of the entire airline industry. First, many of the

more serious incidents may be reported on contracting airlines simply because a consistent approach to

their management is available. Second, the management of in-flight medical incidents may differ from

the management of incidents on other airlines. For

example, because knowledgeable emergency medical

staff are involved, the number of flight diversions for

medical reasons may decrease. Although conclusions

about the value of specific medical equipment or

supplies can be made about incidents managed under

the auspices of MedAire, the application of those

conclusions to the airline industry in general may not

be appropriate. Essentially, any conclusions about

the larger population of medical incidents are somewhat speculative.

Category

Agreement

Rate

(%)

Cardiac 92.2

Trauma 100.0

Vasovagal 92.9

Respiratory 98.3

Miscellaneous 94.6

GI 97.1

Neurological 94.1

Vascular 92.9

OB/GYN 99.2

Endocrine 97.5

ENT 100.0

Allergic Reaction 100.0

Psychological 98.7

Urological 99.6

Table 19. Comparison of In-flight and

Hospital Diagnoses for all Categories.

Frequency of In-flight Medical Events. We analyzed 1132 in-flight medical incidents that occurred

aboard five US domestic airlines from October 1,

1996 to September 30, 1997. These airlines carried

approximately 1.4 million passengers during that

time; therefore, our in-flight medical incident rate

was about 8 per million enplanements. This rate is

low compared with rates found in earlier studies. For

example, a 1996 Air Transport Association survey

yielded 17 incidents per million enplanements (Air

Transport Association, 1998), while a British Airways study found 31 incidents per million

enplanements (Harding & Mills, 1993), and a Qantas

study reported 48 incidents per million enplanements

(Davis & Degotardi, 1982). Differences between this

study and similar studies are probably due to the

different methodologies employed. Only those incidents that involved an air-to-ground radio patch are

included in the MedAire data. Minor in-flight medical incidents, that would have presumably been included in the other studies, would not have been

included in this study because they would not have

required an air-to-ground patch.

Categories of In-flight Medical Events. The six

most common causes of in-flight medical events were

vasovagal, cardiac, neurological, respiratory, gastrointestinal, and trauma. Category frequencies in

similar studies vary widely as shown in Table 20.

Differences in data collection methods and classification schemes employed in the various studies

make meaningful comparison between studies difficult. For example, some studies were limited to a

single airline and included only cases where the inflight medical kit was opened and a medical record

form, contained in the kit, was completed (Cottrell et

al., 1989). Other studies limited data collection to

passengers arriving at a single airport (Cummins &

Schubach, 1989; Speizer, Rennie & Breton, 1989).

In addition, the categorization of in-flight events

varied from one study to another. As an example,

some studies clearly defined cases as “vasovagal syncope” (Harding & Mills, 1993), while others were

not as clear as to what was included in the classification of “syncope” (Cummins & Schubach, 1989).

Diversions of Flights With In-flight Medical

Events. Diversions for medical reasons occurred for

only one in one million passengers. The same rate has

been found in earlier studies (Cummins & Schubach,

1989; Schoken & Lederer, 1970), indicating that

despite advances in medicine over the years, the
13

introduction of the in-flight medical kit in 1986, and

the more recent incorporation of in-flight telemedicine, the diversion rate for medical reasons has

remained small but constant.

Although most operations that occur on a “oncein-a-million” basis can generally be considered an

acceptable risk, there are two reasons that medical

diversions are important: (1) they are time consuming and expensive events, and (2) many of them can

be avoided. Diversions can affect the schedules of

large numbers of passengers who require accommodation and possible financial compensation for their

inconvenience. As an example, diversions cost British

Airways up to £500,000 ($893,000 US) in 1996

(Kahn, 1996). In addition, a series of time-consuming steps must be taken for any diversion to take

place. Not only must arrangements be made to receive and transport the ill passenger on landing, but

the available medical facilities at a potential alternate

destination must be considered. It would be unwise

to divert to another airport and determine too late

that ground transportation is not available for the

patient, or that the local medical facility cannot

provide the care required for the patient’s condition.

Also, the pilot, along with flight dispatch, must

determine a suitable landing airport, which may or

may not be serviced by the company or be familiar to the

flight crew. Landing weight is also a consideration, and

valuable fuel may have to be jettisoned to attain a

suitable landing weight for a premature touch-down.

Consequently, methods of avoiding flight diversions are constantly being sought. Three possibilities

include: (1) the presence of an onboard physician, (2)

passenger education, and (3) medical kit improvements. However, results showed that physicians were

onboard only 40% of the time and were associated

with the highest diversion rate among in-flight medical care providers. Educating travelers about the

nature of the aircraft cabin environment has been

suggested, since many passengers believe that cabin

pressure is the same as sea level and know very little

about hypoxia, dehydration, or the heightened effects of medication or alcohol at altitude (Kahn,

1996). Assertions that the kits were inadequate for

dealing with in-flight emergencies (Rosenberg &

Pak, 1997), passengers did not benefit from the

equipment or drugs available (Speizer, Rennie, &

Breton, 1989), and no deaths were prevented (Speizer,

Rennie, & Breton, 1989), have led researchers to

suggest several improvements (Thibeault, 1998).

Approximately 28 out of the 145 (19%), of the

flight diversions in this study were probably unnecessary in light of subsequent follow-up information.

In three of the 28 cases (two cardiac cases and one

Common Causes of In-flight Medical Incidents

(Percent of Total Incidents)

CAMI/

MedAire

(N=1132)

Donaldson

& Pearn

(1996)

(N=454)

Cummins &

Schubach

(1989)1

(N=1107)

Davies &

Degotardi

(1982)2

(N=45)

Speizer

et al. (1989)

(N=260)3

Cottrell

Et al.

(1989)

(N=362)

Harding

& Mills

(1993) 5

(N=2139)

Vasovagal 22 35 4 10 6 29 20

Cardiac 20 16 20 29 20 16 3

Neurological 12 4 8 4 4 4 03

Respiratory 8 6 8 2 9 10 5

Gastrointestinal 8 13 15 6 12 04 12

Trauma 5 4 14 7 6 04 04

1

In-flight cases only.

2

Physician reported incidents only.

3

Includes only the 123 cases where emergency department diagnosis was given.

4

Category was not listed among the six most common in this study.

5

Data from April 1990 to March 1991 British Airways study.

Table 20. Common Causes of In-flight Medical Incidents.
14

respiratory case) the passengers refused further medical advice; therefore, there was no post-flight followup. The remaining 25 cases did not appear to be

serious enough to have warranted a flight diversion

for medical reasons, according to post-flight treatment facility discharge information. Of the 25 cases,

nine were eventually diagnosed as vasovagal syncope,

five as dehydration, four as gastroenteritis, two as

viral infections, two as non-cardiac chest pain, one as

anxiety, one as false labor, and one as sickle cell

anemia. However, it must be emphasized that these

determinations were arrived at after careful consideration of post-flight treatment data that were not

available during the flight. Earlier studies reported an

even higher percentage of unnecessary diversions. In

their study, Schoken and Lederer (1970) estimated

that about half of the unscheduled landings could

have been avoided, while Cummins and Schubach

(1989) stated that all seven of the unscheduled landings in their study were probably unnecessary.

Diversion Categories for In-flight Medical Events.

It is interesting to note that those categories of inflight medical events that occurred with the highest

frequency did not necessarily account for the greatest

number of flight diversions. As an example, while

vasovagal incidents represented the greatest number

of cases, the percentage of diversions for that category

was low compared with other, more serious, categories. Other studies showed similar results. The three

categories that accounted for the most diversions in

this study were cardiac, neurological, and vasovagal,

while a 1970 American Airlines study (Schoken &

Lederer) listed the three most common reasons as

syncope, heart attack, and dyspnea.

Diversions and Medical Kit Use. In this study

there was a proportionately greater likelihood that

the IMK was used when there was a flight diversion.

Although this association is statistically significant, it

is probably confounded by differences in severity

between categories. This may be because the medical

kit is used more frequently in severe incidents, which

are more likely to result in a diversion; whereas,

minor incidents, which are less likely to cause the kit

to be used, are also less likely to result in a diversion.

Overall Patient Response In-flight . It is encouraging to note that in over half of the cases in our

study, passenger condition improved, whereas passenger condition worsened in only a few cases. Although patient condition improved most of the time

when there was a physician onboard, it was not

significantly different from when a physician was not

present. It is also possible that the 26% of unreported

cases were of a less serious nature, whereas the more

serious cases were followed-up and reported on. This

would imply that more patients might have actually

improved than are indicated by the data. These data

suggest that even under the difficult conditions encountered in-flight, diagnoses and treatment of passengers appears to be appropriate most of the time,

whether or not a physician is aboard. These data are

more encouraging than the 32% improvement rate

reported by Cottrell et al. (1989).

Patient Response Associated With In-flight Medical Kit Use. Our results showed that medical kit use

appeared to have an inverse relationship on patient

response; that is, kit use was associated with worsening patient condition. While these results appear to

be illogical, they are not, because the data are not the

result of a repeated measures experiment. The patients in the three categories (worsened, unchanged,

and improved) were different; therefore, the severity

of each case was a confounding variable. It is possible

that those patients whose condition improved had

less severe medical conditions that improved without

kit use, while patients whose condition worsened

may have had more severe medical conditions that

would have become worse with or without kit use. It

is also interesting to note that, while 60% of patients

improved overall in-flight, as shown in Table 5, only

31% of patients improved when the IMK was used as

shown in Table 7. This is probably because the

medical kit was used for more serious cases and was

not required for less severe cases. Stated differently,

those cases that involved medical kit use also involved the more seriously ill passengers who were less

likely to improve in-flight.

Medical Personnel Onboard and Medical Kit

User. While physicians identified themselves in-flight

approximately 40% of the time, they were the medical provider over half the time when the IMK was

used. In other studies, the availability of physicians

during in-flight medical events has been shown to

vary widely, from about 8% to approximately 85%

(Mills & Harding, 1983; Speizer, Rennie & Breton,

1989; Cummins et al., 1988; Cottrell et al., 1989;

and Hordinsky & George, 1991b). It is not clear,

however, whether physicians were actually onboard

more often but simply did not identify themselves.

For example, one study reported that at least one half

of physicians surveyed stated they were reluctant to
15

respond, usually because the problem would be outside their field of practice, or because they believed

they would be greatly hampered in conducting treatment on an aircraft (Hays, 1977).

Diversions and Medical Kit User. The results

imply that when the kit is not used (“None” in Table

10), flight diversions occur less frequently. Again,

this may be because when the medical kit is not used,

the incident may not be as serious, and a diversion

will be less likely.

While EMTs experienced the lowest percentage of

diversions among identifiable medical provider groups

responsible for diversions (2%), physicians had the

highest (30%). The higher proportion of diversions

for physicians might have resulted for a number of

reasons. Physicians would normally be expected to

take charge during the most serious in-flight events

that would ordinarily require a flight diversion. Also,

when they did suggested that a flight should divert,

their medical opinion may have weighed more heavily

with the flight crew and the MedAire physician than

when less highly trained health care professionals

made the same suggestion under similar circumstances. Some of the groups were represented by such

low frequencies, however, that small changes in the

number of cases could have produced large changes

in the percentage of diversions for that group, preventing meaningful analysis.

Patient Disposition Following In-flight Medical

Events. Out of 1,119 passengers who experienced an

in-flight medical event with a known outcome, 345

(31%) refused medical advice (RMA). This proportion is much greater than a 1989 study by Cummins

and Schubach which found that only 1% of passengers with in-flight emergencies declined recommended

advice.

A cancellation implied that either the medical

situation changed and treatment was no longer indicated, or the patient declined further medical treatment. Although it appears that few treatment

cancellations were made by the patient, there is no

way of determining how many cancellations may

have originated with the patient and been relayed by

the aircrew. Cancellations made by the aircrew or

patient imply that a physician may not have been

involved in the decision. Fortunately, the MedAire

physician was responsible for the majority of cancellations, which is the best situation, as it reflects a

decision made by a medical professional in possession of the best available information.

One hundred seventy-three patients were admitted to the hospital during the study, with an average

length of stay of 2.8, days compared with the national

average of 5.2 days for the same period (Centers for

Disease Control, 1999). The service to which they

were admitted was known in only 10 of the 173 cases;

therefore, meaningful conclusions could not be drawn.

Fatalities Associated With In-flight Medical

Events. There were 15 fatalities during the one-year

period of the study for a case fatality rate of 13.3 per

1000 patients. The mean age for fatalities was 59.3

years and the range was 32 to 80 years.

Officially, none of the 15 fatalities expired on the

aircraft. They were either pronounced dead at the

gate or at the hospital. However, information on

three of the patients suggests that they may have died

on the aircraft (cases indicated with an asterisk in

Table 13). This implies that more passengers may die

onboard airplanes than are reported each year.

The fatality rate was 0.107 fatalities per million

enplanements. This rate is about one-third of that

found in similar studies. Of the 120 International Air

Transport Association (IATA) member airlines, 42

airlines reported a total of 577 in-flight deaths between 1977 and 1984 averaging 0.31 fatalities per

million enplanements (Airline Transport Association, 1998). A 1996 Qantas study reported a fatality

rate of 0.38 per million enplanements (Donaldson &

Pern, 1996). The comparatively lower in-flight death

rate in this study might be due to two factors: (1) the

data were limited to US domestic flights that might

have been able to divert in less time than many of the

IATA or Qantas flights, which were mostly international flights, and (2) all MedAire flights were managed by an air-to-ground radio patch with an

emergency room physician, which should have resulted in an improved outcome.

The Airline Transport Association (ATA) reported

42 in-flight deaths in 1996 (Airline Transport Association, 1998). Adjusting for the size of the ATA

sample, which represented approximately 90% of US

domestic enplanements for that year, yields an industry-wide in-flight death rate of approximately 47

fatalities per year. Assuming the experience of the five

MedAire companies in this study could reasonably be

considered representative of the airline industry at

large, and adjusting for sample size, an industry-wide

rate of approximately 75 in-flight fatalities per year is

derived. The disparity in the number of deaths between the two studies is probably due to reporting
16

differences. The ATA study only accounted for individuals who were pronounced dead on the aircraft or

on the jetway while, in the current study, individuals

who were pronounced dead in-flight and post-flight

at the gate, in transit, or at the hospital were included.

In fact, only three cases would probably have been

reported as fatalities in the current study if data

collection had been limited to individuals who expired aboard the aircraft. The other twelve cases were

determined from information collected during follow-up.

Only four out of the 15 fatal cases were diverted

implying a flight diversion rate for fatalities of 27%.

In a similar study Cummins (Cummins et al. 1988)

found a diversion rate for in-flight fatalities of only

14%, citing the unavailability of diversion locations

on international flights as a possible explanation.

This unavailability could account for the difference

in rates, as all flights in this study were US domestic

flights with many suitable diversion locations available. It may not be unusual that 11 out of 15 fatal

cases were not diverted. Although each patient was

officially pronounced dead at the gate or at a later

time, it appears that at least some may have actually

expired onboard the aircraft, and a diversion might

not have been indicated in these cases. In other cases,

the destination may have been as close as any suitable

diversion location, or the medical facilities at the

destination may have been better than those available

at a diversion city.

The most common cause of death in-flight was

cardiac (12 of 15, or 80%), followed by pre-existing

medical conditions (2 of 15, or 13%). Cummins

(Cummins et al. 1988) also found cardiac deaths to

be the most common (56%), followed by deaths due

to pre-existing medical conditions (19%), while a

Qantas Airlines study (Davies & Degotardi, 1982)

listed myocardial infarction as the leading cause of

in-flight death (11 of 25, or 44%), followed by

cerebral vascular accident (2 of 25, or 8%).

Potential Additions to the Medical Kit. Our study

indicated bronchodilator inhalers, oral antihistamines, and non-narcotic analgesics were used frequently enough to suggest including them in the

medical kit to deal with several common in-flight

medical events. While Cotrell et al. (1989) also

concluded that a bronchodilator inhaler should be

added to the medical kit, Thibeault (1998) suggested

the addition of a bronchodilator inhaler, an antihistamine, and an analgesic, among other items.

In addition, oxygen, supportive care, and close patient monitoring were associated with an improvement

in patient condition. Good medical practice should

include oxygen therapy when a bronchodilator is used,

especially given the mildly hypoxic cabin environment.

For example, the oxygen saturation of a normal individual at a cabin altitude of approximately 8000 feet is

about 85%. While the majority of patients who received

both bronchodilator and oxygen therapy improved,

there were not enough cases that did not receive oxygen

with bronchodilator therapy to analyze.

Comparison of In-flight and Hospital Discharge

Diagnostic Categories. There was good overall agreement between in-flight and post-flight diagnostic categories. This agreement suggests that in-flight diagnoses

were generally accurate, even under the difficult conditions encountered onboard aircraft. However, the data

suggest that non-neurological cases were over-diagnosed as neurological cases in-flight, and vascular cases

appeared to have been under-diagnosed and attributed

to other causes in-flight.

Severity of In-flight Medical Events. As was previously discussed, there was no independent means of

determining the severity of cases. Unless patients can

successfully be grouped by severity, it may not be

possible to completely evaluate in-flight medical care

delivery, or understand the role of medical kit use,

patient response, diversions, or other important questions. At this point, it can only be said that in-flight

medical care and medical kit use have a significant

relationship to patient response that appears to be

confounded by the severity of the event.

CONCLUSIONS

Data collection was limited to airlines contracting

with MedAire, Inc. and may not be representative of

medical incidents occurring on other airlines. While

conclusions about the airline industry in general are

speculative, this study contains valuable data because it

represents a systematic attempt to follow patients from

the air transport system into the healthcare system.

The frequency of in-flight medical incidents was low

when compared with similar studies; however, the true

rate may actually have been greater because cases not

serious enough to warrant an air-to-ground radio patch

were not included. Cardiac events were the most common serious in-flight medical incidents and accounted

for the greatest percentage of aircraft diversions for

medical reasons.
17

Although the fatality rate included passengers who

expired after removal from the aircraft, cases were

limited to domestic flights that were managed by airto-ground communication with a physician, which

could explain the lower fatality rate found in this

study compared to earlier studies; however, the rate

would have been even lower if only passengers that

died onboard were included. In addition, the diversion rate for fatalities is about double the rate for nonfatal events, probably because fatal cases were generally

more serious and required a flight diversion more

often than non-fatal cases.

In-flight diagnoses were in close agreement with

hospital discharge diagnoses, and patients’ conditions generally improved, implying that in-flight

medical care delivery aboard US domestic air carriers

is generally well managed. However, there did not

appear to be a significant difference between patient

improvement and the presence or absence of a physician onboard.

The data suggest that oxygen, supportive care, and

close patient monitoring were associated with an improvement in patient condition. The data also support

the addition of a non-narcotic oral analgesic, a bronchodilator inhaler, and an oral antihistamine to the

medical kit. These items have been recommended in

other studies and are currently carried by several international air carriers. Unfortunately, due to the poor

response to certain questions by onboard care givers,

this survey could not address potential medical kit items

that are frequently needed for relatively common conditions but are rarely available because they are not routinely carried by other passengers.

RECOMMENDATIONS

Using the criteria adopted in this study, the items

that should be considered for possible addition to a

future medical kit include a non-narcotic oral analgesic, a bronchodilator inhaler, and an oral antihistamine. Since these data were collected from airlines

that did not have cardiac defibrillators onboard, no

recommendations are presented regarding the value

of adding cardiac medications to the kit that could be

used to support an onboard defibrillator. The inflight medical kit should be re-evaluated once

defibrillators become widely available on US domestic air carriers to determine additions to the kit that

would be appropriate to support the use of automatic

external defibrillators.

If the impact of in-flight medical care delivery and

medical kit use is to be fully analyzed, it may be

necessary to design a voluntary study to include a

larger segment of the air transport industry. One

method of facilitating data collection might be to

include an event reporting form in the medical kit, to

be completed at the time of the incident. If this is not

possible, mandatory reporting might be necessary; however, our experience (DeJohn, Véronneau, & Hordinsky,

1997), is that voluntary cooperation is superior to

mandatory reporting and yields better results.

REFERENCES

Federal Aviation Administration. (1986). Emergency

medical equipment requirement; final rule, Washington, DC, Federal Register 51(6): 1218-23.

Speizer, C., Rennie, C.J., & Breton, H. (1989). Prevalence of in-flight medical emergencies on commercial airlines. Ann of Emerg Med 18, 26-9.

Cottrell, J.J., Callaghan, J.T., Kohn, G.M., Hensler,

E.C., & Rogers, R.M. (1989). In-flight medical

emergencies. JAMA. 262(12), 1653-6.

Cummins, R.O., & Shubach, J.A. (1989). Frequency

and types of medical emergencies among commercial air travelers. JAMA, 261(9), 1295-9.

Rosenberg, C.A., & Pak, F. (1997). Emergencies in the

air: Problems, management, and prevention. J

Emerg Med, 15(2), 159-164.

Prew, S.J. (1997). Defibrillators – the pressure is on.

Cabin Safety Update, 3, 1-2.

Rodenberg, H. (1987). Medical emergencies aboard

commercial aircraft. Ann of Emerg Med 16(12),

1373-7.

Cummins, R.O., Chapman, P.J.C., Chamberlain, D.A.,

Shubach, J.A., & Litwin, P.E. (1988). In-flight

deaths during commercial air travel. JAMA.

259(13), 1983-8.

Hordinsky, J.R., & George, M.H. (1991a). Utilization

of emergency kits by air carriers. Federal Aviation

Administration, Office of Aviation Medicine,

Washington, DC, Technical Report No. DOT/

FAA/AM-91/2.
18

Hordinsky, J.R., & George, M.H. (1991b). Response

capability during civil air carrier in-flight medical

emergencies. Federal Aviation Administration,

Office of Aviation Medicine, Washington, DC,

Technical Report No. DOT/FAA/AM-91/3.

DeJohn, C.A., Véronneau, S.J.H., & Hordinsky, J.R.

(1997). In-flight medical care: an update. Federal

Aviation Administration, Office of Aviation Medicine, Washington, D.C., DOT/FAA/AM-97/2.

Austin, S. (1997). [Passenger enplanements for 1996]

Unpublished raw data from FAA, AFS-1.

Airline Transport Association (1998). ATA completes

in-flight medical study. ATA Press Release No. 4.

1-14-98.

Harding, R.M., & Mills, F.J. (1993). Medical emergencies in the air. In Aviat Med (pp. 7-24). London: BMJ Publishing Group.

Davies, G.R., & Degotardi, P.R., (1982). In-flight

medical emergencies. Aviat Space Environ Med

53(7), 694-700.

Schoken, V., & Lederer, L.G. (1970). Unscheduled

landings for medical reasons. A five year survey of

the experience of American Airlines. In: D.E.

Busby (Ed.), Recent advances in aerospace medicine. Proceedings of the 18th International Congress

of Aviation and Space Medicine (pp 126-9).

Dordrecht, Netherlands: Reidel Publishing.

Kahn, F. (1996, July 6 & 7). We have an emergency –

is there a doctor on the flight? Financial Times.

pp. 12.

Mills, F.J., & Harding, R.M. (1983). Medical emergencies in the air. Br Med J (286), 1204-6.

Hays, M.B. (1997). Physicians and airline medical

emergencies. Aviat Space Environ Med 48(5), 468-

70.

Centers for Disease Control Website (1999). http://

www.cdc.gov/nchswww/. US hospital utilization,

average length of stay in days. Accessed July 30,

1999.

Donaldson, E., & Pearn, J. (1996). First aid in the air.

Aust. N.Z. J. Surg. 66, 431-4.

Thibeault, C. (1998). Emergency medical kit for commercial airlines. Aviat Space Environ Med 69(11),

1112-3.
A1

APPENDIX A

Kit Item Frequency Percent

Sphygmomanometer 522 46.1

Stethoscope 518 45.8

Nitroglycerin 45 4.0

Syringes and needles 17 1.5

Diphenhydramine 9 0.8

Epinephrine 8 0.7

Dextrose 4 0.4

Airways 0 0.0

Table A-1. Frequency of Use of Medical Kit Items for Five Air

Carriers Over a 12 Month Period.

Item Frequency Percent

Oxygen 659 58.2

Supportive therapy 462 40.8

Monitor 409 36.1

Analgesic 46 4.1

Nitroglycerin 38 3.4

Bronchodilator inhaler 18 1.6

Oral antihistamine 11 1.0

Anti-acid 9 0.8

Other 7 0.6

Anti-coagulant 6 0.5

Narcotic analgesic 5 0.4

Benzodiazepines 4 0.4

Hyperglycemic 3 0.3

Hypoglycemic 3 0.3

Anti-emetic 2 0.2

Diuretic 2 0.2

Anti-arrhythmic 1 0.1

Topical antihistamine 1 0.1

Vasodilator, other 1 0.1

Table A-2. Frequency of Use for Medical Items not in Kits.
A2

List A-1. Information Provided by MedAire

Radio patch number

Date of event

Aircraft type

Origin

Destination

Company station (Whether the diversion airport had

facilities operated by the airline.)

Age of patient

Gender of patient

Presentation (Signs and symptoms.)

In-flight diagnosis

Medical history

Medication history

In-flight treatment

Medical personnel on board

In-flight medical kit use (Whether or not the in-flight

medical kit was used.)

In-flight medical kit user

In-flight medical kit items used

Respirations

Pulse

Blood pressure

Items that could have been used but were not available

in the in-flight medical kit

Recommendations for medical kit changes

Overall patient response in-flight

Category of medical response waiting at gate (i.e.,

ACLS, BLS, etc.)

Patient response to medical care at gate

Outcome

Narrative

Discharge diagnosis

Diversion (Whether the flight diverted and diversion

airport.)

Diversion status (Whether or not the diversion was

coordinated by MedAire.).

List A-2. Data Coded by CAMI

Gender

Patient presentation

In-flight diagnosis

In-flight diagnostic category

Treatment

In-flight medical kit usage

In-flight medical kit items used

Diversion

Outcome

Discharge diagnostic category

Agreement between in-flight diagnostic category and

discharge diagnostic category

List A-3. CAMI Diagnostic Code Categories

Allergic reaction

Cardiac

Endocrine

Ear-nose-throat (ENT)

Gastrointestinal

Neurological

Obstetrical/gynecological (Ob-Gyn)

Psychological

Respiratory

Trauma

Urological

Vascular

Vasovagal

Miscellaneous

Unknown
A3

List A-4. Treatment Code Categories

Analgesic

Anti-acid

Antiarrhythmic

Anticoagulant

Antiemetic

Benzodiazepine

Bronchodilator inhaler

Diuretic

Hyperglycemic

Hypoglycemic

Monitor

Narcotic analgesic

Oral antihistamine

Oxygen

Supportive therapy

Topical antihistamine

Vasodilator

Other

Not reported

List A-5. Discharge Diagnostic Code Categories

Allergic reaction

Cardiac

Endocrine

ENT

Gastrointestinal

Miscellaneous

Neurological

Not applicable

Not reported

Obstetrical/Gynecological

Psychological

Respiratory

Trauma

Unknown

Urological

Vascular

Vasovagal

List A-6. Outcome Code Categories

Admitted to hospital

Days in hospital

Admitted to intensive/critical care unit

Days in intensive/critical care unit

Type of intensive care unit

Days in intermediate care unit

Type of intermediate care unit

Admitted to floor/service

Days on floor/service

Floor service admitted to

Admitted to telemetry unit

Days in telemetry unit

Treated and released in airport clinic

Treated and released from emergency room

Medical response canceled

Who canceled medical response

Refused medical advice

Fatality

Where pronounced

Miscellaneous

Not reported
A4