# Presentation: 005183

## PERSONAL PROTECTIVE EQUIPMENT IN HEALTHCARE FACILITIES AFTER TERRORIST EVENTS

**Veterans Health Administration Office of Public Health and Environmental Hazards**

## OUTLINE

**Background**
**Three considerations**
**Expert opinions**
**Regulatory analysis**
**Modeling**
**Conclusions**

## Hot

Warm

Luke-warm
	(“yellow”)
Cold

**Warm**
**Luke-warm**
**	****(“yellow”)**
**Cold**

**Site of active release,  Size defined by existing SOPs**
**Removed from immediate release, decon activities**
**After primary decon (hospital receiving areas after initial decon)**
**Contaminant-free zones  (emergency room)**

**HAZARDOUS MATERIALS ZONES****Traditional ****and newer terminology**

## Hot
Warm
Luke-warm
Cold

**Warm**
**Luke-warm**
**Cold**

**A, B, C**
**B, C**
**C**
**none**

**ZONES and PPE****Who wears what where**

## PPE and Chemical Terrorism Incidents

**Incidents are like to occur in high-density area (subways, stadiums, etc)**
**“****Hot zone” is likely to be defined by standard procedures in emergency management (HAZWOPER, DOT)**
**Local decontamination will occur as patients move into “warm zone” and beyond to uncontaminated areas**
**Local drift and operations may spread size of “warm zone”**
**Although hospitals will be involved, they are likely to represent a “luke-warm” or “yellow” zone**

## Contaminated patients and hospitals

**Patients are likely to appear at hospitals under four conditions and scenarios**
**Planned**
**Ambulatory - residual decon need ( “bus full of patients)  **
**after primary decon**
**after suspected exposure but no documentation**
**Stretcher-bound – symptomatic after primary decon**
**Unplanned**
**Walk-ins**
**“****pick-up truck scenario” – unconscious patient in a pick-up truck, cab, or private motor vehicle with unknown degree of contamination **

## Who may need to don ppe?

**Security staff, to maintain order and control access**
**Physicians or midlevel providers to triage and make preliminary diagnoses**
**Decontamination personnel**
**Waste management and equipment crews**

## Healthcare PPE issues

**Providers must be able to triage**
**Identify respirations / airway patency**
**Pulse and blood pressure**
**Providers may need to do CPR and insert iv lines**
**Life support precedes decon (radiation rule)**

**Decon must happen outside (exposure minimization)**
**Airlines may foul outside**
**SCBA are unwieldy and impair balance**
**Time limitations on wearer  from level B vs C**

**Clinical issues**

**PPE  issues**

## ISSUE: WHAT LEVEL OF PPE IS APPROPRIATE?

- Classified list of ~200 requested for CRT
- National Institute for Standards and Technology, National Institute for Occupational Safety and Health, and Soldier Biological Chemical-Command are developing personal protective equipment standards for hot-zone and warm-zone work
- PPE both enhances (protects) and interferes with performance

## THREE APPROACHES

**Consensus among experts **
**Regulatory Analysis**
**Modeling**

## I. EMERGING CONSENSUS ppe in healthcare facilities

**JAMA article: levels C**
**AG Macintyre et al. Weapons of mass destruction events with contaminated casualties: effective planning for health care facilities. JAMA. 2000;283:242-9.**
**Fairfax Inova Hospital: Level C**
**GWU: Level C**
**Washington VAMC: Level C**
**NMRT: Level C**
**Annals Emergency Medicine: level C **
**Hick JL, et al. Protective equipment for health care facility decontamination personnel. Ann Emerg Med. 2003 Sep;42(3):370-380**

## OSHA: healthcare response guidance document to be published fall 2003
AHRQ: healthcare response guidance document to be published fall 2003
Both will incorporate these considerations

**AHRQ: healthcare response guidance document to be published fall 2003**
**Both will incorporate these considerations**

**I. EMERGING CONSENSUS ppe in healthcare facilities: impending regulatory actions**

## II. REGULATORY ANALYSIS 1. HAZWOPER

**HAZWOPER (1910.120): **
**ICS **
**Emergency response handling or controlling exposure**
**Exposed to agents from release**
**Unknown: at least level B protection**
**Not strictly applicable  because**
**No active major release**
**Not in direct ICS**
**Not engaged in handling or controlling release**

## 1910.120 (q)(6)(2): compliance interpretations
Hospital personnel in decon should be trained to operations level
OSHA is unable to determine specific exposure levels and cannot recommend a specific level
Hospitals should conduct a risk assessment to determine likely risk

**Hospital personnel in decon should be trained to operations level**
**OSHA is unable to determine specific exposure levels and cannot recommend a specific level**
**Hospitals should conduct a risk assessment to determine likely risk**

**II. REGULATORY ANALYSIS ****1. HAZWOPER**

## Respiratory protection standard 1910.134
Program
Hazard assessment required to determine needed level of protection
Personal protective equipment
Hazard assessment

**Program**
**Hazard assessment required to determine needed level of protection**
**Personal protective equipment**
**Hazard assessment**

**II. REGULATORY ANALYSIS ****2. Respiratory protection**

## III. MODELINGGENERAL APPROACH

- Define range of likely or possible scenarios of patients coming to hospital
- Table-top exercise to identify likely important predictors of exposure
- Range finding with limited number of representative  agents to identify critical factors
- Model selected agents under varying assumptions to define likely exposures (hazard assessment)
- Identify needed protection factor and select ppe

## PATIENTS AS A SOURCE OF CONTAMINATION

- Assumptions aligned with NIST, NIOSH, and SBC-COM hot-zone and warm-zone modeling and extrapolated to down-stream scenarios (“luke-warm” zone)
- 10 gm of agent likely  individual dose based on technology
- 1⁄2 to 2/3 of dose on clothing; clothing removal and effective disposal
- Evaporation between hot-zone and hospital is a function of time, vapor pressure, and ambient conditions

## INITIAL SCENARIO ASSUMPTIONS

**50 patients****	****	****	****Stable weather**
**Outside staging area****	****	****Clear**
**Windspeed 3 m/sec****	****	****Temperature ****65****o**
**3 zones: ****	****	****	****Typical terrorist devices**
**	****initial staging and triage **
**	****Decon tent**
**	****Holding area**

**Scenario 1****: 2 at a time by ambulance, planned operations with sequential controlled disrobing  and decon**

**Scenario 2****: 50 at once by bus, chaos**

## DETERMINANTS OF EXPOSURE

**CT = integrated total exposure concentration**
**M****0****= mass deposition (gm /m****3****)**
**A****p****= contaminated surface area**
**A****w**** = area of column of air**
**U****w ****= wind velocity**
**T****s ****= start time for integration**
**Τ = evaporation time constant**

## Total integrated exposure concentration (CT) of CWA for medical personnel as a function of the evaporation time constant 

## Slide 21

## PHYSICAL CHARACTERISTICS OF WMD AGENTS

**Chlorine****	****2.5*10****7****	****6.67*10****-4**** ****	****	****	****190,000**
**Phosgen****	****1.0*10****6**** ****	****1.67*10****-3**** ****	****	****	****    3,200**
**Cyanide****	****1****.1*10****6**** ****	****1.50*10****-2****	****	****	****    2,000**
**Water****	****	****2.3*10****4**** ****	****7.28*10****-1****	**
**Sarin****	****	****2.2*****10****4****	****7.58*10****-1****	****5.9*10****1****	****  ****       35**
**Tabun****	****6.1*10****2****	****1.6*10****-3****	****1.5*10****3****	****        70**
**Mustard****	****9.2*****10****2****	****1.81*10****1**** ****	****7.1*10****1****	****    1,000**
**VX****	****	****1*****10****1**** ****	****	****1.67*10****3**** ****	****2.0*10****4****	****         15**

**AGENT**

**VP mg/m****3**

**Tau**

**LD****50**
**(mg)**

**LCt****50****(mg • min)/m**** **

## Number of lethal doses resulting from a 100 g deposition of a chemical warfare agent 

## Preliminary results that affect exposure control strategies

- Major predictor of exposure is time since exposure in hot-zone
- Lying vs standing patient affects concentrations
- Clothing functions as a secondary source (requires exposure control strategy)
- Decontamination effluent run-off may function as secondary source
- Site operations planning and lay-out affects exposures
- Equipment needs include clothing storage and fans for exposure control

## Slide 25

## MODELING

- Shape of dose distribution on victins
- Temperature
- Enclosures around staging
- Ambient conditions
- Serial vs synchronous arrival
- Disrobing
- Time since hot-zone / event
- Clothing removal

## Monte Carlo forecast of total integrated exposure concentration (CT) of sarin when the mass deposition (mo) is represented by a triangular distribution with a maximum value of 100 g and a likeliest value of 10 g 

## CONCLUSIONS:

**Primary determinants of exposure**
**Time since exposure**
**Vapor pressure of agent**
**Clothing removal**
**Secondary contributors**
**Persistent sources (clothing storage, shower run-off, )**
**Unimportant **
**shape of distribution**
**Protection**
**PF of 500 brings internal concentrations below 2.1 mg*min/m****3  ****(new NIOSH APR standard)**
**Worst case (no clothing removal, unfavorable wind directions, ...) leads to over-exposure of 2% of population**

## RECOMMENDATIONS

**National**
**	****EMT triage / algorithms for treatment (Mark I, CN****-****)**
**AEPC**
**	****Clothing removal before transport**
**Local**
**Medical surveillance  (no susceptibility testing)**
**Heat illness protocols**
**Site planning / lay-out / secondary exposure control**
**Level C ppe ensembles (PF ~ 1000: PAPR)**

## OUTSIDE (non-VHA)  GROUP MEMBERS

**Paul Fedele, PhD - Physicist, ECBC/SBC-COM**
**Paul Lioy, PhD - Exposure assessment EOSHI, UMDMJ/Rutgers**
**Panos Georgopoulos, PhD  - Exposure modeling  EOSHI, UMDMJ/Rutgers**
**Jack Longmire, MD, MPH - Occupational Medicine, OSHA**
**Meldoy Sands, MS – Health Care Enforcement, OSHA**
**Cynthia Duffield, MS, CIH - Exposure assessment, OSHA**
**Scott Deitchmann, MD, MPH - Occupational Medicine, NIOSH**

## Occupational and Environmental Health Strategic Healthcare Group
Michael Hodgson, MD, MPH
Mark Brown, Ph.D.

**Michael Hodgson, MD, MPH**
**Mark Brown, Ph.D.**

**VHA  GROUP MEMBERS**