Multi-center Evaluation of the NEMO Gauge to Aid in Correct Positioning of the Endotracheal Tube After Intubation of Critically Ill Patients
Phase: NA
Conditions: Respiratory Failure
Sponsor: Loma Linda University

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NEMOTM Gauge Page: 1 
A Multi-center Evaluation of the NEMO™ Gauge to Aid in Correct Positioning of the 
Endotracheal Tube after Intubation of Critically Ill Patients 
 
STUDY PROTOCOL 
Revision 1 
 
Study Lead Investigator: H. Bryant Nguyen MD, MS, Division of Pulmonary and Critical Care 
Medicine, Loma Linda University, California 
 
Loma Linda University 
Medical Center 
Site Principal Investigator: 
   Laren Tan, MD= 
Loma Linda Veterans Affairs 
Medical Center 
Site Principal Investigator: 
   James Anholm, MD$ 
 
Riverside University Medical 
Center 
Site Principal Investigator: 
   Ramiz Fargo, MD^ 
 
 
 
=Division of Pulmonary and Critical Care Medicine, Department of Medicine, Loma Linda 
University, Loma Linda, CA. 
$Medical Service, Pulmonary and Critical Care Section, VA Loma Linda Healthcare System, 
Loma Linda, CA. 
^Department of Pulmonary and Critical Care Medicine, Riverside University Medical Center, 
Moreno Valley, CA. 
 
 
 

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Background and Significance: 
 
Endotracheal tube (ETT) malposition is associated with high incidence of adverse 
outcomes such as severe atelectasis, pneumothorax, refractory hypoxemia, and even death1. The 
rate of ETT malposition among experienced clinicians in the literature is reported to be between 
9 and 16%2-5. 
In the setting of emergent intervention that determines life altering outcomes, physicians 
often rely on point of care devices and modalities to guide their management plans. Currently, 
chest radiographs are utilized to assess for ETT position after intubation6. The median cost of a 
chest radiograph typically ranges between $100 and $5007. The average time between the request 
for a chest radiograph and visual evaluation of the study by a radiologist or experienced clinician 
is rarely less than one hour.   Novel and cost-effective technology is needed to rapidly aid in 
confirming ETT position immediately after a critically ill patient is intubated.  
 
Device Overview: 
The NEMOTM Gauge (Ciel Medical, San Carlos, CA) is an ETT positioning bougie that 
has color-coded depth markers to help the user determine and confirm the position and depth of 
the tip of the ETT. The NEMOTM Gauge is commercially available in the USA and falls under 
the FDA regulation Section 868.5790 Tracheal tube stylet, and Classification Product Code BSR 
(Figure 1). 
 
 
[A] Deployment Cap 
[B] Handle 
[C] Measurement Marking 
[D] Catheter Shaft 
[E] Expandable Tip 
[F] Positioning Clip 
Figure 1: Overview of the NEMOTM Gauge 
 
When the deployment cap (A) is engaged, the expandable tip (E) is advanced out of the catheter 
providing a bumper to engage with the carina in the patient’s airway. 

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Figure 2: Deployed expandable tip 
 
The expandable tip of the NEMOTM Gauge is made of formed spring wires that are covered with 
a Pebax sleeve (Figure 2). Pebax is the trade name for a Nylon plastic commonly used in medical 
devices. The ends of the expandable tip are rounded to present a smooth, round surface on 
contact with the trachea wall. 
The manafacturer’s instructions for use include: 
1. The user removes the positioning clip from the device handle and aligns it on the ETT 
between the marked distances:  
 
2. The user inserts the NEMOTM Gauge into the ETT until the WHITE measurement marker on 
the NEMOTM Gauge is visible in the positioning clip window. This indicates that the distal 
end of the NEMOTM Gauge is aligned with the tip of the ETT. 
3. The user expands the distal tip by advancing the deployment cap and continues to advance 
the NEMOTM Gauge until resistance is felt, and the expandable tip has reached the carina.  
 
  
 
 

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4. Once resistance is felt, the user refers to the color of the measurement marker on the 
NEMOTM Gauge that is present in the positioning clip window. If the window is completely 
filled by the GREEN measurement marker, the ETT is safely positioned and the NEMOTM 
Gauge may be removed. 
5. If the YELLOW measurement marker on the NEMOTM Gauge is present in the positioning 
clip window, the ETT position should be adjusted until the GREEN marker is present as 
shown in the figure below: 
 
 
ETT position too high 
Adjustment of ETT tube to proper location 
 
 
Green marking represented by white and dark grey diagonal stripes 
 
Previous Device Testing: 
 
Prior testing of the device by the manufacturer has focused on two main areas:  
• Evaluating efficacy of the device in human cadavers  
• Evaluating safety of the device in bench models and live porcine models.  
Efficacy 
 
Cadaver testing during development of the NEMOTM Gauge has been completed on 
seven adult cadaver specimens, four male and three female cadavers. All cadaver specimens 
were fresh (i.e. not embalmed) and were provided by the Stanford University Anatomy 
Department.  At no point during development was any visible damage observed on the tracheal 
wall or carina of these cadavers.  

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During a June 2014 cadaver lab, eight Stanford Hospital respiratory therapists were asked 
to evaluate the feasibility and ease of use of the NEMOTM Gauge. All therapists were provided 
with a brief in-service training on the use of the device and then asked to confirm ETT position 
in a cadaveric model. The results were as follows:  
• All eight were successful in placing the ETT 2-5 cm above the carina (confirmed by 
rigid bronchoscopy).  
• Of the participants that completed a survey following use (5/8 participants), all of 
them stated that the tactile feedback during use of the device was adequate and/or that 
it was clear when they reached the carina.  
• On a scale of 1-5, all survey respondents rated the ease of use of the device as a “2 - 
easy”. (1-very easy, 2-easy, 3-neutral, 4-somewhat difficult, 5-difficult).  
 
Testing in human cadavers has shown the device to be effective at confirming the ETT 
location as 2-5 cm above the carina.  
Safety 
 
The NEMOTM Gauge has been used in a live porcine model to evaluate the risk for 
mucosal damage during use of the device. A 66-kg pig was intubated with a size 8 ETT.  Due to 
the long length of the porcine airway, the NEMOTM Gauge was not used to position the ETT 2-5 
cm above the carina (as expected in humans), but the device was advanced approximately 10 cm 
through the airway until it engaged with the carina (Figure 3). 
 
Figure 3:  Chest x-ray taken of the porcine model showing the NEMOTM Gauge (blue arrow)  
expanded within the porcine airway.  

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Images were taken before and after use of the NEMOTM Gauge device with a fiberoptic 
bronchoscope to evaluate mucosal damage (Figure 4 and 5). There was no visible bleeding seen 
with bronchoscopy. 
 
 
 
 Figure 4: Bronchoscopy images taken before use of the NEMOTM Gauge.  
 
 
 
Figure 5: Bronchoscopy images taken after repeated (4x) use of the NEMOTM Gauge. 
 
 
A second, bench model was used to characterize the forces exerted on the tracheal wall 
by the NEMOTM Gauge during use.  The device was inserted into an acrylic 18 mm tracheal 
model and a 1 mm thick, 1 cm wide, and 6 cm long pressure sensor (TactArray Pressure Sensor, 
PPS, Los Angeles, CA) was placed on the tracheal internal surface. The maximum pressure 
exerted by the device was acquired using dedicated software (PPS Camelon TVR Software, PPS, 
Los Angeles, CA). The average maximum pressure recorded during advancement of the 
NEMOTM Gauge was 0.54 psi (0.82 psi max). The average maximum pressure recorded during 
adjustment of the ETT depth in the simulated trachea was 1.78 psi (2.80psi max). Thus, the 

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forces exerted during advancement of the NEMOTM Gauge are significantly less than the forces 
exerted during routine adjustment of the ETT.  
 
The above testing suggests that the NEMOTM Gauge is safe for human use.  An IRB 
approved trial is currently underway at a U.S. academic medical center (per Ciel Medical, the 
manufacturer). This prospective trial studies the use of the NEMOTM Gauge in up to 50 intubated 
patients undergoing bronchoscopy.  Main outcomes include confirmation of accurate 
measurement of the ETT tip-to-carina distance using the NEMOTM Gauge compared to 
bronchoscopy measurement, and assessment of mucosal damage during the use of the NEMOTM 
Gauge.  In this study, a bronchoscopy was performed after the use of the NEMOTM Gauge.  An 
interim analysis of 17 patients showed 94% accurate measurement using NEMOTM Gauge (2-
5cm from the carina). In one patient (6%) the ETT tip was determined to be inside the 2-5 cm 
range using the NEMOTM Gauge but was actually at 5.5cm.  Eight (8) patients displayed signs of 
mild mucosal irritation and nine (9) patients showed no irritation after use of the device.  No 
adverse events have been reported to date (ongoing study, unpublished results provided by Ciel 
Medical). 
 
Specific Aims: 
The aim of this study is to investigate the NEMOTM Gauge’s ability to accurately and 
safely determine ETT position, and if needed, guide repositioning of the ETT into the correct 
position, compared with standard chest radiography. 
 
Inclusion Criteria: 
1. Adult patients ≥ 18 years of age admitted to the intensive care unit (ICU) 
2. Patients who have been intubated or at high risk of being intubated, requiring 
confirmation of ETT position after intubation as determined by the clinical team 
3. Endotracheal tube size 7.0 mm to 8.5 mm in diameter 
 
Exclusion Criteria: 
1. Patients with active hemoptysis 
2. Patients with known tracheal or bronchial masses prior to endotracheal intubation 
3. Patients with known tracheal or bronchial abnormalities requiring surgical repair 

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4. Patients with ongoing hypoxemia (defined as SaO2 < 85%) after endotracheal intubation  
5. Any individual involuntarily confined or detained in a penal institution 
 
Study Procedure: 
 
Study physicians will be trained on the use of the NEMOTM Gauge device by viewing a 
video tutorial, reading the manufacture instructions provided with the device, and performing an 
ETT position confirmation with the NEMOTM Gauge on a trachea simulation model 
(mannequin).   
Patients who are intubated and meet enrollment criteria will be selected for the study 
procedure (Figure 6).  After intubation, the patient will be positioned for the chest radiograph by 
standard practice.   Prior to obtaining the chest radiograph, the NEMOTM Gauge will be used to 
determine proper tube positioning and should it be necessary the ET tube will be repositioned as 
per the NEMOTM Gauge’s manufacture instructions.   Additionally, the operator will auscultate 
the patient’s lung for bilateral breath sounds. 
Immediately after use of the NEMOTM Gauge and confirmation of bilateral breath 
sounds, a chest radiograph will be completed.  The distance from the tip of the ET tube to the 
carina will be measured on the radiograph and will be recorded. Based on current clinical 
practice 8-9, the ET tube will be considered a malposition if it is located less than 2 cm from the 
main carina, more than 5 cm from the main carina, in the right main stem bronchus, or in the left 
main stem bronchus. 
If the ET tube is considered in a malposition as determined by the chest radiograph, it 
will be re-adjusted as per standard practice, now without the NEMOTM Gauge.  The distance that 
the ET tube is adjusted will be recorded.  
Demographics, diagnostic data, ventilator settings, and ongoing treatments will be 
recorded. The reason for intubation, ETT size, ETT position, and ETT adjustments will also be 
recorded.  Any complication as a result of the intubation, ETT positioning, and/or NEMOTM 
Gauge will be recorded.  
 
 

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Figure 6: An outline of the Study Procedure  
 
 
 
NEMO Green Zone and 
Bilateral Breath Sounds 
ET Tube 2 – 5 cm 
From 1° carina 
Intubation 
Position Patient  
For CXR 
NEMO 
With Adjustment 
Record ET tube at 
teeth and lip prior to 
NEMO adjustment 
CXR 
Appropriate  
Position 
Re-adjust  
Without  
NEMO 
Record amount 
needed to  
Re-adjust 
Malpositioned 
< 2 cm or > 5 cm 
From 1° carina 

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Primary Outcome: 
The percentage of correct ETT position as confirmed by chest radiographs after using the 
NEMOTM Gauge.  
 
Sample Size / Number of Subjects: 
Based on our literature review, correct ETT position after intubation are observed in 
approximately 91% of patients when verified by standard chest radiograph (the null hypothesis).   
We hypothesize that use of the NEMOTM Gauge to detect ETT position and make necessary 
adjustments will result in 98% correct ETT position.   
Using a one-sided binomial test, a sample size of 68 patients will detect an increase in 
ETT correct position of 7% with the use of the NEMOTM Gauge, having a power of 0.84 and a 
significance level of 0.0492.    
 
Statistical Analysis: 
 
Simple descriptive analysis will be performed, including the percentage of correct ETT 
position and any complication after the use of the NEMOTM Gauge.  See also Interim Analysis 
below. 
 
Study Duration: 
 
The duration of study enrollment will be 6 months with expected enrollment of 
approximately 1 patient per week at each participating intitution (1 patient x 3 sites x 4 weeks x 6 
months ~ 72 patients).  We plan to terminate the study after 68 evaluable patients with complete 
data are enrolled, per the above sample size calculation.   Enrollment is planned to start on June 
1st, 2016.  An interim analysis will be performed at one-half enrollment. 
 
Data Collection: 
The investigators at each respective site will collect all data on a standardized case report 
form. See next paragraph for a listing of the specific data to be collected.  All study records, 
including those which could provide identification, will be kept in a locked file cabinet in a 
locked office.  All electronic records will be kept on a password protected network drive at the 

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respective sites. Only non-personally identifiable information will be shared with Loma Linda 
University for data analysis purposes. 
 
Data share agreement between a study site and Loma Linda University must be 
completed before any data is transferred from the site to Loma Linda University Medical Center 
(LLUMC).  Each study site will submit subject case report forms to the study lead investigator 
(SLI) for entry into a common database stored at LLUMC.  The database is stored on a password 
protected computer network drive, accessible in the SLI’s locked office and research laboratory 
at LLUMC.   Data are de-identified with no PHI. 
 
Data Collected: 
The following data variables will be collected for every subject:  Date of enrollment 
(consent), name of individual obtaining consent, date of use of the NEMO™ device, name of 
physician investigator who used the device, patient identifiers, age, height, weight, medical 
comorbidities,  presence/absence of bilateral breath sounds following intubation, endotracheal 
tube (ETT) size and positioning measurements, record of ETT position changes after use of 
NEMO™ Gauge, duration of time for the use of the NEMO™ Gauge, time of ordering chest 
radiograph (CXR), time CXR performed, CXR findings and recording of distance from distal 
ETT to the main carina, documentation of any additional re-position of the ETT, complications 
(if any) with intubation and/or use of the NEMO™ Gauge, investigator assessment of whether 
any complications were related to use of the NEMO™ Gauge.  
 
Human Subjects/Consent: 
 
The enrollment criteria for this study consist of patients requiring or at high risk for 
requiring intubation and placement on invasive mechanical ventilation. These patients may have 
altered sensorium and may not be able to provide written informed consent at the time of 
meeting study enrollment criteria. In such case informed consent may be obtained from a legal 
authorized representative (LAR). 
Patients admitted to the ICU service (irrespective of physical location in the hospital) or 
their LAR will be presented information about this study and given an opportunity to participate 
after all their questions have been answered. No study procedures will occur prior to their written 
informed consent.  The consent process is as follows in the figure: 

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Since it is impossible to know in advance which patients will require intubation and 
mechanical ventilation in the ICU, we will obtain prospective written informed consent shortly 
after ICU admission in all patients who may or may not yet require intubation.   Not all ICU 
admitted patients will require intubation during their ICU stay.  Thus, we anticipate that only a 
portion of consented patients may ultimately have study procedures performed on them. 
 
Potential Risks: 
Endotracheal intubation is associated with a significant number of adverse events, some 
of which are serious.  These events related to intubation are relatively common and have been 
studied extensively.  Our study is NOT examining the intubation itself, but rather the correct 
adjustment (if any) of the endotracheal tube AFTER intubation has already occurred.  With this 
in mind, one of the study investigators, not directly involved in the patient care or study 
procedures will make a determination whether or not events surrounding the intubation are 
related to intubation vs. to the NEMOTM Gauge. 
Nearly all intubated patients undergo suctioning of airway secretions right after 
intubation and on a regular, as needed basis, multiple times each day for as long as they remain 
intubated.  Suction catheters frequently cause irritation and occasionally bleeding from the 
tracheal mucosa.  The risks associated with the use of the NEMOTM Gauge are approximately 
similar to the risks associated with routine endotracheal suctioning. 
Patient is 
admitted to 
the MICU 
Service
Informed 
Consent 
obtained
NEMO study 
data collected
Patient/surrogate declines
No further NEMO study 
involvement
Patient / 
surrogate 
approached to 
obtain informed 
consent
Patient 
subsequently 
Intubated
Yes
No
No further NEMO study 
involvement

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There are always unforeseen risks beyond those of routine endotracheal suctioning; 
however, we believe the incremental risks from use of this device are minimal.  This is based on 
the pre-clinical device testing (described above) that has occurred as well as to the clinical 
experience with the device since it has been on the market. The major potential risk associated 
with this device is the possibility of minor tracheal damage from contact with the tracheal wall.  
There is a theoretical possibility that the forces exerted on the tracheal wall may cause local 
mucosal damage during use.   The manufacturer has conducted technical performance testing in 
both live porcine models and bench models to show similar exertion forces as other 
commercially available products, with favorable results.  However, if signs of tissue damage are 
apparent during use, the NEMOTM Gauge will be removed and the investigators will evaluate the 
severity of the adverse event and, as needed, will initiate immediate corrective measures. The 
investigators will determine if any adverse event is attributed to the NEMOTM device. Any 
serious and/or unexpected adverse device events will be reported to the IRB at the respective site 
and appropriate federal agencies per their requirements (see Data Safety Monitoring below). 
 
Plan for Communication among IRB: 
Any serious adverse events (SAE) associated with this trial will be reported to the local 
institution IRB immediately in accordance with local reporting regulations. Other non-serious 
adverse events will be recorded in the local study records and reported to the IRB at the time of 
continuing review. 
 
Data safety monitoring: 
 
We will follow the FDA guidance, “Medical Device Reporting for User Facilities”: 
(http://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocu
ments/UCM095266.pdf). 

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All deaths and serious injuries at a study site that are determined to be caused by or contributed 
by the NEMOTM Gauge shall be reported by the site PI, following the site’s institutional process 
for medical device reporting to the FDA; i.e. the same process used for any FDA‐approved 
medical device. The timeline for reporting should follow the FDA requirements as in Table 1 
above. 
In addition to the required FDA reporting, the site PI will also submit the report (FDA 
Form 3500A) to the study lead investigator (SLI) within 72 hours of the event. The SLI will then 
notify all study sites and the IRB at Loma Linda University of such event. 
If the site PI did not voluntarily report the event to MedWatch, the SLI will report such 
event to MedWatch: 
https://www.accessdata.fda.gov/scripts/medwatch/index.cfm?action=reporting.home. Such 
voluntary reporting to MedWatch will potentially be beneficial to society regarding the risk of 
the NEMO gauge device. 
The SLI will also report other deaths or serious injuries to the FDA, MedWatch, and the 
IRB at Loma Linda University that have not been reported by the individual sites. 
 
Interim Analysis: 
A Data Safety Monitoring Board (DSMB) will be organized to provide oversight of the 
study. The DSMB will consist of two (2) independent intensivists and one (1) biomedical ethicist 

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unrelated to the study. Dr. Gerald Winslow, PhD, Vice‐President for Mission and Culture at 
Loma Linda University, will be invited as our ethicist on the DSMB. 
The SLI will organize a mid‐study interim analysis at one‐half enrollment (34 out of total 
68 subjects). Data will be analyzed by the study team (including the SLI, site PI’s, and 
statistician). Results of the analysis will include the percentage of correct endotracheal tube 
position and any adverse events (including serious injuries and deaths) from the use of the 
NEMOTM Gauge. 
The results of the mid‐study analysis will be submitted to the DSMB for review. 
Depending on the number and severity of adverse events, the SLI and DSMB will determine 
whether enrollment at all study sites should cease. 
The SLI will also perform an event related interim analysis throughout the study period if 
a death or serious injury is determined to be caused by or contributed by the NEMO gauge. The 
event will be reported to the IRB at Loma Linda University. In such situation, the SLI and 
DSMB will determine whether enrollment at all study sites should cease until a complete review 
of the event is completed. 
 
References: 
[1] Hagberg C, Georgi R, Krier C. Complications of managing the airway. Best Pract Res 
Clin Anaesthesiol. 2005;19:641-59. 
[2] Salem MR. Verification of endotracheal tube position. Anesthesiol Clin North America. 
2001;19:813-39. 
[3] Brunel W, Coleman DL, Schwartz DE, Peper E, Cohen NH. Assessment of routine chest 
roentgenograms and the physical examination to confirm endotracheal tube position. 
Chest. 1989;96:1043-5. 
[4] Lotano R, Gerber D, Aseron C, Santarelli R, Pratter M. Utility of postintubation chest 
radiographs in the intensive care unit. Crit Care. 2000;4:50-3. 
[5] Brunel W, Coleman DL, Schwartz DE, Peper E, Cohen NH. Assessment of routine chest 
roentgenograms and the physical examination to confirm endotracheal tube position. 
Chest. 1989;96:1043-5. 

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[6] Schwartz DE, Lieberman JA, Cohen NH. Women are at greater risk than men for 
malpositioning of the endotracheal tube after emergent intubation. Crit Care Med. 
1994;22:1127-31. 
[7] Chen SI, Dharmarajan K, Kim N, et al. Procedure intensity and the cost of care. Circ 
Cardiovasc Qual Outcomes. 2012;5:308-13. 
[8] Goodman LR, Conrardy PA, Laing F, Singer MM. Radiographic evaluation of 
endotracheal tube position. AJR Am J Roentgenol. 1976;127:433-4. 
[9] Conrardy PA, Goodman LR, Lainge F, Singer MM. Alteration of endotracheal tube 
position. Flexion and extension of the neck. Crit Care Med. 1976;4:8-12.