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October 24, 2005
9:00:00 AM - 11:00:00 AM
Hall C4
A Comparison of Different Types of HAZMAT Respirators by Anesthesiologists
Keith A. Candiotti, M.D., Bruce A. Saltzman, M.D., Luciana M. Curia, M.D., Yiliam F. Rodriguez, M.D., David A. Lubarsky, M.D., M.B.A.
Anesthesiology/Perioperative Medicine, University of Miami, Miami, Florida, United States

The threat of weapons of mass destruction has existed for many years. However, only recently has the medical community become aware of the actual dangers. In addition, the recent emergence of virulent viruses, SARS and The Avian Flu, have made the need for better protective gear for the anesthesiologist imperative. Existing research has looked at the performance of medical personnel wearing protective gear (1), but has not focused on the use of it by anesthesiologists. We compared the performance of anesthesiologists intubating a simulator while wearing different types of respirators, a positive pressure respirator (PPR) or a negative pressure respirator (NPR).


Three participants practiced intubations on a simulator (MetiTM HPS ver. 6) until comfortable with the task. The intubation task was divided into 2 steps: #1 start until the endotracheal tube was placed (time 1) measuring gross motor function; #2 included inflation of the ETT balloon until first breath was given by an ambubag, (time 2) measuring fine motor function. Each subject performed 10 timed repetitions, initially without any gear, then while wearing a protective suit, gloves and respirator (3M Breath Easy PPR or 3M 7000 NPR). All subjects performed tasks with both respirators, then rated the gear.


(table 1 & 2)

A) Positive characteristics of PPR: 1) Comfortable

B) Negative characteristics of PPR: 1) Drape was constantly in the way, 2) Unable to auscultate lungs

C) Positive characteristics of NPR: 1) No interference with tasks, 2) No assembly required

D) Negative characteristics of NPR: 1) Unable to wear glasses, 2) Unable to auscultate lungs, 3) Heavy to wear, 4) Harder to breath

Of the total 90 intubations only one proved to be esophageal and undetected initially. (Subject wore PPR).


It appears that the use of an NPR or PPR, does not preclude an anesthesiologist from successfully intubating a simulator. A trend toward slower performance times was noted with the PPR compared to the NPR. While perhaps not significant it is anticipated that under real life conditions performance may deteriorate even further (2). The slightly better performance with the NPR is weighed against the improved comfort of the PPR and the fact that users could wear eye glasses. Of major note was the fact that neither type of gear allowed the users to auscultate the lung fields to confirm correct ETT placement, one esophageal intubation occurred while wearing the PPR.

The results of this pilot study have prompted us to begin a full investigation into the optimal protective gear for anesthesiologists. This project will be completed by the time of the ASA and data will be available to be presented.


1.Mil Med 2000; 165(4):272-4

2.A&A 2004; 98:1753-8[table1][table2]

Anesthesiology 2005; 103: A1194
Table 1: Performance Times
Avg. Time 1Avg. Time 2Avg. Total Time
No gear7.43 ±1.036.62 ±1.7814.23 ±2.61
Neg. Pressure Respirator8.05 ±2.168.39 ±1.3716.45 ±3.41
Pos. Pressure Respirator9.37 ±2.259.30 ±2.4718.68 ±4.63
Total time(seconds)= time1+2
Table 2: Gear Ratings
Questionnaire's ResultsPositive Pressure RespiratorNegative Pressure Respirator
Ease of use3.63.0
Comfort of gear2.63.6
Ability to perform step 13.63.3
Ability to perform step 24.34.0
Degree of Visual Impairment3.32.3
Confidence in ETT placement4.04.0
*Scale: 1-5 (from Easy:1 to difficult:5 or comfortable:1 to uncomfortable:5)