INTRODUCTIONThe ErgoMaskTM is a new facemask designed to ergonomically fi t the clinicians’ left hand. The dome of the ErgoMaskTM contains grooves and edges enabling the operator to use an asymmetrical left-hand grip, with the posterior part of the mask higher than the anterior. This design should better enable full contact between the operator’s hand and the mask, avoid hand fatigue, allowing for better control of the facemask. We hypothesized that ventilation with the ErgoMaskTM would result in greater delivered tidal breaths as compared to a standard facemask.

METHODSAllied health students with minimal airway management training used a standard or ErgoMaskTM to ventilate a Laerdal®Airway Management Trainer in a random, crossover design using their left hands. A Pulmonetics LTV®1200 volume-cycled ventilator set to deliver a tidal volume of 500 mL, 12 times per minute, at an inspiratory-to-expiratory ratio of 1:4 (cycle-length 5 seconds) provided the actual ventilation. Participants squeezed a breathing bag with their right hand in time with the ventilator-delivered breath to simulate actual bag-valve-mask (BVM) ventilation.

Special Thanks Lenora Parr

After a brief tutorial on each mask, participants performed basic airway maneuvers on the airway trainer and obtained a mask seal prior to the fi rst ventilator-delivered breath. The returned tidal volume was recorded for each of 12 breaths for each participant for each mask. Differences in minute ventilation between masks were assessed by paired student T-Test with a signifi cance defi ned by a p-value of <0.05.

Any effect on the ability to ventilate over time with each mask was assessed by a repeated measure analysis of variance (RM-ANOVA) with tidal volume set as the response variable and mask type, number of breaths, and gender as dependent variables with signifi cance defi ned as a p-value <0.05.

RESULTSThe following results are based on an RM-ANOVA analysis with the following dependent variables: mask type, time, gender, and the interaction between mask type: time and mask type: gender.

•Minute ventilation was signifi cantly greater with the ErgoMaskTM than the standard mask.

•Overall, tidal volumes were signifi cantly higher at all time points using the ErgoMaskTM compared to the standard mask.

•Over time, ventilation via the ErgoMaskTM did not signifi cantly decrease (0.13 Ml/breath) whereas use of the standard mask resulted in a linear decrease in ventilation by 10 ml/breath (p < 0.001).

•This decay in ventilation over time was unaffected by gender. However, males performed better in terms of tidal volume than females at all time points regardless of mask type used.

CONCLUSIONSNovice airway managers were able to more effectively ventilate via a facemask by using an ergonomically designed device, the ErgoMaskTM, compared with a traditional standard mask. Further, performance did not decay over time when subjects were using the ErgoMaskTM, whereas signifi cant decay did occur with the standard mask. Insofar as BVM is likely to be necessary for more than the 1-minute tested here in actual clinical resuscitation scenarios, using the ErgoMaskTM may have an even greater impact than what we have shown. Clinical correlation and further examination of gender differences is needed.

Contact Person:Eric B. Bauman, PhD, RNDepartment of AnesthesiologyUniversity of Wisconsin School of Medicine and Public Health600 Highland AvenueMadison, WI 53792ebauman@wisc.edu

Simulation-based Evaluation of an Ergonomically Designed Face Mask among Novice Users

1Bauman EB, 1Joffe AM, 2Devries SA, 2Lenz L, 1Hetzel SJ, 1Seider SP, 1Han S 1University of Wisconsin School of Medicine and Public Health, Madison, WI

2Western Technical College, LaCrosse WI

Figure 1: Summary of repeated measures ANOVA with fi tted regression lines: Y = tidal volume; X =

number of breaths; Dots represent ErgoMaskTM; Triangles represent Standard mask; Red repre-

sent Males; Black represents Females.

Table 1: Mean (sd) tidal volume (mL) by Breath and Mask Type

Breath* Standard Mask ErgoMask p-value**

1 330.3 (124.8) 376.9 (98.6) 0.682

2 316.5 (136.4) 369.0 (104.1) 0.594

3 304.2 (141.9) 364.1 (105.7) 0.369

4 264.1 (163.2) 361.0 (123.8) 0.040

5 261.3 (154.7) 371.9 (114.3) 0.011

6 260.1 (160.5) 369.8 (105.7) 0.023

7 256.8 (151.7) 363.3 (122.4) 0.049

8 243.7 (165.7) 369.6 (118.2) 0.005

9 234.4 (169.6) 368.0 (107.7) 0.005

10 218.4 (164.3) 364.6 (114.4) 0.003

11 223.3 (167.9) 370.2 (114.0) < 0.001

12 216.4 (170.3) 370.1 (118.8) 0.001

* Breaths were taken successively every 5 seconds

** paired T-Tests and are Bonferroni adjusted for 12 comparisons

This project was supported in part by the University of Wisconsin Institute for Clinical and Translational Research (UW ICTR), funded through an NIH Clinical and Translational Science Award (CTSA),