# A Comparison of Two-Handed Face-Mask Ventilation Techniques by Trainees: A Prospective Observational Study

## TL;DR

This study compares two two-handed face-mask ventilation techniques used by trainee anesthesiologists and finds that hand size affects ventilation effectiveness.

## Contribution

The study introduces a comparison of two two-handed techniques and their relation to trainee hand size in face-mask ventilation.

## Key findings

- The VE technique delivered larger tidal volumes compared to the CE technique.
- Hand size measurements were inversely correlated with ventilation effectiveness.
- Smaller-handed trainees benefited more from the VE technique.

## Abstract

Background: Effective face-mask ventilation (FMV) is a crucial step for oxygenation after anesthesia induction and prior to airway instrumentation. Preceding literature demonstrates that specific physical characteristics of providers affect tidal volume (Vt) delivery during FMV. In difficult ventilation scenarios, FMV success rates are improved using two-handed techniques, CE or VE. We hypothesized that anesthesia trainees' Vt delivery efficacy would differ with each technique and related to their hand size.

Methods: In this prospective crossover trial, 38 anesthesia trainees performed FMV on elective surgical patients after induction of general anesthesia with both CE and VE techniques. We recorded differences in delivered Vt with each method and analyzed its relation to multiple trainee hand size measurements, including palm circumference, hand length, and hand span.

Results: Thirty-eight operators (females 55.3%, n=21, males 44.7%, n=17) performed FMV on 38 patients (age 48.1+16.7 years, male sex 65.8%, n=25). Larger median Vts were obtained with VE vs. CE (10.0 (5.8-13.6) mL/kg vs. 11.9 (8.9-14.5) mL/kg, p = 0.008) without a significant change in achieving TV of 4 mL/kg (15% vs. 8%, p=0.32). The differences in VE and CE were inversely proportional to hand measurements (circumference: R-square = 0.15, p=0.02, length: R-square = 0.24, p=0.002, and span: R-square = 0.23, p=0.002). When stratifying by quartile of hand size, significant differences were observed as follows: hand size (circumference: first quartile p=0.039, hand length: first quartile p=0.018, second quartile p=0.028, hand span: second quartile p=0.001).

Conclusions: In novice anesthesiology providers, hand size is correlated with delivered Vt during two-hand FMV. The VE modification increases the delivery of Vt, especially in trainees with smaller hands.