# Efficacy of a novel oxygen scavenger mask in reducing local oxygen concentrations below the surgical fire risk threshold: an experimental proof-of-concept study

## TL;DR

A new oxygen scavenger mask was tested and shown to reduce oxygen levels in the surgical area below the fire risk threshold during oxygen therapy.

## Contribution

A novel oxygen scavenger mask was developed and experimentally validated to reduce surgical fire risk during nasal oxygen delivery.

## Key findings

- The mask reduced mean oxygen concentration from 24.8% to 20.95% in the surgical field.
- The device kept oxygen levels below the 23% fire threshold at all three flow rates.
- Oxygen levels correlated with flow rate in unmasked conditions but not with the mask.

## Abstract

This study aims to evaluate the efficacy of an oxygen scavenging mask device in reducing local oxygen concentrations from nasal cannula ventilation compared to a standard open facial surgical field.

This is a controlled experiment using a custom-fabricated silicone midfacial oxygen scavenging device, SimMan airway management trainer manikin (Laerdal Medical, Stavanger, Norway), handheld oxygen detector (Forensics Detectors, Los Angeles, United States) and oxygen from a Datex Ohmeda Aisys Carestation anesthesia unit (GE HealthCare, Chicago, United States). Oxygen concentrations were measured at 18 facial landmarks (Fig. 1) with nasal cannula flow of 2, 4, and 6 L/min of 100% FiO2 in both masked and unmasked conditions (Fig. 2).

The mean oxygen concentration in the facial surgical field was 20.95% with the scavenger mask and 24.8% without (P < 0.001; two-tailed paired t-test). The unmasked condition was associated with suprathreshold oxygen concentration levels at 13 of 18 facial landmarks (Table 1). The device significantly reduced local oxygen concentration at 16 of 18 facial landmarks (Table 1). The device provided safe oxygen concentration levels at all three flow rates, and measured oxygen concentrations directly correlated with oxygen flow rate in the unmasked condition (Table 2).

An oxygen scavenger mask device reduced local oxygen concentrations from nasal cannula ventilation to below the 23% fire threshold in the entire facial surgical field external to the mask in these experiments. The device may reduce intraoperative fire risk in patients that require supplementary oxygen during surgery.

The online version contains supplementary material available at 10.1186/s13037-024-00411-1.