Surgical operatory fires continue to occur in the United States, often with devastating consequences. Because more than 21% concentrations of oxygen are necessary for the onset of such combustion, this study examined fluctuations of surgical site oxygen levels. Better understanding how these more than 21% concentrations occur will not only add to surgical fire prevention efforts generally but also potentially reduce patient or staff harm and practitioner liability as well.
Performing an in situ dental procedure with supplemental nasal-cannulated oxygen and a dental dam, we measured oxygen pooling, defined as any fraction of inspired oxygen (FIO2) greater than the 21% FIO2 of air, on top of and behind a dental dam, and during the application of high-volume intraoral suction.
Findings indicated statistically significantly higher concentrations (as much as twice the <30% recommended safe level) behind the dental dam compared with on top of it. During real-time measurements of FIO2 for four 120-second trials per participant, oxygen levels exhibited significant fluctuation above and below a more stringent 24.9% safety threshold established in prior research. Application of high-speed intraoral dental suction reduced FIO2 to near atmospheric levels in 30 (96.7%) of 31 of the cases by 60 seconds.
These results demonstrate the elevated risk associated with above-safe levels of oxygen pooling during a simple dental procedure. Although future research is needed to still more exactly characterize conditions leading to the onset of surgical fires, this study also demonstrates the ability of high-speed intraoral suction to dramatically and rapidly decrease that risk.