Objectives: 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.
Methods: 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.
Results: 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.
Conclusions: 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.