Effect of nasal cannula oxygen administration on oxygen concentration at facial and adjacent landmarks

Abstract

SummaryAn oxygen-enriched atmosphere enhances the potential for operating-room fires. We thus determined oxygen concentrations at various facial landmarks during oxygen administration via nasal cannulae. Thirteen supine volunteers were draped similarly to patients undergoing a cervicalnode biopsy. Oxygen was delivered in random order through nasal cannulae at rates of 2, 4, and 6 l.min )1 . Oxygen concentration was measured at pre-determined facial landmarks and also distal to the drape at non-facial sites. At a flow of 2 l.min )1 , oxygen concentrations exceeded 23%only within a few centimetres of the nasal cannula. Concentration increased as a function of flow, but rarely exceeded 26%. At all flow rates, concentrations distal to the drape were < 24%. To reduce combustion risk, ignition sources should be kept at least 10 cm from the oxygen outlet when using nasal cannula at a flow rate ‡ 4 l.min.

Incêndio no centro cirúrgico

“…All the critical landmarks were less than 10 cm away from the catheter outlet. However, at 6 L.min -1 , all landmarks presented a concentration higher than 24.9%, except for the glabella and the septal nucleus of the right eye 12 .…”

“…An oxygen concentration of 26% to 28% is necessary to increase the combustion rate. Therefore, the International Electrotechnical Commission (IEC 1977) does not suggest additional precaution in environments with oxygen concentration 4% higher than ambient air (24.9%) 12 .…”

The Efficacy of a Midfacial Seal Drape in Reducing Oculofacial Surgical Field Fire Risk

“…7 Importantly, the corner of the mouth had oxygen levels above threshold even at the lowest (2 l/min) flow rate. In general, oxygen concentrations may become dangerous (greater than 26%) at facial landmarks close to the nasal cannula or at flow rates above 4 l/min.…”

Nasal cannula oxygen administration and oxygen concentration around the face

“…We were pleased to read Orhan-Sungur et al's paper [1] exploring nasal cannula oxygen administration and its effect on oxygen concentration around the face. The authors mention 'oxygen enriched atmospheres enhancing the potential for operating-room fires…'.…”

“…An oxygen enriched environment or atmosphere is defined as oxygen concentration exceeding 21% by Fickling et al [1] thus: 'Sparks can provide enough initial heat to ignite some fuels, especially in an oxygen enriched (greater than 21% of room air) atmosphere…'. However, Barnes et al [2] note that 'In some situations, this definition has been modified to 23.5% to account for the upper limit of oxygen concentration in compressed air' [3].…”