The efficacy of oxygen wafting using different delivery devices, flow Rates, and device positioning

Background: Oxygen delivery to pediatric patients in the emergency room can be a challenging task. Wafting provides a non-contact alternative that might be better tolerated by uncooperative children. Despite this being common practice, little research has been done on wafting techniques and no studies have evaluated its clinical effectiveness. Objectives: The aim of this study was to identify the combination of oxygen delivery device, oxygen flow rate, and device positioning that produces the highest concentrations of oxygen at the mouth and nose of a simulated patient. Methods: A simulated patient and oxygen sensor were used to compare six oxygen delivery devices (pediatric simple face mask, pediatric non-rebreather mask, adult simple face mask, adult non-rebreather mask, adult nebulizer, and simple oxygen tubing) in various positions in front of and below the simulated patient’s face, with oxygen flow rates ranging from 6 to 15 liters per minute (L/min). Results: Only oxygen tubing and the pediatric non-rebreather mask consistently produced oxygen concentrations above 30%. At 15 L/min, oxygen tubing held in front of and aimed at the face produced oxygen concentrations ranging from 31.2% (at 15 cm) to 56.7% (at 5 cm); reducing the flow rate to 6–8 L/min had no meaningful effect on the measured oxygen concentrations. The pediatric non-rebreather mask held below the face produced oxygen concentrations ranging from 35.0% (at 10 cm) to 39.8% (at 5 cm). When tubing was used and held below the face, flow rates between 6–8 L/min produced somewhat higher concentrations than 15 L/min (at 5 cm: 36.3% vs. 30.9%). Conclusion: When delivering oxygen by wafting, the highest oxygen concentrations (>50%) are achieved when positioning oxygen tubing 5–15 cm in front of and aimed at the face; oxygen concentrations between 30% and 40% can be achieved using either oxygen tubing or a pediatric non-rebreather mask positioned 5–10 cm below the face. When tubing is used, the flow rate of oxygen may be decreased to 6–8 L/min without reducing the oxygen concentrations. These findings should be considered by emergency department staff when administering oxygen via wafting to pediatric patients. They will also be incorporated into a future study using transcutaneous oxygen monitoring to test the clinical effectiveness of wafting with these devices