The efficacy of noncontact oxygen delivery methods

"Wafting" oxygen is a possible strategy to deliver oxygen to a patient who may not tolerate delivery systems that involve contact on the face. We wished to assess the concentration of oxygen delivered to the patient with various methods of "wafting" oxygen.

Three methods of wafting oxygen were examined: an infant resuscitator bag, a standard pediatric Hudson RCI face mask, and a piece of standard green oxygen tubing. Contour lines for oxygen concentrations of 30% to 70% in 10% intervals were found with a Teledyne oxygen meter, at an oxygen flow rate of 5 L/min and 10 L/min. Experimental conditions simulated an infant in a cot in a pediatric ward.

The resuscitator bag can not be recommended for wafting oxygen delivery, as the flow-back valve may close and result in insignificant levels of oxygen delivery. Oxygen tubing gave a useable area too narrow for use with an active patient, with 30% oxygen concentration being available in an area with width of only 18 cm. This is, however, a suitable method in short-term attended administration, either during feeding, or in the situation of a neonatal resuscitation. The standard pediatric Hudson RCI face mask, at a flow rate of 10 L/min, delivers 30% oxygen to an area 35 cm wide and 32 cm from the top of the mask. At 10 L/min, 40% oxygen is delivered to an area 16 cm wide and 14 cm from the top of the mask. This is an area large enough to be usable in the infant who will not tolerate other methods of oxygen delivery. The contour lines are presented graphically.

Although wafting can never replace conventional methods of oxygen delivery to children, if these have failed, a standard pediatric oxygen mask can give significant oxygen therapy without irritating the patient. Care should be taken to place the mask in the area described (ie, opposite the chest) to give the maximum benefit. Short-term administration can be appropriate with standard oxygen tubing aimed at the airway.