Oxygen Concentrators

the excess weight dragging on the patient's mask or endotracheal tube. I use a flow rate of 5 L-min ~ for preoxygenation and on termination of the anaesthetic. To diminish the diluting effect &the added flow of oxygen to the inspired concentration of halothane, I reduce the oxygen flow to 1 L.min -l during maintenance of anaesthesia. This conserves our supply of halothane, also a costly item in this part of the world. The Haloxair ~ has an oxygen flowmeter calibrated from 1-3 L.min -I to which a cylinder of compressed gas can be connected. I keep a cylinder attached, in case of power failure. The types of cases done at our hospital using this simple circuit include an oesophagectomy, laparotomy for ruptured ectopic pregnancy, Caesarean section, and repair of an oomphalocele in a newborn. It has also been a means of using oxygen in the resuscitation of newborns, children, and adults. There have been no clinical signs of hypoxia. I feel that in remote areas where use of the Haloxair ~ is appropriate and cylinders of oxygen are not readily obtainable but electricity is available, the use of an oxygen concentrator in conjunction with the Haloxair ~ adds an immeasurable margin of safety and offers a very satisfactory method of giving general anaesthesia.