The oxygen concentrator is a suitable alternative to oxygen cylinders in Nepal.

Purpose: To review the efficacy and reliability of oxygen concentrators used over the last six years in Nepal. The apparatus used was a DeVilbiss(R) oxygen concentrator that provided O(2) for anesthesia supplemented with compressed air to drive a Penlon Manley Multivent Ventilator(R). It remains difficult to supply oxygen in cylinders to peripheral hospitals in Nepal due to lack of proper roads.

Methods: We conducted a retrospective analysis of a sample of 378 cases anesthetized at the Bir Hospital and at a private hospital in Kathmandu from April through October 1999. The Bain circuit or its modification was used in adults, and Bain or Ayre's T piece in children. High flows from the oxygen concentrator used with the Bain and Ayre's T-circuits were reduced to 2 L/min, delivered through the halothane vaporizer, supplemented by room air in the modified Bain circuit. Positive pressure ventilation was provided with an Ambubag, Oxford Inflating Bellows or Penlon Manley Multivent Ventilator. Blood pressure, electrocardiogram, FiO(2) and SpO(2) were monitored in all cases.

Results: Surgery included urologic, general surgery, obstetrics and gynecological procedures, neurosurgery and closed mitral valvotomy. Age ranged from six months to 78 yr. The anesthetic time lasted from 45 min to 12 hr. The FiO(2) ranged from 0.5 to 0.6 in the Bain and Ayre's T circuits, and from 0.34 to 0.40 in the modified Bain circuit with a flow of oxygen of 2 L/min from the concentrator.

Conclusion: With regular maintenance and servicing done locally, the oxygen concentrator can be used safely in adults and children. Use of the oxygen concentrator is a suitable alternative to oxygen cylinders in the developing world.