Thorax 1989;44:588-590 Personal View

Studies of domiciliary oxygen in a common cause Shortly after our first report of the clinical and physiological benefits oflong term ambulatory oxygen appeared in 1967 ' David Flenley paid a visit to Denver. Always interested in applied physiology and improvements in patient care, he wanted to see some of our home care patients who were receiving long term oxygen using a new portable oxygen system. He also wanted to view Pikes Peak and take photographs for teaching medical students and house officers in Edinburgh, being well aware of the fact that the Haldane expedition in 1913 to the summit (4300 metres) had helped to characterise the effects of substantial hypoxia on normal volunteers. "Partial anoxia means not a mere slowing down of life but progressive and perhaps irreparable damage to living structure": this direct quote from Haldane's report in 1919 also describes, accurately and suc-cinctly, the impact of oxygen lack on patients with chronic respiratory insufficiency.2 Haldane was aware that the clinical manifestations of impaired oxygen transport to the tissues could be corrected with supplemental oxygen delivered via nasal cannulas. Flenley taught and wrote extensively on the physiology of tissue oxygen transport3 and thus wanted to experience and see the original laboratory used for the oxygen experiments in Colorado. Our initial observations about long term oxygen were soon confirmed by a similar study from Bir-mingham, which appeared one year after our original report.4 Both came to the same conclusion-namely, that long term oxygen could reverse the pulmonary hypertension and control the erythrocytosis that were responses to chronic hypoxaemia in patients with chronic bronchitis and emphysema. Moreover, the sustained use of oxygen did not lead to uncompen-sated retention of carbon dioxide and respiratory acidosis, a feared but infrequent complication of oxygen therapy that was usually found only in the acutely ill patient with advanced chronic obstructive lung disease, applying to both chronic bronchitis and emphysema