AIR-TRAVEL AND ADULTS WITH CYANOTIC CONGENITAL HEART DISEASE

Background Concern has been expressed that a reduction of partial oxyg en pressure during flight in commercial aircraft may induce dangerous hypoxemia in patients with cyanotic congenital heart disease. Methods and Results To evaluate the validity of this concern, the transcutaneo us Sao, was measured in 12 adults with this type of heart disease and 27 control subjects during simulated commercial flights of 1.5 and 7 h ours in a hypobaric chamber. Ten of those patients and 6 control subje cts also were evaluated during two actual flights of approximately 2.5 hours in a DC-10 and an A-310, respectively. During the prolonged sim ulated and actual flights, the capillary blood pH, gases, and lactic a cid were analyzed in the patients and during one of the actual flights also in the control subjects. During the simulated flights the Sao, w as at all times lower in the patients than in the control subjects. Ho wever, the maximal mean actual percentage decrease, as compared with s ea level values, did not exceed 8.8% in either patients or control sub jects. During the actual flights, this maximal decrease in the patient s was 6%. In-flight reduction of the capillary Po-2 was considerable i n the control subjects but not in the patients. It is our hypothesis t hat the lack of a significant decrease of the Po-2 in the patients mig ht possibly be due to a high concentration of 2.3 diphosphoglycerate i n the red cells. The flights had no influence on the capillary blood p H, Pco(2), bicarbonate, or lactic acid levels in either patients or co ntrol subjects. Conclusions Atmospheric pressure changes during commer cial air travel do not appear to be detrimental to patients with cyano tic congenital heart disease.