Effects of Carbohydrates on Carbon Dioxide Excretion in Patients with Airway Disease

¹ From the Department of Medicine, Veterans Administration Hospital, Long Beach, Calif.

Thirteen patients with stable airway disease were fed a diet high in carbohydrates, and 35 minutes later metabolic and ventilatory effects were observed. The six patients who did not retain carbon dioxide increased their mean respiratory quotient from 0.86 ± 0.07 to 1.03 ± 0.04, their mean minute ventilation from 10.3 ± 3.0 to 12.8 ± 4.0 L/min, mean carbon dioxide production from 0.23 ± 0.04 to 0.29 ± 0.02 L/min, and mean oxygen consumption from 0.27 ± 0.07 to 0.29 ± 0.03 L/min (all P < 0.05). The arterial carbon dioxide tension (PaCO₂) did not change significantly from baseline values. The seven patients who retained carbon dioxide responded similarly, except that their mean arterial oxygen pressure (PaO₂) increased significantly from 50.9 ± 4.4 to 57.7 ± 5.5 torr (P < 0.05). In addition, the mean PaCO₂ increased from 54.5 ± 6.4 to 54.9 ± 6.4 torr (not significant). We conclude that the increased endogenous carbon dioxide load resulting from a meal high in carbohydrates is well tolerated by most patients with chronic airway disease.