Renal function was studied in 27 men in whom respiratory failure was accompanied by peripheral edema, increased heart size, and rapid diuresis during recovery. All were hypoxic and 24 were hypercapnic. Excretion of water loads (20 ml/kg body weight) was impaired during respiratory failure and usually improved during recovery. When arterial blood oxygen tension (Pao2) was raised, urine flow and renal function decreased and when Pao2 was lowered, renal function increased. However, it decreased abruptly when hypoxia became severe, Pao2 below 40 mm Hg. The arterial blood tension of carbon dioxide had no measurable effect until it reached 65 mm Hg and abruptly reduced a renal function. These effects of acute changes in Pao2 and Paco2 may help explain fluid retention in patients with cor pulmonale who have severe hypercapnia, severe hypoxia, or both.
Kilburn KH, Dowell AR. Renal Function in Respiratory FailureEffects of Hypoxia, Hyperoxia, and Hypercapnia. Arch Intern Med. 1971;127(4):754–762. doi:10.1001/archinte.1971.00310160232020