The effect of furosemide during normoxemia and hypoxemia

The effect of furosemide infusion was studied in 6 normal subjects and 6 patients with severe COPD and right ventricular failure during normoxemia and hypoxemia. In normal subjects, hypoxemia alone caused an insignificant (p less than 0.15) fall in plasma aldosterone concentrations (PAC). Intravenously administered furosemide resulted in significant (p less than 0.05) increases in PAC during both normoxemia and hypoxemia. After furosemide treatment mean arterial pressure (MAP) was significantly lower and arginine vasopressin (AVP) was significantly higher (p less than 0.05) with hypoxemia than with normoxemia. These changes in MAP and AVP were strongly correlated (r = -0.84). Urinary losses of water and sodium were similar after furosemide treatment with hypoxemia and normoxemia. In patients with right ventricular failure, neither changes in oxygenation nor furosemide infusion affected the markedly elevated baseline PRA and PAC levels. Arginine vasopressin levels were significantly higher with hypoxemia than with normoxemia, but urinary losses of water and salt did not differ between the 2 study days. We conclude that hypoxemia does not affect the PAC increase or urinary volume and sodium response to furosemide.