Blood volume and arterial blood gases in patients with chronic obstructive lung disease during and after acute respiratory failure.

The blood volume and arterial blood gases of 18 patients with chronic obstructive lung disease were studied over a period of 1/2 to 5 years, including 35 acute exacerbations of the lung disease. Treatment during exacerbation was directed at infection, bronchial obstruction and hypervolemia. Long-term diuretic therapy was instituted during the follow-up period. On admission all patients suffered from severe dyspnoea, all but two had signs of peripheral oedema and/or liver congestion and one-third had increased jugular venous pressure. Blood volume was increased in all patients and eight of them had a hematocrit above 50%. PaCO2 was severely reduced and PaCO2 increased on admission. At discharge, these symptoms and signs had all diminished or disappeared. Blood volume had fallen an average of 11 and a further reduction of 0.41 was noticed during the follow-up period. Blood gases had improved by discharge and a further improvement accompanied the reduction of blood volume during the follow-up period. It is suggested that 1) hypervolemia is common in patients with advanced chronic obstructive lung disease; 2) hypervolemia may impair arterial oxygenation; 3) long-term diuretic therapy seems to be necessary for maintaining a normal blood volume.