Intravenous hydrochloric acid in patients with metabolic alkalosis and hypercapnia.

During a seven-year period, 15 patients admitted to an intensive care unit with a metabolic alkalosis resistant to saline and potassium chloride infusions and with an arterial pH of greater than 7.44 and arterial carbon dioxide pressure (PaCO2) of greater than 50 mm Hg, while breathing spontaneously, were given hydrochloric acid at 200 mmol/24 h through a central venous line until the arterial pH had decreased to less than 7.36 or PaCO2 had decreased to less than 40 mm Hg. Five patients without respiratory failure had a significant decrease in PaCO2, pH, bicarbonate Ion (HCO3-), and base excess (BE). Four patients with acute respiratory failure had a significant decrease in PaCO2, HCO3-, and BE and an increase in arterial oxygen pressure, indicating that in both of these patient groups alveolar ventilation had improved. Six patients with chronic respiratory failure had a significant decrease in pH, HCO3-, and BE, although there was no significant change in PaCO2, indicating that in this patient group alveolar ventilation could not be consistently increased in response to a reduction in arterial pH.