Lactate Production by the Lungs in Acute Lung Injury

Arteriovenous differences in lactate (AVLAC) across the lungs are usually small and close to zero. However, it has recently been reported that the lungs can produce increased amounts of lactate in some patients with acute respiratory distress syndrome (ARDS). The aim of this study was to evaluate lactate production in various types of acute lung injury requiring mechanical ventilation and hemodynamic monitoring. Since the differences involved are usually small, minor errors in lactate measurement could greatly influence AVLAC. Based on an analysis of these errors (see text for details), we averaged five arterial and venous samples for each measurement. We investigated 122 patients: 43 with acute lung injury (ALI), nine with cardiogenic pulmonary edema (CPE), 37 with bronchopneumonia (BPN), seven with single lung transplantation (LTX), and 26 with other causes of respiratory failure (OTHER). There was no difference in arterial lactate between the various groups. AVLAC was higher in patients with ALI than i...