Estimation of pulmonary oxygen consumption in the early postoperative period after thoracic surgery

Lung injury, including pneumonia, can occur in the early postoperative period following thoracic surgery. Pulmonary oxygen consumption is thought to increase in patients with pulmonary infection. This study measured oxygen consumption in relationship to lung injury in the early postoperative period after thoracic surgery. Thirty-five patients who underwent thoraco-abdominal oesophagectomy for oesophageal cancer were studied. Measured oxygen-consumption was obtained by indirect calorimetry and calculated oxygen-consumption was simultaneously determined by the reverse Fick method. The difference in oxygen consumption was attributed to pulmonary oxygen consumption. The difference in oxygen consumption increased to 23.1 ml.min(-1).m(-2) on postoperative day 2. In patients with pneumonia the difference in oxygen consumption increased significantly to 39.0 ml.min(-1).m(-2) the day before clinical onset of pneumonia, and it increased further to 65.7 ml.min(-1).m(-2) on the day that pneumonia became clinically apparent. These findings suggest that the difference in oxygen consumption may be useful for estimating the extent of lung injury and for predicting pulmonary complications in the postoperative period.