Respiratory failure and intraoperative oxygenation following oesophagectomy

Abstract

Respiratory complications are a major cause of morbidity and mortality following oesophagectomy.1 We hypothesized that patients who develop postoperative respiratory failure would have an unstable intraoperative course. Two stage oesophagectomy requires a period of one lung ventilation (OLV) and one measure of intraoperative instability is desaturation during OLV. We therefore studied the relationship betweenSaO2 during OLV and postoperative course. Previous work has focused on preoperative factors associated with postoperative complications.2 There is little information on intraoperative factors that may influence outcome. We performed a retrospective analysis of all elective oesophagectomies performed between January 1998 and August 1999. Seventy-seven patients had a 2-stage sub-total oesophagectomy requiring OLV. Oxygen saturation recorded on the anaesthetic chart during OLV was plotted on a fixed linear scale of 0–100% against time for each patient. The area above the curve was calculated, as a measure of intraoperative oxygenation during OLV. This was standardized by dividing the area by the OLV duration, thus obtaining the Area Per Unit Time (APUT). The postoperative course of each patient was recorded including outcome, total duration of ITU stay and the worstPaO2/FIO2 ratio attained. ARDS was defined using the American-European Consensus Conference on ARDS criteria. Twenty-one patients had a prolonged ITU stay (>48 h) and all had a persistentPaO2/FIO2 Total OLV time was not significantly different between the groups but patients who developed ARDS had significantly greater intraoperative hypoxaemia as measured by the APUT (Table 17). We conclude that intraoperative hypoxaemia is associated with respiratory failure following oesophagectomy.