The mortality from acute respiratory distress syndrome after pulmonary resection is reducing: a 10-year single institutional experience.

OBJECTIVE: Acute respiratory distress syndrome (ARDS) is a major cause of death following lung resection. At this institution we reported an incidence of 3.2% and a mortality of 72.2% in a review of patients who underwent pulmonary resection from 1991 to 1997 [Kutlu C, Williams E, Evans E, Pastorino U, Goldstraw P. Acute lung injury and acute respiratory distress syndrome after pulmonary resection. Ann Thorac Surg 2000;69:376-80]. The current study compares our recent experience with this historical data to assess if improved recognition of ARDS and treatment strategies has had an impact on the incidence and mortality.

METHODS: We identified and studied all patients who developed ARDS following a lung resection of any magnitude between 2000 and 2005 using the 1994 consensus definition: characteristic chest X-ray or CT, PaO2/FiO2 < 200 mmHg, pulmonary capillary wedge pressure < 18 mmHg and clinical acute onset. Overall incidence and mortality were recorded. Univariate analyses (t-test or chi(2), as appropriate) were carried out to identify correlations between pre-, peri- and postoperative variables and outcomes.

RESULTS: We performed 1376 lung resections during the study period. Of these 705 (51.2%) were for lung cancer and 671 (48.8%) for other diseases. Twenty-two patients fulfilled the criteria for ARDS with 10 deaths in this group. The incidence and mortality from ARDS had fallen significantly over the two study periods (incidence from 3.2% to 1.6%, p=0.01; mortality from 72% to 45%, p=0.05). Although no significant correlations with incidence and mortality were identified, we found a number of significant trends. In keeping with the ARDS network study recommendations, postoperative tidal volumes were maintained at a lower level when a higher number of pulmonary segments were excised (p=0.001). Furthermore, consistent with findings in previous studies, the highest incidence and death from ARDS were in pneumonectomy patients (incidence 11.4%; mortality 50%). Although the incidence and mortality from ARDS following pneumonectomy were not significantly different between the two study periods (p=0.08, p=0.35), we found that fewer pneumonectomies were performed in the later period (pneumonectomy rate of 6.4% vs 17.4%).

CONCLUSIONS: The incidence and mortality of ARDS have decreased in our institution. We postulate that this is due to more aggressive strategies to avoid pneumonectomy, greater attention to protective ventilation strategies during surgery and to the improved ICU management of ARDS.