Delayed lung injury on the nonsurgical side increases mortality in patients after lung cancer surgery: a retrospective cohort study

Background: The incidence of pulmonary complications following lung cancer surgery has declined recently; however, postoperative acute lung injury (PALI) is still common. The present study aimed to assess the prognosis of PALI after lung cancer surgery on different injury sides, describe its clinical characteristics and identify risk factors.Methods: This was a monocenter retrospective study conducted in a university surgical intensive care unit (SICU). Patients requiring respiratory support with severe hypoxemia after lung cancer surgery were included. Patients were categorized based on the radiographic assessment of lung edema (RALE) score ratio, which calculates the severity of surgical/nonsurgical side of lung injury [RRALE; RALE score of the surgical side (RALES) divided by RALE score of nonsurgical side (RALENS)], into two groups: the nonsurgical-side lung injury group (RRALE <1) and others (RRALE >_1). The primary outcome was 90-day mortality, and secondary outcomes included in-hospital 28-day mortality, total intensive care unit (ICU) length of stay (LOS), hospital LOS and 6-month survival.Results: Sixteen patients were enrolled in this study. Nine patients were included in the RRALE <1 group and seven patients were included in the RRALE >_1 group. At 90 days, six patients in the RRALE <1 group had died, whereas none died in the RRALE >_1 group (P=0.01). No significant difference was observed in in-hospital 28-day all-cause mortality (P=0.48) or ICU or hospital LOS (P=0.34 and P=0.36, respectively) between the two groups. Survival at 6 months was significantly lower in the RRALE <1 group (33.33%) than in the RRALE >_1 group (100.00%) (P=0.009).Conclusions: Patients with severe lung injury on the nonsurgical side after lung cancer surgery had high 90-day mortality rates. Large prospective studies and accurate monitoring data are needed in the future to identify the risk factors and therapy for such lung injury.