[Outcomes of idiopathic pulmonary fibrosis patients with high body mass index undergoing extracorporeal membrane oxygenation support].

Objective: To evaluate the extracorporeal membrane oxygenation (ECMO) related outcomes during hospitalization during the intensive care unit (ICU) in idiopathic pulmonary fibrosis (IPF) patients with high body mass index (BMI, > 25 kg/m 2 ) undergoing lung transplantation with ECMO support.

Methods: A retrospective observational study was conducted. IPF patients who received ECMO during lung transplantation admitted to the Affiliated Wuxi People's Hospital of Nanjing Medical University from 2019 to 2020 were enrolled. Preoperative indicators including, demographics, comorbidities, arterial blood gas, and laboratory indicators; intraoperative indicators, such as lung lobe volume reduction, surgical type, surgical time, cold ischemia time, blood loss and transfusion volume; immediate indicators upon admission to the ICU, such as blood gas analysis and laboratory indicators; ECMO related outcomes, such as ECMO mode, ECMO support time, ECMO related complications (bleeding at the catheterization site, intraductal thrombosis, lower limb ischemia), and the length of ICU stay, duration of mechanical ventilation, and 30-day survival rate were collected. According to BMI, patients were divided into three groups: light weight group (BMI < 18.5 kg/m 2 ), normal weight group (BMI 18.5-24.9 kg/m 2 ), and overweight group (BMI ≥ 25.0 kg/m 2 ). Mainly to compare the relevant outcomes of ECMO among patients during ICU.

Results: A total of 114 IPF patients who received ECMO support during lung transplantation were collected, including 23 cases in the light weight group, 63 cases in the normal weight group, and 28 cases in the overweight group. Compared with patients with underweight and normal weight, overweight patients were more likely to have hypertension (46.4% vs. 8.7%, 23.8%, P < 0.01) and coronary heart disease (32.1% vs. 4.3%, 20.6%, P < 0.05) before surgery, which was consistent with international guidelines for obesity. Other clinical data (preoperative, intraoperative, ICU characteristics) showed no statistically significant differences and were comparable. There was no statistically significant difference in terms of ECMO related outcomes, such as ECMO related complications [veno-venous (V-V) mode: 78.3%, 77.8%, 78.6%, veno-arterial (V-A) mode: 21.7%, 22.2%, 21.4%], ECMO support time (hours: 61.70±20.03, 44.57±5.76, 41.77±7.26), ECMO related complications (bleeding at the catheterization site: 4.3%, 7.9%, 14.3%; intraductal thrombosis: 8.7%, 12.7%, 17.9%; lower limb ischemia: 8.7%, 12.7%, 14.3%), and the length of ICU stay (days: 11±3, 7±1, 9±1), duration of mechanical ventilation [days: 2 (2, 11), 2 (2, 6), 3 (2, 8)] among the light weight group, normal weight group, and overweight group (all P > 0.05). Kaplan-Meier survival curve analysis showed that there was no statistically significant difference in the 30-day cumulative survival rate among the three groups (Log-Rank test: χ 2 = 0.919, P = 0.632).

Conclusions: High BMI does not worsen ECMO-related outcomes or adversely affect early prognosis in IPF patients undergoing lung transplantation. BMI as a single parameter should not be a contraindication for the use of ECMO in lung transplantation surgery for IPF patients.