Carlos Ferrando1,2, Julian Librero3, Gerardo Tusman4, Ary Serpa-Neto5,6,7, Jesús Villar2,8,9, Francisco J Belda6, Eduardo Costa10,11, Marcelo B P Amato10, Fernando Suarez-Sipmann2,12,13. 1. Department of Anesthesiology and Critical Care, Hospital Clínic, Institut D'investigació August Pi i Sunyer, Barcelona, Spain. 2. CIBER de Enfermedades Respiratorias, Instituto de Salud Carlos III, Madrid, Spain. 3. Navarrabiomed, Complejo Hospitalario de Navarra, UPNA, REDISSEC (Red de Investigación en Servicios de Salud), La Palma de Cervelló, Spain. 4. Department of Anesthesiology, Hospital Privado de Comunidad, Mar de Plata, Argentina. 5. Australian and New Zealand Intensive Care-Research Centre (ANZIC-RC), Monash University, Melbourne, Vic., Australia. 6. Department of Critical Care Medicine, Hospital Israelita Albert Einstein, Sao Paulo, Brazil. 7. Department of Critical Care, Melbourne Medical School, University of Melbourne, Austin Hospital, Melbourne, Vic., Australia. 8. Multidisciplinary Organ Dysfunction Evaluation Research Network, Research Unit, Hospital Universitario Dr. Negrín, Las Palmas de Gran Canaria, Spain. 9. Keenan Research Center for Biomedical Science at the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada. 10. Cardio-Pulmonary Department, Pulmonary Division, Heart Institute (Incor), University of São Paulo, Sao Paulo, Brazil. 11. Research and Education Institute, Hospital Sirio-Libanês, Sao Paulo, Brazil. 12. Department of Surgical Sciences, Hedenstierna Laboratory, Uppsala University Hospital, Uppsala, Sweden. 13. Department of Intensive Care, Hospital Universitario La Princesa, Madrid, Spain.
Abstract
BACKGROUND: The preventive role of an intraoperative recruitment maneuver plus open lung approach (RM + OLA) ventilation on postoperative pulmonary complications (PPC) remains unclear. We aimed at investigating whether an intraoperative open lung condition reduces the risk of developing a composite of PPCs. METHODS: Post hoc analysis of two randomized controlled trials including patients undergoing abdominal surgery. Patients were classified according to the intraoperative lung condition as "open" (OL) or "non-open" (NOL) if PaO2 /FIO2 ratio was ≥ or <400 mmHg, respectively. We used a multivariable logistic regression model that included potential confounders selected with directed acyclic graphs (DAG) using Dagitty software built with variables that were considered clinically relevant based on biological mechanism or evidence from previously published data. PPCs included severe acute respiratory failure, acute respiratory distress syndrome, and pneumonia. RESULTS: A total of 1480 patients were included in the final analysis, with 718 (49%) classified as OL. The rate of severe PPCs during the first seven postoperative days was 6.0% (7.9% in the NOL and 4.4% in the OL group, p = .007). OL was independently associated with a lower risk for severe PPCs during the first 7 and 30 postoperative days [odds ratio of 0.58 (95% CI 0.34-0.99, p = .04) and 0.56 (95% CI 0.34-0.94, p = .03), respectively]. CONCLUSIONS: An intraoperative open lung condition was associated with a reduced risk of developing severe PPCs in intermediate-to-high risk patients undergoing abdominal surgery. TRIAL REGISTRATION: Registered at clinicaltrials.gov NCT02158923 (iPROVE), NCT02776046 (iPROVE-O2).
BACKGROUND: The preventive role of an intraoperative recruitment maneuver plus open lung approach (RM + OLA) ventilation on postoperative pulmonary complications (PPC) remains unclear. We aimed at investigating whether an intraoperative open lung condition reduces the risk of developing a composite of PPCs. METHODS: Post hoc analysis of two randomized controlled trials including patients undergoing abdominal surgery. Patients were classified according to the intraoperative lung condition as "open" (OL) or "non-open" (NOL) if PaO2 /FIO2 ratio was ≥ or <400 mmHg, respectively. We used a multivariable logistic regression model that included potential confounders selected with directed acyclic graphs (DAG) using Dagitty software built with variables that were considered clinically relevant based on biological mechanism or evidence from previously published data. PPCs included severe acute respiratory failure, acute respiratory distress syndrome, and pneumonia. RESULTS: A total of 1480 patients were included in the final analysis, with 718 (49%) classified as OL. The rate of severe PPCs during the first seven postoperative days was 6.0% (7.9% in the NOL and 4.4% in the OL group, p = .007). OL was independently associated with a lower risk for severe PPCs during the first 7 and 30 postoperative days [odds ratio of 0.58 (95% CI 0.34-0.99, p = .04) and 0.56 (95% CI 0.34-0.94, p = .03), respectively]. CONCLUSIONS: An intraoperative open lung condition was associated with a reduced risk of developing severe PPCs in intermediate-to-high risk patients undergoing abdominal surgery. TRIAL REGISTRATION: Registered at clinicaltrials.gov NCT02158923 (iPROVE), NCT02776046 (iPROVE-O2).