Extracorporeal Membrane Oxygenation for Respiratory Failure Related to COVID-19: A Nationwide Cohort Study.

BACKGROUND: Despite expanding use, knowledge on extracorporeal membrane oxygenation support during the COVID-19 pandemic remains limited. The objective was to report characteristics, management, and outcomes of patients receiving extracorporeal membrane oxygenation with a diagnosis of COVID-19 in France and to identify pre-extracorporeal membrane oxygenation factors associated with in-hospital mortality. A hypothesis of similar mortality rates and risk factors for COVID-19 and non-COVID-19 patients on venovenous extracorporeal membrane oxygenation was made. METHODS: The Extracorporeal Membrane Oxygenation for Respiratory Failure and/or Heart failure related to Severe Acute Respiratory Syndrome-Coronavirus 2 (ECMOSARS) registry included COVID-19 patients supported by extracorporeal membrane oxygenation in France. This study analyzed patients included in this registry up to October 25, 2020, and supported by venovenous extracorporeal membrane oxygenation for respiratory failure with a minimum follow-up of 28 days after cannulation. The primary outcome was in-hospital mortality. Risk factors for in-hospital mortality were analyzed. RESULTS: Among 494 extracorporeal membrane oxygenation patients included in the registry, 429 were initially supported by venovenous extracorporeal membrane oxygenation and followed for at least 28 days. The median (interquartile range) age was 54 yr (46 to 60 yr), and 338 of 429 (79%) were men. Management before extracorporeal membrane oxygenation cannulation included prone positioning for 411 of 429 (96%), neuromuscular blockage for 419 of 427 (98%), and NO for 161 of 401 (40%). A total of 192 of 429 (45%) patients were cannulated by a mobile extracorporeal membrane oxygenation unit. In-hospital mortality was 219 of 429 (51%), with a median follow-up of 49 days (33 to 70 days). Among pre-extracorporeal membrane oxygenation modifiable exposure variables, neuromuscular blockage use (hazard ratio, 0.286; 95% CI, 0.101 to 0.81) and duration of ventilation (more than 7 days compared to less than 2 days; hazard ratio, 1.74; 95% CI, 1.07 to 2.83) were independently associated with in-hospital mortality. Both age (per 10-yr increase; hazard ratio, 1.27; 95% CI, 1.07 to 1.50) and total bilirubin at cannulation (6.0 mg/dl or more compared to less than 1.2 mg/dl; hazard ratio, 2.65; 95% CI, 1.09 to 6.5) were confounders significantly associated with in-hospital mortality. CONCLUSIONS: In-hospital mortality was higher than recently reported, but nearly half of the patients survived. A high proportion of patients were cannulated by a mobile extracorporeal membrane oxygenation unit. Several factors associated with mortality were identified. Venovenous extracorporeal membrane oxygenation support should be considered early within the first week of mechanical ventilation initiation.

Critical Preoperative Hemoglobin Value to Predict Anemia-Related Complications After Cardiac Surgery.

OBJECTIVES: Preoperative anemia is frequent in patients undergoing cardiac surgery and is associated with increased postoperative complications. The purpose of this observational study was to estimate the critical preoperative hemoglobin threshold associated with the occurrence of complications after cardiac surgery. DESIGN: A retrospective observational cohort study. SETTING: A tertiary-care medical center from January 2019 to April 2020. PARTICIPANTS: A total of 1,004 patients undergoing elective cardiac surgery were included. INTERVENTIONS: None (observational study). MEASUREMENTS AND MAIN RESULTS: The primary study endpoint was to define the hemoglobin threshold that predicted the occurrence of postoperative major complications after elective cardiac surgery. Postoperative complications were a composite criterion, including transient ischemic attack or stroke, myocardial infarction, acute kidney injury, respiratory failure, mediastinitis, or mesenteric ischemia. A discrimination threshold was determined by using receiver operating characteristic curves. The discrimination threshold for hemoglobin concentration with the best sensitivity/specificity ratio for the occurrence of postoperative complications was 13 g/dL for male patients and 11.8 g/dL for female patients. The incidence of postoperative complications was 17.2% in the total population. Independent risks were preoperative hemoglobin concentration, red blood cell transfusion, European System for Cardiac Operative Risk Evaluation II, and the type of surgery. CONCLUSIONS: The critical preoperative hemoglobin thresholds associated with the occurrence of postoperative complications with the best sensitivity/specificity ratio were 13 g/dL for men and 11.8 g/dL for women, which were very similar to the World Health Organization criteria defining anemia.