Impact of obesity on survival in COVID-19 ARDS patients receiving ECMO: results from an ambispective observational cohort

Abstract

Background Since March 2020, health care systems were importantly affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, with some patients presenting severe acute respiratory distress syndrome (ARDS), requiring extra-corporeal membrane oxygenation (ECMO). We designed an ambispective observational cohort study including all consecutive adult patients admitted to 5 different ICUs from a university hospital. The main objective was to identify the risk factors of severe COVID-19 ARDS patients supported by ECMO associated with 90-day survival. Results Between March 1st and November 30th 2020, 76 patients with severe COVID-19 ARDS were supported by ECMO. Median (interquartile range IQR) duration of mechanical ventilation (MV) prior to ECMO was of 6 (3–10) days. At ECMO initiation, patients had a median PaO2:FiO2 of 71 mmHg (IQR 62–81), median PaCO2 of 58 mmHg (IQR 51–66) and a median arterial pH of 7.33 (IQR 7.25–7.38). Forty-five patients (59%) were weaned from ECMO. Twenty-eight day, 60-day and 90-day survival rates were, respectively, 92, 62 and 51%. In multivariate logistic regression analysis, with 2 models, one with the RESP score and one with the PRESERVE score, we found that higher BMI was associated with higher 90-day survival [odds ratio (OR): 0.775 (0.644–0.934), p = 0.007) and 0.631 (0.462–0.862), respectively]. Younger age was also associated with 90-day survival in both models [OR: 1.1354 (1.004–1.285), p = 0.044 and 1.187 (1.035–1.362), p = 0.014 respectively]. Obese patients were ventilated with higher PEEP than non-obese patients and presented slightly higher respiratory system compliance. Conclusion In this ambispective observational cohort of COVID-19 severe ARDS supported by ECMO, obesity was an independent factor associated with improved survival at 90-day.

Key characteristics impacting survival of COVID-19 extracorporeal membrane oxygenation

“…BMI > 35 was only compared to BMI < 25 and not against healthy weight and underweight patients. Nevertheless, our result is in line with current evidence suggesting improved 90-day survival in obese COVID-19 ECMO patients [ 25 ] or corroborating that obesity is not a risk factor for a worse outcome [ 26 ].…”

Duration of invasive mechanical ventilation prior to extracorporeal membrane oxygenation is not associated with survival in acute respiratory distress syndrome caused by coronavirus disease 2019

“…In our patient population, the median duration of pre-ECMO IMV was 7.7 days in survivors and 6.8 days in non-survivors. Similar to other observations [ 14 – 17 ], we found no correlation between pre-ECMO IMV duration and survival.…”

Evolving outcomes of extracorporeal membrane oxygenation during the first 2 years of the COVID-19 pandemic: a systematic review and meta-analysis

“…1 , Additional file 1 : Table S4) [ 3 , 5 , 16 – 65 ]. All studies were retrospective and observational in nature; 22 studies were conducted by studies centres from Europe [ 5 , 17 , 19 , 23 , 27 , 29 , 31 – 34 , 36 , 39 , 42 , 43 , 45 , 46 , 50 , 55 , 56 , 60 , 63 , 65 ], 17 from North America [ 16 , 18 , 20 – 22 , 24 , 25 , 37 , 40 , 47 , 48 , 52 – 54 , 57 , 58 , 61 ], 6 from the Asia–Pacific [ 26 , 28 , 35 , 38 , 41 , 44 ], 2 from South-West Asia and Africa,[ 51 , 62 ] 2 from Latin America [ 30 , 64 ], and 3 were studies conducted by centres from multiple ELSO regions [ 3 , 49 , 59 ], of which 2 were based on registry data [ 3 , 49 ]. The pooled age was 52.5 years (95% CI 50.7 to 54.3), and the majority of patients were male (75.0%, 95% CI 72.4% to 77.4%) and obese (BMI: 31.0, 95% CI 30.2 to 31.8).…”