Veno-venous extracorporeal membrane oxygenation (ECMO) is increasingly being used for the treatment of severe acute respiratory distress syndrome. However, the tolerance to enteral feeds might be impaired during ECMO for several reasons, including gut hypoperfusion and the frequent need for sedation and muscle paralysis. The objective of this study was to compare the tolerance to enteral feeding assessed by the gastric residual volum in patients with severe acute respiratory distress syndrome treated with or without ECMO, and to search for an association between gastric residual volume and the amount of vasopressors, sedatives and neuromuscular blocking agents used.

Patients admitted in the Department of Intensive Care of the Erasme University Hospital in Brussels for severe acute respiratory distress syndrome between January 2014 and September 2015 were included. Admission data included demographic variables, severity scores, severity of acute respiratory distress syndrome (PaO₂/FiO₂ ratio). Daily data included the use of vasopressors, sedatives and neuromuscular blocking agents; the percentage of days with the medications was calculated. The cumulative gastric residual volume was recorded up to a maximum of 7 days. A cut-off value of 250mL was used to define intolerance to enteral feeding. The statistical analysis used an analysis of variance and a Mann–Whitney test, with a statistical significance set at 0.05.

Sixty patients were included (ECMO: n=30; non-ECMO: n=30). The characteristics were well matched (age 49±14 vs. 56±15 years, BMI 29±10 vs. 27±6kg/m², APACHE II score 23±4 vs. 20±7, PaO₂/FiO₂ ratio 138±91 and 156±69, SOFA score 12±4 vs. 11±3, for the ECMO and non-ECMO groups, respectively; NS). The percentage of days with vasopressors, sedatives and neuromuscular blocking agents were higher in ECMO than in non-ECMO patients (74±29 vs. 39±40%), sedatives (88±18 vs. 54±33%) and neuromuscular blocking agents (72±29 vs. 28±30%). The median gastric residual volume values were higher in the ECMO than in the non-ECMO group (47 [0–200] mL vs. 164 [58–299] mL, P=0.04).

The use of ECMO for severe acute respiratory distress syndrome was associated with higher gastric residual volume, implying a poorer tolerance to enteral feeding than in cases managed without ECMO; the implication of gut hypoperfusion was suggested by the more frequent use of vasopressors, and the implication of sedation and muscle paralysis were supported by the prolonged use of sedatives and neuromuscular blocking agents in the ECMO group.