Protein requirements for critically ill ventilator-dependent patients with COVID-19

Abstract

Background: Recent studies indicate critically ill patients with coronavirus disease 2019 (COVID-19) are hypermetabolic; however, protein requirements in critically ill COVID-19 patients are unknown. Our intent was to evaluate the nitrogen accretion response to varying protein intakes for critically ill ventilator-dependent patients with COVID-19.

Methods: Adult patients (age ≥ 18 years) with COVID-19, admitted to the intensive care unit (ICU) and who required mechanical ventilation were retrospectively evaluated. Patients received continuous enteral nutrition (EN), including supplemental protein boluses, and had a 24-h urine collection for determination of nitrogen balance (NBAL). Data are expressed as mean ± SD with a P-value < .05 as significant.

Results: Twenty-two patients provided 29 NBAL determinations. Protein intake from EN and protein supplements was 0.9 ± 0.7 g/kg/day at the time of the NBAL with an NBAL of -12.1 ± 10.9 g/day at 7 ± 4 days in the ICU. Combined caloric intake from EN and propofol at the time of the NBAL was 12 ± 8 kcal/kg/day. Nitrogen equilibrium (NBAL of -4 g/day or better) occurred in five patients. Patients achieving nitrogen equilibrium received more protein than those with a negative NBAL (1.2 ± 0.4 g/kg/day vs 0.8 ± 0.8 g/kg/day, P = .046). The linear regression for NBAL in response to graded increases in protein intake was as follows: NBAL = 8.5 × protein intake (g/kg/day) - 18.8 (r = 0.450, P < .001).

Conclusion: Critically ill ventilator-dependent patients with COVID-19 exhibit significant variability in nitrogen accretion response to increases in protein intake and often have a markedly negative NBAL.

Keywords: COVID-19; critical illness; enteral nutrition; nitrogen balance; nutrition support; protein.