Discussion
The present study investigated the association between enteral feeding
and survival levels in COVID-19 patients admitted to the ICU. The group
of patients who survived had lower smoking and incidences of chronic
diseases compared with the group of patients who died during the
experimental period. Our results indicated that the mortality was
inversely associated with high volume and high protein formula, after
adjustments for age and sex, underlying diseases, smoking, BMI, and
APACHII.
Previous studies reported that there was a positive association between
smoking and the mortality rate in CODIV-19 patients (15). As evident in
this study and those reported in the past, critical COVID-19 patients
may have a relatively high risk of sudden death due to the underlying
comorbidities including cardiovascular disease, chronic obstructive
pulmonary disease (COPD), chronic kidney disease (CKD), and obstructive
sleep apnea-hypopnea syndrome (OSAHS). Also, the underlying
comorbidities were reported to be associated with higher in-hospital
mortality (16) and lower survival rates (17).
The present study suggested an inverse relationship between mortality
with high-volume and high-protein formula use in COVID-19 patients. In
line with this study, Martindale et al. recommend using a standard
high-protein (≥20% protein) polymeric iso-osmotic enteral formula in
the early acute phase of critical illness (18). Martindale et al
reported that enteral nutrition (EN) should be initiated early after
admission to the intensive care unit (ICU), while careful monitoring for
gastrointestinal intolerance, hemodynamic instability, and metabolic
derangements are essential (18, 19). In addition, a recent retrospective
study has shown that early EN in paralyzed patients was associated with
less hospital mortality, and there was no increase in
ventilator-associated pneumonia (20). However, some studies reported
contradictory results where no significant association between mortality
and high protein formula was found (21). These results together strongly
emphasize the importance of enteral feeding for survival levels in ICU
patients with COVID-19. Hyperglycemia when occurring in a critical
physiological state (22, 23) is likely to contribute to poor clinical
outcomes (24). Insulin resistance and hyperglycemia result in muscle
protein breakdown (25, 26). Hence, high-protein nutrition helps glucose
control, reduces insulin requirements, improves muscle synthesis, and
provides substrates needed at the sites of tissue injury in critically
ill patients (27, 28). The positive effect of protein is also
attributable to the maintenance of nitrogen balance and lean body mass
(29) and its effect on the production of neurotransmitters, glutathione
synthesis, and other compounds required during the acute infection phase
(30).