The role of early enteral nutrition in critical patients with COVID-19: A retrospective study

Nutritional support is considered an important component in the management of critically ill patients. This study was carried out retrospectively with 135 intensive care unit (ICU) patients diagnosed with COVID-19 and hospitalized in the COVID-19 Intensive Care Units of Ankara City Hospital Neurology Orthopedics Hospital. The study aims to define the relationship between enteral nutrition (EN) initation time and Prognostic Nutritional Index (PNI) score, Neutrophil-lymphocyte ratio (NLR) value, oxygenation status [oxygen pressure in arterial blood (PaO2)/inspired oxygen fraction (FiO2) ratio], mechanical ventilation (MV), duration of ICU stay and hospital stay, general mortality relationship, and the status of patients meeting nutritional goals, failure to achieve goals and reasons for delaying EN in intubated patients fed with EN. According to the time of initiation of feeding, patients were divided into two groups as patients fed within the first 48 hours as early EN (EEN) (n:101) and after 48 hours were as late EN (LEN) (n:34). Demographic, clinical, biochemical and nutritional data of the patients were taken daily from patient files and electronic database. The nutritional goals of the patients were determined. The starting time of feeding, feeding route, method, product, amount and duration, and the daily energy, protein, fiber and water intake of the patients were calculated. Targeted energy and protein intake, time to reach, and EN complications were determined for the patients. The mean age, body mass index (BMI) values and comorbid diseases of the EEN and LEN groups were found to be similar (p>0.05). The rate of use of corticosteroid and anticoagulant drugs (93.1% and 100%) of the patients in the EEN group was significantly higher than that of the LEN group (76.5% and 94.1%) (p<0.05). The values in PNI scores, PaO2/FiO2 and NLR values of the EEN and LEN groups were similar between the two groups on admission day, discharge day and the rates of change in the ICU process (p>0.05). MV, ICU, and hospital stays were similar in the EEN and LEN groups (9.11 [7.78] and 6.41 [8.28], p>0.05; 9.28 [8.69] and 6.41 [10.37], p>0.05; 9.28 [9.24] and 6.41 [10.37] days, p>0.05, respectively). In the LEN group, the serum CRP level on the 7th day was found to be significantly higher compared to the EEN group (0.1±0.1 and 0.1±0.07 mg/L, p<0.05,respectively). The rate of change of bicarbonate (HCO3) between day 1 and day 7 was higher in the EEN group compared to the LEN group (-3.1 [6.6] and -0.65 [5.1], p<0.05). The amount of energy, protein, dietary fiber and water reached in the EEN group was found to be significantly higher than the LEN group (p<0.001). The frequency of hyperglycemia was found to be significantly higher in the EEN group compared to the LEN group (p<0.05). In the univariate logistic regression analysis performed to evaluate the factors affecting survival, age, NRS-2002, APACHE II, PNI scores, length of hospital stay, length of ICU stay and serum CRP were determined as independent risk factors affecting survival. For each 1-unit increase in age, the mortality risk was 1.07-fold (OR: 1.07, 95% CI (1.01-1.12), p: 0.016); 3.15-fold (OR: 3.15, 95% CI (1.31-7.54), p:0.010) for the NRS-2002 score; It was found to increase 84% (OR: 0.84, 95% CI (0.76-0.93), p: 0.001) for the APACHE II score and 75% for the serum CRP level (OR: 0.75, 95% CI (0.59-0.94), p: 0.014). The risk of mortality increased 1.4 times with each unit decrease in the PNI score in patients (OR: 1.4, 95% CI (1.05-1.87), p:0.021). A 1-day reduction in hospital stay increased the mortality risk by 84% (OR: 0.84, 95% CI (0.76-0.93), p:0.001). One day reduction in ICU length of stay increases the risk of mortality by 87% (OR: 0.87, 95% CI (0.8-0.95, p: 0.002). In multivariate logistic regression analysis, the significant effects of age, NRS-2002, PNI scores and serum CRP values on survival disappeared (p>0.05). The APACHE II score was borderline significant [OR: 1.482, 95% CI (0.998-2.201), p: 0.051). As a result, it was determined that all of the patients included in the study were at risk in terms of nutrition and that nutritional goals could not be achieved in most of the patients. No correlation was found between the onset time of EN and PNI score, NLR value, PaO2/FiO2 ratio, MV duration, ICU length of stay, length of hospital stay, and overall mortality. Providing nutritional support to patients in the early period is important in achieving nutritional goals. More research is needed to evaluate the clinical efficacy of early enteral nutritional support.