[Analysis of risk factors of early enteral nutrition intolerance in extremely severe burn patients]

Objective: To explore the risk factors of early enteral nutrition intolerance in extremely severe burn patients. Methods: A retrospective case-control study was performed. From January 2018 to December 2020, seventy-six adult patients with extremely severe burns who met the inclusion criteria were admitted to Hwa Mei Hospital of University of Chinese Academy of Sciences, including 55 males and 21 females, aged (45±11) years with burns of 62% (52%, 82%) total body surface area. Depending on the patient's tolerance to early enteral nutrition, they were divided into tolerance group (47 patients) and intolerance group (29 patients), and their clinical data were statistically analyzed, including age, sex, body mass index (BMI), underlying disease, total burn area, full-thickness burn area, abbreviated burn severity index (ABSI) score, implementation of mechanical ventilation on the day of admission, stable shock state, vomiting before feeding. The following data were recorded including the onset time, duration length, and frequency of enteral nutrition intolerance of patients in intolerance group, and the number of operations, the length of hospitalization, the occurrence of sepsis within 2 weeks after injury, the outcome, as well as the serum hypersensitive C-reactive protein (hs-CRP), albumin, fasting blood glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and γ-glutamyl transpeptidase (γ-GT) on post burn day (PBD) 1, 5, 9, and 13 of patients in the two groups. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test to screen the related factors of early enteral nutrition intolerance of the patients. Binary univariate and multivariate logistic regression analysis were used to analyze the independent risk factors of early enteral nutrition intolerance of the patients. Results: There were no statistically significant differences in age, sex, BMI, and percentage of underlying disease of patients between the two groups (P>0.05). The total burn area, full-thickness burn area, ABSI score, mechanical ventilation percentage on the day of admission, percentage of unstable shock period, percentage of vomiting before feeding of patients in intolerance group were significantly higher than those in tolerance group (Z=-4.559, -3.378, -4.067, χ=18.375, 23.319, 8.339, P<0.01). In intolerance group, the onset time of intolerance was (9±4) d after injury, and the duration length was 4 (2, 6) d, with a total of 46 times occurred. Compared with tolerance group, the percentage of sepsis and mortality of patients in intolerance group were significantly higher within 2 weeks after injury (χ=16.571, 12.665, P<0.01). The number of operation and length of hospitalization of patients in the two groups were similar (P>0.05); however the length of hospitalization of patients in the intolerance group was significantly more than that in tolerance group after excluding the death cases (Z=-2.266, P<0.05). On PBD 1, the level of fasting blood glucose and AST of patients in intolerance group were significantly higher than those in tolerance group (t=3.070, Z=-3.070, P<0.01). On PBD 5, the levels of hs-CRP, albumin, fasting blood-glucose, ALT, AST, and γ-GT of patients in the two groups were similar (P>0.05). On PBD 9, the level of hs-CRP of patients in intolerance group was significantly higher than that in tolerance group (t=2.836, P<0.01), and the levels of ALT and γ-GT of patients in intolerance group were significantly lower than those in tolerance group (Z=-3.932, -2.052, P<0.05 or P<0.01). On PBD 13, the level of hs-CRP of patients in intolerance group was significantly higher than that in tolerance group (t=3.794, P<0.01), and the levels of fasting blood glucose, ALT, and γ-GT of patients in intolerance group were significantly lower than those in tolerance group (t=-2.176, Z=-2.945, -2.250, P<0.05 or P<0.01). Binary univariate logistic regression analysis showed that total burn area, full-thickness burn area, ABSI score, implementation of mechanical ventilation on the day of admission, unstable shock period, vomiting before feeding, and fasting blood-glucose on PBD 1 of patients were related to early enteral nutrition intolerance (odds ratio=1.086, 1.052, 1.775, 9.167, 12.797, 10.125, 1.249, 95% confidence interval=1.045-1.129, 1.019-1.085, 1.320-2.387, 3.132-26.829, 4.199-39.000, 2.003-51.172, 1.066-1.464, P<0.01). Multivariate logistic regression analysis showed that the large total burn area, unstable shock period, vomiting before feeding, and high fasting blood-glucose on PBD 1 of patients were the independent risk factors of early enteral nutrition intolerance in patients (odds ratio=1.073, 6.390, 9.004, 1.246, 95% confidence interval=1.021-1.128, 1.527-26.734, 1.134-71.496, 1.007-1.540, P<0.05 or P<0.01). Conclusions: The percentage of early enteral nutrition intolerance is very high in extremely severe burn patients, which is closely related to poor prognosis. Large total burn area, vomiting before feeding, unstable shock phase, high fasting glucose on PBD 1 of patients are the independent risk factors for early enteral nutrition intolerance in extremely severe burn patients. The benefits and risks should be carefully evaluated before starting enteral nutrition in such patients, and early enteral nutrition should not be blindly pursued.