[Impact of permissive underfeeding versus standard enteral feeding on outcomes in critical patients requiring mechanical ventilation: a prospective randomized controlled study].

OBJECTIVE: To compare the impact of permissive underfeeding versus standard enteral feeding on outcomes in critical patients requiring mechanical ventilation (MV).

METHODS: A prospective randomized controlled study was conducted. Eighty-two patients requiring MV admitted to intensive care unit (ICU) of Anji People's Hospital from January 2015 to March 2017 were enrolled, and they were randomly divided into the permissive underfeeding group (n = 40, non-protein heat was 52.3-62.8 kJ×kg-1 ×d-1 , protein was 1.2-1.5 g×kg-1 ×d-1 ) and standard enteral feeding group (n = 42, non-protein heat was 104.6-125.5 kJ×kg-1 ×d-1 , protein was 1.2-1.5 g×kg-1 ×d-1 ). Permissive underfeeding group received 50% of their daily energy expenditure via enteral nutrition (EN) and standard enteral feeding group received 100% of their daily energy expenditure via EN in 24-48 hours after admitted to ICU. Nutritional status [pro-albumin (PA), serum albumin (ALB)], inflammation state [procalcitonin (PCT), hypersensitive C-reactive protein (hs-CRP)] were detected before treatment and 7 days after treatment. Duration of MV, length of ICU stay, daily insulin dosage, 28-day mortality, hospital acquired pneumonia (HAP), urinary tract infection, septic shock and other secondary infection, and the nutrition related complications were recorded.

RESULTS: Compared with before treatment, the levels of serum PA (mg/L) and ALB (g/L) were significantly increased, the levels of PCT (ng/L) and hs-CRP (mg/L) were significantly decreased at 7 days after treatment in both groups [permissive underfeeding group: PA was 127.42±65.83 vs. 80.92±60.14, ALB was 30.16±4.32 vs. 25.36±6.21, PCT was 375.8±227.2 vs. 762.3±314.5, hs-CRP was 32.19±7.53 vs. 120.48±60.24; standard enteral feeding group: PA was 132.56±61.32 vs. 86.78±47.06, ALB was 31.25±4.63 vs. 26.71±5.48, PCT was 412.1±323.4 vs. 821.7±408.6, hs-CRP was 35.86±5.69 vs. 116.38±72.16, all P < 0.05], but there was no significant difference in PA, ALB, PCT or hs-CRP at 7 days after treatment between two groups (all P > 0.05). There was no significant difference in the duration of MV, length of ICU stay, 28-day mortality or ICU-associated infection between two groups [duration of MV (hours): 162.35±20.37 vs. 153.48±18.65, length of ICU stay (days): 7.52±1.61 vs. 6.34±1.87, 28-day mortality: 17.5% vs. 19.0%, ICU-associated infection: 45.0% vs. 47.6%, all P > 0.05]. Compared with standard enteral feeding, insulin demand was significantly decreased (U/d: 13.68±10.36 vs. 26.24±18.53), and gastrointestinal intolerance was less frequent (32.5% vs. 54.8%) in the permissive underfeeding group (both P < 0.05). Kaplan-Meier survival curve analysis showed that there was no significant difference between the two groups (χ2 = 3.216, P = 0.068).

CONCLUSIONS: The curative effect and prognosis of MV severe patients receiving permissive underfeeding are similar to those of standard enteral feeding, but it can reduce the dosage of insulin with better gastrointestinal tolerance.