Higher versus lower enteral calorie delivery and gastrointestinal dysfunction in critical illness: A systematic review and meta-analysis.

BACKGROUND AND AIMS: In critical illness, enteral nutrition (EN) is frequently limited by gastrointestinal (GI) dysfunction. The aim of this systematic review and meta-analysis was to determine relationships between enteral calorie delivery and GI dysfunction in critically ill adults. METHODS: MEDLINE, EMCARE, EMBASE, and CINAHL databases were searched from 1 January 2000 to 11 August 2021 to identify parallel group randomised controlled trials of an EN intervention that resulted in a significant difference in calorie delivery between groups and reported at least one outcome relating to GI dysfunction. Study groups were categorised as 'higher' or 'lower' calorie delivery and data were extracted on study interventions, GI dysfunction and clinical outcomes. Extracted data were aggregated using a random effects model and presented as risk ratio with 95% confidence intervals. A P-value <0.05 was considered significant. The risk of publication bias was assessed graphically using a funnel plot. RESULTS: From 13 studies involving 6824 patients the mean calorie delivery in the higher calorie group was 1673 ± 468 kcal/day compared to 1121 ± 312 kcal/day in the lower calorie group. The higher calorie group had an increased risk of a large (any volume ≥300 ml) gastric residual volume (GRV) (RR 1.40; 95% CI 1.09, 1.80; P = 0.009) and prokinetic administration (RR 1.18; 95% CI 1.11, 1.27; P < 0.00001). There were no between group differences in the presence of vomiting/regurgitation (RR 0.93; 95% CI 0.58, 1.49; P = 0.76), diarrhoea (RR 1.12; 95% CI 0.93, 1.35; P = 0.22) or abdominal distension (RR 0.71; 95% CI 0.49, 1.04; P = 0.08). There was no evidence of publication bias. CONCLUSION: Higher calorie delivery is associated with increased rates of GRV≥300 ml and prokinetic administration, but not vomiting/regurgitation, diarrhoea or abdominal distension. OTHER: No funding was received for the conduct of this systematic review and meta-analysis. The protocol was prospectively registered with PROSPERO (CRD42021268876).

Protein delivery in mechanically ventilated adults in Australia and New Zealand: current practice.

Objective: To quantify current protein prescription and delivery in critically ill adults in Australia and New Zealand and compare it with international guidelines. Design: Prospective, multicentre, observational study. Setting: Five intensive care units (ICUs) across Australia and New Zealand. Participants: Mechanically ventilated adults who were anticipated to receive enteral nutrition for ≥ 24 hours. Main outcome measures: Baseline demographic and nutrition data in ICU, including assessment of requirements, prescription and delivery of enteral nutrition, parenteral nutrition and protein supplementation, were collected. The primary outcome was enteral nutrition protein delivery (g/kg ideal body weight [IBW] per day). Data are reported as mean ± standard deviation or n (%). Results: 120 patients were studied (sex, 60% male; mean age, 59 ± 16 years; mean admission APACHE II score, 20 ± 8). Enteral nutrition was delivered on 88%, parenteral nutrition on 6.8%, and protein supplements on 0.3% of 1156 study days. For the 73% (88/120) of patients who had a nutritional assessment, the mean estimated protein requirements were 99 ± 22 g/day (1.46 ± 0.55 g/kg IBW per day). The mean daily protein delivery was 54 ± 23 g (0.85 ± 0.35 g/kg IBW per day) from enteral nutrition and 56 ± 23 g (0.88 ± 0.35 g/kg IBW per day) from all sources (enteral nutrition, parenteral nutrition, protein supplements). Protein delivery was ≥ 1.2 g/kg IBW per day on 29% of the total study days per patient. Conclusions: Protein delivery as a part of current usual care to critically ill adults in Australia and New Zealand remains below that recommended in international guidelines.

Acceleration of Gastric Emptying by Insulin-Induced Hypoglycemia is Dependent on the Degree of Hypoglycemia.

CONTEXT: Hypoglycemia is a major barrier to optimal glycemic control in insulin-treated diabetes. Recent guidelines from the American Diabetes Association have subcategorized "non-severe" hypoglycemia into level 1 (<3.9 mmol/L) and 2 (<3 mmol/L) hypoglycemia. Gastric emptying of carbohydrate is a major determinant of postprandial glycemia but its role in hypoglycemia counter-regulation remains underappreciated. "Marked" hypoglycemia (~2.6 mmol/L) accelerates gastric emptying and increases carbohydrate absorption in health and type 1 diabetes, but the impact of "mild" hypoglycemia (3.0-3.9 mmol/L) is unknown. OBJECTIVE: To determine the effects of 2 levels of hypoglycemia, 2.6 mmol/L ("marked") and 3.6 mmol/L ("mild"), on gastric emptying in health. DESIGN, SETTING, AND SUBJECTS: Fourteen healthy male participants (mean age: 32.9 ±â€…8.3 years; body mass index: 24.5 ±â€…3.4 kg/m2) from the general community underwent measurement of gastric emptying of a radiolabeled solid meal (100 g beef) by scintigraphy over 120 minutes on 3 separate occasions, while blood glucose was maintained at either ~2.6 mmol/L, ~3.6 mmol/L, or ~6 mmol/L in random order from 15 minutes before until 60 minutes after meal ingestion using glucose-insulin clamp. Blood glucose was then maintained at 6 mmol/L from 60 to 120 minutes on all days. RESULTS: Gastric emptying was accelerated during both mild (P = 0.011) and marked (P = 0.001) hypoglycemia when compared to euglycemia, and was more rapid during marked compared with mild hypoglycemia (P = 0.008). Hypoglycemia-induced gastric emptying acceleration during mild (r = 0.57, P = 0.030) and marked (r = 0.76, P = 0.0014) hypoglycemia was related to gastric emptying during euglycemia. CONCLUSION: In health, acceleration of gastric emptying by insulin-induced hypoglycemia is dependent on the degree of hypoglycemia and baseline rate of emptying.

Postoperative nutrition practices in abdominal surgery patients in a tertiary referral hospital Intensive Care Unit: A prospective analysis.

BACKGROUND: Benefit of early enteral feeds in surgical patients admitted to Intensive Care Units (ICUs) has been emphasized by several studies. Apprehensions about anastomotic leaks in gastrointestinal surgical patients prevent initiation of early enteral nutrition (EN). The impact of these practices on outcome in Indian scenario is less studied. AIMS: This study compares the impact of early EN (within 48 h after surgery) with late EN (48 h postsurgery) on outcomes in abdominal surgical ICU patients. SETTINGS AND DESIGN: Postabdominal surgery patients admitted to a tertiary referral hospital ICU over a 2-year period were analyzed. METHODS: Only patients directly admitted to ICU after abdominal surgery were included in this study. ICU stay>3 days was considered as prolonged; with average ICU length of stay (LOS) for this ICU being 3 days. The primary outcome was in-patient mortality. ICU LOS, hospital LOS, infection rates, and ventilator days were secondary outcome measures. Acute Physiology and Chronic Health Evaluation II scores were calculated. SPSS and Microsoft Excel were used for analysis. RESULTS: Of 91 ICU patients included, 58 received early EN and 33 late EN. Hospital LOS and infection rates were less in early EN group. Use of parenteral nutrition (odds ratio [OR] 5.25, 95% confidence interval (CI); P = 0.003) and number of nil-per-oral days (OR 8.25, 95% CI; P ≤ 0.001) were other predictors of prolonged LOS. CONCLUSIONS: Early EN in postabdominal surgery ICU patients was associated with reduced hospital LOS and infection rates. ICU LOS, duration of mechanical ventilation and mortality rates did not vary.