Effects of Standard vs Energy-Dense Formulae on Gastric Retention, Energy Delivery, and Glycemia in Critically Ill Patients

BACKGROUND

Energy-dense formulae are often provided to critically ill patients with enteral feed intolerance with the aim of increasing energy delivery, yet the effect on gastric emptying is unknown. The rate of gastric emptying of a standard compared with an energy-dense formula was quantified in critically ill patients.

METHODS

Mechanically ventilated adults were randomized to receive radiolabeled intragastric infusions of 200 mL standard (1 kcal/mL) or 100 mL energy-dense (2 kcal/mL) enteral formulae on consecutive days in this noninferiority, blinded, crossover trial. The primary outcome was scintigraphic measurement of gastric retention (percentage at 120 minutes). Other measures included area under the curve (AUC) for gastric retention and intestinal energy delivery (calculated from gastric retention of formulae over time), blood glucose (peak and AUC), and intestinal glucose absorption (using 3-O-methyl-D-gluco-pyranose [3-OMG] concentrations). Comparisons were undertaken using paired mixed-effects models. Data presented are mean ± SE.

RESULTS

Eighteen patients were studied (male/female, 14:4; age, 55.2 ± 5.3 years). Gastric retention at 120 minutes was greater with the energy-dense formula (standard, 17.0 ± 5.9 vs energy-dense, 32.5 ± 7.1; difference, 12.7% [90% confidence interval, 0.8%-30.1%]). Energy delivery (AUC₁₂₀ , 13,038 ± 1119 vs 9763 ± 1346 kcal/120 minutes; P = 0.057), glucose control (peak glucose, 10.1 ± 0.3 vs 9.7 ± 0.3 mmol/L, P = 0.362; and glucose AUC₁₂₀ 8.7 ± 0.3 vs 8.5 ± 0.3 mmol/L.120 minutes, P = 0.661), and absorption (3-OMG AUC₁₂₀ , 38.5 ± 4.0 vs 35.7 ± 4.0 mmol/L.120 minutes; P = .508) were not improved with the energy-dense formula.

CONCLUSION

In critical illness, administration of an energy-dense formula does not reduce gastric retention, increase energy delivery to the small intestine, or improve glucose absorption or glucose control; instead, there is a signal for delayed gastric emptying.

Dietary Management of Blood Glucose in Medical Critically Ill Overweight and Obese Patients: An Open-Label Randomized Trial

BACKGROUND

Enteral nutrition (EN) increases hyperglycemia due to high carbohydrate concentrations while providing insufficient protein. The study tested whether an EN formula with very high-protein- and low-carbohydrate-facilitated glucose control delivered higher protein concentrations within a hypocaloric protocol.

METHODS

This was a multicenter, randomized, open-label clinical trial with parallel design in overweight/obese mechanically ventilated critically ill patients prescribed 1.5 g protein/kg ideal body weight/day. Patients received either an experimental very high-protein (37%) and low-carbohydrate (29%) or control high-protein (25%) and conventional-carbohydrate (45%) EN formula.

RESULTS

A prespecified interim analysis was performed after enrollment of 105 patients (52 experimental, 53 control). Protein and energy delivery for controls and experimental groups on days 1-5 were 1.2 ± 0.4 and 1.1 ± 0.3 g/kg ideal body weight/day (P = .83), and 18.2 ± 6.0 and 12.5 ± 3.7 kcals/kg ideal body weight/day (P < .0001), respectively. The combined rate of glucose events outside the range of >110 and ≤150 mg/dL were not different (P = .54, primary endpoint); thereby the trial was terminated. The mean blood glucose for the control and the experimental groups were 138 (-SD 108, +SD 177) and 126 (-SD 99, +SD 160) mg/dL (P = .004), respectively. Mean rate of glucose events >150 mg/dL decreased (Δ = -13%, P = .015), whereas that of 80-110 mg/dL increased (Δ = 14%, P = .0007). Insulin administration decreased 10.9% (95% CI, -22% to 0.1%; P = .048) in the experimental group relative to the controls. Glycemic events ≤80 mg/dL and rescue dextrose use were not different (P = .23 and P = .53).

CONCLUSIONS

A very high-protein and low-carbohydrate EN formula in a hypocaloric protocol reduces hyperglycemic events and insulin requirements while increasing glycemic events between 80-110 mg/dL.

Volume-based feeding improves nutritional adequacy in surgical patients

BACKGROUND

Critically ill surgical patients often receive inadequate enteral nutrition using traditional rate-based feeding methods. An alternative strategy is volume-based feeding, in which feeding rates are adjusted to deliver a goal volume per day.

METHODS

This prospective quality improvement study in a single surgical, trauma, and burn ICU compared volume-based feeding to rate-based feeding in a before-and-after design. Outcomes included calories and protein delivered, length of stay, infection, and mortality.

RESULTS

A total of 50 patients received volume-based feeding and 49 rate-based feeding. The volume-based group received a higher proportion of goal calories (84.5% vs. 73.4%; p = 0.005) and protein (86.2% vs. 77.4%; p = 0.01), as well as increased total daily calories (1604 vs. 1356 kcal; p = 0.02). There was no difference in length of stay, mortality, aspiration, or gastrointestinal intolerance.

CONCLUSIONS

Volume-based feeding improved nutritional intake in critically ill surgical patients, although this study was underpowered to determine differences in clinical outcomes.

Energy-Dense Formulae May Slow Gastric Emptying in the Critically Ill

BACKGROUND

Enteral feed intolerance occurs frequently in critically ill patients and can be associated with adverse outcomes. "Energy-dense formulae" (ie, >1 kcal/mL) are often prescribed to critically ill patients to reduce administered volume and are presumed to maintain or increase calorie delivery. The aim of this study was to compare gastric emptying of standard and energy-dense formulae in critically ill patients.

METHODS

In a retrospective comparison of 2 studies, data were analyzed from 2 groups of patients that received a radiolabeled 100-mL "meal" containing either standard calories (1 kcal/mL) or concentrated calories (energy-dense formulae; 2 kcal/mL). Gastric emptying was measured using a scintigraphic technique. Radioisotope data were collected for 4 hours and gastric emptying quantified. Data are presented as mean ± SE or median [interquartile range] as appropriate.

RESULTS

Forty patients were studied (n = 18, energy-dense formulae; n = 22, standard). Groups were well matched in terms of demographics. However, patients in the energy-dense formula group were studied earlier in their intensive care unit admission (P = .02) and had a greater proportion requiring inotropes (P = .002). A similar amount of calories emptied out of the stomach per unit time (P = .57), but in patients receiving energy-dense formulae, a greater volume of meal was retained in the stomach (P = .045), consistent with slower gastric emptying.

CONCLUSIONS

In critically ill patients, the administration of the same volume of a concentrated enteral nutrition formula may not result in the delivery of more calories to the small intestine over time because gastric emptying is slowed.

Nationwide survey of nutritional management in an Asian upper-middle income developing country government hospitals: Combination of quantitative survey and focus group discussion

BACKGROUND & AIMS

The objective of this study was to identify the differences in pattern, process, and management of nutrition care in government hospitals in Thailand (an Asian upper-middle income developing country).

METHODS

This is a combination of a quantitative nationwide questionnaire survey and focus group discussions. A total of 2300 questionnaires were sent to government hospitals across Thailand. The responders were divided by routine-nutrition screening/assessment unit vs. non-routine-nutrition screening/assessment unit (RSA vs. NRSA). The comparison between the groups was reported as percentage and cross-sectional odds ratio (CS-OR) with 95% confidence interval (CI). The significant difference was defined as p < 0.05.

RESULTS

A total of 814 questionnaires (35.4%) were returned. The three most common tools of RSA were 42% Bhumibol Nutrition Triage (BNT), 21.2% Subjective Global Assessment (SGA) and 20.2% Nutrition Alert Form (NAF). The RSA was significantly higher in proportion for the role of the nurses (RSA vs. NRSA; CS-OR [95% CI]: 68.3% vs. 11.9%; 15.8 [11.1 to 22.7]; p < 0.01), the multidisciplinary team (90.1% vs. 0.4%; 2266 [558 to 1909]; p < 0.01), the nutrition management guidelines (60.6% vs. 2.8%; 53.6 [29.6 to 102.8]; p < 0.01), the nurse-driven enteral feeding protocols (31.7% vs. 17.5%; 2.2 [1.5 to 3.1]; p < 0.01) and preference for hospital formula enteral nutrition (91.4% vs.69.7%; 4.6 [2.9 to 7.4]; p < 0.01). For focus group discussions, the main barrier of RSA implementation was that there was no national recommendation of a screening/assessment tool, inconsistency of policy and reimbursement, and professional and acceptable workload.

CONCLUSION

Nutrition screening/assessment tools were found to be varied in Thailand. RSA affected the nutrition management working process and the types of nutrition support. The main barriers of RSA implementation were inconsistency of policy and reimbursement, acceptable workload, and national guidance as regards - screening/assessment tools.

Adequacy of early enteral nutrition in adult patients in the intensive care unit

AIMS AND OBJECTIVES

To evaluate the adequacy of energy and protein intake of patients in a Korean intensive care unit in the first four days after initiation of enteral feeding and to investigate the factors that had impact on adequate intake.

BACKGROUND

Underfeeding is a common problem for patients hospitalised in the intensive care unit and is associated with severe negative consequences, including increased morbidity and mortality.

DESIGN

A prospective, cohort study was conducted in a medical intensive care unit of a university hospital in Korea.

METHODS

A total of 34 adult patients who had a primary medical diagnosis and who had received bolus enteral nutrition for the first four days after initiation of enteral nutrition were enrolled in this study. The data on prescription and intake of energy and protein, feeding method and feeding interruption were recorded during the first four days after enteral feeding initiation. Underfeeding was defined as the intake <90% of required energy and protein.

RESULTS

Most patients (62%) received insufficient energy, although some (29%) received adequate energy. More than half of patients (56%) had insufficient protein intake during the first four days after enteral feeding was initiated. Logistic regression analysis showed that the factors associated with underfeeding of energy were early initiation of enteral nutrition, under-prescription of energy and prolonged interruption of prescribed enteral nutrition.

CONCLUSION

Underfeeding is frequent in Korean critically ill patients owing to early initiation, under-prescription and prolonged interruption of enteral feeding.

RELEVANCE TO CLINICAL PRACTICE

  Interventions need to be developed and tested that address early initiation, under-prescription and prolonged interruption of enteral nutrition. Findings from this study are important as they form the foundation for the development of evidence-based care that is badly needed to eliminate underfeeding in this large vulnerable Korean intensive care unit population.

Landmark survival as an end-point for trials in critically ill patients--comparison of alternative durations of follow-up: an exploratory analysis

Introduction

Interventional ICU trials have followed up patients for variable duration. However, the optimal duration of follow-up for the determination of mortality endpoint in such trials is uncertain. We aimed to determine the most logical and practical mortality end-point in clinical trials of critically ill patients.

Methods

We performed a retrospective analysis of prospectively collected data involving 369 patients with one of the three specific diagnoses (i) Sepsis (ii) Community acquired pneumonia (iii) Non operative trauma admitted to the Royal Perth Hospital ICU, a large teaching hospital in Western Australia (WA cohort). Their in-hospital and post discharge survival outcome was assessed by linkage to the WA Death Registry. A validation cohort involving 4609 patients admitted during same time period with identical diagnoses from 55 ICUs across Australia (CORE cohort) was used to compare the patient characteristics and in-hospital survival to look at the Australia-wide applicability of the long term survival data from the WA cohort.

Results

The long term outcome data of the WA cohort indicate that mortality reached a plateau at 90 days after ICU admission particularly for sepsis and pneumonia. Mortality after hospital discharge before 90 days was not uncommon in these two groups. Severity of acute illness as measured by the total number of organ failures or acute physiology score was the main predictor of 90-day mortality. The adjusted in-hospital survival for the WA cohort was not significantly different from that of the CORE cohort in all three diagnostic groups; sepsis (P = 0.19), community acquired pneumonia (P = 0.86), non-operative trauma (P = 0.47).

Conclusions

A minimum of 90 days follow-up is necessary to fully capture the mortality effect of sepsis and community acquired pneumonia. A shorter period of follow-up time may be sufficient for non-operative trauma.