Effect of Permissive Underfeeding with Intensive Insulin Therapy on MCP-1, sICAM-1, and TF in Critically Ill Patients.

PURPOSE: This study examined the effect of permissive underfeeding compared to target feeding and intensive insulin therapy (IIT) compared to conventional insulin therapy (CIT) on the inflammatory mediators monocyte chemoattractant protein 1 (MCP-1), soluble intercellular adhesion molecule 1 (sICAM-1), and tissue factor (TF) in critically ill patients. METHODOLOGY: This was a substudy of a 2 × 2 factorial design randomized controlled trial in which intensive care unit (ICU) patients were randomized into permissive underfeeding compared to target feeding groups and into IIT compared to CIT groups (ISRCTN96294863). In this substudy, we included 91 patients with almost equal numbers across randomization groups. Blood samples were collected at baseline and at days 3, 5, and 7 of an ICU stay. Linear mixed models were used to assess the differences in MCP-1, sICAM-1, and TF across randomization groups over time. RESULTS: Baseline characteristics were balanced across randomization groups. Daily caloric intake was significantly higher in the target feeding than in the permissive underfeeding groups (P-value < 0.01), and the daily insulin dose was significantly higher in the IIT than in the CIT groups (P-value < 0.01). MCP-1, sICAM-1, and TF did not show any significant difference between the randomization groups, while there was a time effect for MCP-1. Baseline sequential organ failure assessment (SOFA) score and platelets had a significant effect on sICAM-1 (P-value < 0.01). For TF, there was a significant association with age (P-value < 0.01). CONCLUSIONS: Although it has been previously demonstrated that insulin inhibits MCP-1, sICAM-1 in critically ill patients, and TF in non-critically ill patients, our study demonstrated that IIT in critically ill patients did not affect these inflammatory mediators. Similarly, caloric intake had a negligible effect on the inflammatory mediators studied.

Permissive Underfeeding or Standard Enteral Feeding in High- and Low-Nutritional-Risk Critically Ill Adults. Post Hoc Analysis of the PermiT Trial.

RATIONALE: The optimal nutritional strategy for critically ill adults at high nutritional risk is unclear. OBJECTIVES: To examine the effect of permissive underfeeding with full protein intake compared with standard feeding on 90-day mortality in patients with different baseline nutritional risk. METHODS: This is a post hoc analysis of the PermiT (Permissive Underfeeding versus Target Enteral Feeding in Adult Critically Ill Patients) trial. MEASUREMENTS AND MAIN RESULTS: Nutritional risk was categorized by the modified Nutrition Risk in Critically Ill score, with high nutritional risk defined as a score of 5-9 and low nutritional risk as a score of 0-4. Additional analyses were performed by categorizing patients by body mass index, prealbumin, transferrin, phosphate, urinary urea nitrogen, and nitrogen balance. Based on the Nutrition Risk in Critically Ill score, 378 of 894 (42.3%) patients were categorized as high nutritional risk and 516 of 894 (57.7%) as low nutritional risk. There was no association between feeding strategy and mortality in the two categories; adjusted odds ratio (aOR) of 0.84 (95% confidence interval [CI], 0.56-1.27) for high nutritional risk and 1.01 (95% CI, 0.64-1.61) for low nutritional risk (interaction P = 0.53). Findings were similar in analyses using other definitions, with the exception of prealbumin. The association of permissive underfeeding versus standard feeding and 90-day mortality differed when patients were categorized by baseline prealbumin level (≤0.10 g/L: aOR, 0.57 [95% CI, 0.31-1.05]; >0.10 and ≤0.15 g/L: aOR, 0.79 [95% CI, 0.42-1.48]; >0.15 g/L: aOR, 1.55 [95% CI, 0.80, 3.01]; interaction P = 0.009). CONCLUSIONS: Among patients with high and low nutritional risk, permissive underfeeding with full protein intake was associated with similar outcomes as standard feeding.

Permissive Underfeeding or Standard Enteral Feeding in Critically Ill Adults.

BACKGROUND: The appropriate caloric goal for critically ill adults is unclear. We evaluated the effect of restriction of nonprotein calories (permissive underfeeding), as compared with standard enteral feeding, on 90-day mortality among critically ill adults, with maintenance of the full recommended amount of protein in both groups. METHODS: At seven centers, we randomly assigned 894 critically ill adults with a medical, surgical, or trauma admission category to permissive underfeeding (40 to 60% of calculated caloric requirements) or standard enteral feeding (70 to 100%) for up to 14 days while maintaining a similar protein intake in the two groups. The primary outcome was 90-day mortality. RESULTS: Baseline characteristics were similar in the two groups; 96.8% of the patients were receiving mechanical ventilation. During the intervention period, the permissive-underfeeding group received fewer mean (±SD) calories than did the standard-feeding group (835±297 kcal per day vs. 1299±467 kcal per day, P<0.001; 46±14% vs. 71±22% of caloric requirements, P<0.001). Protein intake was similar in the two groups (57±24 g per day and 59±25 g per day, respectively; P=0.29). The 90-day mortality was similar: 121 of 445 patients (27.2%) in the permissive-underfeeding group and 127 of 440 patients (28.9%) in the standard-feeding group died (relative risk with permissive underfeeding, 0.94; 95% confidence interval [CI], 0.76 to 1.16; P=0.58). No serious adverse events were reported; there were no significant between-group differences with respect to feeding intolerance, diarrhea, infections acquired in the intensive care unit (ICU), or ICU or hospital length of stay. CONCLUSIONS: Enteral feeding to deliver a moderate amount of nonprotein calories to critically ill adults was not associated with lower mortality than that associated with planned delivery of a full amount of nonprotein calories. (Funded by the King Abdullah International Medical Research Center; PermiT Current Controlled Trials number, ISRCTN68144998.).

Permissive underfeeding and intensive insulin therapy in critically ill patients: a randomized controlled trial.

BACKGROUND: Nutritional support has been recognized as an essential part of intensive care unit management. However, the appropriate caloric intake for critically ill patients remains ill defined. OBJECTIVE: We examined the effect of permissive underfeeding compared with that of target feeding and of intensive insulin therapy (IIT) compared with that of conventional insulin therapy (CIT) on the outcomes of critically ill patients. DESIGN: This study had a 2 × 2 factorial, randomized, controlled design. Eligible patients were randomly assigned to permissive underfeeding or target feeding groups (caloric goal: 60-70% compared with 90-100% of calculated requirement, respectively) with either IIT or CIT (target blood glucose: 4.4-6.1 compared with 10-11.1 mmol/L, respectively). RESULTS: Twenty-eight-day all-cause mortality was 18.3% in the permissive underfeeding group compared with 23.3% in the target feeding group (relative risk: 0.79; 95% CI: 0.48, 1.29; P = 0.34). Hospital mortality was lower in the permissive underfeeding group than in the target group (30.0% compared with 42.5%; relative risk: 0.71; 95% CI: 0.50, 0.99; P = 0.04). No significant differences in outcomes were observed between the IIT and CIT groups. CONCLUSION: In critically ill patients, permissive underfeeding may be associated with lower mortality rates than target feeding. This trial was registered at controlled-trials.com as ISRCTN96294863.

Near-target caloric intake in critically ill medical-surgical patients is associated with adverse outcomes.

BACKGROUND: The objective of this study was to determine whether caloric intake independently influences mortality and morbidity of critically ill patients. METHODS: The study was conducted as a nested cohort study within a randomized controlled trial in a tertiary care intensive care unit (ICU). The main exposure in the study was average caloric intake/target for the first 7 ICU days. The primary outcomes were ICU and hospital mortality. Secondary outcomes included ICU-acquired infections, ventilator-associated pneumonia (VAP), duration of mechanical ventilation days, and ICU and hospital length of stay (LOS). The authors divided patients (n = 523) into 3 tertiles according to the percentage of caloric intake/target: tertile I <33.4%, tertile II 33.4%-64.6%, and tertile III >64.6%. To adjust for potentially confounding variables, the authors assessed the association between caloric intake/target and the different outcomes using multivariate logistic regression for categorical outcomes (tertile I was used as reference) and multiple linear regression for continuous outcomes. RESULTS: Tertile III was associated with higher adjusted hospital mortality, higher risk of ICU-acquired infections, and a trend toward higher VAP rate. Increasing caloric intake was independently associated with a significant increase in duration of mechanical ventilation, ICU LOS, and hospital LOS. CONCLUSIONS: The data demonstrate that near-target caloric intake is associated with significantly increased hospital mortality, ICU-acquired infections, mechanical ventilation duration, and ICU and hospital LOS. Further studies are needed to explore whether reducing caloric intake would improve the outcomes in critically ill patients.

Intensive versus conventional insulin therapy: a randomized controlled trial in medical and surgical critically ill patients.

OBJECTIVE: The role of intensive insulin therapy in medical surgical intensive care patients remains unclear. The objective of this study was to examine the effect of intensive insulin therapy on mortality in medical surgical intensive care unit patients. DESIGN: Randomized controlled trial. SETTINGS: Tertiary care intensive care unit. PATIENTS: Medical surgical intensive care unit patients with admission blood glucose of > 6.1 mmol/L or 110 mg/dL. INTERVENTION: A total of 523 patients were randomly assigned to receive intensive insulin therapy (target blood glucose 4.4-6.1 mmol/L or 80-110 mg/dL) or conventional insulin therapy (target blood glucose 10-11.1 mmol/L or 180-200 mg/dL). MEASUREMENTS AND MAIN OUTCOMES: The primary end point was intensive care unit mortality. Secondary end points included hospital mortality, intensive care unit and hospital length of stay, mechanical ventilation duration, the need for renal replacement therapy and packed red blood cells transfusion, and the rates of intensive care unit acquired infections as well as the rate of hypoglycemia (defined as blood glucose < or = 2.2 mmol/L or 40 mg/dL). There was no significant difference in intensive care unit mortality between the intensive insulin therapy and conventional insulin therapy groups (13.5% vs. 17.1%, p = 0.30). After adjustment for baseline characteristics, intensive insulin therapy was not associated with mortality difference (adjusted hazard ratio 1.09, 95% confidence interval 0.70-1.72). Hypoglycemia occurred more frequently with intensive insulin therapy (28.6% vs. 3.1% of patients; p < 0.0001 or 6.8/100 treatment days vs. 0.4/100 treatment days; p < 0.0001). There was no difference between the intensive insulin therapy and conventional insulin therapy in any of the other secondary end points. CONCLUSIONS: Intensive insulin therapy was not associated with improved survival among medical surgical intensive care unit patients and was associated with increased occurrence of hypoglycemia. Based on these results, we do not advocate universal application of intensive insulin therapy in intensive care unit patients. TRIAL REGISTRATION: Current Controlled Trials registry (ISRCTN07413772) http://www.controlled-trials.com/ISRCTN07413772/07413772; 2005.