Metabolic effects of beta-blockers in critically ill patients: A retrospective cohort study.

BACKGROUND: Beta-blockers have potential protective features during critical illness. Heart rate reduction, with limited effect on blood pressure and beneficial effects on metabolism, organ function and inflammation have been reported. We examined metabolic effects of beta-blockers among ICU patients, to address the effect on the estimated energy expenditure, measured by carbon dioxide production (VCO2). Furthermore, we investigated effects on organ function and inflammation. METHODS: A retrospective study in adult patients admitted to our 17-beds mixed medical-surgical ICU from January 2013 to March 2016. Mechanically ventilated patients who commenced beta-blockers were eligible for inclusion. Exclusion criteria were: beta-blocker therapy in the 7 previous days, treatment duration <48 h, therapeutic hypothermia, and no VCO2 measurements. Outcome parameters were obtained at 6 different time points from 24 h before until 48 h after beta-blocker commencement. Linear mixed models were used to evaluate trends. RESULTS: In total 58 patients were included. Various types of beta-blockers were administered, with a median equivalent daily dose to metoprolol of 50.0 mg (IQR 25.0-62.5). The mean heart rate decreased from 103 ± 20 to 91 ± 19 beats per minute after 48 h (p < 0.001), with unaltered blood pressures. Metabolic and other parameters did not show significant differences over time, or parameter changes were due to trends that had already started before beta-blocker commencement. CONCLUSIONS: No changes in VCO2 after beta-blocker commencement were demonstrated suggesting no alterations in energy expenditure. Heart rates significantly decreased with unaltered blood pressures. Other parameters did not show trends that could be attributed to beta-blockers effects.

Associations of hyperosmolar medications administered via nasogastric or nasoduodenal tubes and feeding adequacy, food intolerance and gastrointestinal complications amongst critically ill patients: A retrospective study.

BACKGROUND: Adequate nutrition is essential during critical illness. However, providing adequate nutrition is often hindered by gastro-intestinal complications, including feeding intolerance. It is suggested that hyperosmolar medications could be causally involved in the development of gastro-intestinal complications. The aims of the present study were 1) to determine the osmolality of common enterally administered dissolved medications and 2) to study the associations between nasogastric and nasoduodenal administered hyperosmolar medications and nutritional adequacy as well as food intolerance and gastro-intestinal symptoms. METHODS: This retrospective observational cohort study was performed in a medical-surgical ICU in the Netherlands. Adult critically ill patients receiving enteral nutrition and admitted for a minimum ICU duration of 7 days were eligible. The osmolalities of commonly used enterally administrated medications were measured using an osmometer. Patients were divided in two groups: Use of hyperosmolar medications (>500 mOsm/kg) on at least one day during the first week versus none. The associations between the use of hyperosmolar medications and nutritional adequacy were assessed using multiple logistic regression analysis. The associations between hyperosmolar medication and food intolerance as well as gastrointestinal symptoms were assessed using ordinal logistic regression. RESULTS: In total 443 patients met the inclusion criteria. Of the assessed medications, only three medications were found hyperosmolar. We observed no associations between the use of hyperosmolar medications and nutritional adequacy in the first week of ICU admission (caloric intake ß -0.27 95%CI -1.38; 0.83, protein intake ß 0.32 95%CI -0.90; 1.53). In addition, no associations were found for enteral feeding intolerance, diarrhea, obstipation, gastric residual volume, nausea and vomiting in ICU patients receiving hyperosmolar medications via a nasogastric tube. A subgroup analysis of patients on duodenal feeding showed that postpyloric administration of hyperosmolar medications was associated with increased risk of diarrhea (OR 138.7 95%CI 2.33; 8245). CONCLUSIONS: Our results suggest that nasogastric administration of hyperosmolar medication via a nasogastric tube does not affect nutritional adequacy, development of enteral feeding intolerance and other gastro-intestinal complications during the first week after ICU admission. During nasoduodenal administration an increased diarrhea incidence may be encountered.