Jpen Parenter Enter
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Jpen Parenter Enter · Jan 2003
Achievement of steady state optimizes results when performing indirect calorimetry.
The use of steady state as the endpoint for performance of indirect calorimetry (IC) is controversial. We designed this prospective study to evaluate the necessity and significance of achieving steady state. ⋯ These data support the use of steady state, best defined as an interval of 5 consecutive minutes whereby VO2 and VCO2 change by <10%. The mean REE from this period correlates best to the 24-hour TEE regardless of CV. IC testing can be completed after achievement of steady state. Activity factors of 10% to 15% should not be added to the steady-state REE, because this practice significantly decreases the accuracy. In patients who fail to achieve steady state, the CV helps to determine the appropriate duration of IC testing. In those patients with a low CV (< or = 9.0), 30-minute test duration is adequate. In patients with CV >9.0, test duration of at least 60 minutes may be required. These latter patients should be considered for 24-hour IC testing.
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Jpen Parenter Enter · Jan 2003
Effect of neuromuscular blockade on energy expenditure in patients with severe head injury.
The purpose of this study was to determine the effect of neuromuscular blockade on energy expenditure in severely head-injured patients; to determine the effects of body temperature, nutrition support, and morphine use on metabolic rate; and to compare measured energy expenditure with values from predictive equations. ⋯ Neuromuscular blockade in severely head-injured patients decreases energy expenditure to basal levels, independent of morphine use, body temperature, and feeding. Levels of hypermetabolism in both the head-injured and trauma groups were relatively low, at 19% and 5% above predicted values, respectively. This study provides useful information for the management of nutrition support in severely traumatized patients.
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Jpen Parenter Enter · Jan 2003
Preoperative albumin and surgical site identify surgical risk for major postoperative complications.
Although malnutrition contributes to morbidity, studies of pre- and postoperative nutrition often include well-nourished patients unlikely to benefit from therapy and usually do not stratify by the site of surgical pathology. This study evaluates whether perceived preoperative markers of nutritional status recorded in charts correlates with postoperative complications and resource use in patients who receive no preoperative nutrition support and reinterprets the results of several conflicting randomized, prospective studies in this context. ⋯ Elective, non-emergent esophageal and pancreatic procedures performed in patients who could have had surgery delayed for preoperative nutrition, but did not, result in higher risk than colon surgery at any given level of serum albumin below 3.25 g/dL. Patient populations in trials should be stratified by operative site and by markers of nutritional status. Degree of hypoalbuminemia and other potential markers of nutritional status may explain many of the discrepancies between trials of nutrition support. Preexisting hypoalbuminemia in patients undergoing elective surgery remains underappreciated, unrecognized, and untreated in many hospitalized patients.
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Jpen Parenter Enter · Jan 2003
Effects of particle size on blood clearance and tissue uptake of lipid emulsions with different triglyceride compositions.
Particle size of IV lipid emulsions affects the catabolism of long-chain triglyceride (LCT) emulsions, but little is known about its effect on the catabolism of medium-chain triglyceride (MCT)- and fish oil (FO)-containing emulsions. ⋯ In a mouse model, FO addition to large emulsions increased blood clearance and changed organ delivery. In contrast, there was no or little effect when particle size became smaller. We hypothesize that in humans, FO addition to lipid emulsions can help target emulsion delivery to certain extrahepatic tissues, a factor that may be of use for delivering specific fatty acids, or even drugs, to specific organs.
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Jpen Parenter Enter · Nov 2002
Glutamine supplementation fails to affect muscle protein kinetics in critically ill patients.
In vitro work suggests that glutamine availability may be an important factor in controlling the rate of muscle protein synthesis. The objective of this study was to determine if enteral administration of glutamine affects muscle protein metabolism in critically ill patients. ⋯ Enteral glutamine supplementation to critically ill patients fails to alter muscle glutamine metabolism or muscle protein synthesis. This suggests a possible restriction in transport of glutamine into muscle of critically ill patients.