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.

Because energy expenditure is difficult to predict on the basis of conventional equations, patients in long-term acute care facilities routinely are overfed and underfed, with only 25% receiving calories within 10% of required needs. Measuring a patient's energy requirement at least once by IC is important, because the degree of metabolism predicts how easily a patient will be underfed or overfed. The amount of infused calories should be compared with caloric requirements measured by IC, because the accuracy or degree of underfeeding or overfeeding has an impact on ventilatory status and the likelihood for developing azotemia. Although physician practice or bias may reduce the optimal clinical effect, the use of IC to determine caloric requirements may result in significant cost savings.

This review of 23 papers involving indirect calorimetry published over the past 18 months shows how our understanding of the metabolic response to injury has changed, highlights the problems introduced by use of predictive equations and alterations in indirect calorimetry testing protocol, and emphasizes the need to monitor cumulative energy balance by comparing daily caloric intake to energy expenditure.

Background: Patients in a long-term nursing care center (NCC) are at risk for the complications of malnutrition because of altered mental status and reduced mobility. Objective: This prospective study sought to determine the need for accurately measuring energy expenditure by indirect calorimetry (IC) and providing sufficient nutrition support, by evaluating the effect of energy balance on nutrition-related complications in the NCC. Design: Patients residing in one NCC were included in this study if there was evidence of hypoalbuminemia, pressure sores, weight loss, actualhdeal body weight less than 85% or more than 150%, or the need for enteral tube feeding or total parenteral nutrition (TPN). After 4 weeks of initial monitoring, patients were evaluated weekly by IC for 8 weeks. Caloric requirements were defined by the measured resting energy expenditure with 10% to 15% added for an activity factor. hionitors included: daily temperature and stool frequency; weekly calorie count, Norton scale (NS), weight, pressure sore number/stage, and serum prealbumin level; and monthly quality of life measure by hiinimum Data Set. Results: Of 110 patients screened, 41 met study criteria but 17 were excluded for reasons of agitation, refusal to participate, discharge from the NCC, or death. Of the 24 patients completing the study, 20.8% were male with a mean age of 77.1 years (range 29 to 104 years) and could be grouped on the basis of energy balance. Group 1 (n = 13) had positive cumulative energy balance for the 8 weeks of the study, 30.8% lost weight, 53.8% showed a slight increase in their risk for pressure sores (as evidenced by decreases in NS score) but only 15.4% developed pressure sores. Group 2 (n = 11) had negative cumulative energy balance for the 8 weeks of the study, 63.6% lost weight (odds ratio [OR] = 0.25; 95% confidence interval [CII: 0.03 to 1.82), 27.3% showed a slight increase in their risk for pressure sores with decreases in NS score (OR = 3.11; 95% CI: 0.43 to 25.76) but in contrast, 36.4% developed pressure sores (OR = 0.32; 95% CI: 0.02 to 3.08). The mean cost of treatment for the pressure sores in group 1 was much less than that for group 2, $296 2 $863 us $1,960 * $3,501, respectively ( p = .399). There was 64% noncompliance to the recommendations based on IC in group 2 due to advanced directives prohibiting tube feeds, disbelief in the accuracy of the calorie count, or desire for weight loss in obese patients by primary care physicians. Cumulative energy balance was weakly correlated with development of a pressure sore ( r = -3 4 , p = .390) when all patients were considered; however, when stratified by risk of pressure sores as measured by the NS score at baseline, those a t moderate risk for pressure sores had a much stronger association between cumulative energy balance and development of pressure sores (r = -0.604; p = .085) than did those a t high risk for pressure sores (I. = -0.070, p = .847). Conclusions: Use of IC to determine energy balance identified patients at risk for nutrition-relate...