ARE PATIENTS FED APPROPRIATELY ACCORDING TO THEIR CALORIC REQUIREMENTS

Background: Specific morbidity related to underfeeding and overfeeding necessitates the design of nutrition support regimens that provide ca lories equal to those required on the basis of energy expenditure. Thi s prospective multicenter trial was designed to determine what percent of patients in long-term acute care facilities receive feeding approp riate to their needs and whether accuracy of feeding has an impact on patient clinical status. Methods: Patients on mechanical ventilation w ho were hospitalized at 32 Vencor Hospitals over a g-week period and w ho were receiving only enteral nutrition by continuous infusion at a p resumed goal rate were evaluated once by indirect calorimetry (IC) whi le on feeding. Caloric intake over the preceding 24 hours was determin ed by physician orders and by patient intake/output (I/O) record. Calo ric requirements were defined by measured resting energy expenditure ( REE) + 10% for activity. Degree of metabolism was defined by the ratio : (measured PEE/Harris-Benedict predicted REE) x 100, and the degree o f feeding by the ratio: (calories provided/calories required) x 100. R esults: IC was performed on 335 patients (mean, 11.2 patients per cent er; range, 1 to 32), of which 72 were excluded for nonphysiological re sults or failure to achieve steady state, 21 for receiving parenteral nutrition, and 29 for not being on mechanical ventilation at time of t esting. The 213 study patients were 58.7% male with mean age 70.1 year s (range, 20 to 90 years). Measured REE was <25 kcal/kg in 66.2% of pa tients and 25 to 35 kcal/kg in 28.6%. Barely half (48.4%) of this pati ent population was hypermetabolic. Based on physician orders, the majo rity of patients (58.2%) were overfed, receiving >110% of required cal ories, and 12.2% were underfed, receiving <90% of requirements. Discre pancies based on I/O records, however, suggested that 36.1% of patient s received <90% of those calories ordered. By either basis, only about 25% of patients received feeding within 10% of required calories. The percent of patients being overfed varied between centers, ranging fro m 32.2% to 92.8%, and was not affected by years of facility IC experie nce or volume of IC studies per month. The pattern of caloric provisio n as measured by degree of feeding correlated inversely to degree of m etabolism (p <.0001, R-2 =.24). Accuracy of feeding had an impact on v entilatory status, as degree of feeding correlated inversely with minu te ventilation (p =.001, R-2 =.05). Degree of overfeeding also led to significant increases in azotemia (p =.033, R-2 =.02). Extrapolating s tudy data over 1 year, reduction in excess volume of enteral formula w ould have resulted in a cost savings of up to $1.3 million for the Ven cor system. Conclusions: Because energy expenditure is difficult to pr edict on the basis of conventional equations, patients in long-term ac ute 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 degr ee of metabolism predicts how easily a patient will be underfed or ove rfed. The amount of infused calories should be compared with caloric r equirements measured by IC, because the accuracy or degree of underfee ding or overfeeding has an impact on ventilatory status and the likeli hood 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.