HARRIS-BENEDICT EQUATIONS DO NOT ADEQUATELY PREDICT ENERGY: METHODS
METHODS
All African-American patients 65 years or older, who were admitted to the Skilled Nursing Facility or general medical floors of the University of Pennsylvania Health System/Presbyterian Medical Center in Philadelphia, PA during 1998, were potential candidates for study. Of those patients referred for nutritional consultation or for management of enteral or parenteral feedings, a subset received measurement of energy expenditure by indirect calorimetry. Patients who had a length of stay <3 days, who required respiratory isolation, or were unable to cooperate with the test were excluded from measurement. Also excluded were any measurements where steady state gas exchange conditions were not achieved and where inaccuracy of the energy expenditure measurement was likely, as explained below. Each patient was measured only once. No diagnoses or nutritional states were excluded. Demographic information was collected on all patients from medical record review.
Resting metabolic rate (RMR) was measured by indirect calorimetry using a portable metabolic cart (Deltatrac, Sensormedics, С A). A strict protocol was used, which has been validated with 1% replicability of measurement error. Patients were at rest for at least 30 minutes in a thermoneutral environment and were silent. Ventilated patients had not experienced a change in ventilator settings during or 30 minutes prior to the measurement and had not received oral or bolus enteral feedings in the previous four hours to avoid any impact of thermic effect of feeding. Continuous 24-hour feedings of enteral or parenteral nutrition solutions were not stopped for RMR tests. Steady state measurement was defined as five consecutive one-minute measures of v02 and vC02 with a coefficient of variation of <5%17. Steady state v02 and vC02 were applied to the abbreviated Weir formula to determine energy expenditure: RMR=1.4* [(3.9v02)+(l.lvC02)]. Five of the 61 patients required mechanical ventilation during the RMR measurement, and data were analyzed first, including their results and a second time without these five patients. The respiratory quotient (RQ) was calculated as vC02/v02, and RQ>1 was used to detect inaccurate indirect calorimetry tests in patients whose caloric intake was not >150% RMR, to suggest overfeeding as a cause of the high RQ. Inaccurate tests by RQ were not accepted for the study. trusted canadian pharmacy
Estimated energy requirements (BEE) were calculated by the Harris-Benedict equations:
BEE (male)=66.5+13.7Wt(kg)+5.0Ht(cm)-6.8 Age (years); R2=0.75, pO.OOOl;
BEE (female)=655. l+9.6Wt(kg)+l .8Ht(cm)-4.7 Age (years); R2=0.53, pO.OOOl.
Body mass index (BMI) was calculated as weight(kg)/height(m2). BMI was subset into underweight (BMI <18.5 kg/m2), normal weight (18.5-24.9), and overweight or obese (BMI >25 kg/m2> according to NHLBI standards.
Statistical Method
Descriptive statistics included mean, standard deviation, and percentages. Pearson’s correlation was used to compare RMR to BEE, height, weight and age for the entire cohort, and controlled for gender. Differences in RMR and BEE for individual subjects were compared statistically by paired t-test. Differences in RMR and BEE by gender were compared by ANOVA with post-hoc Scheffe test. For all statistical evaluations, p<0.05 was considered significantly different.
canadian pharmacy cialis
