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Predicted vs Measured Energy Expenditure in Critically Ill, Underweight Patients
Author(s) -
Campbell Christina Gayer,
Zander Elin,
Thorland William
Publication year - 2005
Publication title -
nutrition in clinical practice
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 71
eISSN - 1941-2452
pISSN - 0884-5336
DOI - 10.1177/0115426505020002276
Subject(s) - medicine , critically ill , underweight , energy expenditure , intensive care medicine , critical illness , body mass index , overweight
A retrospective analysis was conducted to compare 4 energy‐prediction equations against measured resting energy expenditure (MREE) determined via indirect calorimetry. Data from a heterogeneous group of 42 critically ill, severely underweight (59.50 ± 17.30 kg; 77.1 ± 9.7% ideal body weight [IBW]) male patients were assessed. The Hamwi formula was used to determine IBW. The Harris‐Benedict (HB) equation was calculated for patients <90% IBW using both current body weight (CBW) and IBW. Energy needs were also estimated with an Ireton‐Jones formula for all mechanically ventilated patients ( n = 37). For patients <85% IBW ( n = 31), an adjusted body weight was determined ([CBW + IBW]/2) and used in the HB formula. The HB formula using the IBW, CBW, and adjusted body weight was significantly different ( p < .05) than MREE. The Ireton‐Jones equation was not significantly different ( p > .05) from MREE but tended to overestimate energy needs (109.3% ± 16.8% MREE). Conversely, using the CBW or IBW in the HB underestimated the patient's energy needs; 77.0% ± 11.6% MREE and 90.9 ± 16.1% MREE, respectively. For patients <85% IBW, use of the adjusted body weight in the HB represented 84.2% ± 13.9% MREE. The average caloric need was 31.2 ± 6.0 kcal/kg CBW. Indirect calorimetry remains the best method of determining a patient's energy needs. Until a large prospective trial is conducted, a combination of prediction equations tempered with clinical judgment and monitoring the appropriateness of the nutrition prescription remains the best approach to quality patient care.