Background and aims: An accurate energy balance is difficult to achieve in hospitalized patients. The aim of the study was to measure the daily cumulative energy balance in critically ill patients receiving mechanical ventilation using a bedside computerized information system (CIS), and to assess its impact on outcome.
Methods: Fifty intensive care unit (ICU) patients (33 male, 17 female, mean age 59 +/- 18 years) were prospectively followed. Mean body mass index was 26.85 +/- 5.23 kg/m2 and mean APACHE II score, 23.1 +/- 7.7. Resting energy expenditure was measured daily with indirect calorimetry (Deltatrac II, Datex-Ohmeda, Finland), and daily macronutrient intake was measured with a bedside CIS (iMDsoft, Israel) connected to all caloric sources. End-point measures were morbidity (acquired organ dysfunction, pressure sores, need for surgery) and mortality. One- and two-way analysis of variance and stepwise logistic regression for predicted probability were used for statistical analysis.
Results: Mean energy intake was 1512 kcal/day and mean cumulative energy balance for an overall ICU stay of 566 days was -4767 kcal (range +4747 to -17,274). A strong association of maximum negative energy balance with adult respiratory distress syndrome (P = 0.0003), sepsis (P = 0.0035), renal failure (P = 0.0001), pressure sores (P = 0.013), need for surgery (P = 0.023), and total complication rate (P = 0.0001), but not with length of ventilation, ICU stay, or hospitalization, or mortality.
Conclusions: Negative energy balance may be correlated with the occurrence of complications in the ICU. The bedside CIS provides accurate information on energy balance in critically ill patients and may allow for early detection and prevention of severe negative energy balance and complications.