Reassessing caloric requirements in pediatric burn patients

New formulas for estimating the caloric requirements of burned children have been suggested. These formulas appeared to exceed the caloric estimates made by the Galveston Shriners Burns Institute formula. This study was undertaken to compare the Curreri Junior formulas and the Galveston Shriners Burns Institute formula with the actual intake required by pediatric patients with burns greater than 30% total body surface area to maintain weight. The 121 patients studied were divided into three age groups to coincide with those in the Curreri Junior formulas and calorie requirements as estimated by both formulas were determined. The comparison of these estimations with the actual intake required to maintain weight indicated that there is a significant difference in the caloric requirement per m2 burn between the age three and under group and the older age group. The results also suggest that overfeeding may occur with the historic formulas.     

Current treatment reduces calories required to maintain weight in pediatric patients with burns

A previous study indicated that formulas for determining caloric requirements of severely burned children overestimated their needs. This study was undertaken to determine the caloric intake required to maintain weight in patients under 12 years of age with burns over more than 30% total body surface area. The 102 patients studied were divided into two groups according to weight changes. A comparison of the actual caloric intakes of these groups was conducted. Multivariate regression analysis indicated that body surface area in square meters and burn surface were significant predictors of caloric requirements to maintain weight in these patients. It was determined that 1800 kcal was a plausible value for the calories per body surface area. Therefore the regression was formed with 1800 kcal as the multiplier of body surface area, and the multiplier of burn surface area was estimated. The resulting formula provides 1300 kcal/m2 burned, which is 900 kcal/m2 burned less than our previously suggested formula.     

The respiratory quotient has little value in evaluating the state of feeding in burn patients

The respiratory quotient (RQ) is frequently used to predict over or under feeding in burn patients. The purpose of our study was to evaluate the usefulness of RQ obtained from indirect calorimetry to assess feeding adequacy in pediatric burn Intensive Care Unit patients. We evaluated pediatric patients who received enteral nutrition by continuous duodenal tube feeding at a calculated goal rate in the burn intensive care unit from January 2003 to March 2006. RQ lower than 0.85 indicated underfeeding and RQ greater than 1.0 indicated overfeeding. Actual energy intake was recorded and compared with the energy intake divided by measured resting energy expenditure. Underfeeding was defined as a nutritional regimen providing <90% of caloric requirement; appropriate feeding was provision of within +/-10% of caloric requirements and overfeeding was provision of >110% of caloric requirements. On the basis of regression analysis, there was no relationship between energy intake divided by measured resting energy expenditure and RQ (R2 = 0.0059). There was also no relationship between measured RQ and the degree of feeding (N = 222). RQ <0.85 as an indicator of underfeeding had a low sensitivity of 40% and specificity of 77%. RQ >1.0 as an indicator of overfeeding had a poor sensitivity of 23% and a specificity of 85%. The RQ, used in isolation, is a poor method to assess over or underfeeding. Future prospective studies are needed to determine the optimal methodology for the assessment of nutritional needs in children with burn injury.     

Caloric and nitrogen balances as predictors of nutritional outcome in patients with burns.

Measurement of energy expenditure with indirect calorimetry allows determination of caloric balance. The present study was done to determine the predictive value of caloric and nitrogen balances for nutritional outcome. Energy expenditure was obtained weekly and interpolated between measurements for daily caloric balance. Nitrogen balance was obtained weekly. Because nitrogen output fluctuated, interpolation of daily values was not possible. Nutritional outcome was defined by whether body weight was lost or maintained and by levels of visceral proteins (albumin, prealbumin, and transferrin). The study group included 12 patients with 7% to 82.5% total body surface area burns. Eleven patients survived their burn injuries, and one died of congestive heart failure at 38 days, after her burn wounds had healed. Nine patients had good nutritional outcomes (group 1) and three had poor nutritional outcomes (group 2) (including the one who died). Nitrogen balance was 1.3 +/- 1.0 gm/day in group 1 and 4.5 +/- 1.7 gm/day in group 2 (mean +/- SEM; p > 0.10). Caloric balance was 515 +/- 130 kcal/day in group 1 and -667 +/- 140 in group 2 (p < 0.001). Caloric balance was significantly different between the two groups, whereas nitrogen balance was not. Caloric intake correlated positively with nitrogen intake (r = 0.92). Nitrogen intake was 16% of total caloric intake. Nitrogen intake from blood products was appreciable and averaged 15% of total nitrogen intake (range, 0% to 47%); 11.3 +/- 1.6 gm/day in group 1 and 14.8 +/- 3 gm/day in group 2 (p > 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)     

Caloric needs of adolescent patients with burns

Formulas for estimating the caloric requirements of pediatric and adult patients with burns have been suggested. However, the needs of adolescent patients with burns have not been specifically addressed. This study was undertaken to determine the calorie intake required to maintain weight of adolescent patients with burns over more than 35% of the total body surface area. The 29 patients studied were divided into two groups according to sex. Caloric requirements were determined with the use of the Galveston surface area formula and the Curreri formula. The comparison of these estimations with the actual intake required to maintain weight indicated that there is a significant difference between the calories indicated by the formulas and the actual intake. A surface area formula that also correlates with the results of indirect-calorimetry studies is suggested for this adolescent population with burns.     

Use and efficacy of a nutrition protocol for patients with burns in intensive care

The University of Michigan Burn Center uses a protocol to standardize the assessment, initiation, and monitoring of nutritional support for patients with burns of greater than 30% total body surface area (TBSA). Six patients with 20% to 80% TBSA burns were followed for 3 weeks to determine the effect of the protocol on the assessment, initiation, monitoring, and adequacy of nutritional support. The protocol calls for resting energy expenditure (REE) measurement within 24 hours of injury, to be repeated 3 times per week, for assessment of caloric requirements. Patients experienced an average delay before first REE measurement of 3 days after burn injury because measurements were unavailable on weekends and surgical days. REE measurements were used to determine caloric requirements and to tailor nutritional support to fluctuating metabolic needs. In four of the six patients a Dobhoff feeding tube (Biosearch Medical Products, Inc., Somerville, N.J.) was placed in the small bowel and enteral nutrition was initiated within 24 hours of admission, as outlined in the protocol. Two patients received concurrent parenteral nutrition because of difficulty in placing the Dobhoff feeding tube when fluoroscopy was not available. The three patients receiving nutrition solely through enteral feeding had achieved 100% of their caloric requirements by day 2, 4, and greater than 7 days after injury, respectively. Overall, the six patients received enterally an average of 75% of their caloric requirements. The major reason for inadequate enteral support was interruption of tube feedings because of tube dislodgment or multiple surgical procedures. The protocol used weekly measurements of total iron-binding capacity and prealbumin level s parameters of nutritional support.(ABSTRACT TRUNCATED AT 250 WORDS)     

Longitudinal assessment of Integra in primary burn management: a randomized pediatric clinical trial

BACKGROUND: Early excision with autograft-allograft closure is standard in severe burn management. Cadaver skin is associated with risks such as antigenicity, infection, and limited availability and shelf life. Previous studies have shown that Integra is safe to use in burns of <20% total body surface area. However, the suitability of its use in large burns (>50% total body surface area), its effects on postburn hypermetabolism, and the long-term cosmetic and functional results have not yet been evaluated. MATERIALS AND METHODS: Twenty children with an average burn size of 73 +/- 15% total body surface area (71 +/- 15% full-thickness burn) were randomized to be treated with either Integra or with autograft-allograft technique. Outcome measures such as length of hospital stay, mortality, incidence of infection and sepsis, acute phase protein levels, and muscle fractional synthetic rate were compared between and within groups during the acute stay (admission to discharge). Outcome measures such as resting energy expenditure, body composition data (measured by dual-energy radiograph absorptiometry), cardiac function indexes, and number of reconstructive procedures were compared during acute hospital stay and at long-term follow-up (up to 2 yrs postinjury). Scar evaluation was performed at long-term follow-up. RESULTS: There were no significant differences between Integra and controls in burn size (70 +/- 5% vs. 74 +/- 4% total body surface area), mortality (40% vs. 30%), and length of stay (41 +/- 4 vs. 39 +/- 4 days). In the short term, resting energy expenditure significantly decreased (p < .01), and serum levels of constitutive proteins significantly increased (p < .03) in the Integra group compared with controls. Long-term follow-up revealed a significant increase in bone mineral content and density (24 months postburn, p < .05), as well as improved scarring in terms of height, thickness, vascularity, and pigmentation (12 months and 18-24 months, p < .01) in the Integra group. CONCLUSION: Integra can be used for immediate wound coverage in children with severe burns without the associated risks of cadaver skin.     

Measured and predicted caloric expenditure in the acutely ill

Predicted energy requirements calculated from the Harris-Benedict basal energy expenditure (BEE) formulas, and caloric allowances recommended by the Food and Nutrition Board National Research Council, were compared to metabolic expenditures measured by indirect calorimetry, using a feedback-controlled gas replenishment technique with a prototype device for the continuous determination of oxygen consumption (VO2) and carbon dioxide production (VCO2). In a group of 50 acutely ill surgical patients, predicted metabolic requirements based on ideal body weight (1.75 BEE) averaged 59% greater than metabolic expenditures measured by indirect calorimetry. Metabolic requirements based on actual body weight averaged 52% greater; recommended caloric allowances averaged 39% greater. Thus, accepted methods of predicting metabolic requirements significantly overestimated the caloric needs of these acutely ill patients. These results should encourage the development of new bedside equipment for measuring VO2 and VCO2, so that indirect calorimetry can be used to guide nutritional support in the clinical setting.     

The effect of kappa opioid receptor antagonism on energy expenditure in the obese Zucker rat

Food intake and, subsequently, body weight are influenced by endogenous opioids acting in the central nervous system. Agonists for the opioid receptor increase food intake, whereas antagonists reduce food intake. Body weight, however, is the result of food consumed and energy expended. Although much has been reported about the effect of opioid antagonism on food intake, less has been reported about its effect on energy expended. This study investigated the effect of selective antagonism of the kappa opioid receptor on food intake, body weight, and indicators of energy expenditure in male obese Zucker rats (n=10). Energy expenditure was measured by indirect calorimetry, whereas general activity and body temperature were measured by implanted radio frequency telemetry. Central administration of 30 microg of the kappa opioid receptor (KOR) antagonist norbinaltorphamine resulted in a significant 34% reduction in food intake (p =.001), a small reduction in body weight, a reduction in resting energy expenditure (p = .06), a reduction in respiratory quotient (p =.06), a 14% reduction in general activity, and a reduction in core body temperature. Reduction in body weight as a result of KOR inhibition in this study was related to a decrease in food intake but not related to an increase in energy expended or activity.     

Hyperglycemia exacerbates muscle protein catabolism in burn-injured patients

OBJECTIVE: The purpose of this study was to assess if hyperglycemia influences energy expenditure or the extent of muscle protein catabolism in severely burned adults. DESIGN: Retrospective study. SETTING: Burn intensive care unit at a university hospital. PATIENTS: Adults with burns on >/=40% of their body surface area. INTERVENTIONS: Simultaneous measurement of indirect calorimetry and leg net balance of phenylalanine (as an index of muscle protein catabolism). Patients were stratified by plasma glucose values at the time of metabolic measurements (i.e., normal, glucose at 200 mg/dL). MEASUREMENTS AND MAIN RESULTS: Normal (n = 9; plasma glucose, 109 +/- 13 mg/dL [mean +/- sd]), mildly hyperglycemic (n = 13l plasma glucose, 156 +/- 17 mg/dL), and severely hyperglycemic subjects (n = 7, glucose 231 +/- 32 mg/dL) were similar in age, body weight, extent of burn area, and daily caloric intake. Severe hyperglycemia was associated with significantly higher arterial concentrations of phenylalanine (normal, 0.079 +/- 0.027 micromol/L; severe hyperglycemia, 0.116 +/- 0.028; p <.05) and a significantly greater net efflux of phenylalanine from the leg (normal, -0.067 +/- 0.072 micromol.min(-1).100 mL(-1) leg volume; severe hyperglycemia, -0.151 +/- 0.080 micromol.min(-1).100 mL(-1) leg volume; p <.05). Resting energy expenditure and respiratory quotient were similar between patient groups. CONCLUSIONS: These findings demonstrate an association between hyperglycemia and an increased rate of muscle protein catabolism in severely burned patients. This suggests a possible link between resistance of muscle to the action of insulin for both glucose clearance and muscle protein catabolism.     

Assessment of nutritional and metabolic status of paraplegics

Nutritional and metabolic assessment using anthropometric, biochemical, immunological, and indirect calorimetric techniques was performed on 17 healthy paraplegic males with a mean age of 44.2 +/- 14.6 years and mean duration of injury of 17.8 +/- 12.3 years. Significant differences in energy expenditure were observed; only 29.4 percent were normometabolic [measured resting energy expenditure: (MREE) 90-110 percent of predicted resting energy expenditure (PREE)], 35.3 percent were hypermetabolic (MREE greater than 110 percent of PREE) and 35.3 percent were hypometabolic (MREE less than 90 percent of PREE). Obesity (weight greater than 110 percent ideal body weight) was maximum in hypometabolic patients (83.3 percent) due to the imbalance between caloric intake and energy expenditure (p less than 0.05). None of the patients had normal values for all four objective measurements of nutritional assessment (albumin, transferrin, total lymphocyte count, and cutaneous hypersensitivity). Mild malnutrition was evidenced in 47 percent of patients; 53 percent of patients demonstrated some index of moderate malnutrition. We conclude that nutritional therapy based on measurements of energy expenditure instead of predictive equations will benefit these patients. A larger long-term study is needed to determine the ideal predictive measurements of nutritional assessment with their optimal cutoff values applicable to the spinal cord-injured patient.     

Oxygen consumption, energy expenditure, and substrate utilization after cardiac surgery in children.

OBJECTIVE: To determine the oxygen consumption (VO2), resting energy expenditure, and substrate utilization after cardiac surgery in children. DESIGN: Prospective, observational, cross-sectional study with factorial design. SETTING: Pediatric ICU at a university hospital. PATIENTS: Twenty-six consecutive children during the first 3 days after open-heart surgery. INTERVENTIONS: Patients were mechanically ventilated and received routine therapeutic interventions. MEASUREMENTS AND MAIN RESULTS: VO2, resting energy expenditure, and substrate utilization were determined by indirect calorimetry. Cardiac index was calculated using the Fick equation from the measured VO2 and the arterial-mixed venous oxygen content difference, and this cardiac index value was compared with a simultaneous cardiac index value that was measured by thermodilution whenever possible. There were excellent correlation and agreement between cardiac index measurements by Fick equation and thermodilution, indicating accurate VO2 measurements. VO2 was consistent with predicted values in healthy resting children. Resting energy expenditure was consistent with the predicted basal metabolic rate. The mean caloric intake was 19% of the mean energy expenditure. The respiratory quotient was 0.74 +/- 0.05. The substrate utilization showed a shift toward fat oxidation and either gluconeogenesis or impaired carbohydrate utilization. CONCLUSIONS: Cardiovascular surgery in children does not significantly alter resting energy expenditure but influences the substrate utilization. Perioperative hormonal stress responses and therapeutically administered catecholamines may explain the shift toward fat oxidation.     

Comparison of measured resting energy expenditure versus predictive equations in pediatric burn patients

Many equations have been developed to estimate resting energy expenditure (REE) in thermally injured patients. A consensus has not been reached on the accuracy of these equations in children. The purpose of our study was to compare three predictive equations: Harris Benedict x 2 multiplier (HB x 2), Mayes (MG), and the WorId Health Organization x 2 multiplier (WHO x 2) with measured resting energy expenditure x I.3 multiplier (MREE x 1.3) in pediatric burn patients. MREE was measured by open-circuit indirect calorimetry in 10 burned children (6 boys, 4 girls) aged 2 to 10 years with TBSA burn ranges from 35% to 97%. MREE x 1.3 was compared with values obtained by HB x 2, MG, and WHO x 2 predictive equations. When comparing MREE x 1.3 with all three equations, significant differences were found when compared with HB x 2 and MG, but there were no significant difference between MREE x 1.3 vs WHO x 2. The HB x 2 and MG equations overpredicted MREE x 1.3 by 29% and 19%, respectively. Many predictive equations have been developed to predict energy expenditure in burns, but their accuracy in predicting MREE x 1.3 is variable. A larger study comparing/contrasting predictive equations and resting energy expenditure measured by indirect calorimetry is needed to improve the prediction of energy needs in burned children.     

Serial measurements of energy expenditure in critically ill children: useful in optimizing nutritional therapy?

OBJECTIVES: To determine the variation in total daily energy expenditure (TDEE) and respiratory quotient (RQ) in mechanically ventilated children and examine the relation to daily and cumulative energy balance toward optimizing nutritional therapy. METHODS: Serial measurements of TDEE and RQ were performed in 18 patients (median age 16 months) with an indirect calorimeter during admission (total 69 TDEE measurements). Daily caloric intake was recorded, and after determination of the amount of carbohydrates and fat a RQ of these macronutrients (RQ(macr)) was obtained. Daily 24-h urine was analyzed for urinary nitrogen excretion. RESULTS: There was a great variability in the median serial TDEE between children (40-64 kcal/kg), while the variation within individual children was small; the mean intraindividual coefficient of variation (CV) in daily measurements of TDEE was less than 10% in 15 of the 18 children (83%). On the last day of measurement 8 children with a positive cumulative energy balance (+98 kcal/kg) had a significantly higher RQ than 10 with a negative cumulative energy balance (-24 kcal/kg, 0.89 vs. 0.84). From the difference between RQ and RQ(macr) the optimal caloric intake was determined as 1.4x TDEE, divided into 60% carbohydrates and 40% fat. From the median nitrogen excretion of 33 samples (300 mg/kg per day, range 60-708) optimal daily protein intake was calculated as 1.9 g/kg (range 0.4-4.4). CONCLUSIONS: For most children a single measurement of TDEE gave a good insight in the daily energy needs. RQ is strongly affected by the ratio energy intake/TDEE and by the cumulative energy balance. Optimal caloric intake was found to be 1.4x TDEE with a daily protein intake of 1.9 g/kg.     

Restoring nitrogen balance after burn injury

The metabolic response to burn injury is characterized by weight loss and marked protein wasting. This phenomenon is mediated hormonally, resulting in hypermetabolism. Energy expenditure increases linearly with the extent of burn injury, reaching a plateau of twice resting energy expenditure when 50% of the total body surface area is involved. It is therefore essential to minimize other factors that may further augment postburn catabolism. Occlusive dressings, a warm ambient environment, analgesics, and timely closure of the burn wound are all important therapeutic measures in this regard. Furthermore, it is imperative to institute early nutritional support in order to offset the negative metabolic effects of severe burn injury.     

Influence of parenteral nutrition on rates of net substrate oxidation in severe trauma patients

Optimal nutritional support should use a patient's energy expenditure as a guide for administering sufficient but not excessive caloric intake. Eight patients requiring parenteral nutrition were evaluated, using indirect calorimetry measurements, to determine the nutritional influence on the rates of substrate utilization in the critical period of catabolic illness due to accidental trauma. Five days of total parenteral nutrition, providing calories to match the measured basal resting energy expenditure and N to replace the initial urinary losses a) shifted the RQ from 0.74 +/- 0.03 to 0.81 +/- 0.03, b) improved but could not reverse negative N balance, c) decreased net fat oxidation, d) increased carbohydrate and protein oxidation, e) elevated daily norepinephrine and epinephrine excretion rates, and f) attained positive energy balance. The results suggest that positive energy balance could be achieved in trauma patients by providing total energy intake matching their basal measured energy expenditure plus 7% to 10% for activity energy expenditure. To prevent further loss of lean body mass, an N intake of 350 mg/kg.day was needed in these catabolic ICU patients.     

Energy expenditure in 100 ventilated, critically ill children: improving the accuracy of predictive equations

OBJECTIVE: The purpose of this study was to evaluate current methods of predicting energy requirements and to develop and validate new equations derived from energy expenditure measurements of ventilated, critically ill children. DESIGN: Prospective, observational, sequential study. SETTING: Pediatric intensive care unit. PATIENTS: A total of 100 ventilated, critically ill children who fit the criteria of energy expenditure measurement. Additional patients (n = 25) were included in the validation study. INTERVENTION: An indirect calorimeter was used to measure energy expenditure for a period of 30 mins. MEASUREMENTS AND MAIN RESULTS: The mean measured energy expenditure was 185+/-51 kJ/kg per day. Predicted energy expenditure from standard equations was compared with measured energy expenditure by using the Bland and Altman "methods comparison procedure," and poor precision and accuracy were observed. Patient variables were collected at the time of measurement, and multiple regression analysis was performed to determine the independent contribution of each variable to measure energy expenditure. New predictive equations were formulated and validated with additional energy expenditure measurements. Patient variables that did not correlate significantly with energy expenditure were gender, Pediatric Risk of Mortality score, and commencement of nutritional support. An equation was derived from patient variables (age, weight, weight for age Z score, body temperature, number of days after intensive care admission, and primary reason for admission) that correlated significantly (r2 = .898) with measured energy expenditure. A second, simplified equation (energy expenditure kJ/day = ?17 x age [months]? + ?48 x weight [kg]? + ?292 x body temperature degrees C? - 9,677) was produced (r2 = .867). Validation found no significant difference between measured and predicted energy expenditure by the new equations; however, the equations did not predict accurately for patients <2 months of age. CONCLUSION: The new equations provide a more accurate alternative to current predictive methods in assessing energy requirements of ventilated, critically ill children.     

Energy expenditure in critically ill children

OBJECTIVES: To measure energy expenditure in critically ill children and compare it with the energy expenditure predicted by recommended formulas, and relate the measured energy expenditure to nutritional and clinical indices. DESIGN: A prospective, clinical study. SETTING: Tertiary care pediatric intensive care unit in a university children's hospital. PATIENTS: A total of 37 patients with critical illness who were mechanically ventilated for > or =24 hrs were studied. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Chronic protein-energy malnutrition (CPEM) and acute protein-energy malnutrition were defined by the Waterlow's stages and fat and protein stores were classified as defined by Frisancho, Ryan, and Martinez. Severity of illness was assessed by the Pediatric Risk of Mortality Score, the Therapeutic Intervention Scoring System, and indices of organ failure. Oxygen consumption, carbon dioxide production, and the respiratory quotient were measured by indirect calorimetry, and energy expenditure (MEE) was calculated using the modified Weir formula. Resting energy expenditure (PBMR), predicted energy expenditure, and caloric intake were calculated using recommended formulas. A total of 77 measurements were made in 37 children. MEE was significantly lower than PBMR as estimated by all equations except the Talbot equations. MEE was significantly lower than predicted energy expenditure and the recommended daily allowances. On the first day, the MEE/PBMR ratio was <0.9 in 56.8%, 0.9-1.1 in 21.6%, and >1.1 in 21.6% of patients. MEE did not differ significantly among disease groups or between medical and surgical patients. There was no difference in MEE with or without neuromuscular blockade. MEE was lower in the presence of multiple organ system failure (MOSF) (1019 + 166 kcal/m2 without MOSF vs. 862 + 241 with MOSF; p = .025). A total of 21% had CPEM and 8.1% had acute protein-energy malnutrition. Multivariate stepwise regression analysis showed that the protein intake, midarm muscle area, midarm fat area, the use of vasoactive agents, and sedation correlated with MEE (p < .05). With CPEM, MEE was correlated to the severity of illness (p < .05). Patients at risk for protein stores depletion (midarm muscle areas 1 and 2) had a higher incidence of MOSF compared with nutritionally normal children (p < .05), whereas patients with fat stores depletion (midarm fat area 2) had a higher probability of death (50% vs. 6%, respectively). CONCLUSIONS: Recommended daily allowances and energy expenditure predicted by using a stress-related correction to the resting energy expenditure grossly overestimate MEE. MEE is close to PBMR and in many patients, it is lower than PBMR. MEE that is lower than PBMR is associated with a higher morbidity. Nutritional repletion should thus be based on MEE to avoid the problems of over- or underfeeding.     

Energy expenditure in patients with severe head injury: Controlled normothermia with sedation and neuromuscular blockade

Objectives

Providing optimal caloric intake is important for patients with severe traumatic brain injury. Insufficient nutrition worsens prognosis, and excessive nutrition may lead to complications such as weaning delay from mechanical ventilation. However, using controlled normothermia with sedation and neuromuscular blockade for patients with anticipated severe brain edema, the optimal caloric intake is still unclear.

Methods

Ten patients with severe traumatic brain injury were studied. All patients received midazolam and vecuronium or pancuronium to control body temperature to 36.0°C. Energy expenditure was measured using indirect calorimetry. Age, body height, body weight, heart rate, blood pressure, body temperature, and minute ventilation volume were evaluated at the time of the study. Differences between the mean measured energy expenditures (MEEs) and predicted basal energy expenditures (PEEs from the Harris-Benedict equation) were analyzed using paired t test. Furthermore, the relationships between these variables and MEEs were analyzed with multiple regression analysis.

Results

The result of MEE was 1279 ± 244 kcal/d. When compared with PEE, MEE/PEE was 87.2% ± 10%. Multiple regression analysis showed that age, body height, body weight, heart rate, and minute ventilation volume were related with MEE.

Conclusions

Energy expenditure in patients with severe traumatic brain injury who need mechanical ventilation and have received controlled normothermia with sedation and neuromuscular blockade was 13% less than predicted basal levels. Energy expenditure might be obtained from age, body height, body weight, heart rate, and minute ventilation.     

Metabolic predictors of obesity. Contribution of resting energy expenditure, thermic effect of food, and fuel utilization to four-year weight gain of post-obese and never-obese women.

This prospective study was designed to identify abnormalities of energy expenditure and fuel utilization which distinguish post-obese women from never-obese controls. 24 moderately obese, postmenopausal, nondiabetic women with a familial predisposition to obesity underwent assessments of body composition, fasting and postprandial energy expenditure, and fuel utilization in the obese state and after weight loss (mean 12.9 kg) to a post-obese, normal-weight state. The post-obese women were compared with 24 never-obese women of comparable age and body composition. Four years later, without intervention, body weight was reassessed in both groups. Results indicated that all parameters measured in the post-obese women were similar to the never-obese controls: mean resting energy expenditure, thermic effect of food, and fasting and postprandial substrate oxidation and insulin-glucose patterns. Four years later, post-obese women regained a mean of 10.9 kg while control subjects remained lean (mean gain 1.7 kg) (P < 0.001 between groups). Neither energy expenditure nor fuel oxidation correlated with 4-yr weight changes, whereas self-reported physical inactivity was associated with greater weight regain. The data suggest that weight gain in obesity-prone women may be due to maladaptive responses to the environment, such as physical inactivity or excess energy intake, rather than to reduced energy requirements.