Resting energy expenditure in brain death

Abstract

In brain dead patients, REE decreases to values lower than BMR. This can be attributed to the cessation of cerebral blood flow and consequently cerebral metabolism and not to hypothermia.

Hypermetabolism following Moderate to Severe Traumatic Acute Brain Injury: A Systematic Review

“…From this pool of 56 articles, 32 were excluded (Table 2). Following final review, 24 articles remained which comprised the final sample (Bitzani et al, 1999;Borzotta et al, 1994;Bruder et al, 1991Bruder et al, , 1994Bruder et al, , 1998Chiolero et al, 1989b;Clifton et al, 1984Clifton et al, , 1986Dempsey et al, 1985;Dickerson et al, 1990;Esper et al, 2006;Hadfield et al, 1992;Haider et al, 1975;Kolpek et al, 1989;McCall et al, 2003;Moore et al, 1989;Ott et al, 1994;Petersen et al, 1993;Raurich and Ibanez, 1994;Robertson et al, 1984Robertson et al, , 1985Weekes and Elia, 1996;Young et al, 1985Young et al, , 1996.…”

“…The mean ages of patients enrolled in all studies ranged from 21 (Bruder et al, 1991;Moore et al, 1989) to 47 (Bitzani et al, 1999) years. Eight trials included a proportion of subjects (up to 40%) who were less than 18 years (Clifton et al, , 1986Dempsey et al, 1985;Dickerson et al, 1990;Haider et al, 1975;Moore et al, 1989;Robertson et al, 1984).…”

“…Mean Glasgow Coma Scale (GCS) scores ranged from 4.8 (Dickerson et al, 1990) to 9 (Petersen et al, 1993) among the 18 trials where the value was reported or could be calculated. In four cases where a mean GCS score was not provided, scores ranged from 3 to 8 (Bitzani et al, 1999;Clifton et al, 1986), 4 to 7 , or were all below 7 (Robertson et al, 1985). The authors of one trial (Hadfield et al, 1992) reported that the Abbreviated Injury Scores for the head and neck were all either 4 or 5, indicating severe to critical injury (Baker et al, 1974).…”

“…The percentage of patients within individual trials suffering from extracranial injuries ranged from 21% to 100% (Petersen et al, 1993). Only one study included subjects suffering exclusively from isolated head injury (Bitzani et al, 1999). It was unclear whether subjects with extracranial injuries had been included in six trials (Clifton et al, 1986;Esper et al, 2006;Haider et al, 1975;Kolpek et al, 1989;Robertson et al, 1984Robertson et al, , 1985.…”

“…The authors of two studies stated that patients were not receiving neuromuscular blockade at the time of metabolic assessment (Haider et al, 1975;Young et al, 1985), and Chiolero et al (1989b) stated that measurements were taken during periods when there was no significant muscular activity. Twelve authors specified measurement of REE (Bitzani et al, 1999;Chiolero et al, 1989b;Clifton et al, 1984;Dempsey et al, 1985;Dickerson et al, 1990;McCall et al, 2003;Moore et al, 1989;Petersen et al, 1993;Raurich and Ibanez, 1994;Robertson et al, 1984Robertson et al, , 1985 or basal metabolic rate (Weekes and Elia, 1996), while the remainder simply stated that they had measured ''energy expenditure.'' The authors of most studies conducted metabolic measurements without feeding interruptions (Borzotta et al, 1994;Bruder et al, 1991;Clifton et al, 1984Clifton et al, , 1986Hadfield et al, 1992;Haider et al, 1975;Kolpek et al, 1989;McCall et al, 2003;Moore et al, 1989;Ott et al, 1994;Raurich and Ibanez, 1994;Robertson et al, 1984Robertson et al, , 1985Young et al, 1996), while patients in four trials were fasted prior to assessments (Chiolero et al, 1989b;Dickerson et al, 1990;Petersen et al, 1993;Weekes and Elia, 1996).…”