Quantitative analysis of the relationship between sedation and resting energy expenditure in postoperative patients.
OBJECTIVE
To analyze quantitatively the relationship between sedation and resting energy expenditure or oxygen consumption in postoperative patients.


METHODS
A prospective, clinical study.


METHODS
An eight-bed intensive care unit at a university hospital.


METHODS
Thirty-two postoperative patients undergoing either esophagectomy or surgery of malignant tumors of the head and neck who required mechanical ventilation and sedation for > or = 2 days postoperatively.


METHODS
None.


RESULTS
A total of 133 metabolic measurements were performed. Ramsay sedation scale (RSS), body temperature, and the dose of midazolam were evaluated at the time of the metabolic cart study. All patients received analgesia with buprenorphine at a fixed dose of 0.625 microg x kg(-1) x hr(-1) continuously. Midazolam was used for induction and maintenance of intravenous sedation after admission to the intensive care unit. The initial dose was 0.04 mg x kg(-1) x hr(-1) and was adjusted to achieve a desired depth of sedation at 3, 4, or 5 on the RSS every 4 hrs. The degree of sedation was classified into three states: light sedation (RSS 2-3; n = 49), moderate sedation (RSS 4; n = 39), and heavy sedation (RSS 5-6; n = 45).


RESULTS
With increasing the depth of sedation, oxygen consumption index (mL x min(-1) x m(-2)), resting energy expenditure index (REEI; kcal x day(-1) x m(-2)), and REE/basal energy expenditure (BEE) decreased significantly. Oxygen consumption index (mean +/- SD), REEI, and REE/BEE were 151 +/- 18, 1032 +/- 120, and 1.29 +/- 0.17 in the light sedation, 139 +/- 22, 947 +/- 143, and 1.20 +/- 0.16 in the moderate sedation, and 125 +/- 16, 865 +/- 105, and 1.13 +/- 0.12 in the heavy sedation, respectively.


CONCLUSIONS
An increase in the depth of sedation progressively decreases in oxygen consumption index and REEI in postoperative patients.
Terao
Yoshiaki
Y
Department of Anesthesiology, Nagasaki University School of Medicine, Japan. eisuketerao@aol.com
Miura
Kosuke
K
Saito
Masataka
M
Sekino
Motohiro
M
Fukusaki
Makoto
M
Sumikawa
Koji
K
D000328:Adult; D000367:Age Factors; D000368:Aged; D001481:Basal Metabolism; D001827:Body Height; D001835:Body Weight; D001944:Breath Tests / Q000379:methods; D002153:Calorimetry, Indirect / Q000379:methods* / Q000592:standards; D002245:Carbon Dioxide / Q000032:analysis; D016292:Procedural Sedation / Q000145:classification* / Q000379:methods; D016903:Drug Monitoring / Q000379:methods* / Q000592:standards; D004734:Energy Metabolism / Q000187:drug effects*; D016629:Esophagectomy; D005260:Female; D006258:Head and Neck Neoplasms / Q000601:surgery; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D008874:Midazolam / Q000627:therapeutic use; D008875:Middle Aged; D010101:Oxygen Consumption / Q000187:drug effects; D011184:Postoperative Period; D011446:Prospective Studies; D012121:Respiration, Artificial; D012146:Rest; D013997:Time Factors
D006993:Hypnotics and Sedatives; D002245:Carbon Dioxide; D008874:Midazolam