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Study Objective: To determine the relationship between bispectral index (BIS) and sedation., Design: Prospective, observational clinical study., Setting: Intensive care unit of a public hospital in Japan., Patients: 22 ASA physical status I, II, and III middle-aged (18-65 yrs) and elderly (>65 yrs) patients receiving postoperative sedation with midazolam., Interventions: Patients were allocated to two groups: Group M was composed of middle-aged patients (<65 yrs) and Group H elderly patients (>65 yrs). Midazolam was administered at a bolus dose of 0.1 mg/kg, followed by a continuous dose of 0.04 mg/kg per hour, which was adjusted every two hours to achieve a target level of sedation at 3-6 on the Ramsay Sedation Scale (RSS); buprenorphine was administered at a constant rate (0.625 microg kg(-1) hr(-1))., Measurements: BIS value, RSS, midazolam dose, body temperature (BT), heart rate, dopamine dose, and mean arterial pressure were recorded every two hours by an independent nurse. Data were analyzed using Spearman rank correlation and the Mann-Whitney U test., Main Results: BIS values decreased depending on depth of sedation; a significant correlation was noted between groups in RSS and BIS. The BIS values at levels of RSS 5 and 6 were significantly lower in Group H than Group M., Conclusion: BIS correlated with sedation depth, with BIS scores in group H than group M at a deep sedation depth.

Background: The change of oxygen consumption after withdrawal of sedation is controversial. We evaluated the changes of sedation depth, oxygen consumption and hemodynamics after withdrawal of midazolam sedation in the patients undergoing major abdominal surgery., Methods: We evaluated 18 patients after major abdominal surgery. Midazolam was used for intravenous sedation after admission to the ICU. Midazolam was administered at a bolus dose of 0.1 mg kg(-1), followed by continuous infusion at 0.04 mg kg(-1) hr(-1), which was adjusted every 2 hrs to achieve a desired level of sedation of 4 on Ramsay sedation scale (RSS). After about 14 hours of sedation, we stopped the infusion of midazolam. From that time, we measured systolic and mean arterial pressure, heart rate, minute volume and oxygen consumption, and evaluated RSS every 5 minutes for 1 hour. We evaluated RSS as sedation depth, oxygen consumption index (V(O2)I) and rate pressure product (RPP=systolic arterial pressure x heart rate) as hemodynamic parameters., Results: RSS significantly decreased gradually, but the other parameters including V(O2)I and RPP were unchanged., Conclusions: After withdrawal of midazolam sedation in the patients undergoing major abdominal surgery, the sedation depth became lighter, but V(O2)I and RPP were unchanged.

Unlabelled: Acute withdrawal syndromes, including agitation and a long weaning time, are common adverse effects after long-term sedation with midazolam. We performed this study to determine whether the sequential use of midazolam and propofol could reduce adverse effects as compared with midazolam alone. We studied 26 patients receiving mechanical ventilation for three or more days after surgery. Patients were randomly assigned to two groups. In Group M, patients were sedated with midazolam alone. In Group M-P, midazolam was switched to propofol approximately 24 h before the expected stopping of sedation. The level of sedation was maintained at 4 or 5 on the Ramsay sedation scale. The sedation agitation scale was evaluated for 24 h after extubation. The recovery time from stopping of sedation to extubation was significantly shorter in Group M-P (1.3 +/- 0.4 h) compared with Group M (4.0 +/- 2.4 h). The incidence of agitation in Group M-P (8%) was significantly less frequent than that in Group M (54%). The results indicate that sequential use of midazolam and propofol for long-term sedation could reduce the incidence of agitation compared with midazolam alone., Implications: Our study indicates that sequential use of midazolam and propofol could reduce the incidence of agitation compared with midazolam alone.

Objective: To analyze quantitatively the relationship between sedation and resting energy expenditure or oxygen consumption in postoperative patients., Design: A prospective, clinical study., Setting: An eight-bed intensive care unit at a university hospital., Patients: 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., Interventions: None., Measurements and Main 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., Conclusion: An increase in the depth of sedation progressively decreases in oxygen consumption index and REEI in postoperative patients.

Purpose: Patients undergoing extensive cervical spine surgery (ECSS) occasionally require emergency reintubation due to postoperative airway complications. To avoid it, an endotracheal tube is retained in patients maintained under sedation overnight. This study was conducted to determine whether dexmedetomidine would be superior in sedative effects to propofol for postoperative sedation after ECSS. Methods: We studied 32 consecutive patients undergoing ECSS who required prophylactic intubation postoperatively under sedation overnight. The patients were randomly divided into two groups. Group D ( n = 16) received dexmedetomidine 0.1 μg/kg/min for 10 min as a loading dose, followed by a continuous infusion at 0.4 μg/kg/h. Group P ( n = 16) received propofol 0.1 mg/kg/min for 10 min as a loading dose, followed by a continuous infusion at 1 mg/kg/h. All patients received analgesia with buprenorphine. Ramsay sedation scale, extremity movement, and pain intensity were recorded every 2 h. Dexmedetomidine and propofol dosages were adjusted to maintain a desired sedation level. Nursing staff adjusted dopamine to maintain systolic blood pressure >100 mmHg and administered atropine when the heart rate was <50 bpm. Results: The proportions of adequate sedation level, movement, and pain status were similar between groups. In group D, heart rates were lower, frequency of atropine use was greater, and dopamine dose was higher than in group P. Conclusion: Both sedatives are efficacious after ECSS; however, dexmedetomidine decreased heart rate and required higher dose of dopamine. [ABSTRACT FROM AUTHOR]