Biomed Res Int. 2015;2015:635737. doi: 10.1155/2015/635737. Epub 2015 Oct 19.
Dexmedetomidine is a highly selective α 2 agonist used as a sedative agent. It also provides anxiolysis and sympatholysis without significant respiratory compromise or delirium. We conducted a systematic review to examine whether sedation of patients in the intensive care unit (ICU) with dexmedetomidine was associated with a lower incidence of delirium as compared to other nondexmedetomidine sedation strategies. A search of PUBMED, EMBASE, and the Cochrane Database of Systematic Reviews yielded only three trials from 1966 through April 2015 that met our predefined inclusion criteria and assessed dexmedetomidine and outcomes of delirium as their primary endpoint. The studies varied in regard to population, comparator sedation regimen, delirium outcome measure, and dexmedetomidine dosing. All trials are limited by design issues that limit our ability definitively to conclude that dexmedetomidine prevents delirium. Evidence does suggest that dexmedetomidine may allow for avoidance of deep sedation and use of benzodiazepines, factors both observed to increase the risk for developing delirium. Our assessment of currently published literature highlights the need for ongoing research to better delineate the role of dexmedetomidine for delirium prevention.
BACKGROUND: Dexmedetomidine (DEX) is a centrally acting alpha-2-adrenoceptor agonist that has potential in the management of alcohol withdrawal syndrome (AWS) owing to its ability to produce arousable sedation and to inhibit the adrenergic system without respiratory depression. The objective of this randomized controlled study was to evaluate whether addition of DEX to benzodiazepine (BZD) therapy is effective and safe for AWS patients in the intensive care unit (ICU). METHODS: Eligible participants were randomly assigned to intervention (Group D; n = 36) or control (Group C; n = 36). In Group D, DEX infusion was started at a dose of 0.2-1.4 μg/kg/h and titrated to achieve the target sedation level (-2 to 0 on the Richmond Agitation Sedation Scale (RASS)) with symptom-triggered BZD (10 mg diazepam bolus) was used as needed. Patients in Group C received only symptom-triggered 10 mg boluses of diazepam. The primary efficacy outcomes were 24-h diazepam consumption and cumulative diazepam dose required over the course of the ICU stay; secondary outcomes included length of ICU stay, sedation and communication quality and haloperidol requirements. RESULTS: Median 24-h diazepam consumption during the study was significantly lower in Group D (20 vs. 40 mg, p < 0.001), as well as median cumulative diazepam dose during the ICU stay (60 vs. 90 mg, p < 0.001). The median percentage of time in the target sedation range was higher in Group D (median 90 % (90-95) vs. 64.5 % (60-72.5; p < 0.001). DEX infusion was also associated with better nurse-assessed patient communication (<0.001) and fewer patients requiring haloperidol treatment (2 vs. 10 p = 0.02). One patient in Group D and four in Group C were excluded owing to insufficient control of AWS symptoms and use of additional sedatives (p = 0.36). There were no severe adverse events in either group. Spontaneous breathing remained normal in all patients. Bradycardia was a common adverse event in Group D (10 vs. 2; p = 0.03). CONCLUSIONS: DEX significantly reduced diazepam requirements in ICU patients with AWS and decreased the number of patients who required haloperidol for severe agitation and hallucinations. DEX use was also associated with improvement in diverse aspects of sedation quality and the quality of patient communication.
BACKGROUND AND AIM: Sedation plays a pivotal role in the care of the critically ill patient. It is equally important to assess depth of sedation. The present study had been designed to compare dexmedetomidine and propofol for sedation in mechanically ventilated intensive care patients. It also intended to verify the clinical validity, reliability and applicability of objective assessment tool bispectral index (BIS) for monitoring sedationand observe for correlation with the commonly used subjective scale, Ramsay sedation score (RSS). MATERIALS AND METHODS: This prospective randomized study was carried out in 60 haemodynamically stable patients, aged between 18 to 80 years, requiring sedation and mechanical ventilation. These were divided equally into two groups. Group A received dexmedetomidine loading dose (1μg/kg) over 10 min followed by maintenance infusion of 0.5μg/kg/hr (0.2-0.7 μg/kg/hr). Group B received propofol loading dose (1mg/kg) over 5 min followed by infusion of 2mg/kg/hr (1-3mg/kg/hr). All patients received fentanyl 1 μg/kg prior to the study drugs. Vital parameters andsedation levels (using RSS and BIS) were monitored for the study period of 12 hours with level 4 or 5 of RSS as target for sedation. Ramsay score was compared with the average of BIS values. Statistical analysis was done using SPSS VERSION 17 software. RESULTS: The study revealed statistically significant lower heart rates during sedation in dexmedetomidine group whereas fall in mean arterial pressure (MAP) following loading dose in propofol group. Patients sedated with dexmedetomidine were easily arousable. Need for rescue drug for achieving the desired RSS as well as incidence of bradycardia was more in dexmedetomidine group than other. Good correlation exists between Ramsay score and BIS values. CONCLUSION: Dexmedetomidine reduces heart rate while propofol transiently affects MAP. However, adequate sedation is achieved with both the drugs. The data obtained from the study validate BIS monitoring for ICU sedation. KEYWORDS: Bispectral index (BIS); Dexmedetomidine; Propofol; Ramsay sedation score (RSS); Sedation in ICU