A phase II study to evaluate the efficacy of dexmedetomidine for sedation in the medical intensive care unit.
OBJECTIVE
To evaluate dexmedetomidine for sedation of patients in the medical ICU.


METHODS
Prospective observational study in an intensive care unit of a university hospital. PATIENTS. Twelve ventilated patients with median APACHE II score 23 (range 10-26).


METHODS
Patients received a loading dexmedetomidine infusion of 1 microg x kg(-1) over 10 min followed by a maintenance infusion rate of 0.2-0.7 microg x kg(-1) x h(-1) for up to 7 days. After experience with the first four patients this maintenance rate of infusion was increased to a maximum of 2.5 microg kg(-1) x h(-1). If required, propofol and morphine provided rescue sedation and analgesia, respectively.


RESULTS
The first four patients with dexmedetomidine infusion at 0.7 microg x kg(-1) x h(-1)all required rescue sedation with a propofol infusion. A protocol amendment allowed the next eight patients to receive higher dexmedetomidine infusions (mean 1.0+/- microg x kg(-1) x h(-1)). Five of the next eight patients did not required propofol, and two patients only required minimal propofol infusions (20-40 mg x h(-1)). A further patient, with hepatic encephalopathy, required a propofol at 50-100 mg x h(-1). Only modest falls in arterial pressure, heart rate and cardiac output were seen, and no rebound sequelae occurred on discontinuation of dexmedetomidine. Adverse cardiovascular events were nearly all confined to the initial loading dose period of dexmedetomidine.


CONCLUSIONS
Sedation with dexmedetomidine is efficacious in critically ill medical patients requiring mechanical ventilation in the intensive care unit. A reduction in loading infusion is advised, but higher maintenance infusions may be required to that seen previously in the postoperative ICU patient.
Venn
M
M
Department of Anaesthesia and Intensive Care, Worthing Hospital, Lyndhurst Road, Worthing, West Sussex BN11 2DH, UK, richard@svenn.freeserve.co.uk
Newman
J
J
Grounds
M
M
D018806:APACHE; D000316:Adrenergic alpha-Agonists / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018712:Analgesics, Non-Narcotic / Q000009:adverse effects / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D002496:Central Venous Pressure / Q000187:drug effects; D016292:Procedural Sedation / Q000009:adverse effects / Q000379:methods*; D003422:Critical Care / Q000379:methods*; D020927:Dexmedetomidine / Q000009:adverse effects / Q000627:therapeutic use*; D016903:Drug Monitoring; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000009:adverse effects / Q000627:therapeutic use*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012121:Respiration, Artificial / Q000009:adverse effects; D012449:Safety; D013997:Time Factors; D016896:Treatment Outcome
D000316:Adrenergic alpha-Agonists; D018712:Analgesics, Non-Narcotic; D006993:Hypnotics and Sedatives; D020927:Dexmedetomidine