Severe alcohol withdrawal syndrome (AWS) and alcohol withdrawal delirium (AWD) are frequent principal indication/s for admission to intensive care units. Additionally, unanticipated alcohol withdrawal complicates other critical illnesses and peri-operative states. Alcohol intoxication and withdrawal syndrome are characterized by classic symptoms of adrenergic activation, psychiatric agitation including seizures, as well as metabolic and respiratory dysfunction. The majority of patients with severe AWS are effectively managed with combinations of benzodiazepine (BZD) sedatives (e.g. lorazepam) and butyrophenone antipsychotics (e.g. haloperidol) and require intensive care admission for 2-3 days. However, almost 25% of patients with SAWS have a prolonged critical care course, often complicated by respiratory failure and associated with excessive sedation and risk for complications such as ventilator-associated pneumonia (VAP). AWS is frequently difficult to manage with usual care including benzodiazepines. Additionally, while intermittent bolus dose sedation is recommended for AWS, high dose BZD alone is associated with excessive respiratory suppression and metabolic acidosis. Such therapy increases the likelihood of respiratory failure with its attendant complications of hospital acquired pneumonia and sepsis. Further, patients with underlying chronic liver disease are at greater risk for prolonged sedative effects of BZD and progression of hepatic encephalopathy. The requirement for mechanical ventilation additionally prolongs the course of treatment for AWD because of the need for prolonged sedation. Strategies to control AWS/AWD that control symptoms but avoid adverse effects of excessive respiratory suppression are anticipated to improve the short and medium-term outcomes of AWS.
BZD infusions have also been shown by several investigators to result in excessive and prolonged sedation. However, reasonable alternatives for effective control of psychomotor and adrenergic activation have until recently, been unavailable. The centrally acting alpha-2 receptor agonist, clonidine has been suggested as a useful adjunctive therapy to BZD. However, clonidine is only a mild sedative and can result in significant hemodynamic compromise. By contrast, dexmedetomidine (Precedex), a more potent alpha-2 receptor agonist, is potentially a more effective adjunctive therapy. Precedex is currently marketed in the USA for short-term use as a potent peri-operative sedative and analgesic. This agent has a short circulating half-life and has significantly fewer hemodynamic side effects than clonidine. In addition to its cardiovascular properties, dexmedetomidine possesses anxiolytic, hypnotic/sedative, anesthetic-sparing and analgesic actions and is devoid of significant respiratory depressant effects.
Precedex has been shown to be a safe and effective single agent sedative for critically ill medical and surgical patients in prolonged infusions up to thirty days and is associated with significantly lower incidence of delirium than sedation with the benzodiazepine, midazolam. Preclinical experience and case reports suggest anecdotally Precedex may be of particular benefit in patients with SAWS.
Measures of sedation and delirium will be assessed with the Minnesota Detoxification Scale (MINDS) derived for use in critically ill adults from the validated Clinical Institute Withdrawal Assessment (CIWA-r) scale.
