Dexmedetomidine for peri‐operative sedation and analgesia in alcohol addiction

I report on the use of dexmedetomidine for peri-operative analgesia and sedation prophylaxis of alcohol withdrawal syndrome in two alcoholic patients. A 60-year-old man presented for laparoscopic nephrectomy. His medical history included hypertension, anxiety neurosis, emphysema, smoking and alcoholism. He was anxious, with a heart rate of 107 beats.min−1 and blood pressure of 159/97 mmHg. Intravenous dexmedetomidine infusion was commenced with a loading dose of 1 μg.kg−1 over 15 min, followed by a continuous infusion of 0.5–0.7 μg.kg−1.h−1. He was adequately sedated, and maintained verbal communication. Anaesthesia was induced with fentanyl 100 μg and propofol 200 mg, and maintained using isoflurane and dexmedetomidine infusion, with vecuronium for muscle paralysis. At completion of surgery, the isoflurane was stopped and residual neuromuscular blockade reversed. With the patient obeying commands and breathing adequately, the dexmedetomidine was discontinued and he was extubated. The intra-operative course and emergence were smooth. Postoperatively, he remained sedated and comfortable, with a pain score of 0/10 in the first hour and 3/10 in the second hour before discharge from the recovery unit. No opioid analgesic was administered after induction. A 29-year-old man presented for laparoscopic inguinal herniorrhaphy. His medical history included depression, panic attacks and alcoholism. His heart rate was 99 beats.min−1 and blood pressure was 140/90 mmHg. Intravenous dexmedetomidine infusion was commenced using the same regimen as in the first case. He was adequately sedated, but easily rousable. Anaesthesia was induced with propofol 200 mg, and maintained using isoflurane and dexmedetomidine infusion, with atracurium for muscle paralysis. On completion of surgery, the isoflurane was stopped and residual neuromuscular blockade was reversed. With adequate respiration and response, the dexmedetomidine was stopped and the patient extubated. The intra-operative course and emergence were smooth. Postoperatively, he remained calm and comfortable, with a pain score of 0/10 in the first hour and 4/10 in the second hour before discharge from the recovery unit. Again, no opioid analgesic was administered peri-operatively. The peri-operative risks of alcohol addiction and intoxication may be significant [1]. Anxiety and pain can precipitate alcohol ideation, withdrawal syndrome and addiction relapse [2-4]. Adequate premedication and analgesia is paramount. However, administration of sedatives and analgesics must be judicious to minimise the risk of abnormal pharmacodynamics, cross-addiction and addiction relapse [5]. Anxiolytics administered peri-operatively include benzodiazepines and opioids. However, there are anecdotal reports of alcohol craving following administration of these medications to rehabilitated alcoholics [2, 3]. This may be a cross-addiction, and some patients are afraid of the abuse potential of premedication [5]. Opioid antagonists such as naltrexone reduce alcohol ideation, but also increase analgesia requirement [6]. Anticonvulsants can minimise alcohol-mediated neuronal hyperexcitability, but they reduce the efficacy of non-depolarising neuromuscular blockers. Alpha-2 adrenoceptor agonists have sedative, amnesic and analgesic properties. They are not addictive and do not play any role in cross-addiction. Clonidine is the prototypical alpha-2 agonist and has been investigated for the prophylaxis of peri-operative alcohol withdrawal syndrome [7]. Dexmedetomidine is a newer alpha-2 agonist with a short half-life of 2.3 h and 10 times the potency of clonidine. The high potency of dexmedetomidine implies that it is a full agonist at alpha-2 adrenoceptors, and can be administered at relatively high doses for sedation and analgesia without cardiovascular and respiratory depression. Dexmedetomidine provided adequate pre-operative and postoperative sedation for the two alcohol-dependent patients described. Both patients were calm and pleased. The drug also provided good intra-operative analgesia. The patients did not require intra-operative opioids, and were comfortable postoperatively. Although dexmedetomidine is only licensed for ICU sedation, it is used peri-operatively for its analgesic effect [8]. In conclusion, dexmedetomidine provides good peri-operative sedation and analgesia in alcoholics, and offers a better approach than the use of benzodiazepines, opioids or anticonvulsants.