Article Text
Abstract
Background and aims Opioids are frequently used for intra- and postoperative analgesia, and often unavoidable for major surgery. However, side effects of systemic opioids, including postoperative nausea/vomiting, postoperative hyperalgesia, neurologic and cardiorespiratory depression, and an association with tumor angiogenesis and recurrence are major concerns, especially for craniotomy for brain tumor resection.
Methods Post-craniotomy pain is generally described to be of moderate to severe intensity, but an anaesthetic technique relying primarily on regional scalp block and dexmedetomidine infusion is proposed as a means to obviate the use of opioids.
Results A 50-year-old ASA 2 patient underwent left craniotomy and excision of sphenoid-wing meningioma under general anaesthesia. Intra-operative monitoring instituted included ECG, SpO2, invasive arterial BP, ETCO2, bispectral index, rectal temperature and urine output. After a loading dose of IV 75 µg (equivalent to 1 µg/kg) dexmedetomidine over 10 min, induction and maintenance of anaesthesia was conducted with propofol TCI (effect-site, Schnider model). A selective left-sided scalp block using landmark technique with 12 ml 0.5% bupivacaine was performed. Intra-operative analgesia was afforded by IV dexmedetomidine infusion (0.2–0.7 µg/kg/hr) totalling 206 µg, IV magnesium sulphate 20mmol, IV paracetamol 1 g and the scalp block. Postoperatively, she spent one day in the ICU, requiring two doses of IV 1 g paracetamol before transfer to the general ward, where she required two doses of PO 1 g paracetamol. She required no further analgesia (including no opioid medications) during her 6 day hospitalization and was discharged well.
Conclusions Opioid-free anaesthesia is an appealing concept, and non-opioid analgesic adjuncts including dexmedetomidine in conjunction with scalp regional block may sufficiently achieve that.