Management of acute postoperative pain (APP) in patients in therapy for opioid use disorder (OUD), may be difficult due to increased pain sensitivity and opioid tolerance and considering the fear from clinicians, that the use of an opioid during an episode of acute pain could trigger a relapse OUD. Spine surgery is burdened with a significant APP and a long recovery period. Therefore, a multimodal analgesia is desirable in this scenario.

Case presentation

A fifty-four-year-old man of 72 kg with HIV and HCV infection and history of OUD in treatment with methadone 20 mg po qid, underwent total discectomy with vertebral stabilization at L4-L5. The first daily dose of methadone was administered as usual. Prior to the induction of general anesthesia, a 12.5 MHz line probe and a 22-gauge 10 cm needle, ESPB was performed bilaterally at level L3-L4, with cranio-caudal injection of ropivacaine 50mg and dexamethasone 2 mg in a volume of 20 ml per side. After induction with Propofol 2 mg/kg and fentanyl 100 mcg, intraoperative maintenance was guaranteed with desflurane and continuous infusion of ketamine 0,2 mcg/kg/min. Paracetamol 1000mg was administered 30 minutes before the end.  After estubation, the patient was transferred to the recovery room with ongoing ketamine infusion and prescription of Paracetamol 1000 mg tid. If NRS > 6, morphine could be used as rescue therapy for the next 2 days. Multiparametric monitoring was conducted. After 2 hours ketamine was interrupted and the patient was transferred to the ward. Methadone resumed 6 hours after the end of the operation, with no use of morphine. No symptoms of withdrawal or insufficient pain control, no psychomimetic adverse events were observed until patient’s discharge from hospital.

Conclusion

Multimodal analgesia can lead to optimal APP management in patients with clinical characteristics that make opioid-based approaches such as those with OUD, difficult to apply.