Tramadol overdose in total knee arthroplasty: A case report.

Background: Tramadol is a synthetic opioid analgesic commonly employed in postoperative pain control due to its moderate efficacy and comparatively favorable safety profile. Nonetheless, overdose can result in significant adverse effects, notably central nervous system depression. This risk is amplified in individuals with chronic kidney disease (CKD), where reduced renal clearance may potentiate drug accumulation and toxicity. Elderly patients are particularly at risk owing to age-associated alterations in pharmacokinetics and pharmacodynamics. We describe a case of tramadol overdose in a 77-year-old male with stage 3 CKD following total knee arthroplasty.

Case summary: A 77-year-old male with diabetes mellitus and CKD stage 3 underwent elective right total knee arthroplasty for grade 4 osteoarthritis under spinal anesthesia. Preoperative evaluation revealed deranged renal function tests but no other significant abnormalities. Postoperative pain was managed with multimodal analgesics, including intravenous tramadol and a buprenorphine skin patch. On postoperative third day, the patient was found unconscious (Glasgow Coma Scale 8/15) with mild respiratory depression. Investigations ruled out stroke, pulmonary embolism, or other cardiopulmonary events. Elevated serum tramadol levels suggested opioid toxicity exacerbated by impaired renal clearance. The buprenorphine patch was removed, and diuresis was initiated. Supportive management, including prophylactic intubation, led to recovery of consciousness within 48 hours, and the patient was extubated and mobilized by postoperative sixth day. Pain control was maintained with oral paracetamol and pregabalin. The patient was discharged on postoperative tenth day in stable condition with improved pain scores and mobility. This case underscores the need for cautious use of tramadol in elderly patients with CKD due to impaired drug clearance and the potential for toxicity. It highlights the importance of close monitoring, judicious analgesic use, and prompt management of complications to ensure favorable postoperative outcomes in high-risk populations.

Conclusion: This case underscores the necessity for judicious tramadol administration in elderly patients with CKD, as diminished renal function markedly impairs drug clearance, predisposing to toxicity. Vigilant assessment of renal function and individualized dose adjustments are essential to mitigate the risk of adverse events in this demographic. Clinicians should maintain a heightened awareness of potential opioid toxicity in postoperative patients presenting with unexplained neurological manifestations. Timely identification and initiation of appropriate supportive measures are pivotal in achieving favorable clinical outcomes.