Intravenous Ketamine Infusion for Managing Chronic Postoperative Pain After Inguinal Herniorrhaphy: A Case Report

Chronic postsurgical pain (CPSP) is a debilitating condition that affects up to 50% of patients after procedures like inguinal herniorrhaphy, significantly impairing quality of life. This case report describes a 63-year-old male who experienced refractory CPSP for 5 years following inguinal hernia repair. The patient reported persistent pain despite multiple pharmacological treatments, including amitriptyline, gabapentin, and codeine, as well as nerve blocks and nonpharmacological interventions like acupuncture. Periodic intravenous ketamine infusions (30 mg every 30 days) were introduced, resulting in substantial pain relief, improved mobility, and enhanced functionality. Ketamine, a noncompetitive NMDA receptor antagonist, has shown promise in modulating central sensitization in chronic pain, with minimal adverse effects at low doses. This case aligns with the 2018 consensus guidelines on ketamine use in chronic pain and contributes to the growing body of evidence supporting its efficacy in CPSP management. While this therapy demonstrated remarkable clinical benefits, further research is essential to establish optimal protocols and long-term outcomes for ketamine use in chronic postoperative pain.