Outpatient intravenous multimodal elastomeric pump with methadone in ambulatory surgery

Analgesia in Ambulatory Surgery (AS) needs to evolve in parallel with surgical complexity. We designed a study to try to improve analgesia in painful surgery using an intravenous elastomeric pump. As a novelty, methadone was included.

An observational study, physical status ASA I-II, underwent ambulatory surgeries with moderate-severe postoperative pain. Analgesia was administered for 48h by an intravenous multimodal elastomeric pump (methadone, tramadol, dexketoprofen and ondansetron at low doses). Visual Analogue Scale (VAS) at rest and movement were evaluated at 24 and 48h. Andersen Scale, Lattinen Test, rescue analgesia and side-effects were recorded at 24h after surgery.

We included 73 patients: 37% abdominal wall surgery, 30% hemorrhoidectomies and 33% perineal surgery. Median VAS score at rest and movement were 0 and 3 at 24h, and 0 and 2 at 48h. At 24h, Andersen's Scale score was ≤1 in 89%, and Lattinen Test ≤6 in 90% of patients. Rescue medication was administered in 30% of patients. Two patients had vomiting at 24 and 48h. Minor catheter and pump dysfunctions were observed in 8% of patients.

Multimodal analgesia with intravenous methadone administered by elastomeric perfusion at home is effective and safe. However, monitoring is needed to diagnosis dysfunction of devices.