Short summary

A single dose of methadone reduces postoperative pain and opioid consumption. However, the safety of using methadone for elderly and fragile patients is unknown. We wish to determine the maximal tolerable dose of methadone in elderly hip fracture patients by testing 3 doses: 0.10 mg/kg, 0.15 mg/kg, or 0.20 mg/kg of methadone administered intravenously at the beginning of surgery. Patients will only receive one dose and then they will be monitored for 3 days postoperatively.

Rationale

Danish hospitals encounter 140 hip fracture patients per 100.000 inhabitants per year. That is roughly 8000 fractures every year. The median age is 81 which means that the fragile and elderly are greatly affected. They all require surgical interventions within 24 hours and are associated with significant pain even at rest. Postoperative pain is insufficiently treated in more than half of patients which increases the risk of chronic pain, delays discharge and prevents early mobilization and rehabilitation. Furthermore, it increases morbidity and increases the risk of delirium in elderly patients.

Numerous studies suggest, that a single dose of Methadone given during the surgery significantly ameliorates postoperative pain and reduces postoperative opioid consumption. However, it is not routinely used in the elderly and fragile and there is insufficient reliable evidence on the subject. Further investigation of the beneficial effects of perioperative Methadone and general improvement of postoperative analgesic treatment are consequently highly relevant and necessary.

In most studies Methadone is given perioperatively in dosages of 0.10-0.30 mg/kg and is commenced at the induction of anesthesia or the initiation of surgery. However, these doses have not been tested in an acute setting or on the elderly and fragile patients. Consequently we investigate the safety of three doses: 0.10 mg/kg, 0.15 mg/kg, or 0.20 mg/kg of methadone administered intravenously at the beginning of surgery.

The aim of the study is to determine the optimal dose of Methadone for a future randomized controlled trial (RCT).

Description of the cohort

Patients diagnosed with a hip fracture on x-rays in the emergency department at Sygehus Sønderjylland (collum femoris fractures, pertrochanteric fractures and subtrocantheric fractures). Patients must be ≥ 60 years.

Data and biological material

Primary outcome is the occurence of respiratory depression. Secondary outcomes include time spent in post-anesthesia care unit (PACU), verbal rating pain score, opioid consumption, and nausea/vomiting. An observation chart will be completed by nursing staff at 6, 24 and 72 hours postoperatively.