Abstract
We carried out a comparison of the analgesic requirements, length of stay in hospital, complications and cost effectiveness of patients who had either a continuous disposable infusion pump or standard treatment for unicompartmental knee replacement.
This study began as an audit. We completed the audit loop with a prospective study after implementing our recommendations. The device is a single use disposable elastometric pump, set immediately after surgery to deliver a continuous flow of 0.5% bupivacaine at a rate of 2mls per hour for 48 hrs into the knee joint via a fine catheter with a fenestrated tip.
The case notes of all patients in the study were analysed to establish their total analgesic requirements for 48hrs following surgery. Complications and length of stay in hospital were recorded This has changed our clinical practice. Results of our study of 50 patients, 25 in each group (age and sex matched) confirmed that there was a significant reduction in opiate requirements after introduction of the pain pump. Length of stay in hospital was reduced from 5.7 to 3.9 days. Patients' requirements for NSAIDs were reduced. There were no significant complications in the pain pump group. The costs of the pump (£40) were offset by the reduction in analgesic requirements and shortened length of stay in hospital.
We conclude this form of analgesia is safe, effective and cost effective. Our department has now changed to using the pump for all unicompartmental knee replacements.
