Abstract
Background
Arthroplasty requires an interdisciplinary multimodal approach with anaesthetists playing a key role; providing stable intra-operative conditions, allowing rapid patient recovery, optimising analgeisa and minimizing side-effects. The incidence of post-operative urinary retention (POUR) varies significantly in joint arthroplasty (10–84%). Current literature quotes lower doses of opioids have been shown to reduce POUR, however studies consistently show spinal opioids influence bladder function causing urinary retention. Existing literature fails to comment upon the rate of POUR following joint arthroplasty comparing intrathecal diamorphine against intrathecal local anaesthetic (ITLA) within a modern fast track arthroplasty system (FTA).
Methods
A two-year (2009–11) retrospective analysis was conducted encompassing a multi-surgeon duel-centre review. Rates of POUR were compared when utilising ITLA and multimodal analgesia including local anaesthetic infiltration (LIA) (site A) against ITLA in combination with intrathecal diamorphine (site B) for joint arthroplasty under spinal analgesia. Outcomes were analysed using 30-day POUR rates coding data and cross-referenced against patient records. Information was collected on patient co-morbidity, age, gender, surgery duration and renal function. Patients were excluded for previous POUR, prostate pathology, postoperative PCA, and conversion to general anaesthetic.
Results
2343 patients underwent joint arthroplasty within this period. At Site A 12 episodes of POUR were identified, whilst 71 were identified at site B. After exclusions, 56 cases underwent analysis. All had a clinical and radiological diagnosis of POUR. The study participants' mean age was 71 years, BMI 27.9 (range 20–47) and 96% were male. Patients across both sites had comparable co-morbidities. All patients at site B had intrathecal morphine with 96% having 3 micrograms of diamorphine. 30-day POUR rates at Site A (ITLA and LAI) were 1.2% and Site B (ITLA and intrathecal morphine) 5.4% (p=0.0001).
Conclusion
The absence of intrathecal diamorphine in spinal anaesthesia significantly reduces the rates of POUR in patients undergoing joint arthroplasty.
