Yoeri Bemelmans

Postoperative urinary retention after hip and knee arthroplasty 63 5 general anesthesia with intravenous fluid restriction (max. 1000 ml). Local infiltration analgesia (LIA) was used intraoperative in knee arthroplasty [24]. In order to prevent PONV, intravenous dexamethasone (single shot, 8 mg) was administrated during the surgery. Oral tranexamic acid (1 g if weight <100 kg, 1.5 g if weight >100 kg) was provided preoperatively. At wound closure, the same doseswere given intravenous for prevention of blood loss. Nowound drains were used. An opioid-sparing pain protocol was provided (Table 1). In case of inadequate pain control, tramadol was used with a maximum of two times 50mg per day, and occasional oxycodone was usedwhen the patient experienced side effects from tramadol. After surgery, patients were observed in the recovery room until their cardiorespiratory status was stable and pain control was adequate before transferring them to the orthopedic ward. Directly postoperative at the recovery room and every 3 h at the orthopedic ward, bladder volume was monitored until spontaneous voiding (Fig. 2). If the bladder volume exceeded more than 600 ml, with the inability to void spontaneously, catheterization was performedwith an indwelling catheter to copewith a possible overdistension of the bladder [23]. In case of catheterization, the catheter was removed the next day. If the patient was able to void spontaneously, with a bladder volume <100 ml, monitoring was discontinued. Within 6 h postoperative, the patient was mobilized under supervision of a physiotherapist after recovery from anesthesia. After the first mobilization, patients were transferred to the restroom under guidance of a nurse in case of urge to void. Patients were discharged from the hospital if they met the discharge criteria: overall general well-being, spontaneous voiding with bladder volume <100 ml, a dry wound, adequate pain control, individual and safe mobilization with transfer into and out of bed and chair, walk independently with a walking aid, and if necessary walking stairs with crutches. Outcome The primary outcome of this study was the incidence of POUR defined as the inability to void spontaneously with a bladder volume >600 ml, detected with a bladder scan, requiring indwelling catheterization. Secondary, to detect potential risk factors: gender, age, body mass index (BMI), ASA classification, preoperative bladder volume, type of anesthesia, type of arthroplasty, perioperative fluid administration, and bladder volume at the recovery roomwere analysed between POUR and non-POUR patients. All outcomeswere recorded in the patients’ digital clinical record. This studywas performed in compliance with the Declaration of Helsinki 1975, as revised in 2000, and the study was approved by the IRB (METC Zuyderland, Heerlen, the Netherlands, IRB Nr. 15-N- 136) and conducted in accordance with the guidelines for Good Clinical Practice (GCP).