Yoeri Bemelmans

Postoperative urinary retention after hip and knee arthroplasty 67 5 the orthopaedic ward until spontaneous voiding. As far as we know, this is the first study showing that >200ml of bladder volume on the recovery room is a risk factor (OR 5.049) for POUR after hip or knee arthroplasty. Previously, Keita et al. [20] found >270 ml at the post anesthesia care unit as a predictive factor for POUR (OR 4.8), but these results were found after surgeries of different specialties (e.g., orthopedic, abdominal, urologic). Bladder volume monitoring should be performed directly postoperative to detect an early development of POUR [14]. For patients who exceed >200 ml of bladder volume at the recovery room, a more stringent follow-up, in terms of frequent bladder scan monitoring at the orthopaedic ward, should be considered. Treatment strategies in case of POUR (intermittent vs. indwelling catheterization) and duration of catheterization remain controversial [3]. Zhang et al. [29] found that indwelling catheterization was superior to intermittent catheterization in the prevention of POUR after the routine use of indwelling catheterization for all patients undergoing THA or TKA. They found comparable risk of urinary tract infection. The superior treatment of POUR, without the routine use of preoperative indwelling catheterization, remains questionable. In case of POUR and treatment with indwelling catheterization in the postoperative phase, the present study found no recurrent POUR as seen after intermittent catheterization [5, 6, 12]. Literature on anesthesia technique as a risk factor for POUR is divided. Several studies found that the use of spinal anesthesia increased the risk of POUR [5, 6, 15, 22], as other studies concluded that type of anesthesia did not influence the incidence of POUR [1, 21, 26]. Based on the negative influence on detrusor activity, which can lead to a subsequent atonic bladder, postoperative epidural anesthetics can increase POUR [2, 21]. Patient-controlled analgesia [15] and intrathecal morphine use [10, 11, 27, 28] were also found to be risk factors and should be avoided in the pain management to prevent for POUR. Higher amounts of perioperative fluid administration are related to increased risk of POUR [3, 13]. Unfortunately, a precise cutoff value is unknown. When using a restrictive protocol (max. 1000 ml), perioperative fluid administration did not increase the risk of POUR in the present study. Several studies reported male gender as a risk factor for POUR [1–3, 11, 13, 15, 21, 26]. Bjerregaard et al. [5] did not find gender to be a risk factor, but an increased International Prostate SymptomScore (IPSS) was related to POUR. In a retrospective analysis on 376 male THA patients, Hollman et al. [15] could not confirm these results since they found no relation between POUR and prostate pathology. Nevertheless, a high incidence (39.9%) of POUR after THA in men was reported [15]. This study has several limitations. Firstly, the presented study examined a general applicable protocol for hip and knee arthroplasty patients following a fast-track pathway, without consideration of the patients’ specific comorbidity (e.g., IPSS, urologic or renal comorbidities), which could have led to confounding results. Secondly, there is no consensus on cutoff value’s for bladder volume. Therefore, the presented incidence of POUR, when using a cutoff value of more than 600 ml, could be