Impact of Intrathecal Dexmedetomidine versus Intrathecal Fentanyl as Adjuvants to Bupivacaine on Post Spinal Urinary Retention in Knee Joint Arthroscopic Surgeries

Abstract Background Patients undergoing orthopedic surgery are prone to developing postoperative urinary retention (POUR). They have an estimated relative risk of 8% to 55% higher than other surgical patients. This inability to void increases patient’s risk of urinary tract infections (UTIs) and bacteremia, and can lead to chronic voiding difficulties due to bladder architecture alterations. A great degree of variability exists among studies describing the prevalence and risk factors of postoperative urinary retention and its management strategies. Objective To compare the effects of Dexmedetomidine or Fentanyl added to intrathecal bupivacaine in knee arthroscopic procedures in terms of the occurrence of postoperative urinary retention. Patients and Methods This prospective randomized clinical study was conducted at tertiary care hospital at Ain Shams University hospitals from September 2021 till Mars 2022 and performed on a total of 70 patients who assigned for knee joints orthoscopic surgery. Results The current study results revealed that the incidence of postoperative urine retention in dexmedetomidine group was 5.7% while was 28.6% in Fentanyl group, the difference was statistically significant. however, the need to postoperative urinary catheterization was statistically non-significantly among the two groups. The current study results revealed that the Time to achieve maximum block was significantly shorter in dexmedetomidine group and the duration of motor block statistically was significantly longer in dexmedetomidine group. Conclusion On the basis of current evidence, when compared to fentanyl, our study revealed that intrathecal dexmedetomidine, as adjuvant to local anesthetics for intrathecal injection, can statistically significantly prolong the duration of sensory and motor block, as well as the pain free period, meanwhile significantly reducing the incidence of urinary retention. Intrathecal dexmedetomidine seems to be an attractive alternative as an adjuvant to spinal bupivacaine in surgical procedures, especially those requiring long time. It has excellent quality of postoperative analgesia with minimal side effects.