Comparison of Intrathecal Dexmedetomidine Versus Fentanyl as Adjuvants to Bupivacaine on Post-operative Urinary Retention in Knee Joint Arthroscopic Surgeries

The aim of this study was to assess the effect of intrathecally injected 5 µg dexmedetomidine or 25 µg fentanyl as adjuvants to bupivacaine in low dose spinal anesthesia for unilateral arthroscopic knee surgeries, on post-operative urinary retention (POUR), time needed to reach sensory block at the tenth thoracic dermatome (T10), the maximum sensory level achieved, the onset of motor block, the intra-operative fluids given, the duration of sensory and motor blocks, time to micturition or insertion of an intermittent urinary catheter and the number of patients who needed an indwelling (Foley's) catheter. Seventy patients, ASA physical status I or II, from 21 to 50 years old, scheduled to undergo unilateral arthroscopic knee surgeries under spinal anesthesia, were randomly divided into two equal groups; the Bupivacaine- Dexmedetomidine group (BD) patients and the Bupivacaine-Fentanyl group (BF) patients.

Inclusion Criteria:ASA physical status I and IIaged 21-50 yearsscheduled to undergo unilateral arthroscopic knee surgeries under spinal anesthesiaExclusion Criteria:Patients' refusalcontraindications to spinal anesthesiapatients with coagulopathyinfection at the lumbar regionpre-existing neurological deficits in the lower limbsknown allergy to any of the study drugsurinary incontinencecysto-ureteric refluxpatients with congestive heart failurepatients with dysrhythmiapatients with heart blockdiabetic patientspatients on α2-adrenergic receptors antagonistscalcium channel blockers