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

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 II
• aged 21-50 years
• scheduled to undergo unilateral arthroscopic knee surgeries under spinal anesthesia

Exclusion Criteria:

• Patients' refusal
• contraindications to spinal anesthesia
• patients with coagulopathy
• infection at the lumbar region
• pre-existing neurological deficits in the lower limbs
• known allergy to any of the study drugs
• urinary incontinence
• cysto-ureteric reflux
• patients with congestive heart failure
• patients with dysrhythmia
• patients with heart block
• diabetic patients
• patients on α2-adrenergic receptors antagonists
• calcium channel blockers