The Effects of Intrathecal Dexmedetomidine on Spinal Anesthesia Using Diluted Low-Dose Bupivacaine for Transurethral Resection of Prostate in Elderly
Condition: Benign Prostatic Hypertrophy
MeSH terms: Prostatic Hyperplasia; Hypertrophy
Study type: Interventional

Summary: 
      Spinal block is the most common anesthetic technique for transurethral resection of
      prostatectomy (TURP). Most patients undergoing TURP are elderly and frequently present with
      cardiopulmonary and endocrine diseases. Low-dose local anesthetic is commonly administer to
      limit the block level to minimize the hemodynamic changes. However, sometimes it may not
      provide an adequate level of sensory block. Thus, intrathecal additive is frequently
      administer with local anesthetic to improve analgesic effect.

      Dexmedetomidine(DXM), a selective 2-adrenoreceptor agonist, has been used in the epidural
      space in humans without any reports of neurological deficits. Previous clinical studies
      showed that intravenous dexmedetomidine administration prolonged the sensory and motor blocks
      of bupivacaine spinal analgesia. But clinical studies about the use of intrathecal DXM with
      local anesthesia in humans are scarce in the literature. Kanazi et al. found that 3μg DXM
      added to 12 mg spinal bupivacaine produced the significant short onset of sensory and motor
      block as well as significantly longer duration of sensory and motor block than bupivacaine.
      And Al-Mustafa et al. reported that intrathecal dexmedetomidine as an adjuvant to 12.5mg
      bupivacaine in spinal anesthesia has a dose dependant effect on the onset and regression of
      sensory and motor block.

      In our previous study, low-dose diluted bupivacaine 5 mg provided sufficient anesthetic level
      when opioid was added with local anesthetic. However, opioid-induced side effects, such as
      pruritus, nausea, or vomiting, could be an obstacle in common use. The aim of this study is
      to evaluate whether DXM-low-dose bupivacaine spinal anesthesia can provide the effective
      spinal anesthesia and postoperative analgesia with minimal side effect compare to the local
      anesthetic only group.

      This study was conducted in a randomized, double-blind, controlled fashion. Patients were
      randomly allocated to DXM group or Saline group. DMT group received hyperbaric bupivacaine
      0.5% (1.2 ml) (6 mg) in dextrose 8% solution + DMT 0.3 ml (3 µg)-in total, bupivacaine 0.4%
      (1.5 ml) intrathecally and Saline group received hyperbaric bupivacaine 0.5% (1.2 ml) (6 mg)
      in dextrose 8% solution + normal saline 0.3 ml -in total, bupivacaine 0.4% (1.5 ml)
      intrathecally. After spinal block, the level of sensory block, defined as the dermatomal
      segment with loss of pain sensation to pin-prick with a 22 G hypodermic needle and cold
      sensation to alcohol swab was measured every 2 min after intrathecal injection. The
      investigators recorded the peak sensory block level, time to peak block level from
      intrathecal injection, blood pressure and heart rate, and analgesic supplementation during
      operation. The maximum motor block level was assessed according to the modified Bromage
      scale. During postoperative period, the frequency of analgesic requirement, time to the first
      analgesic request, and pain scores were evaluated by blind investigator.
    


Intervention name(s): spinal anesthesia; spinal anesthesia
Intervention type(s): Drug; Drug
Intervention description(s): 0.4% bupivacaine(normal saline 0.3ml with dexmedetomidine 3 mcg); 0.4% bupivacaine(normal saline 0.3 ml with 0.5% bupivacaine 1.2 ml)
Intervention MeSH terms: Anesthetics
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care