Evaluation of Dexmedetomidine as an Adjuvant to Intrathecal Bupivacaine in Infraumbilical Surgeries

Abstract

IntrOductIOnSpinal anaesthesia is the gold standard for lower abdominal surgeries. It has got the advantage of being, cost-effective, easy administration technique, rapid onset of action, with relatively less adverse effects and most importantly patient remaining aroused throughout the procedure [1]. But at times short duration and uncomfortable postoperative period offset the above advantages. Therefore, in order to extend the intraoperative analgesia into postoperative period, following spinal anaesthesia, various spinal adjuvants like morphine, buprenorphine and fentanyl, clonidine, ketamine are being used in anaesthetic practice. Such adjuvants have been helpful in induction of early ambulation along with prolongation of analgesia but at the cost of their associated adverse effects. Therefore search for an effective adjuvant is still going on.Alpha-2 (α 2 ) adrenergic receptor agonists have been tried by many clinicians due to their sedative, anxiolytic, hypnotic, analgesic, perioperative sympatholytic and stable haemodynamic properties [2]. The initiation for the use of α 2 agonists in anaesthesia resulted from observations made in patients who were receiving clonidine therapy. Dexmedetomidine, a Dextro (s) isomer of medetomidine was approved for short term sedation in 1999. It possesses all the above properties but lacks respiratory depressant action; making it a relatively safe agent [3]. Currently its adjuvant action in spinal anaesthesia is being explored. Various adjuvants like morphine, buprenorphine and fentanyl, clonidine, ketamine are being used in anaesthetic practice since long for improvement of peri-operative analgesia following spinal anaesthesia. Such adjuvants have been helpful in induction of early ambulation but at the cost of their associated adverse effects. Therefore search for an effective adjuvant is still going on. Currently Dexmedetomidine, a highly selective α 2 -adrenoreceptor agonist is being studied for its adjuvant action in spinal anaesthesia.

Dexmedetomidine as a neuraxial adjuvant for prevention of perioperative shivering: Meta-analysis of randomized controlled trials

“…Of the included 15 studies, twelve studies showed the characteristics of the block, including the onset of sensory block [22, 23, 25, 26, 28, 30, 38, 39], the onset of motor block [22, 23, 25, 26, 28, 44, 45], the duration of the sensory block [22, 24–28, 30, 39, 44, 45], the duration of motor block [22, 24–28, 38, 44, 45], and the time to rescue analgesia [22, 23, 25–28, 30, 38, 44, 45]. Side effects were reported in 15 studies, comprising neurological complications [24, 25, 28, 30], respiratory depression [22, 24–26, 28–30, 38, 44, 45], bradycardia [22–30, 36, 38, 44, 45], hypotension [22–27, 29, 30, 36, 38, 44, 45], nausea/vomiting [22–30, 3...…”

“…Side effects were reported in 15 studies, comprising neurological complications [24, 25, 28, 30], respiratory depression [22, 24–26, 28–30, 38, 44, 45], bradycardia [22–30, 36, 38, 44, 45], hypotension [22–27, 29, 30, 36, 38, 44, 45], nausea/vomiting [22–30, 36–39, 44, 45]. None of the studies reported mortality and major cardiovascular complications, such as non-fatal myocardial infarction, stroke, or cardiac arrest.…”

“…All trials were described as having a randomized trial design, while 8 [22, 26, 28–30, 34, 43, 44] of 24 studies did not describe detailed information about random sequence generation. Two studies [28, 39] did not describe the methods of allocation concealment, and all reports were double-blinded.…”

Dexmedetomidine versus sufentanil with high‐ or low‐concentration ropivacaine for labor epidural analgesia: A randomized trial

“…The results suggested that ropivacaine combined with dexmedetomidine was better in sedation and analgesia than ropivacaine combined with sufentanil. Dexmedetomidine activates presynaptic α2‐adrenergic receptor to reduce the release of norepinephrine, while stimulates postsynaptic α2‐adrenergic receptor to inhibit the release of pain signals . Meanwhile, dexmedetomidine is characterized by fat‐soluble, which means that it can be easily absorbed by epidural adipose tissue, reducing the body's perception of pain and strengthening sedative effect .…”

Comparison of Intrathecal Dexmedetomidine with Morphine as Adjuvants in Cesarean Sections

“…Some studies have shown that the intrathecal administration of dexmedetomidine increases anesthetic effects, [10][11][12] provides stable hemodynamic conditions, and improves the quality of intraoperative and prolongs postoperative analgesia with minimal side effects. 13,14) There are no such studies that compare the intrathecal administration of dexmedetomidine with intrathecal morphine during cesarean sections. Hence, the aim of the present study was to investigate and compare intrathecal morphine and dexmedetomidine as adjuvants to bupivacaine to examine their effects on efficacy, post-operative analgesia, side effects and neonatal conditions in cesarean sections.…”