Comparative evaluation of intrathecal midazolam and low dose clonidine: Efficacy, safety and duration of analgesia. A randomized, double blind, prospective clinical trial

Abstract

Background:The study was planned to assess the comparative efficacy, safety and duration of analgesia produced by low-dose clonidine and midazolam when used as adjuvant for spinal anesthesia.Materials and Methods:This is a randomized, participant and observer blind, prospective, parallel group clinical trial. Fifty ASA grade I and II patients posted for lower abdominal surgery were randomly allocated into two groups. BC group received spinal clonidine 30 μg and BM group received preservative-free midazolam 2 mg with 15 mg hyperbaric bupivacaine. Postoperative analgesia, analgesic requirement in 24 hours, onset and duration of block, hemodynamic stability and adverse effects were observed (P<0.05 – considered significant, P<0.01 considered highly significant).Results:The duration of postoperative analgesia was prolonged in BM group (391.64 ± 132.98 min) than BC group (296.60 ± 52.77 min) (P<0.01). The mean verbal rating pain score was significantly less in BM group than BC group (P<0.01). The number of analgesic doses in 24 hours were significantly less in BM group (P<0.05). Nine patients (36%) in BC group required additional analgesia as against none in BM group (P<0.01). The onset of sensory block and peak sensory level was significantly earlier in BM group as compared to BC group. Duration of sensory block was longer in BM group (P<0.05). Subjects in BC group(36%) had bradycardia as compared to none in BM group (P<0.01). Hypotension was observed in 44% patients in BC group as against 16% in BM group (P<0.05).Conclusion:Postoperative analgesia with clonidine is short lived with some bradycardia. Intrathecal midazolam provides superior analgesia without clinically relevant adverse effects.

Efficacy of intrathecal midazolam versus fentanyl for endoscopic urology surgery

“…22 Another study, comparing intrathecal midazolam with clonidine, reported that 2 mg intrathecal midazolam provided superior analgesia than 30 μg clonidine with fewer adverse effects in patients undergoing lower abdominal surgeries. 23 Intrathecal midazolam did not affect the duration of motor blockade in the present study. Although a few studies have reported prolongation of motor blockade after intrathecal midazolam, 12,14 a meta-analysis aiming to evaluate the effectiveness and side-effects of intrathecal midazolam in the perioperative setting reported that intrathecal midazolam did not affect the duration of motor blockade.…”

Intrathecal Midazolam as an Adjuvant in Pregnancy-Induced Hypertensive Patients Undergoing an Elective Caesarean Section: A Clinical Comparative Study

“…Similar observations have been reported by other studies (33,34). Further investigations have shown that the addition of midazolam or fentanyl to intrathecal bupivacaine does not alter the peak level of the sensory block (9,35,36). Similar observations were noted in our study.…”

A comparative study of hemodynamic changes and adverse effects of intrathecal bupivacaine with fentanyl and intrathecal bupivacaine with clonidine in infra-umbilical abdominal and lower limb surgery

“…Intrathecal use of low dose clonidine and fentanyl as adjuvant to bupivacaine has not been shown to be associated with respiratory depression in literature. [26][27][28][29][30][31][32] Thus, the findings in this present study indicated a safe ventilatory profile of both drugs which did not end up in a respiratory depression and is consistent with the findings reported in literature. Although a few case reports describes respiratory depression after intrathecal fentanyl (after 100 mcg of epidural fentanyl) yet its use in low-dosage as an adjuvant to bupivacaine is relatively safe and rarely ends up in respiratory depression.…”