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


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).


CONCLUSIONS
Postoperative analgesia with clonidine is short lived with some bradycardia. Intrathecal midazolam provides superior analgesia without clinically relevant adverse effects.
Department of Anaesthesiology and Pharmacology, Shri Bhausaheb Hire Govt. Medical College, Dhule, Maharashtra, India. suchita_khadke@rediffmail.com
Suchita A
SA
Joshi
Venkatesh V
VV
Khadke
Rajesh D
RD
Subhedar
Arun W
AW
Patil
Vijay M
VM
Motghare