Effect of intrathecal midazolam on the anterior horn cells of adult albino rat's spinal cord experimental and microscopical study

Midazolam, is the only clinically available water soluble beuzodiazepine, has an analgesic action by its effect on the benzodiazepine GABA receptors complex. It can be used as an adjuvant to potentiate the effect of local anesthetics when injected intrathecally to relieve chronic medronical low back pain, but its safety is still in need for more evaluation. In the present study, 21 adult Albino rats were used and divided into 3 equal groups. The first group was considered a control, while animals in the second group were injected with a single intrathecal dose of midazolam. Animals of the third group were injected with three successive doses of the same drug. The spinal cord at the level of the cervical region was dissected, paraffin sections were prepared at 6 urn thickness and stained by H. and E. stain, toluidin blue stain, Nauta and Gygax stain and methyl green pyronin stain. The results showed no changes in either cell diameter or nuclear diameter after single dose of intrathecal injection of the Midazolam. Also, no changes in nucleic acid contents were detected. Repeated intrathecal injections led to a decrease in the diameters of both the cell and its nuclei as well as nuclei/cytoplasmic ratio [N/C ratio]. The nucleic acid contents were still also not affected

Clonidine as an adjuvant for lidocaine in peribulbar block a comparison of three doses

The dose response relationship of clonidine added to lidocaine in peribulber block were assessed in 52 adult patients of both sexes, undergoing cataract surgery. They were given 7 mL mixture of 2% lidocaine with clonidine in 0.5 micro g / kg [0.5 Clon]. 1.0 micro g /kg [1.0 Clon] and 1.5 micro g / kg [1.5 Clon] doses and compared to lidocaine alone [control]. The onset and duration of lid and globe akinesia and globe anaesthesia and analgesia, adverse effects [hypotension, bradycardia, hypoxia and sedation] and postoperative analgesic requirement were recorded. The success rate and onset of block were comparable in all groups. The duration of lid and globe akinesia, globe anaesthesia and analgesia was significantly prolonged in patients receiving 1.0 and 1.5 micro g/kg clonidine as compared with the control group [P <0.01]. Perioperative pain score and analgesic requirement were significantly less in these groups, 0.5 micro g/kg clonidine did not significantly increase the duration of anaesthesia and analgesia. Hypotension and dizziness were observed more in patients receiving 1.5 mirco g /kg clonidine as compared to other groups. In conclusion, clonidine 1.0 mirco g / kg mixture with lidocaine [2%] was significantly prolonged the duration of anaesthesia and analgesia after peribulbar block with limited side effects

Comparative study of rocuronium and vecuronium on the neuromuscular activity in experimental animals

Rocuronium is one of the newest non depolarizing neuromuscular blocking drugs. In this study, the effects of rocuronium and vecuronium as neuromuscular blocking agents on isolated rat phrenic nerve diaphragm and intact gastrocnemius sciatic nerve preparation in the cat were compared. The effect of gradually increasing doses of rocuronium [3-48 mu g /ml] and vecuronium [0.58 mu g/ ml] on the amplitude of contraction of isolated muscle in response to indirect electrical stimulation was recorded. Also, the effect of rocuronium [0.06-0.12 mg / Kg] and vecuronium [0.01-0.02 mg / kg] on the electrically induced gastrocnemius sciatic nerve was studied. Both drugs produced significant dose dependent reductions in the amplitude of rat phrenic nerve diaphragmatic contractions, but the effect of vecuronium was more than rocuronium. On cats gastrocnemius sciatic nerve preparations, the pattern of neuromuscular blockade [magnitude on set to maximum blockade and duration of block] of both drugs was also dose dependent. The results of this study demonstrated that rocuronium had significantly shorter time of onset, less potent with shorter duration of motor block than vecuronium