الفهرس 
ANATOMICAL AND PHYSIOLOGICAL CONSIDERATION OF OPHTHALMIC REGIONAL ANESTHESIAOnly 14 pages are availabe for public view
 |  | from | 116 |  |  |
| | | from | 116 | | |
Abstract
Cataract surgery frequently employs peribulbar anesthesia. When compared to retrobulbar anesthesia, this approach is associated with less significant consequences. However, it has the disadvantages of a sluggish onset of orbital akinesia and the frequent requirement for block supplementation.
A neuromuscular blocking medication with no side effects and a rapid onset of action, such as rocuronium; its effects in a low dose on the quality of peribulbar anesthesia (onset time and requirement for additional injection of local anesthetics) have not been well investigated. Magnesium sulphate has been used empirically for many years to treat convulsions in patients with preeclampsia.
Magnesium ions are required for many metabolic activities, and a deficit can have serious implications. Many of its pharmacological effects were only recently discovered. Its putative antinociceptive action has a promising biological basis. This action is mostly due to physiological calcium antagonism, which is the voltage-dependent regulation of calcium influx into the cell, as well as noncompetitive antagonism of N-Methyl-D-Aspartate (NMDA) receptors.
In the current ”Prospective Double-blind Randomized ”study we aimed to compare the effect of adding magnesium sulfate (50 mg in 1 ml of 0.9% saline) versus rocuronium (0.06 mg/kg (maximum 5 mg) in 1 ml saline) to standard local anesthetics mixture (9ml of the local anesthetic: 4.5 ml of 0.5% bupivacaine and 4.5 ml of 2% lidocaine mixed with hyaluronidase (150 U)) in peribulbar block in ophthalmic surgeries and assessment of the effect of this mixture on the time of onset of globe and lid akinesia and corneal anesthesia. Each group enrolled 25 cataract patients.
The success of the block was assessed by scoring motor block (the mobility of the globe and the eyelid) and sensory block (by assessing corneal anesthesia using a small piece of cotton wool) at 2.5, 5, 7.5, and 10 min after injection.
Evaluation of globe akinesia: It was done using a three-point scale (0-2) for each of the four cardinal directions (upward, downward, nasal and temporal) (Total score of 8). Ocular movement in each direction was scored as: 0 if there is no directional movement. 1 if it is limited. 2 if it is normal. A total score of 10 is obtained when we add the globe akinesia score (0–8) and the lid akinesia score (0–2).
Corneal anesthesia: The assessment was done by assessing the cornea whether it is sensitive or not using a small piece of cotton wool at 2.5, 5, 7.5, and 10 min after injection.
After collecting the data, the statistical analysis was done, and we found that;
The participants in the three groups were matched as there was no statistically significant difference between groups according to demographic data about age, sex, ASA physical status and globe axial length.
Our study found statistically significant more rapid onset of action (mean time to start surgery) in rocuronium group (7.00±1.22) than control group and magnesium sulfate group (9.00±1.47 and 9.00±1.15) respectively, (p<0.001); Moreover, no statistically significant difference was reported between control group and magnesium sulfate group. In addition, no significant difference was reported regarding duration of surgery between groups
Regarding hemodynamic changes in our study; the three groups did not report significant difference in pulse, MAP, SPo2, and pain in the overall time of surgery (p>0.05).
Regarding globe and lid akinesia; rocuronium group showed better significant results in 2.5, 5, 7.5, and 10min after injection than both control and magnesium sulfate groups; moreover, magnesium sulfate group showed significantly better results than control group only at 5 min and 7.5 min
The rocuronium group did not need any supplemental injection. However, only 16% in magnesium sulfate group and 24% in control group need supplemental injection with statistically significant difference between groups
Regarding corneal anesthesia in our study; at first 2.5 min; magnesium sulfate group showed significantly more rapid onset of sensory block 19 (76.0%) than rocuronium group 17 (68.0%), and both groups showed significantly more rapid onset of sensory block than control group 8 (32.0%). However, no statistically significant difference between the three groups was reported in 5, 7.5 and 10 mins.