Comtinuous Suxamenthonium Infusion After Neostigmine,A Modified Approach Of An Old Trchnique

SummarySuccinylcholine is the only depolarizing muscle relaxant in general use today. The continued popularity of Sch is due to its rapid onset and short duration of action which can be prolonged after administration of neostigmine.Sch infusion is an old technique previously was used to maintain surgical relaxation but the development of nondepolarizing muscle relaxant with little or no side effects makes this technique seldom used today.In the present work we assumed that Sch infusion after neostigmine will give the chance of dealing with muscle relaxant in the form of on /off therapy without cumulative effect and side effects of Sch infusion.The present study was allocated to one hundred fifty patients of ASA class I or II status of average weight and height all undergo elective intraabdominal operations and were divided randomly into two equal groups; group I (n=75) received Sch infusion and group II(n=75) received Sch infusion preceeded by 2.5mg neostigmine with appropriate dose of atropine.The present study monitored the following parameters Heart rate, Blood pressure, onset and recovery time after infusion, Serum potassium, IOP, POM, Twitch height, and Phase II block.The present study revealed that there is no significant difference between two groups concerning the onset time. There is significant increase between two groups concerning the recovery time where it was 3.5 ± 2.46 min in group I and 5.007±2.99 min meaning that it is rapid even if phase II block was developed where it recovers spontaneously during Sch infusion or after stoppage of Sch infusion.The present study shows that Sch infusion with or without neostigmine is effective in maintaining good surgical relaxationDuring recovery from Sch infusion about 68% in group I and 80% in group II recovered by augmentation of twitch height while the remaining patients recovered with depression of twitch height but they were recovered clinically well.The present study shows that the dose required for 90% depression of the twitch height is 77.7 µg/kg/min in group I with significant increase compared to group II (57.5 µ/kg/min) with wide variability in both groups.The present study shows that the development of phase II block is variable in onset, dose and duration and about 66.7% of patients in group I and 71.1% of patients in group II recovered from phase II, block spontaneously during Sch infusion while the remaining patients were recovered to phase I after stoppage of Sch infusion in a time of 12.9 ± 10.76 min in group I and 12.7 ±10.1 in group II, so phase II block when developed at the end of surgery isn’t a problem where the recovery time didn’t exceed 5 min.The present study shows that the occurrence of POM is more in females at an age group below 40 years and more after ambulation. The incidence of POM is 8.66% and no significant difference between two groups.The present study shows that the development of POM of score 2 is 2 in group I and 5 in group II with no significant difference between two groups.Patients with score 2 relieved by NSAIDS and converted into score 1 in the 2nd day and score 0 in the 3rd day. Patient with POM scoring of 1 relieved spontaneously into score 0, meaning that POM isn’t a major problem.The dose at which POM occurs is 88.7 µg/kg/min in group I and 68.87 µg/kg/min in group II.The present study shows that the intraocular pressure was significantly decreased after 60 and 90 minutes in both groups and didn’t exceed the normal acceptable levels.The present study shows that the serum potassium level tends to decrease singnificantly 2 min after intubation, and after 30 min with no significant difference after 30 minutes till the end of the operation. The serum potassium doesn’t exceed normal level all over the operative time.The present study shows that there is no significant difference between the studied groups concerning the systolic and diastolic blood pressure.The changes in heart rat shows significant decrease at 15 till 180 minutes and the percentage of change between two groups doesn’t exceed 20% of basal heart rate at which the body can compensate, so this technique is effective in patients in need to be towards bradycardia such as thyrotoxic and cardiac patients.From this study, it is proved that this technique is safe and effective in maintaining good muscle relaxation provided that there is no contraindications to succinylcholine.