الفهرس 
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Abstract
Postoperative residual neuromuscular block; a TOF < 0.7; is frequent, dangerous, and difficult to recognize clinically. It is a major risk factor behind critical events in the immediate postoperative period, as it is seen in more than thirds of postoperative patients with ventilatory failure and hypoxia, in addition to serious cardiovascular and hormonal changes. Residual neuromuscular block should therefore be regarded as a serious adverse event in the same way as we regard ventilatory depression due to opioids and anesthetic agents.
This study is designed to assess the incidence of postoperative residual curarization in 180 adult patients of ASA 1 or II, undergone elective surgery requiring perioperative muscle relaxation. Two main points will be examined, namely: the impact of intra-operative neuromuscular transmission monitoring and the type of neuromuscular blocking drug on the incidence of postoperative residual curarization. Patients were subdivided into three main groups; atracurium, pancuronium, and pipecuronium group; each of which consisting of 60 patients. Each group was further subdivided into a, h, and c subgroups; each of which consisting of 20 patients; according to the use of the relaxograph; peripheral nerve stimulator; and the dose of neostigmine.
Each group will be subdivided into 3 subgroups, namely pancuronium, pipecuronium or atracurium subgroup a, h, &c (20 patients in each). In Pancuronium, pipecuronium and atracurium subgroup a (20 patients in each) a perioperative neuromuscular monitoring will not be used, and the timing of administration of either top- up doses of NMBS, or neostigmine 0.05mg/kg will
he based on clinical criteria alone.
Neuromuscular monitoring will be used in the remainder of patients (120 patients), and the timing of administration of either top- up doses of NMBS, or neostigmine will be fixed at Ti of 0.25, but the doses of neostigmine will be either 0.03 mg / kg in pancuronium, pipecuronium and atracurium subgroup b or in a dose of 0.05 mg/kg in pancuronium, pipecuronium and
Summary And Conclusion 201
atracurium subgroup c and the adequacy of neuromuscular recovery will be assessed using the response to TOF ulnar nerve stimulation of the relaxograph
monitor.
Analysis of the results obtained from the clinical study revealed the following.
Neuromuscular monitoring significantly increase the duration of action of the initial dose of neuromuscular blockers, and the pre-reversal time; time from last top — up dose to the administration of antagonist in minutes; than that of clinical subgroups. Moreover, it was associated with a significantly lower doses of the relaxants in mg/ kg/hour in the three groups.
The use of the relaxographic monitoring was also associated with significantly shorter recovery times namely; reversal time, times to make head lift for 5 seconds, and times to good hand grip. Furthermore, it was also associated with a significantly lower incidence of postoperative residual curarization than the clinical subgroups (1/120 versus 5/60, P = 0.046).
High dose of neostigmine (0.05mg/kg) in the presence of relaxograph was associated with significantly shorter recovery times than that associated with low dose of neostigmine (0.03mg/kg). This significant difference was clear in the groups of long acting nondepolarizing neuromuscular blockers; pancuronium and pipecuronium. However, in the intermediately acting group (atracurium) this difference was not significant except for time to make good hand grip, which is not conclusive as it depends on the patient cooperation. Moreover; regardless the presence or absence of relaxographic monitdring which adjust the dose, duration of action of the relaxant, and the time of antagonist
administration; there was no significant difference between’ igh and low doses of neostigmine as regard recovery times (subgroups a + c versus b).
The use of intermediately acting nondepolarizing neuromuscular blockers (NMBS) were associated with significantly shorter recovery times than that associated with long acting NMBS. It was also associated with a significantly lower incidence of postoperative residual curarization (zero versus six patients),
Summary And Conclusion 202
P= 0.014. Moreover, in patients received top up doses of NMBS, there were significantly longer recovery times than patients who did not receive them in the three groups.
We conclude that, routine use of neuromuscular monitoring; preferably electromyography; is mandatory to adjust timing of administration of top — up doses of NMBS, and their antagonist; neostigmine; thus, preventing overdose of the relaxant, with a consecutive infrequent occurrence of postoperative residual curarization (PORC), which, therefore can easily be diagnosed and managed. Moreover, muscle relaxants of short and intermediate duration of action should be preferred, since such agents carry the least risk of residual neuromuscular block postoperatively. Furthermore, smaller dose of neostigmine; 0.03mg/kg; produces adequate antagonism of atracurium-induced neuromuscular block when it is given at T1 of 25%, and it is as potent as higher dose; 0.05mg/kg. However, in the longer acting nondepolarizing neuromuscular blockers, the use of higher dose of neostigmine at 25% recovery of the first response of TOF is preferable to decrease
the incidence of PORC.