الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
 |  | from | 169 |  |  |
| | | from | 169 | | |
Abstract
Myasthenia gravis (MG) is an autoimmune disease, resulting from the production of antibodies against acetylcholine (Ach) receptors of the endplate. These antibodies reduce the number of active receptors, brought about by functional block of the receptors, by increased rate of receptors degradation or by complement mediated lysis. The incidence of MG is about 1 in every 20,000 adults. There is unpredictable susceptibility to muscle relaxants in patients with MG in the form of marked sensitivity to non-depolarizing agents, increased liability to potential phase II block and resistance to depolarizing neuromuscular agents. Also, interaction of anticholinesterase with depolarizing and non-depolarizing muscle relaxants in myasthenic patients were more complex than in normal patients. So, special considerations are required for anaesthetic management because there is an increased risk of perioperative respiratory insufficiency requiring prolonged intubation.
Inhalational anaesthetic enhanced block of neuromuscular junction by non-depolarizing muscle relaxants and can impede their antagonism by anticholinesterase.
In our study we compared two groups of patients with MG undergoing trans-sternal thymectomy, 15 patients each. The first group was anaesthetized by halothane and 60% N2O in 02 after induction with thiopental sodium 3-4 mg/kg while the other group was induced with propofol 2.5 mg/kg I.V. and anaesthesia was maintained with 60% N2O in 02 and propofol 12 mg/kg for 10 minutes, then 10 mg/kg for the next 10 minutes and then decreased to 8 mg/kg for the remaining period of operation. The dose titrated according to the patient response and reduced to 5 mg/kg 10 minutes before the end of operation. Heart rate, systolic and diastolic blood pressure, temperature, oxygen saturation, ETC02, TOF, blood gases were measured every 15 minutes during opertion. PFM was evaluated at 1 hour, 3 hours and 24 hours postoperative in both groups. Results showed that there were highly significant difference within each group at the first 30 minutes after induction then the results became insignificant till the end of the operation for heart rate, systolic and diastolic blood pressure while temperature results showed significant difference between both groups 30 minutes after induction till the end of operation, highly significant difference within halothane group and significant difference in propofol group at the end of operation when compared with preinduction value. Oxygen saturation and ETC02 showed highly significant difference.