Tadjeddein A, Khorgami Zh. Oral and parenteral pyridostigmine in preparing Myasthenia Gravis patients for thymectomy a randomized clinical trial. Tehran Univ Med J 2008; 65 (1) :39-43
URL:
http://tumj.tums.ac.ir/article-1-844-en.html
Abstract: (11228 Views)
Background: Respiratory failure and crisis is one of major complications of thymectomy
in myasthenia gravis patients. There are different medication regimes for preparing these
patients for surgery and reducing post-operative side effects. The goal of this study is to
compare respiratory complications of oral vs. Parenteral preoperative administration of
anticholinesterase agents for thymectomy in myasthenia gravis patients.
Methods: This randomized controlled trial included 101 patients in class IIA or IIB of
myasthenia gravis according to the Osserman classification system. The control group
fasted for eight hours before surgery and oral anticholines-terase agents were replaced
with parenteral ones. The case group also fasted for 8 hours before surgery, but
pyridostigmine was continued at its usual dose until the time of operation and the last
dose was given to patients with a small amount of water in the operating room on the
operating bed.
Results: There was no statistically meaningful difference between the two groups in
terms of age, sex and pathologic findings. In comparison, the mean hospital stay for the
case group was 3.98 days and 6.34 for the control group (p value = 0.003). There were
eight cases of respiratory crisis or failure (16%) in the control group but only 1 case (2%)
was observed in case group (p value = 0.014). Only one patient in the case group required
re-intubation after the surgery however, six patients in control group were re-intubated
(p value = 0.053). Plasmapheresis was required for five patients in the control group and
one patient in the case group (p value = 0.098). Tracheostomy was performed on two
patients in the control group to accommodate prolonged intubation, but none of the case
group required this procedure.
Conclusion: This study shows that continuing oral anticholinesterase agents up to the
time of operation, with the last dose at the operative theater, lowers the incidence of postoperative
myasthenia crisis and respiratory failure, need for plasmapheresis and shortens
the hospital stay. This method may also decrease the need for re-intubation, mechanical
ventilation and tracheostomy, thus decreasing the chance of death resulting from
complications of the thymectomy.