Myasthenia gravis: towards a safe anaesthesia technique, five years clinical experience in Hamad medical corporation, Qatar and review of literature

ABSTRACT

Myasthenia gravis [MG] is a disease with many implications for the safe administration of anesthesia and involves considerable morbidity and mortality. Myasthenia gravis is caused by autoantibodies to postsynaptic nicotinic acetylcholine receptors at the neuromuscular junction, causing weakness of skeletal muscles. Patients with thymoma-associated MG produce autoantibodies to a variety of neuromuscular antigens, including antibodies to the skeletal muscles calcium release channel and antibodies to cytoplasmic filamentous proteins. Thymectomy is a common surgical procedure in patients with myasthenia gravis.. Our aim is to review and document retrospectively our initial experience of providing a safe general anaesthesia technique involving continuation of preoperative anticholinesterase doses, use of non-paralyzing technique, and use of ultra-short acting anesthetics and cautious reintroduction of anticholinesterase after surgery. Eight patients underwent thymectomy from January 2002 to March 2006 under general anaesthesia technique involving continuation of preoperative anticholinesterase doses, avoidance of muscle relaxants, and use of ultra-short acting anesthetics and cautious reintroduction of anticholinesterase after surgery. Demographic and clinical data, preoperative symptomatology, treatment history, intraoperative and post-operative data, and distribution of patients according to intubating grade were recorded and analysed. All our patients who underwent trans-sternal thymectomy using the above technique were extubated on operating table following administration of intravenous anticholinesterase and anticholinergic drugs. There was no postoperative morbidity or mortality. None of our patients needed ventilatory assistance in the postoperative period. Patients can be extubated on table safely after thymectomy if we avoid muscle relaxants and use ultrashort acting anesthetics intraoperatively. Surgical exposure and technique was adequate in all our patients. This technique was safe and effective in all of our 8 patients who underwent trans-sternal thymectomy