A 20-yr-old male patient weighing 40 kg with centronuclear (myotubular) myopathy was admitted to our maxillofacial surgery ward and was scheduled for surgical treatment of deformity of the maxilla and mandible. Several days previously he had been admitted to another hospital because of a choking incident resulting in respiratory and cardiac arrest. He was successfully resuscitated and a tracheostomy was performed. He developed unilateral pneumonia as a complication of the choking incident. The progressive deformity of his jaws had caused serious difficulties in feeding, thus the patient was malnourished before the incident. In addition to narrowing of the posterior part of the oral cavity, muscle weakness resulted in hyporeflexia, which was probably the cause of choking. On this account, the maxillofacial operation was considered as necessary and lifesaving.
Physical examination revealed a thin male, conscious, fully responding to stimulation. His chest was deformed (scoliotic) with decreased breath sounds bilaterally. His arms and legs were shorter than normal and showed varus deformity. He had serious deformity of the maxilla and mandible, malocclusion, narrowing of the isthmus of the fauces and narrowing of the posterior part of the oral cavity (Fig. 1). The medical record revealed a history of complicated premature labour. The diagnosis of congenital myopathy was made at 2 yr of age from physical examination without further specialist investigations. During childhood, he had been treated with intensive rehabilitation. Until the recent choking incident he had been able to move with some difficulty, but unaided. His mental development was not retarded and he was not below average height. He was studying at university and spoke three languages. Neurological examination revealed significant reduction in muscle strength with tetraparesis and absent deep reflexes. Because of the planned surgical operation and still undefined type of myopathy, with possible associated risk of malignant hyperpyrexia, the anaesthesiologist requested more sophisticated neurological examination including electromyography, electroneurography and a biopsy specimen of muscle for histopathological examination. After receiving the results, which confirmed centronuclear (myotubular) myopathy, the patient was prepared for surgery. The ASA status of the patient was Grade III. Because of the myopathy, coexisting related diseases and surgery in the facial area, special anaesthetic precautions were undertaken. Airway protection had already been assured using the pre-existing tracheostomy (with a cuffed tracheostomy tube). Anaesthesia was induced and maintained using a total intravenous (i.v.) anaesthetic technique with propofol and remifentanil both administered by continuous infusion. No muscle relaxant was used. The patient's lungs were ventilated with a 50:50 mixture of oxygen and air.
In the operating room immediately preoperatively, atropine 0.5 mg was administered. Anaesthesia was induced with propofol 80 mg (2 mg kg−1) and a 40 μg bolus of remifentanil (1 μg kg−1). After that, a continuous infusion of remifentanil (50 μg mL−1) was started at 0.5 μg kg−1 min−1 (24 mL h−1) and a continuous infusion of propofol at 10 mg kg−1 h−1. After 10 min into the procedure, the rate of propofol was changed to 36 mL h−1 (8 mg kg−1 h−1). At the end of surgery, the rate of infusion of propofol was 18 mL h−1 (4 mg kg−1 h−1). No additional i.v. medications were administered. During anaesthesia, mean arterial pressure was 60-114 (76 ± 7) mmHg, heart rate 72-109 (80 ± 8) beats min−1, PETCO2 3.2-4.4 kPa, and surface temperature 35.0-35.9°C. The anaesthesia and recovery were smooth and uneventful. There were no significant changes in train-of-four (TOF) nerve stimulation response between pre- and postoperative measurements.
During the operation, abnormally erupted teeth were extracted, the bony deformity was corrected and plastic surgery performed on soft tissue which had narrowed the isthmus of the fauces. Consequently, satisfactory dilatation of the isthmus of the fauces was achieved. After surgery, the patient was admitted to the intensive care unit for further monitoring and observation. During the next 48 h the concentration of creatine kinase was monitored every few hours without any elevation being detected. The postoperative course was complicated by unilateral pneumonia, which resolved successfully. The patient was discharged home 2 weeks after the surgery.
Centronuclear myopathy (CNM) is one of the congenital myopathies (central core disease, nemaline myopathy) involving most muscle fibres throughout the body mass, which has a varying spectrum of presentation. It was first described in 1966. Characteristic features are amyotonia, decreased muscle mass and osteal deformities. Filiform structures can be seen in histological muscle specimens. The illness is inherited either by autosomal-dominant or recessive pattern. The gene responsible for the defect is in the I chromosome. The biochemical defect is unknown. Histological examination is essential for the diagnosis. Three forms can be derived from the dynamics of the course of the disease. (a) Neonatal, onset immediately after labour, characterized by generalized amyotonia, with rapid, progressive symptoms of respiratory distress, which results in death before the end of first year of life. (b) Infantile, a disease course of many years, delayed walking and mild proximal muscle weakness that may not be progressive, the myocardium is also often involved, coexistent severe scoliosis followed by restrictive lung disease and chronic cor pulmonale syndrome; talipes varus is also present. Seizures, some degree of mental retardation, psychosis, or other central nervous system disorders may be seen. (c) Adult, a more stable and slower course than the infantile form, worsening during pregnancy, associated with a different extent of immobilization of the patient, most often wheelchair-bound and cardiomyopathy often present.
Because of several issues directly related to the myopathy, the choice of anaesthetic technique is essential . To date, there have been no reported cases of malignant hyperthermia (MH) during anaesthesia in a patient with centronuclear myopathy, therefore some authors claim that CNM is not associated with an increased risk of malignant hyperpyrexia . However, most anaesthesiologists believe that CNM patients should be treated with necessary precautions to avoid possible triggering of MH . Therefore, muscle relaxants should be avoided so that interaction with the diseased muscle tissue does not occur and no triggering volatile anaesthetic agents should be used. Propofol is considered safe for induction and maintenance of anaesthesia. In addition, regional techniques of anaesthesia can be safely performed. In the case presented here, muscle relaxation was avoided and a non-triggering anaesthetic technique was used. The analgesic remifentanil was administered without complications. The choice of this opioid was based on its pharmacokinetic profile: a short onset and short duration of action. The severe restrictive lung disease, difficult airway, gastroesophageal reflux and chronic cor pulmonale syndrome also were of concern [2,4]. In this patient, the airway was maintained and protected by the tracheostomy that was already in situ. If this had not been the case, it would have been essential either to perform an elective tracheostomy before inducing anaesthesia or to arrange for fibreoptic intubation of the trachea to be performed safely.
We conclude that patients with CNM can be successfully and uneventfully anaesthetized using remifentanil as analgesic provided that appropriate airway maintenance and protection methods are used. The anaesthetic plan should take into account the presence of the underlying myopathy and associated decrements in physiological function.
Department of Anaesthesiology and Intensive Therapy; Medical University of Łódź; Lodz, Poland
Department of Maxillo-Facial Surgery; Medical University of Łódź; Lodz, Poland
1. Gottschalk A, Heiman-Patterson T, de Quevedo R II, Quinn P. General anesthesia for a patient with centronuclear (myotubular) myopathy. Anesthesiology
2. Price SR, Currie J. Anaesthesia for a child with centronuclear myopathy. Paediatr Anaesth
3. Feyerherd F, Wendt M. Anesthesiology risk in neurologic diseases. Anesthesiol Reanim
4. Breslin D, Reid J, Hayes A, Mirakhur RK. Anaesthesia in myotubular (centronuclear) myopathy. Anaesthesia