[Use of Diprivan in muscular diseases and malignant hyperthermia]

Undetected central core disease myopathy in an infant presenting for clubfoot surgery

A 1-year-old child was scheduled for two stage bilateral clubfoot surgery. Preoperative evaluation was normal and total intravenous anesthesia with a continuous sciatic nerve block was performed. Two months later, before the second clubfoot correction, a hip subluxation was evident suggesting a provisional diagnosis of neuromuscular disease. Anesthesia was identical, except that a femoral nerve block, necessary to permit a diagnostic muscle biopsy was performed. The perioperative course was uneventful but result of the muscular biopsy was surprising in that central core disease was diagnosed. Although congenital myopathies of all grades and severity exist, they are often mild and underestimated. Patients affected by central core disease are considered susceptible to malignant hyperthermia. Because a high prevalence of myopathic changes is reported in children undergoing clubfoot surgery, anesthesiologists must take precautions including a hightened awareness of these events and a high index of suspicion.

[Anesthesia in a child presenting a anhydrotic ectodermic dysplasia associated with a multiminicore myopathy]

PURPOSE

To report the perioperative management of anesthesia and analgesia in a child presenting with the association of multiminicore myopathy (MMM) and anhydrotic ectodermic dysplasia (AED).

CLINICAL FEATURES

An eight-year-old girl was admitted for elective orthopedic surgery of the lower limbs. AED is a congenital dermatosis characterized by the absence of sweating and subsequent problems with thermoregulation; in addition, maxillary hypoplasia and abnormal teeth can render intubation difficult. MMM is a rare congenital myopathy characterized by proximal muscle weakness, stable in time or with a slow and progressive evolution. It can involve respiratory muscles and be associated with severe cardiomyopathy. Moreover, MMM shares some characteristics with Central Core Disease which is known to be associated with malignant hyperthermia. Since depolarizing muscle relaxants and halogenated agents could not be used, a combined propofol-based intravenous anesthesia with lumbar epidural analgesia was chosen. This combination provided stable anesthesia, smooth recovery and excellent analgesia during and after the operation, without complications. Temperature was monitored closely during surgery and in the postoperative period.

CONCLUSIONS

The association of MMM and AED requires rapid distinction between hyperthermia secondary to anhydrosis and malignant hyperthermia. The management should provide a "trigger-free" anesthetic and optimal postoperative analgesia without sedation. If appropriate for the surgical procedure, a combination of general with regional anesthesia is particularly attractive in achieving these objectives.

Malignant hyperthermia

Malignant hyperthermia is a rare autosomal dominant trait that predisposes affected individuals to great danger when exposed to certain anaesthetic triggering agents (such as potent volatile anaesthetics and succinylcholine). A sudden hypermetabolic reaction in skeletal muscle leading to hyperthermia and massive rhabdomyolysis can occur. The ultimate treatment is dantrolene sodium a nonspecific muscle relaxant. Certain precautions should be taken before anaesthesia of patients known to be susceptible to malignant hyperthermia. These include the prohibition of the use of triggering agents, monitoring of central body temperature and expired CO2, and immediate availability of dantrolene. In addition, careful cleansing of the anaesthesia machine of vapours of halogenated agents is recommended. If these measures are taken, the chances of an MH episode are greatly reduced. When malignant hyperthermia-does occur in the operating room, prompt recognition and treatment usually prevent a potentially fatal outcome. The most reliable test to establish susceptibility to malignant hyperthermia is currently the in vitro caffeine-halothane contracture test. It is hoped that in the future a genetic test will be available.

[Laparoscopic cholecystectomy in a patient with Steinert disease]

Steinert's disease or myotonic myopathy is associated with chronic restrictive respiratory insufficiency. A case of a patient with Steinert's disease undergoing laparoscopic cholecystectomy, with a full recovery within three days is reported. It is concluded that laparoscopic surgery is a possible therapeutic tool in patients suffering from a myopathy.