The use of bispectral index monitoring in the anesthetic management of a patient with Rett syndrome undergoing scoliosis surgery.

To the Editor: Rett syndrome is a genetically inherited disorder that almost exclusively affects females. It is characterized by severe mental retardation after a period of apparent normal development for the first 6 to 18 months of life [1]. Other characteristics of the disorder are autistic behavior, myoclonic movements, seizures, apneic spells, aerophagia, tachybradyarrhythmias, serotonin imbalance, scoliosis, bruxism (teeth grinding), and autonomic nervous system dysfunction [2]. Prevalence studies show that it is not a rare phenomenon among the population of severely retarded females, and that the prevalence may be as high as 25% [3]. Prevalence rates range from 1:10000 in Sweden to 1:25000 in Japan, rendering Rett syndrome as the leading cause of profound cognitive impairment in females [2]. In general, survival of these patients is quite prolonged; 75% of patients survive to age 35 years compared with 27% for other causes of profound mental retardation. In young patients, deaths occur primarily during sleep, are unrelated to seizures, and largely remain unexplained [4]. Cardiac conduction abnormalities are a possible factor in these deaths; longer corrected QT intervals and T-wave abnormalities [5], as well as severe sinus bradycardia [6], have been described. With increased life expectancy of patients with Rett syndrome, it has become more common to encounter these patients in the operating room (OR). These patients have been reported to be unduly sensitive to sedative drugs, and they exhibit slow recovery from anesthesia [7,8]. We describe and discuss the anesthetic management of a 12-year-old girl with Rett syndrome, undergoing spinal fusion, who could not be awakened after surgery despite strict titration of anesthetic agents to the range of bispectral index (BIS) numbers that were previously reported to lead to successful awakening after anesthesia.