Chloral hydrate

Observational studies

In a retrospective analysis of 1095 children who were sedated for echocardiography with chloral hydrate, vital signs and oxygen saturations were recorded every 5 minutes and adverse events were noted [ ]. There was significant co-morbidity as assessed by the fact that 38% of the subjects were classified as American Society of Anesthesiologists class 3 or 4. Hemodynamic responses to chloral hydrate sedation included at least a 20% fall in heart rate (24% of the patients) and blood pressure (59%). There were no deaths or permanent morbidities. There were adverse events in 11% of patients, including apnea, airway obstruction, hypoxia, hypotension with poor perfusion, vomiting, and prolonged sedation. No intervention was required in 93%, minor interventions were necessary in 7%, and major interventions were required in 0.5%. Multivariate analysis identified only age under 6 months as a predictor for adverse events, whereas cyanosis, hospitalization, American Society of Anesthesiologists class, fasting time, oxygen requirement, and the use of additional sedation were not predictors. Moderate falls in heart rate and blood pressure, in the absence of clinical deterioration, are expected responses to chloral hydrate sedation in this pediatric population.

Cardiovascular

A single dose (1.2 g) in a 4-year-old girl gave rise to a reversible ventricular dysrhythmia [ ].

Nervous system

Two generalized seizures occurred in a 2-year-old boy after he was sedated before echocardiography [ ].

Gastrointestinal

A 78-year-old woman and a 45-year-old man developed Pneumatosis cystoides coli. Both were taking chloral hydrate [ ]. It was speculated that chloral hydrate had caused the abdominal symptoms in these patients.

• A 69-year-old man had daily loose stools with mucous discharge. Repeated stool cultures were negative. Histology confirmed the appearances of pneumatosis cystoides coli. Various treatments had little effect on his symptoms. He had taken chloral hydrate for insomnia for 10 years. Subjectively, his symptoms were worse while taking the drug and resolved after withdrawal. With his consent, an unblinded controlled challenge with chloral hydrate was performed. The results, recorded meticulously in a symptoms diary, were dramatic. Before chloral hydrate, his bowels opened 18 times per week and only two motions contained mucus. After one tablet of chloral hydrate on days 1, 2, 5, and 7 he passed 49 stools in one week, 35 containing mucus. Two weeks later his bowel habit had returned to normal, with 15 movements per week, and only one stool contained mucus. Subsequently his bowel frequency fell to 8–10 times per week with considerable colonoscopic improvement.