Cardiorespiratory Parameters in Newborns During Sedation with Chloral Hydrate

Background: We commonly use chloral hydrate sedation in newbornsto facilitate painless diagnostic procedures, though its cardiorespiratory side effects have not yet been fully investigated. Previous pediatric studies were mostly retrospective, based on intermittent measuring of vital signs and have mainly included older infants and children.

Objective: Our study used continuous recording of cardiorespiratory functions by polygraphy, including end-tidal CO₂ monitoring, with the aim to analyze the impact of chloral hydrate on cardiorespiratory parameters in term newborns.

Methods: We performed a prospective, pre-post single-arm interventional study in 42 term respiratorily and hemodynamically stable newborns. Oxygen saturation (SpO₂), end-tidal CO₂ (ETCO₂), apnea-hypopnea index and respiratory and heart rate were recorded with polygraphy, starting 0.5-1 hour before the administration of chloral hydrate at a dose of 40 mg/kg and stopping 4 hours post-administration.

Results: All measured cardiorespiratory parameters changed significantly after administration of chloral hydrate. The mean basal SpO₂ dropped by 2.0% (from 97.1% to 95.1%; p<.001) and the mean basal ETCO2 increased by 3.9 mmHg (from 25.6 to 29.5 mmHg; p<.001). We also found a significant decrease in minimal SpO₂ values (p<.001) and an increase in the proportion of time spent with SpO₂ <95% and <90% (p<.001). The mean increase of estimated apnea-hypopnea index was 3.5 events per hour (p<.001). The mean respiratory and heart rate were significantly lower 150 min after administration of chloral hydrate when compared with pre-sedation values (51/min and 127/min versus 61/min and 138/min respectively; p<.001).

Conclusions: Chloral hydrate sedation at a dose of 40 mg/kg causes mild changes in SpO₂, ETCO₂, estimated apnea-hypopnea index and respiratory and heart rate. These cardiorespiratory parameters remained within normal limits in most newborns, confirming the safety of chloral hydrate sedation. Nevertheless, since cardiorespiratory effects of chloral hydrate varied considerably among newborns, monitoring of sedated newborns continues to remain necessary.