Utility of endtidal carbon dioxide monitoring in detection of hypoxia during sedation for brain magnetic resonance imaging in children with developmental disabilities.

BACKGROUND

We have shown previously that children with developmental disabilities have three times higher incidence of sedation-related hypoxia when compared with normal children.

OBJECTIVES

Our objectives were to describe the changes in endtidal carbon dioxide (ETCO(2)) values and the utility of ETCO(2) monitoring in earlier identification of hypoxia during sedation for brain magnetic resonance imaging (MRI) in children with developmental disabilities.

METHODS

We conducted a prospective observational study of a convenience sample of 150 children with developmental disabilities aged 1-10 years who received intravenous sedation for brain MRI. Children were sedated and monitored according to the institution's sedation protocol. We recorded ETCO(2) levels, hypoxia, and adverse events during sedation. Hypoxia was defined as SpO(2) < 93%. A change in ETCO(2) level ≥ 10 mm Hg from presedation baseline, an intra-sedation ≥ 50 mm Hg, and loss of capnographic waveform were considered as significant ETCO(2) abnormalities.

RESULTS

Of the children, 80.7% (121/150) were sedated with a combination of pentobarbital and fentanyl. ETCO(2) abnormalities were noted in 42.6% (64/150) of sedation encounters. Hypoxia occurred in 18% (27/150) of subjects. ETCO(2) abnormalities were documented in 19(70%) patients with hypoxia before changes in pulse oximetry were noted. ETCO(2) changes were noted a mean of 4.38 ± 1.89 min prior to occurrence of hypoxia.

CONCLUSIONS

ETCO(2) abnormalities and hypoxia occur commonly during sedation in children with developmental disabilities. ETCO(2) monitoring is useful in early recognition of impending hypoxia during sedation in children with developmental disabilities.