Abstract
Aim: This study aimed to determine whether measures of intermittent hypoxia derived from 24-hour oximetry correlate with measures of apnoea derived from modified nap polysomnography undertaken for preterm infants before discharge.
Methods: Infants born 32 weeks of gestation were recruited from the neonatal intensive care unit and had a modified polysomnography to assess their respiratory stability once they were 35 weeks of postmenstrual age. Infants were defined as unstable if they had more than 10 obstructive events per hour or any apnoea of >20 seconds in length. Infants also had a 24-hour oximetry performed during this period. The results of the 24-oximetry desaturation index (DSI) were compared to nap polysomnography results for central and obstructive apnoea indices and correlations tested.
Results: Twenty-four infants completed the study. There were 15 (63%) infants defined as unstable by the modified polysomnography. The 3% DSI and 4% DSI from the 24-hour oximetry were significantly higher in the unstable infants, and values for all infants correlated with the obstructive index and the central apnoea index from the modified polysomnography.
Conclusion: The 3% DSI and 4% DSI values from a 24-hour oximetry study may provide noninvasive measures of respiratory stability in preterm infants ready for discharge.