Definitions14
ODI – Number of ≥ 3% arterial oxygen desaturations per hour.
AI – Number of arousals/awakenings per hour of sleep.
AHI – Number of apnea and hypopnea events per hour during sleep with apneas defined as a drop in peak excursion of air flow by ≥90% of baseline for at least 2 breaths with or without associated desaturation or arousal and hypopneas defined as a drop in peak excursion of air flow ≥30% for at least 2 breaths with ≥3% desaturation from baseline or with associated arousal
CAI – Number of central apnea events per hour during sleep; respiratory event meeting apnea criteria, associated with absent inspiratory effort throughout the entire duration of the event, and at least one of the following is met:
MAI – Number of mixed apnea events per hour during sleep; events meeting apnea criteria for at least the duration of 2 breaths during baseline breathing and is associated with absent respiratory effort during one portion of the event and the presence of inspiratory effort in another portion, regardless of which portion comes first .
OAI – Number of obstructive apnea events per hour during sleep; events meeting apnea criteria for at least the duration of 2 breaths during baseline breathing and is associated with presence of respiratory effort throughout the entire period of absent airflow.
HI – Number of hypopnea events per hour during sleep.
Pediatric OSA – In children, it is defined as obstructive apnea hypopnea index (OAHI) ≥1 obstructive event per hour with the event being obstructive or mixed apnea or obstructive hypopnea in nature17.
AASM CSA – The AASM defines CSA as central apnea hypopnea index (CAI+HI) ≥5/hr. and that the number of central apnea/hypopnea events is >50% of total apnea/hypopnea events17. This definition is commonly used in the adult population.
Pediatric CSA – Definition of CSA is varied throughout pediatric literature15. In order to help facilitate comparison of our results with other pediatric studies on CSA, we defined pediatric CSA as CAI+HI >1/hr. and number of central apnea/hypopnea events >50% of total apnea/hypopnea events. For the purposes of this study, all CSA referenced will use the Pediatric CSA definition unless otherwise stated.
Elevated CAI – Using the AASM definition of clinically significant pediatric sleep apnea as AHI >1/hr., for the purpose of this study, we defined elevated central apnea index as CAI >1/hr.