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:
- The event lasts 20 seconds or longer.
- The event lasts at least the duration of two breaths during baseline
breathing and is associated with an arousal or ≥3% oxygen
desaturation.
- For infants younger than 1 year of age, the event lasts at least the
duration of two breaths during baseline breathing and is associated
with a decrease in heart rate to less than 50 beats per minute for at
least 5 seconds or less than 60 beats per minute for 15 seconds.
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.