AASM clarifies hypopnea scoring criteria

In August members were notified that the AASM has suspended indefinitely the requirement for accredited sleep centers to score hypopneas in adult patients according to the 3 percent oxygen desaturation criterion in the new AASM scoring manual.

The AASM continues to recommend scoring hypopneas in adults when there is a ≥ 3% oxygen desaturation from pre-event baseline and/or the event is associated with an arousal.  However, it is acceptable for accredited sleep centers to score hypopneas in adults when there is a ≥ 4% oxygen desaturation from pre-event baseline.

AASM sleep centers must specify in the PSG report whether hypopneas were scored using the recommended rule 1A or the acceptable rule 1B:

Recommended

1A. Score a respiratory event as a hypopnea if ALL of the following criteria are met:

a. The peak signal excursions drop by ≥30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative hypopnea sensor (diagnostic study).

b. The duration of the ≥30% drop in signal excursion is ≥10 seconds.

c. There is a ≥3% oxygen desaturation from pre-event baseline and/or the event is associated with an arousal.

OR

Acceptable

1B. Score a respiratory event as a hypopnea if ALL of the following criteria are met:

a. The peak signal excursions drop by ≥30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative hypopnea sensor (diagnostic study).
b. The duration of the ≥30% drop in signal excursion is ≥10 seconds.
c. There is a ≥ 4% oxygen desaturation from pre-event baseline.

Please note that the criterion involving arousals is included in 1A and excluded from 1B.

The AASM also reminds members that this clarification is applicable only to the adult scoring criteria for hypopneas.  Criteria for scoring hypopneas in children, which are provided in a separate section of the scoring manual, remain unaffected.

This revised rule is in effect immediately and is included in the current version of the AASM Manual for the Scoring of Sleep and Associated Events, Version 2.0.2.

Comments about the hypopnea scoring criteria can be submitted to the AASM at scoringmanual@aasm.org. Questions or comments about requirements for accredited sleep centers can be submitted to accreditation@aasm.org.