Hypopnea is defined as?
> 10% reduction in airflow for at least 10 seconds with > 1% desaturation on arousal > 20% reduction in airflow for at least 10 seconds with > 2% desaturation on arousal > 30% reduction in airflow for at least 10 seconds with > 3% desaturation on arousal > 40% reduction in airflow for at least 10 seconds with > 4% desaturation on arousal