Sleep latency
Normal - 5-30 minutes
Sleep efficiency
<75% is abnormal
60%-75% - reduced sleep efficiency
<60% - poor sleep efficiency
Slow wave sleep %
Normal - 1-30% SWS
Higher proportion in young population
REM latency
Normal - 60-130 minutes
Increased - 130-200 minutes
Prolonged - >200 minutes
Sleep Onset REM (SOREM)
<15 minutes
REM sleep %
Normal - 15-25%
Epworth Sleepiness Score (ESS)
0-8 – Normal
9-11 – Mild sleepiness
12-15 – Moderate sleepiness
16-24 – Severe sleepiness
Arousal Index (AI)
Increased if:
Ages <50: AI>20 arousals/hour
Age >50: AI>25 arousals/hour
Sleep fragmentation
associated with respiratory events if the respiratory arousal index:
Normal: respiratory AI < 5 arousals/hour
Mild: respiratory AI 5-14.9 arousals/hour
Moderate: 15-29.9 arousals/hour
Severe: >= 30 arousals/hour
OSA Severity
Based on RDI (AASM criteria 2016)
Mild: 5-14 events/hr
Moderate: 15-29 events/hr
Severe: >= 30 events/hr
Note that Respiratory Effort Related Arousals (RERAs) are included in RDI
Upper Airways Resistance syndrome is diagnosed when:
AHI < 5 events/hr and RDI including RERAs > 5 events/hr
REM RDI: >20 or possibly 15 events/hr – to be significant
Where isolated REM OSA – Opinion based
Oxygen Saturation
Oxygen desaturation – There is no consensus for severity. These are our arbitrary cut offs:
Mild desaturations – 85-89%
Moderate desaturations – 80-84%
Severe desaturations - <80%
Periodic Leg Movement Disorders (PLMD) Severity
• There is no consensus cut offs for PLMD severity
According to the ICSD2 criteria, PLMD in adults should be diagnoses if PLM index is >15/hr
• Our arbitrary cut offs for PLMD severity are:
Mild PLMD – 15-29/hr
Moderate PLMD – 30-49/hr
Severe - >50/hr
Sleep Fragmentation associated with PLMs
If PLM Arousal Index >5 arousals/hr
Mild Sleep Fragmentation – 5-14.9 arousals/hr
Moderate Sleep Fragmentation – 15.29.9 arousals/hr
Severe Sleep Fragmentation - >30 arousals/hr
ECG Rhythm Abnormalities
Ectopic Load - >30%
>30% - Recommend ECG Holter, Echo
10-30% - Grey zone – possibly
Heart Rate - <40 bpm
Sinus pauses - >3 secs
Blood Pressure Abnormalities – National Heart Foundation
Systolic
Mild - 140-159 mmHg
Moderate – 160-179 mmHg
Severe - > 180 mmHg
Diastolic
Mild – 90-99 mmHg
Moderate – 100-109 mmHg
Severe - >100
Obesity Grading – WHO Criteria
BMI
Overweight – 25-29.9 Kg/m2
Obesity – 30-39.9 Kg/m2
Morbid Obesity - >40 Kg/m2
Super Obesity - >50 Kg/m2
Driving Guidelines
National Transport Commission Driving Guidelines 2016 – Increased risk when:
RDI >34 events/hr
ESS > 15