SDS EXAM (NBRC) 2025/2026
QUESTIONS AND ANSWERS 100% PASS
How long is a typical full sleep cycle?
90-110 MIN
4-6 cycles/night (NREM → REM)
What happens to REM duration over the night?
REM gets longer in later cycles
- SLEEP latency: time to fall asleep
(normal <20 min)
REM latency: time from sleep onset - to first REM
(normal = 90-120 min)
(<60 min) → narcolepsy, OSA, depression, or sleep deprivation
NOTE!!!
<60 min: Can still suggest sleep deprivation or poor sleep quality but is not as diagnostic as < 8
min for narcolepsy.
What's the normal impedance for electrodes in PSG?
less than 5k
Gold standard for detecting both apneas and hypopneas.
Nasal pressure transducer
Obstructive Sleep Apnea (OSA)
> Flattened inspiratory flow on nasal pressure
> Paradoxical thoracoabdominal movement
> Oxygen desaturation
pg. 1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,Treatment: CPAP is first-line; BiPAP if hypoventilation present
Central Sleep Apnea (CSA)
>Repeated cessation of airflow without respiratory effort
>Causes: CHF, high-altitude sleep, opioid use, brainstem injury
>Cheyne-Stokes Breathing: Seen in CHF (cyclical waxing/waning pattern)
- Patients with heart failure, opioid use, or high altitude exposure often show greater
desaturation due to poorer oxygen reserve.
PSG Signs:
No thoracic or abdominal effort
Flow stops with no attempt to breathe
Treatment:
FIRST! Optimize underlying disease (e.g., CHF)
Supplemental O2 or adaptive servo-ventilation (ASV)
Complex Sleep Apnea Syndrome (CompSAS)
AKA: Treatment-Emergent Central Sleep Apnea
A form of sleep apnea where central apneas appear or worsen after starting CPAP therapy for
OSA.
Key Features:
Patient diagnosed with OSA → put on CPAP → AHI doesn't improve or worsens due to central
apneas.
!!!!Often found in patients with CHF, neurologic issues, or idiopathic causes.!!!
Treatment:
Try CPAP first
If central apneas persist → switch to Adaptive Servo-Ventilation (ASV) or BiPAP with backup
rate
Optimize heart failure therapy if relevant
Obesity hypoventilation syndrome (OHS)
BMI ≥ 30
Daytime hypercapnia (PaCO₂ ≥ 45 mmHg)
No other cause of hypoventilation (e.g., COPD or neuromuscular)
Signs:
-Loud snoring, hypersomnolence, headaches, poor concentration
pg. 2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, -Elevated CO₂ levels (especially during the day)
-Can overlap with OSA (called "Overlap Syndrome")
PSG Signs:
Severe OSA often present
Sustained hypoventilation (↑ EtCO₂ or ↓ SpO₂)
Treatment:
First line: BiPAP (spontaneous-timed mode if needed)
Weight loss and CPAP if mostly obstructive events
Monitor blood gases (ABG)
UARS (Upper Airway Resistance Syndrome)
RDI > AHI
Subtle airflow limitation + RERAs + daytime sleepiness
Treatment
CPAP or oral appliance if symptomatic
Pediatric OSA
OSA in Kids
-Often due to adenotonsillar hypertrophy
-Symptoms: snoring, hyperactivity, poor growth, Behavior problems, ADHD-like sign
-Diagnosis: AHI ≥1 = abnormal in kids
-Treatment: surgery, Tonsillectomy/adenoidectomy (T&A), CPAP if needed>
Pediatric Red Flags:
-Poor school performance
-Hyperactivity instead of tiredness
-Growth delay
-Mouth breathing, nasal speech
Adult OSA
> Obesity, upper airway anatomy
> AHI diagnostic threshold; ≥5 per hour
> Daytime symptoms; Fatigue, daytime sleepiness.
> Common treatment; CPAP
CSA in Kids
-Can be normal in infants (self-resolving periodic breathing)
CPAP Titration Goals
pg. 3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
QUESTIONS AND ANSWERS 100% PASS
How long is a typical full sleep cycle?
90-110 MIN
4-6 cycles/night (NREM → REM)
What happens to REM duration over the night?
REM gets longer in later cycles
- SLEEP latency: time to fall asleep
(normal <20 min)
REM latency: time from sleep onset - to first REM
(normal = 90-120 min)
(<60 min) → narcolepsy, OSA, depression, or sleep deprivation
NOTE!!!
<60 min: Can still suggest sleep deprivation or poor sleep quality but is not as diagnostic as < 8
min for narcolepsy.
What's the normal impedance for electrodes in PSG?
less than 5k
Gold standard for detecting both apneas and hypopneas.
Nasal pressure transducer
Obstructive Sleep Apnea (OSA)
> Flattened inspiratory flow on nasal pressure
> Paradoxical thoracoabdominal movement
> Oxygen desaturation
pg. 1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,Treatment: CPAP is first-line; BiPAP if hypoventilation present
Central Sleep Apnea (CSA)
>Repeated cessation of airflow without respiratory effort
>Causes: CHF, high-altitude sleep, opioid use, brainstem injury
>Cheyne-Stokes Breathing: Seen in CHF (cyclical waxing/waning pattern)
- Patients with heart failure, opioid use, or high altitude exposure often show greater
desaturation due to poorer oxygen reserve.
PSG Signs:
No thoracic or abdominal effort
Flow stops with no attempt to breathe
Treatment:
FIRST! Optimize underlying disease (e.g., CHF)
Supplemental O2 or adaptive servo-ventilation (ASV)
Complex Sleep Apnea Syndrome (CompSAS)
AKA: Treatment-Emergent Central Sleep Apnea
A form of sleep apnea where central apneas appear or worsen after starting CPAP therapy for
OSA.
Key Features:
Patient diagnosed with OSA → put on CPAP → AHI doesn't improve or worsens due to central
apneas.
!!!!Often found in patients with CHF, neurologic issues, or idiopathic causes.!!!
Treatment:
Try CPAP first
If central apneas persist → switch to Adaptive Servo-Ventilation (ASV) or BiPAP with backup
rate
Optimize heart failure therapy if relevant
Obesity hypoventilation syndrome (OHS)
BMI ≥ 30
Daytime hypercapnia (PaCO₂ ≥ 45 mmHg)
No other cause of hypoventilation (e.g., COPD or neuromuscular)
Signs:
-Loud snoring, hypersomnolence, headaches, poor concentration
pg. 2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, -Elevated CO₂ levels (especially during the day)
-Can overlap with OSA (called "Overlap Syndrome")
PSG Signs:
Severe OSA often present
Sustained hypoventilation (↑ EtCO₂ or ↓ SpO₂)
Treatment:
First line: BiPAP (spontaneous-timed mode if needed)
Weight loss and CPAP if mostly obstructive events
Monitor blood gases (ABG)
UARS (Upper Airway Resistance Syndrome)
RDI > AHI
Subtle airflow limitation + RERAs + daytime sleepiness
Treatment
CPAP or oral appliance if symptomatic
Pediatric OSA
OSA in Kids
-Often due to adenotonsillar hypertrophy
-Symptoms: snoring, hyperactivity, poor growth, Behavior problems, ADHD-like sign
-Diagnosis: AHI ≥1 = abnormal in kids
-Treatment: surgery, Tonsillectomy/adenoidectomy (T&A), CPAP if needed>
Pediatric Red Flags:
-Poor school performance
-Hyperactivity instead of tiredness
-Growth delay
-Mouth breathing, nasal speech
Adult OSA
> Obesity, upper airway anatomy
> AHI diagnostic threshold; ≥5 per hour
> Daytime symptoms; Fatigue, daytime sleepiness.
> Common treatment; CPAP
CSA in Kids
-Can be normal in infants (self-resolving periodic breathing)
CPAP Titration Goals
pg. 3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
