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NBRC SDS study materials
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NBRC SDS: Sleep-Focused Testing and Therapeutic Intervention Performed by Respiratory Therapists

NBRC SDS · Work through your exam, one topic at a time.

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Sleep-Focused Testing and Therapeutic Intervention Performed by Respiratory Therapists

What this domain tests

This domain covers the therapist's hands-on role in sleep medicine: preparing and monitoring polysomnography, applying AASM-aligned scoring logic to the data you generate, and titrating PAP, oxygen, and noninvasive ventilation overnight. Questions are practical - they ask what you would set, change, or document at 02:00, not how to diagnose narcolepsy from scratch.

Core rules and concepts

  • Event definitions: apnea is ≥90% airflow reduction for ≥10 s. Hypopnea is ≥30% reduction for ≥10 s ending in a ≥3% desaturation or an arousal (many labs also score the 4%-desaturation variant). Report AHI per hour of sleep, never per hour of recording time.
  • Titration goal: abolish obstructive events (AHI <5) in supine REM at the lowest effective pressure. Start CPAP near 4–5 cmH₂O and raise by 1–2 cm every 5 minutes while events persist; verify leak and mask fit before escalating.
  • Bilevel: widen the IPAP–EPAP gap for obstructive events; add a backup rate for central apnea or hypoventilation. EtCO₂ or transcutaneous CO₂ guides nocturnal hypoventilation, especially in obesity hypoventilation and pediatric patients.
  • Oxygen is adjunctive: titrate to roughly 88–90% SpO₂, but never as a substitute for PAP in OSA; unopposed oxygen can blunt hypoxic drive and lengthen events.
  • Daytime tests: the MSLT follows a PSG with ≥6 h of sleep; mean sleep latency ≤8 minutes with ≥2 SOREMPs supports narcolepsy. The MWT measures the ability to stay awake across four 40-minute trials.

Worked example

A 58-year-old man with diagnostic AHI 31 is titrated on CPAP. At 10 cmH₂O the residual AHI is 12, all central, appearing only after pressure passed 8 cmH₂O. Reasoning: this is treatment-emergent central sleep apnea - first rule out leak, poor mask fit, and wakefulness mimicking events; then consider lowering pressure or switching to bilevel. ASV is appropriate only when LVEF is above 45%, because ASV increased mortality in heart failure with reduced ejection fraction and central apnea.

Traps that cost marks

Scoring hypopneas with neither desaturation nor arousal; dividing events by recording time; stopping titration before supine REM is captured; calling Cheyne–Stokes respiration obstructive; ordering ASV without an echocardiogram; running an MSLT after a short PSG night.