NRCME Respiratory Health and Sleep Apnea 5 — Questions and Answers
Question 1: The FMCSA recommends that medical examiners use which tool to systematically screen commercial drivers for OSA risk?
- The STOP-BANG questionnaire exclusively
- The Berlin Questionnaire exclusively
- A multivariate risk assessment combining BMI, neck circumference, and symptoms (Correct answer)
- Overnight oximetry as the sole screening method
Correct answer: A multivariate risk assessment combining BMI, neck circumference, and symptoms
FMCSA guidance endorses using multiple risk factors—including BMI, neck circumference, blood pressure, and reported symptoms—rather than any single tool alone.
Question 2: Which arterial blood gas pattern most strongly suggests chronic respiratory failure in a driver with advanced COPD?
- PaO2 85 mmHg, PaCO2 38 mmHg, pH 7.41
- PaO2 58 mmHg, PaCO2 52 mmHg, pH 7.36 with elevated HCO3 (Correct answer)
- PaO2 70 mmHg, PaCO2 30 mmHg, pH 7.48
- PaO2 90 mmHg, PaCO2 44 mmHg, pH 7.39
Correct answer: PaO2 58 mmHg, PaCO2 52 mmHg, pH 7.36 with elevated HCO3
Hypoxemia with hypercapnia and compensatory metabolic alkalosis (elevated bicarbonate, near-normal pH) indicates chronic ventilatory failure.
Question 3: A driver reports using a mandibular advancement device (MAD) for mild OSA. What documentation should the medical examiner request?
- Dental records showing the device was custom-fitted
- Post-treatment sleep study confirming AHI reduction to acceptable levels (Correct answer)
- Receipt showing the device was purchased within the last year
- Letter from the dentist confirming the driver wears the device nightly
Correct answer: Post-treatment sleep study confirming AHI reduction to acceptable levels
Objective evidence of treatment efficacy—via repeat sleep study showing AHI reduction—is required, not just documentation of device ownership.
Question 4: Hypoxic vasoconstriction in the pulmonary vasculature, triggered by OSA-related desaturation, most directly leads to which complication?
- Systemic hypotension
- Pulmonary hypertension (Correct answer)
- Left ventricular hypertrophy
- Aortic stenosis
Correct answer: Pulmonary hypertension
Chronic hypoxic pulmonary vasoconstriction raises pulmonary artery pressure, ultimately causing pulmonary hypertension and right ventricular strain.
Question 5: A driver's home sleep test shows an AHI of 8 events/hour but the device flagged 40% of the study as artifact. What is the best course of action?
- Accept AHI of 8 as mild OSA and certify with treatment recommendation
- Discard the study and certify the driver since no OSA was conclusively proven
- Repeat the sleep study—either HSAT or in-lab PSG—due to inadequate data quality (Correct answer)
- Average the valid-data AHI to estimate the true AHI
Correct answer: Repeat the sleep study—either HSAT or in-lab PSG—due to inadequate data quality
High artifact rates in a home sleep test render results unreliable; a repeat study is needed to obtain valid diagnostic data.
Question 6: Which of the following is NOT a recognized consequence of untreated severe OSA relevant to commercial driver safety?
- Increased risk of motor vehicle crashes
- Impaired sustained attention and vigilance
- Elevated risk of type 2 diabetes
- Improved night vision due to hyperventilation-induced pupil dilation (Correct answer)
Correct answer: Improved night vision due to hyperventilation-induced pupil dilation
Untreated OSA does not improve night vision; rather it causes neurocognitive deficits, metabolic dysfunction, and cardiovascular disease that impair driving safety.
Question 7: A driver taking theophylline for COPD management reports palpitations and tremor. These symptoms are most relevant to the NRCME exam because they suggest:
- Theophylline toxicity, which may cause cardiac arrhythmias disqualifying the driver (Correct answer)
- Normal side effects that do not affect driving fitness
- Need to switch to inhaled therapy only if symptoms are mild
- Anxiety disorder requiring psychiatric clearance before certification
Correct answer: Theophylline toxicity, which may cause cardiac arrhythmias disqualifying the driver
Theophylline has a narrow therapeutic index; toxicity can precipitate serious arrhythmias, seizures, and syncope that directly endanger commercial vehicle operation.
NRCME Respiratory Health and Sleep Apnea 5
The FMCSA recommends that medical examiners use which tool to systematically screen commercial drivers for OSA risk?