RRT Pulmonary Function Testing Flashcards

A maximum inspiratory pressure (MIP or NIF) of -20 cmH2O in a neuromuscular disease patient suggests what?

Answer: Severely reduced inspiratory muscle strength with high intubation risk

A MIP less negative than -20 to -25 cmH2O indicates critically weak inspiratory muscles, predicting respiratory failure in neuromuscular disease.

What does the 6-minute walk test (6MWT) primarily assess in pulmonary patients?

Answer: Functional exercise capacity and submaximal aerobic performance

The 6MWT measures the distance walked in 6 minutes, reflecting submaximal exercise tolerance and correlating with quality of life in COPD and pulmonary hypertension.

Increased airway resistance (Raw) on body plethysmography is most consistent with which condition?

Answer: COPD or asthma

COPD and asthma cause airway narrowing from inflammation, mucus, and bronchospasm, increasing airway resistance measured by body plethysmography.

Which spirometric measure has the highest day-to-day variability and is least recommended for diagnosing obstruction?

Answer: Peak expiratory flow (PEF)

Peak expiratory flow is highly effort-dependent and variable, making it useful for home monitoring but not for definitive diagnosis of airflow obstruction.

In cardiopulmonary exercise testing (CPET), a low anaerobic threshold (AT) is most associated with:

Answer: Cardiovascular deconditioning or heart failure

A low anaerobic threshold indicates early lactate production due to inadequate cardiac output or deconditioning, suggesting cardiovascular limitation to exercise.

Which finding on spirometry is most characteristic of asthma?

Answer: Reversible airflow obstruction with significant post-bronchodilator improvement

Asthma is defined by reversible airflow obstruction; a positive bronchodilator response (≥12% and ≥200 mL FEV1 improvement) is a hallmark finding.