Respiration Practice Test

This is primary metabolic alkalosis without evident respiratory compensation yet. Base excess (BE) >+3 mEq/L supports a metabolic alkalosis.

The venturi mask uses jet entrainment with interchangeable ports to deliver a fixed, precise FiO₂ (commonly 24–50%). This tight control is ideal when you must avoid excessive oxygen.

Simple spirometry records air that moves in and out of the lungs. It cannot capture the air that remains after maximal exhalation. Therefore, residual volume (RV) is not directly measurable by spirometry.

TST is read at 48–72 h. In people without TB risk factors, <5 mm is considered negative.

Thresholds (≥5, ≥10, ≥15 mm) depend on risk category. Hence, 0–4 mm is the negative range in this context.

Non–small cell lung cancer (~85% of cases) is more common than small cell. NSCLC includes adenocarcinoma, squamous cell, and large cell subtypes.

Type II pneumocytes secrete pulmonary surfactant, reducing alveolar surface tension and preventing collapse. Type I cells mediate gas exchange, and “Type III” isn’t a standard pneumocyte category.

Stridor is a high-pitched inspiratory sound from upper airway (larynx/trachea) obstruction. Wheezes are lower-airway, rhonchi suggest secretions in larger airways, and vesicular is a normal breath sound.

Normal arterial pCO₂ is 35–45 mm Hg. Values like 20–40, 25–30, or 30–40 mm Hg are below normal (hypocapnia ranges).

Normal serum bicarbonate is 22–26 mEq/L. This value guides metabolic contributions to acid–base status (also reflected in BE).

TMP-SMX is first-line for P. jirovecii pneumonia. Pentamidine (IV or inhaled) is a recognized alternative when TMP-SMX is contraindicated or not tolerated.

COPD commonly leads to cor pulmonale and right-sided heart failure, and increases risk of pneumonia. Headaches can occur but are symptoms, not a classic complication like the others.

COPD encompasses chronic bronchitis and emphysema. Asthma and bronchiectasis are obstructive diseases that may coexist but are distinct. “Bronchial hypotension” isn’t a recognized disease entity.

A wheeze indicates bronchospasm in narrowed airways (musical, high-pitched). Rhonchi are low-pitched from secretions, stridor is upper-airway, and pleural rub is a grating sound from inflamed pleura.

Guaifenesin is an expectorant that thins mucus to aid clearance. Dextromethorphan, benzonatate, and codeine are antitussives (cough suppressants).

Epinephrine is a sympathomimetic bronchodilator (α/β agonist) that relaxes bronchial smooth muscle.

Acetylcysteine is a mucolytic, guaifenesin an expectorant, and budesonide an inhaled corticosteroid (anti-inflammatory, not a bronchodilator).

Theophylline is a xanthine derivative bronchodilator. Salmeterol (LABA), ipratropium (antimuscarinic), and budesonide (ICS) are not xanthines.

Acetylcysteine breaks disulfide bonds in mucus → mucolysis. Dextromethorphan, phenylephrine, loratadine are not mucolytics.

Inspiratory capacity is the volume that can be inhaled after a normal exhalation of tidal volume (\(\text{IC} = \text{TV} + \text{IRV}\)). IRV alone is the extra volume after a normal inspiration, not after exhalation.

Vital capacity is the maximum exhaled volume after the deepest possible inhalation (\(\text{VC} = \text{IRV} + \text{TV} + \text{ERV}\)).

The respiratory center comprises medullary and pontine centers in the medulla oblongata and pons, coordinating rate and depth of breathing.