LPN exams respiratory practice questions set 6

Correct answer:

Respiratory minute ventilation (VE) is tidal volume (VT) × respiratory rate (RR), fixed here at 6 L/min (6000 ml/min). Alveolar ventilation (VA) is the air reaching alveoli for gas exchange: VA = (VT - VD) × RR, where anatomic dead space (VD) is 150 ml. For 200 ml at 30/min: VE = 200 × 30 = 6000 ml/min, VA = (200 - 150) × 30 = 50 × 30 = 1500 ml/min. For 300 ml at 20/min: VE = 300 × 20 = 6000 ml/min, VA = (300 - 150) × 20 = 150 × 20 = 3000 ml/min. For 400 ml at 15/min: VE = 400 × 15 = 6000 ml/min, VA = (400 - 150) × 15 = 250 × 15 = 3750 ml/min. For 600 ml at 10/min: VE = 600 × 10 = 6000 ml/min, VA = (600 - 150) × 10 = 450 × 10 = 4500 ml/min. The 600 ml at 10/min yields the highest VA (4.5 L/min), as larger VT maximizes air past the fixed VD, despite lower RR. Higher rates with smaller VT waste more ventilation in dead space, reducing VA efficiency, making the deeper, slower pattern optimal.

Correct answer:

Restrictive lung diseases (e.g., pulmonary fibrosis) stiffen lungs, reducing expansion and volumes like forced vital capacity (FVC), which drops below normal (e.g., from 4-5 L to 2-3 L) due to limited inspiratory capacity. Forced expiratory volume in 1 second (FEV1) also decreases proportionally (e.g., from 3-4 L to 1.5-2 L), as less air is available to exhale. However, the FEV1/FVC ratio remains normal or elevated (≥80%) because both values decline similarly, unlike obstructive diseases where FEV1 falls more, lowering the ratio (<70%). Ventilation/perfusion (V/Q) ratio may skew high in restrictive disease (e.g., fibrosis) due to reduced ventilation from stiff lungs, not normal matching. FEV1 and FVC individually are reduced, not normal. The FEV1/FVC ratio's preservation reflects the restrictive pattern impaired volume, not airflow obstruction making it the value least altered relative to healthy norms, a key diagnostic feature in spirometry.

Correct answer:

Zanamivir is an inhaled antiviral used for influenza but is contraindicated in clients with COPD because it can cause bronchospasm, worsening airway obstruction and potentially leading to respiratory distress. For an older client with COPD and sickle cell disease, this risk is amplified, as both conditions compromise oxygen delivery COPD via lung function and sickle cell via reduced blood oxygenation. Oseltamivir (also known as Tamiflu) is an oral antiviral safe for such clients, making it a better choice. Xanax, an anti-anxiety drug, isn't an antiviral and is irrelevant here. The nurse must notify the prescriber about Zanamivir due to its potential to exacerbate the client's respiratory condition, requiring an alternative like Oseltamivir. This decision reflects the nurse's duty to assess medication appropriateness based on the client's comorbidities, preventing harm and ensuring treatment aligns with the client's fragile health status.

Correct answer:

Zanamivir is an inhaled antiviral used for influenza but is contraindicated in clients with COPD because it can cause bronchospasm, worsening airway obstruction and potentially leading to respiratory distress. For an older client with COPD and sickle cell disease, this risk is amplified, as both conditions compromise oxygen delivery COPD via lung function and sickle cell via reduced blood oxygenation. Oseltamivir (also known as Tamiflu) is an oral antiviral safe for such clients, making it a better choice. Xanax, an anti-anxiety drug, isn't an antiviral and is irrelevant here. The nurse must notify the prescriber about Zanamivir due to its potential to exacerbate the client's respiratory condition, requiring an alternative like Oseltamivir. This decision reflects the nurse's duty to assess medication appropriateness based on the client's comorbidities, preventing harm and ensuring treatment aligns with the client's fragile health status.

Correct answer:

The correct answer is B: an increase of the respiratory rate. When carbon dioxide levels rise in the blood, it triggers the body to increase the rate of breathing to eliminate excess carbon dioxide through exhalation. This is known as the respiratory drive, controlled by the respiratory centers in the brainstem. Increasing the respiratory rate helps to restore the balance of gases in the blood. Incorrect Choices: A: Decrease in the rate of breathing - This is incorrect because high levels of carbon dioxide would stimulate an increase in breathing rate, not a decrease. C: Decrease of pulmonary ventilation - This is incorrect as an increase in carbon dioxide would typically lead to an increase, not a decrease, in pulmonary ventilation. D: Decrease of the alveolar ventilation rate - This is incorrect because an increase in carbon dioxide would prompt an increase in alveolar ventilation to remove excess carbon dioxide from the blood.

Correct answer:

Pneumothorax occurs when air enters the pleural space, disrupting negative intrapleural pressure (~-4 mmHg), causing lung collapse and chest wall expansion. The thorax's diameter increases as the chest wall springs outward due to its elastic recoil. Venous return decreases because positive pleural pressure compresses the vena cava, reducing preload, especially in tension pneumothorax. Vital capacity (VC) drops as the collapsed lung reduces expirable volume (e.g., from 4-5 L to much less). However, lung compliance (C = ΔV / ΔP) doesn't increase it's a lung property (stiffness), not directly altered by pneumothorax. The collapsed lung's volume change per pressure is irrelevant, as it's deflated; compliance may appear effectively zero, but the lung tissue itself isn't more compliant. Increased compliance misrepresents pneumothorax's mechanics, where the issue is pressure loss, not lung elasticity, making this the untrue statement.

Correct answer:

Most CO₂ diffusing into blood in systemic capillaries converts to bicarbonate ions in red blood cells (RBCs), making choice C correct. Only about 5-10% remains dissolved as CO₂ (choice A) due to low solubility. Around 20-25% forms carbamino compounds (choice B) by binding to hemoglobin's amino groups, but this is less dominant. The majority (65-70%) enters RBCs, where carbonic anhydrase catalyzes its reaction with H₂O to form carbonic acid (H₂CO₃), which dissociates into H⁺ and HCO₃⁻ (bicarbonate). ' CO₂ doesn't combine directly with hemoglobin significantly carbamino formation is specific. Choice E occurs minimally in plasma (slow without enzyme) compared to RBCs. Bicarbonate then exits RBCs via the chloride shift, maintaining pH balance. This process's efficiency in RBCs, driven by enzymatic speed and volume, ensures C is the primary fate of CO₂ in systemic capillaries.

Correct answer:

The body's natural defenses against influenza include viscous mucus secretions in the respiratory tract that trap viral particles, preventing deeper penetration, and local immunologic defenses like antibodies and inflammatory responses that neutralize the virus at entry points. This inflammation, triggered by immune cells, fights infection but causes symptoms like swelling or fever. Vasodilation occurs, but lowering body temperature isn't a defense fever actually helps combat viruses. Antihistamines aren't naturally released; they're medications, and catecholamines boost alertness, not immunity. Coughing clears mucus, but antidiuretic hormone inhibition isn't a flu defense it relates to fluid balance. The nurse explains mucus and local immunity as key barriers, educating the client on how the body resists influenza naturally before adaptive immunity fully activates, emphasizing their role in limiting viral spread and aiding recovery.

Correct answer:

For a client post-chemotherapy and radiation, the nurse advises that those with weakened immune systems, like her, are more susceptible to infections and severe flu outcomes, making vaccination wise with the inactivated shot, not the live nasal spray. Chemotherapy suppresses immunity, increasing flu risk even months later, and the inactivated vaccine safely boosts protection without infection risk. Saying the vaccine causes flu is false it's inactivated, not live, in the shot form recommended here. Influenza is indeed modifiable vaccination lowers risk, a key point for this vulnerable client. The nasal spray's live virus is contraindicated post-chemo due to immune compromise, but the shot is safe and effective. The nurse's accurate advice emphasizes vaccination's protective role, tailored to her condition, preventing severe illness in someone still recovering immunity, aligning with CDC guidelines for immunocompromised individuals.

Correct answer:

For a client post-chemotherapy and radiation, the nurse advises that those with weakened immune systems, like her, are more susceptible to infections and severe flu outcomes, making vaccination wise with the inactivated shot, not the live nasal spray. Chemotherapy suppresses immunity, increasing flu risk even months later, and the inactivated vaccine safely boosts protection without infection risk. Saying the vaccine causes flu is false it's inactivated, not live, in the shot form recommended here. Influenza is indeed modifiable vaccination lowers risk, a key point for this vulnerable client. The nasal spray's live virus is contraindicated post-chemo due to immune compromise, but the shot is safe and effective. The nurse's accurate advice emphasizes vaccination's protective role, tailored to her condition, preventing severe illness in someone still recovering immunity, aligning with CDC guidelines for immunocompromised individuals.