Introduction
Pulmonary disease and critical care management represent essential competencies for Adult-Gerontology Acute Care Nurse Practitioners, as respiratory conditions are among the most common reasons for acute care admissions and intensive care unit stays. The AGACNP-BC certification examination places significant emphasis on the ability to assess, diagnose, and manage complex pulmonary conditions ranging from acute respiratory failure and mechanical ventilation to chronic obstructive pulmonary disease exacerbations and pulmonary embolism. Mastery of advanced pathophysiology related to gas exchange, ventilation-perfusion matching, and respiratory mechanics is fundamental to providing evidence-based care in acute settings. AGACNPs must demonstrate proficiency in interpreting arterial blood gases, chest radiographs, pulmonary function tests, and other diagnostic studies to guide clinical decision-making. The management of critically ill patients with respiratory compromise requires sophisticated knowledge of mechanical ventilation modes, ventilator settings, weaning protocols, and the prevention of ventilator-associated complications. Understanding the pharmacological management of pulmonary conditions, including bronchodilators, corticosteroids, antibiotics, and anticoagulation therapy, is crucial for optimizing patient outcomes. AGACNPs working in acute care settings must be skilled in recognizing early signs of respiratory deterioration, implementing appropriate interventions, and knowing when to escalate care or consult pulmonary specialists. The integration of evidence-based guidelines for conditions such as acute respiratory distress syndrome (ARDS), pneumonia, asthma exacerbations, and pleural effusions is essential for certification success and clinical excellence. Critical care management extends beyond the respiratory system to include hemodynamic monitoring, fluid management, and the recognition of multisystem organ dysfunction in critically ill patients. The practice questions that follow are designed to challenge your clinical reasoning skills and test your ability to apply advanced knowledge in realistic acute care scenarios. Proficiency in pulmonary disease and critical care not only prepares you for certification but also ensures you can provide the highest level of care to some of the most vulnerable patients in the healthcare system.
Practice Questions
Question 1:
A 68-year-old male with COPD is admitted with acute hypoxemic respiratory failure. ABG results show: pH 7.32, PaCO2 68 mmHg, PaO2 52 mmHg, HCO3 34 mEq/L. What is the most appropriate initial intervention?
A) Intubation and mechanical ventilation
B) Non-invasive positive pressure ventilation (NIPPV)
C) High-flow nasal cannula at 60 L/min
D) Non-rebreather mask at 15 L/min
Correct Answer: B) Non-invasive positive pressure ventilation (NIPPV)
Explanation: This patient presents with acute-on-chronic respiratory acidosis (elevated PaCO2 with compensatory elevated HCO3) and hypoxemia. The pH of 7.32 indicates acute decompensation. For patients with COPD exacerbations and acute hypercapnic respiratory failure who are alert and able to protect their airway, non-invasive positive pressure ventilation (BiPAP) is the first-line intervention. NIPPV has been shown to reduce the need for intubation, decrease mortality, and shorten hospital stays in this population. It provides ventilatory support to reduce work of breathing and improve gas exchange while avoiding the complications associated with invasive mechanical ventilation. Intubation would be reserved for patients who fail NIPPV, have altered mental status, cannot protect their airway, or have contraindications to NIPPV. High-flow nasal cannula, while beneficial for hypoxemic respiratory failure, does not provide the same level of ventilatory support needed for hypercapnic respiratory failure. A non-rebreather mask would provide oxygen but no ventilatory support to address the elevated CO2.
Question 2:
A mechanically ventilated patient has the following settings: AC mode, TV 450 mL, RR 16, PEEP 10, FiO2 0.60. The patient’s ideal body weight is 75 kg. What change should be made to optimize lung-protective ventilation?
A) Increase tidal volume to 600 mL
B) Decrease tidal volume to 375 mL
C) Increase PEEP to 15 cm H2O
D) Decrease respiratory rate to 12
Correct Answer: B) Decrease tidal volume to 375 mL
Explanation: Lung-protective ventilation strategies recommend tidal volumes of 6-8 mL/kg of ideal body weight (IBW). For this patient with an IBW of 75 kg, the current tidal volume of 450 mL equals 6 mL/kg, which is at the lower end of the acceptable range. However, in patients with ARDS or acute lung injury (suggested by the PEEP of 10 and FiO2 of 0.60), reducing to the lower end or even below 6 mL/kg (4-6 mL/kg in severe ARDS) would be more protective. Decreasing to 375 mL (5 mL/kg) would optimize lung protection. Increasing tidal volume would increase the risk of barotrauma and volutrauma. PEEP adjustments should be based on oxygenation needs and hemodynamic tolerance. Decreasing respiratory rate would lead to increased PaCO2 and respiratory acidosis.
Question 3:
A 55-year-old female presents with sudden onset dyspnea and pleuritic chest pain. Vital signs: BP 110/70, HR 118, RR 28, SpO2 88% on room air. Wells score is 6.5. What is the most appropriate next diagnostic test?
A) D-dimer
B) CT pulmonary angiography (CTPA)
C) Ventilation-perfusion (V/Q) scan
D) Lower extremity Doppler ultrasound
Correct Answer: B) CT pulmonary angiography (CTPA)
Explanation: This patient presents with classic signs of pulmonary embolism: sudden dyspnea, pleuritic chest pain, tachycardia, tachypnea, and hypoxemia. The Wells score of 6.5 indicates high probability for PE (score >6 = high probability). In patients with high pretest probability for PE, the most appropriate diagnostic test is CT pulmonary angiography (CTPA), which is the gold standard for PE diagnosis. CTPA provides direct visualization of thrombi in the pulmonary arteries and can also identify alternative diagnoses. D-dimer testing is useful in low-to-moderate probability patients to rule out PE, but in high-probability patients, a negative D-dimer would not be sufficient to exclude PE. V/Q scan is an alternative when CTPA is contraindicated. Lower extremity Doppler may identify DVT but does not diagnose PE and would delay definitive diagnosis and treatment.
Question 4:
A patient with ARDS on mechanical ventilation has a plateau pressure of 35 cm H2O. Current settings: TV 400 mL (6 mL/kg IBW), PEEP 14, FiO2 0.80. What is the most appropriate intervention?
A) Decrease tidal volume to 300 mL
B) Decrease PEEP to 10 cm H2O
C) Increase tidal volume to 500 mL
D) Initiate neuromuscular blockade
Correct Answer: A) Decrease tidal volume to 300 mL
Explanation: In ARDS management, plateau pressure (Pplat) should be maintained at ≤30 cm H2O to prevent ventilator-induced lung injury. This patient’s Pplat of 35 cm H2O is dangerously elevated. The driving pressure (Pplat – PEEP) is 21 cm H2O (35-14), which is also elevated (goal <15 cm H2O). The most appropriate intervention is to decrease tidal volume further, even below the standard 6 mL/kg IBW if necessary, to achieve a Pplat ≤30 cm H2O. This strategy, known as "permissive hypercapnia," accepts higher CO2 levels to protect the lungs from barotrauma. Decreasing PEEP might lower plateau pressure but would also reduce oxygenation and increase atelectasis. Increasing tidal volume would further elevate plateau pressure. Neuromuscular blockade may be considered in severe ARDS but addressing the elevated plateau pressure through ventilator adjustments is the priority.
Question 5:
A 72-year-old male with community-acquired pneumonia has the following ABG on 2L NC: pH 7.48, PaCO2 32 mmHg, PaO2 78 mmHg, HCO3 23 mEq/L. How should this be interpreted?
A) Respiratory alkalosis, uncompensated
B) Respiratory alkalosis, partially compensated
C) Metabolic alkalosis, uncompensated
D) Normal acid-base status
Correct Answer: A) Respiratory alkalosis, uncompensated
Explanation: This ABG shows respiratory alkalosis (elevated pH with decreased PaCO2). The pH is 7.48 (alkalotic, normal 7.35-7.45), PaCO2 is 32 mmHg (low, normal 35-45 mmHg), and HCO3 is 23 mEq/L (normal, 22-26 mEq/L). The primary disturbance is respiratory (low CO2 causing high pH), and there is no metabolic compensation (HCO3 is normal). In respiratory alkalosis, metabolic compensation would involve the kidneys decreasing HCO3 reabsorption, resulting in a low HCO3. Since the HCO3 is normal, this is uncompensated respiratory alkalosis. This is common in pneumonia patients who are tachypneic due to hypoxemia, pain, or anxiety, leading to excessive CO2 elimination. The PaO2 of 78 mmHg on 2L NC indicates mild hypoxemia, which is driving the tachypnea and subsequent respiratory alkalosis.
Question 6:
A patient is being evaluated for COPD. Spirometry results show: FEV1/FVC ratio of 0.65, FEV1 55% predicted, post-bronchodilator FEV1 increase of 8%. What GOLD classification is this?
A) GOLD 1 (Mild)
B) GOLD 2 (Moderate)
C) GOLD 3 (Severe)
D) GOLD 4 (Very Severe)
Correct Answer: B) GOLD 2 (Moderate)
Explanation: The GOLD classification system uses post-bronchodilator FEV1 to stage COPD severity. The FEV1/FVC ratio of 0.65 (<0.70) confirms airflow obstruction consistent with COPD. The post-bronchodilator FEV1 increase of 8% (<12% and <200 mL) indicates the obstruction is not fully reversible, characteristic of COPD. The GOLD classification: GOLD 1 (Mild) = FEV1 ≥80% predicted; GOLD 2 (Moderate) = 50% ≤ FEV1 <80% predicted; GOLD 3 (Severe) = 30% ≤ FEV1 <50% predicted; GOLD 4 (Very Severe) = FEV1 <30% predicted. This patient's FEV1 of 55% predicted falls into GOLD 2 (Moderate). This classification helps guide treatment decisions, with GOLD 2 patients typically requiring long-acting bronchodilators and potentially inhaled corticosteroids depending on exacerbation history and symptom burden.
Question 7:
A mechanically ventilated patient develops sudden hypotension, tachycardia, and decreased breath sounds on the right side. Peak airway pressure has increased from 25 to 45 cm H2O. What is the most likely diagnosis?
A) Mucus plugging
B) Right-sided pneumothorax
C) Pulmonary embolism
D) Ventilator-associated pneumonia
Correct Answer: B) Right-sided pneumothorax
Explanation: This clinical presentation is classic for tension pneumothorax in a mechanically ventilated patient. The sudden onset of hypotension (due to decreased venous return from increased intrathoracic pressure), tachycardia (compensatory response), unilateral decreased breath sounds, and markedly increased peak airway pressure (from 25 to 45 cm H2O) all point to pneumothorax. Positive pressure ventilation can convert a simple pneumothorax into a tension pneumothorax, which is a life-threatening emergency requiring immediate needle decompression followed by chest tube placement. Mucus plugging would cause increased airway pressures and decreased breath sounds but typically wouldn’t cause such severe hemodynamic compromise. Pulmonary embolism would cause hypotension and tachycardia but wouldn’t cause unilateral decreased breath sounds or such a dramatic increase in peak pressures. Ventilator-associated pneumonia develops gradually over days, not suddenly.
Question 8:
A patient with severe ARDS is on the following ventilator settings: PRVC mode, TV 350 mL, RR 28, PEEP 16, FiO2 0.90, with PaO2 55 mmHg. What is the most appropriate next intervention?
A) Increase FiO2 to 1.0
B) Increase PEEP to 18 cm H2O
C) Initiate prone positioning
D) Increase tidal volume to 450 mL
Correct Answer: C) Initiate prone positioning
Explanation: This patient has severe ARDS with refractory hypoxemia despite high PEEP (16) and high FiO2 (0.90). The PaO2 of 55 mmHg indicates severe hypoxemia. In severe ARDS with refractory hypoxemia, prone positioning has been shown to improve oxygenation and reduce mortality. Prone positioning improves ventilation-perfusion matching by redistributing perfusion to better-ventilated dorsal lung regions and recruiting collapsed alveoli. The PROSEVA trial demonstrated that early application of prolonged prone positioning (≥16 hours per day) in severe ARDS significantly reduced mortality. Increasing FiO2 to 1.0 would provide only minimal increase in oxygen delivery and exposes the patient to oxygen toxicity. Increasing PEEP to 18 may improve oxygenation but at this level risks hemodynamic compromise and barotrauma. Increasing tidal volume would violate lung-protective ventilation principles. Other rescue therapies include neuromuscular blockade, inhaled pulmonary vasodilators, and ECMO, but prone positioning should be attempted first.
Question 9:
A 65-year-old female with asthma exacerbation is receiving continuous albuterol nebulization and IV methylprednisolone. Despite treatment, she remains in severe distress with RR 32, HR 128, and inability to speak in full sentences. Peak flow is 35% of predicted. What is the most appropriate next step?
A) Add ipratropium to the nebulizer treatment
B) Administer IV magnesium sulfate
C) Prepare for intubation and mechanical ventilation
D) Increase methylprednisolone dose
Correct Answer: B) Administer IV magnesium sulfate
Explanation: This patient has a severe asthma exacerbation not responding adequately to first-line therapy. Peak flow <40% predicted, inability to speak in full sentences, tachypnea >30, and tachycardia >120 indicate severe exacerbation. Before proceeding to intubation, IV magnesium sulfate (typically 2 grams over 20 minutes) should be administered. Magnesium acts as a bronchodilator by inhibiting calcium-mediated smooth muscle contraction and has been shown to improve lung function and reduce hospital admissions in severe asthma exacerbations. It is recommended by guidelines for patients with severe exacerbations who do not respond to initial treatment. Ipratropium should already be added to albuterol in severe exacerbations. Intubation should be avoided if possible in asthma patients because positive pressure ventilation can worsen air trapping and cause barotrauma; it should be reserved for respiratory arrest, severe altered mental status, or failure of aggressive medical management including magnesium. Increasing corticosteroid dose beyond standard dosing has not been shown to provide additional benefit.
Question 10:
A patient with COPD is being considered for long-term oxygen therapy (LTOT). Which of the following criteria would qualify the patient for LTOT?
A) PaO2 60 mmHg or SpO2 90% at rest
B) PaO2 ≤55 mmHg or SpO2 ≤88% at rest
C) PaO2 65 mmHg with exercise-induced desaturation
D) PaO2 70 mmHg with nocturnal desaturation
Correct Answer: B) PaO2 ≤55 mmHg or SpO2 ≤88% at rest
Explanation: Medicare and clinical guidelines for long-term oxygen therapy (LTOT) in COPD specify that patients qualify if they have: (1) PaO2 ≤55 mmHg or SpO2 ≤88% at rest breathing room air, OR (2) PaO2 56-59 mmHg or SpO2 89% with evidence of cor pulmonale, pulmonary hypertension, or polycythemia (hematocrit >55%). LTOT (≥15 hours per day, ideally 24 hours) has been shown to improve survival in patients with chronic hypoxemia. A PaO2 of 60 mmHg or SpO2 of 90% does not meet criteria for LTOT. Exercise-induced or nocturnal desaturation alone does not qualify for continuous LTOT, though supplemental oxygen may be prescribed specifically for exercise or sleep. The landmark Nocturnal Oxygen Therapy Trial (NOTT) and British Medical Research Council (MRC) studies demonstrated mortality benefit with LTOT in patients meeting these criteria.
Question 11:
A patient develops ventilator-associated pneumonia (VAP). Gram stain of tracheal aspirate shows gram-negative rods. Which empiric antibiotic regimen is most appropriate for suspected Pseudomonas aeruginosa?
A) Vancomycin
B) Ceftriaxone
C) Piperacillin-tazobactam
D) Azithromycin
Correct Answer: C) Piperacillin-tazobactam
Explanation: Ventilator-associated pneumonia caused by gram-negative rods, particularly Pseudomonas aeruginosa, requires empiric coverage with anti-pseudomonal antibiotics. Piperacillin-tazobactam is a broad-spectrum beta-lactam/beta-lactamase inhibitor combination with excellent activity against Pseudomonas and other gram-negative organisms commonly implicated in VAP. Other appropriate anti-pseudomonal agents include cefepime, ceftazidime, meropenem, or imipenem. In patients with risk factors for multidrug-resistant organisms, dual anti-pseudomonal coverage may be warranted. Vancomycin provides coverage for gram-positive organisms, particularly MRSA, and should be added if gram-positive cocci are seen on Gram stain, but it has no activity against gram-negative rods. Ceftriaxone is a third-generation cephalosporin with good gram-negative coverage but lacks reliable anti-pseudomonal activity. Azithromycin is a macrolide antibiotic used for community-acquired pneumonia but is not appropriate for VAP with suspected Pseudomonas.
Question 12:
A patient with a large pleural effusion undergoes thoracentesis. After removing 1,800 mL of fluid, the patient develops sudden dyspnea, cough, and chest tightness. Oxygen saturation drops to 88%. What complication has most likely occurred?
A) Pneumothorax
B) Re-expansion pulmonary edema
C) Hemothorax
D) Pulmonary embolism
Correct Answer: B) Re-expansion pulmonary edema
Explanation: Re-expansion pulmonary edema is a rare but serious complication that can occur after rapid removal of a large volume of pleural fluid (typically >1,500 mL) or after treatment of a pneumothorax. It presents with sudden dyspnea, cough, chest discomfort, and hypoxemia during or shortly after the procedure. The pathophysiology involves increased capillary permeability and hydrostatic pressure changes in the previously collapsed lung as it rapidly re-expands. To prevent this complication, it is recommended to limit fluid removal to 1,000-1,500 mL per thoracentesis and to stop the procedure if the patient develops chest discomfort or persistent cough. Treatment is supportive with supplemental oxygen and, in severe cases, may require positive pressure ventilation. Pneumothorax is also a complication of thoracentesis but typically presents with sudden sharp chest pain and would be confirmed by decreased breath sounds and chest X-ray findings. Hemothorax would present with signs of blood loss and hemorrhagic shock. Pulmonary embolism is not directly related to thoracentesis.
Question 13:
A patient with COPD exacerbation is started on BiPAP with settings IPAP 16, EPAP 5. After 2 hours, the patient remains dyspneic with RR 32, accessory muscle use, and ABG showing pH 7.28, PaCO2 72 mmHg. What is the most appropriate action?
A) Increase IPAP to 20 cm H2O
B) Increase EPAP to 8 cm H2O
C) Prepare for endotracheal intubation
D) Switch to high-flow nasal cannula
Correct Answer: C) Prepare for endotracheal intubation
Explanation: This patient is failing non-invasive positive pressure ventilation (NIPPV), as evidenced by worsening respiratory acidosis (pH 7.28, PaCO2 72 mmHg), persistent tachypnea, and continued respiratory distress after 2 hours of BiPAP therapy. Indications for intubation in a patient failing NIPPV include: worsening or no improvement in ABG after 1-2 hours, worsening mental status, inability to tolerate NIPPV, hemodynamic instability, or inability to clear secretions. The pH of 7.28 indicates severe acidosis that, if not corrected, can lead to cardiac arrhythmias and cardiovascular collapse. While increasing IPAP might provide more ventilatory support, the patient has already failed to improve after 2 hours, and further delay in intubation could lead to respiratory arrest. Increasing EPAP would primarily improve oxygenation rather than ventilation (CO2 removal). Switching to high-flow nasal cannula would provide less support than BiPAP and is not appropriate for a patient with worsening hypercapnic respiratory failure.
Question 14:
A 58-year-old male with idiopathic pulmonary fibrosis (IPF) presents with worsening dyspnea. High-resolution CT shows usual interstitial pneumonia (UIP) pattern with honeycombing. Which medication is indicated to slow disease progression?
A) Prednisone
B) Azathioprine
C) Nintedanib
D) N-acetylcysteine
Correct Answer: C) Nintedanib
Explanation: Nintedanib is an FDA-approved antifibrotic medication for idiopathic pulmonary fibrosis (IPF) that has been shown to slow the decline in lung function and reduce the rate of disease progression. It is a tyrosine kinase inhibitor that targets multiple pathways involved in fibrosis. Pirfenidone is another FDA-approved antifibrotic for IPF with similar benefits. These medications do not reverse existing fibrosis but can slow progression and are recommended for most patients with IPF. Corticosteroids like prednisone were previously used for IPF but have been shown to be ineffective and potentially harmful, increasing the risk of infection and other complications without improving outcomes. Azathioprine, an immunosuppressant, was studied in combination with prednisone and N-acetylcysteine in the PANTHER-IPF trial, which was stopped early due to increased mortality and hospitalizations in the treatment group. N-acetylcysteine alone has not been shown to provide benefit in IPF. Current treatment for IPF focuses on antifibrotic therapy, supplemental oxygen for hypoxemia, pulmonary rehabilitation, and evaluation for lung transplantation in appropriate candidates.
Question 15:
A mechanically ventilated patient is being assessed for readiness to wean. Which of the following parameters best predicts successful extubation?
A) Rapid shallow breathing index (RSBI) <105
B) Maximum inspiratory pressure (MIP) >-20 cm H2O
C) Tidal volume >300 mL
D) PaO2/FiO2 ratio >150
Correct Answer: A) Rapid shallow breathing index (RSBI) <105
Explanation: The rapid shallow breathing index (RSBI), also known as the Yang-Tobin index, is calculated as respiratory rate divided by tidal volume in liters (RR/VT). An RSBI <105 breaths/min/L is the best single predictor of successful extubation and weaning from mechanical ventilation. It is measured during a spontaneous breathing trial (SBT) on minimal support (typically pressure support of 5-7 cm H2O or T-piece). An RSBI <105 indicates the patient has adequate respiratory muscle strength and endurance to maintain spontaneous breathing without excessive work of breathing. Values >105 suggest rapid, shallow breathing pattern indicative of respiratory muscle fatigue and predict weaning failure. Maximum inspiratory pressure (MIP or NIF) >-20 cm H2O indicates adequate inspiratory muscle strength, but the threshold for successful weaning is typically MIP more negative than -30 cm H2O. Tidal volume >300 mL (or >5 mL/kg) is one component of weaning parameters but is less predictive than RSBI. PaO2/FiO2 ratio >150-200 indicates adequate oxygenation and is one criterion for SBT readiness, but it is not as predictive of extubation success as RSBI. Other important factors for successful extubation include adequate cough strength, ability to protect airway, hemodynamic stability, and resolution of the underlying condition that required intubation.