Emergency nurse practitioner board certification question

A 27-year-old woman, G2P1 at 26 weeks' gestation, presents with sudden pleuritic left chest pain and dyspnea that began 3 hours ago. Vital signs: HR 116, RR 24, BP 112/68, T 37.1 C, SpO2 94% on room air. She has no calf pain, swelling or asymmetry. Lungs are clear, and fetal heart tones are 145/min. ECG shows sinus tachycardia. A shielded portable chest radiograph is normal. Renal function is normal. The ENP's clinical suspicion for PE is high, and both CT and nuclear medicine are available.

Question:

Which diagnostic study is MOST appropriate next?

A. Quantitative D-dimer

B. Bilateral lower-extremity compression ultrasound

C. Ventilation-perfusion (V/Q) scan

D. Transthoracic echocardiogram

CORRECT ANSWER: C. Ventilation-perfusion (V/Q) scan

RATIONALE:

Guidance from ATS/Society of Thoracic Radiology and ACOG supports a stepwise approach to suspected PE in pregnancy. With no leg symptoms, the next step is a chest radiograph. When the chest radiograph is normal, V/Q scanning, often perfusion-only, is preferred over CTPA because it yields a high proportion of diagnostic results in young women with normal lungs and delivers substantially less radiation to maternal breast and lung tissue. Fetal radiation from both studies is well below thresholds for harm. CTPA is chosen when the chest radiograph is abnormal, the V/Q is nondiagnostic, or nuclear medicine is unavailable. Given high suspicion, starting therapeutic low-molecular-weight heparin while awaiting imaging is reasonable if bleeding risk is low. DOACs and warfarin are avoided in pregnancy. This patient is tachycardic and mildly hypoxemic, which increases the importance of rapid definitive imaging rather than an indirect or insensitive test.

WHY THE OTHER ANSWERS ARE INCORRECT:

A. D-dimer rises through normal pregnancy, which reduces specificity. Pregnancy-adapted algorithms use it only when pretest probability is not high. In a high-suspicion patient, a D-dimer cannot exclude PE and delays imaging.

B. Compression ultrasound is the first test when leg symptoms are present, because a positive study justifies anticoagulation without chest imaging. Without leg findings its yield is low, and a negative result does not exclude PE.

C. Correct answer (see rationale above).

D. Echocardiography can show RV strain supporting the diagnosis in unstable patients too ill for transport. It is neither sensitive nor specific enough to confirm or exclude PE in a hemodynamically stable patient.

CLINICAL PEARL: Suspected PE in pregnancy: leg symptoms, start with compression ultrasound; no leg symptoms, chest radiograph; normal chest radiograph, V/Q scan; abnormal chest radiograph, CTPA.

RED FLAG / CANNOT-MISS POINT: Withholding indicated imaging out of fear of fetal radiation is a dangerous error; PE is a leading cause of maternal death, and both imaging modalities are fetally safe.

DIFFICULTY: Difficult

COGNITIVE LEVEL: Clinical Decision-Making

AANPCB DOMAIN I (PRACTICE): 02 Medical Decision Making/Differential Diagnosis — Evaluate diagnostic studies based on the differential diagnoses

AANPCB DOMAIN II (PATIENT CONDITION): Thoracic-Respiratory Disorders

CLINICAL DOMAIN: Diagnostic imaging

POPULATION: Obstetric

PRIMARY DIAGNOSIS OR CONCEPT: Imaging choice for suspected PE in pregnancy (V/Q vs CTPA)

TINTINALLI REFERENCE: Tintinalli's Emergency Medicine, 9th ed. — topic: Venous Thromboembolism. Exact chapter citation should be verified against Tintinalli's Emergency Medicine, 9th Edition.

REFERENCES:

Tintinalli, J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D. M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: A comprehensive study guide (9th ed.). McGraw Hill. Topic: Venous Thromboembolism.

Walls, R. M., Hockberger, R. S., Gausche-Hill, M., Erickson, T. B., & Wilcox, S. R. (Eds.). (2023). Rosen's emergency medicine: Concepts and clinical practice (10th ed., Vols. 1-2). Elsevier. Topic: Acute Complications of Pregnancy

A 72-year-old man presents with 2 days of mild exertional dyspnea and fatigue. He has no chest pain, hemoptysis, leg swelling, recent surgery, immobilization, malignancy or prior VTE. Vital signs: HR 104, RR 18, BP 138/82, T 37.0 C, SpO2 95% on room air. Examination shows faint bibasilar crackles and no leg asymmetry. His Wells score is 1.5 (PE unlikely). A high-sensitivity D-dimer is 640 ng/mL FEU (laboratory cutoff 500 ng/mL FEU). Creatinine is normal. Chest radiograph shows mild interstitial prominence.

Question:

Based on the D-dimer result, which of the following is MOST appropriate?

A. No PE imaging; pursue an alternative diagnosis

B. CT pulmonary angiography

C. Ventilation-perfusion scan

D. Empiric therapeutic anticoagulation pending imaging

CORRECT ANSWER: A. No PE imaging; pursue an alternative diagnosis

RATIONALE:

D-dimer levels rise normally with age, which lowers specificity and drives unnecessary CTPA in older adults. For patients older than 50 years with low or 'PE unlikely' pretest probability, the age-adjusted threshold is age multiplied by 10 ng/mL (FEU). For this 72-year-old, the cutoff is 720 ng/mL. His result of 640 ng/mL is below that threshold, so PE is excluded without imaging. The ADJUST-PE study validated this approach, showing a low 3-month VTE failure rate while substantially increasing the proportion of older patients in whom imaging could be safely avoided. The age adjustment applies only to low- or intermediate-probability ('PE unlikely') patients and to assays reported in FEU. Attention should shift to other explanations for his tachycardia and dyspnea, such as early heart failure, arrhythmia, infection or anemia, guided by the crackles and radiograph findings.

WHY THE OTHER ANSWERS ARE INCORRECT:

A. Correct answer (see rationale above).

B. CTPA is warranted when D-dimer exceeds the age-adjusted threshold or pretest probability is high. Here it exposes an older adult to contrast nephropathy risk, radiation and incidental findings without benefit.

C. V/Q scanning is an alternative when CTPA is contraindicated by renal failure or contrast allergy. It is still unnecessary once PE has been excluded by the age-adjusted D-dimer.

D. Empiric anticoagulation pending imaging is reasonable for high clinical suspicion with a delay in imaging and low bleeding risk. It is inappropriate once PE has been excluded and adds bleeding risk in an older adult.

CLINICAL PEARL: For patients older than 50 with low/'unlikely' PE probability, use an age-adjusted D-dimer cutoff of age x 10 ng/mL FEU.

RED FLAG / CANNOT-MISS POINT: Never use a D-dimer to 'rule out' PE in a high-pretest-probability patient; they proceed directly to imaging.

DIFFICULTY: Moderate

COGNITIVE LEVEL: Analysis

AANPCB DOMAIN I (PRACTICE): 02 Medical Decision Making/Differential Diagnosis — Evaluate diagnostic studies based on the differential diagnoses

AANPCB DOMAIN II (PATIENT CONDITION): Thoracic-Respiratory Disorders

CLINICAL DOMAIN: Laboratory interpretation

POPULATION: Geriatric

PRIMARY DIAGNOSIS OR CONCEPT: Age-adjusted D-dimer in PE-unlikely older adult

TINTINALLI REFERENCE: Tintinalli's Emergency Medicine, 9th ed. — topic: Venous Thromboembolism. Exact chapter citation should be verified against Tintinalli's Emergency Medicine, 9th Edition.

REFERENCES:

Tintinalli, J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D. M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: A comprehensive study guide (9th ed.). McGraw Hill. Topic: Venous Thromboembolism.

Walls, R. M., Hockberger, R. S., Gausche-Hill, M., Erickson, T. B., & Wilcox, S. R. (Eds.). (2023). Rosen's emergency medicine: Concepts and clinical practice (10th ed., Vols. 1-2). Elsevier. Topic: Pulmonary Embolism and Deep Vein Thrombosis.

A 61-year-old woman with type 2 diabetes and chronic heart failure (EF 40%) presents to fast-track with 3 days of productive cough, fever and right-sided pleuritic pain. She has not taken antibiotics in the past 3 months and has no recent hospitalization or history of MRSA or Pseudomonas. She is alert and oriented. Vital signs: T 38.4 C, HR 96, RR 20, BP 132/78, SpO2 95% on room air. BUN is 16 mg/dL, glucose 214 mg/dL. Chest radiograph shows a right lower lobe infiltrate. She tolerates oral intake and lives with her husband.

Question:

Which outpatient antibiotic regimen is MOST appropriate?

A. Amoxicillin monotherapy

B. Azithromycin monotherapy

C. Amoxicillin-clavulanate plus doxycycline

D. Admission for IV vancomycin plus cefepime

CORRECT ANSWER: C. Amoxicillin-clavulanate plus doxycycline

RATIONALE:

Her CURB-65 score is 0 (no confusion, BUN under 20, RR under 30, normal blood pressure, age under 65) and she is oxygenating well, so outpatient treatment is appropriate. The 2019 ATS/IDSA community-acquired pneumonia guideline stratifies outpatients by comorbidity. Healthy adults without comorbidities may receive amoxicillin, doxycycline or, where pneumococcal macrolide resistance is under 25%, a macrolide alone. Patients with chronic heart, lung, liver or renal disease, diabetes, alcohol use disorder, malignancy or asplenia need broader coverage: a beta-lactam (amoxicillin-clavulanate or cefpodoxime/cefuroxime) plus a macrolide or doxycycline, or monotherapy with a respiratory fluoroquinolone. This combination covers Streptococcus pneumoniae, beta-lactamase-producing Haemophilus influenzae and Moraxella, and atypical organisms. She has no risk factors for MRSA or Pseudomonas. Discharge instructions should include glucose monitoring, heart failure precautions and follow-up within 48-72 hours.

WHY THE OTHER ANSWERS ARE INCORRECT:

A. Amoxicillin alone is appropriate for a healthy outpatient without comorbidities, but it lacks atypical coverage and beta-lactamase stability, which are needed in patients with diabetes and heart failure.

B. Macrolide monotherapy is acceptable only for healthy adults in regions with low pneumococcal macrolide resistance. It is inadequate for a patient with significant comorbidities.

C. Correct answer (see rationale above).

D. Broad-spectrum anti-MRSA and antipseudomonal therapy is reserved for severe CAP with prior MRSA/Pseudomonas isolation or recent hospitalization with IV antibiotics. It exposes this low-risk patient to unnecessary toxicity and resistance pressure.

CLINICAL PEARL: Outpatient CAP with comorbidities: beta-lactam (amoxicillin-clavulanate or a cephalosporin) plus a macrolide or doxycycline, or a respiratory fluoroquinolone alone.

RED FLAG / CANNOT-MISS POINT: Undertreating a comorbid patient with narrow monotherapy, or reflexively escalating to anti-MRSA/antipseudomonal agents without risk factors, both violate evidence-based CAP care.

DIFFICULTY: Moderate

COGNITIVE LEVEL: Application

AANPCB DOMAIN I (PRACTICE): 03 Patient Management — Prescribe appropriate pharmacologic agents

AANPCB DOMAIN II (PATIENT CONDITION): Thoracic-Respiratory Disorders

CLINICAL DOMAIN: Infectious disease and sepsis

POPULATION: Adult

PRIMARY DIAGNOSIS OR CONCEPT: Outpatient CAP antibiotic selection with comorbidities

TINTINALLI REFERENCE: Tintinalli's Emergency Medicine, 9th ed. — topic: Pneumonia and Pulmonary Infiltrates. Exact chapter citation should be verified against Tintinalli's Emergency Medicine, 9th Edition.

REFERENCES:

Tintinalli, J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D. M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: A comprehensive study guide (9th ed.). McGraw Hill. Topic: Pneumonia and Pulmonary Infiltrates.

Walls, R. M., Hockberger, R. S., Gausche-Hill, M., Erickson, T. B., & Wilcox, S. R. (Eds.). (2023). Rosen's emergency medicine: Concepts and clinical practice (10th ed., Vols. 1-2). Elsevier. Topic: Pneumonia.

66-year-old woman with COPD (FEV1 38% predicted) presents with 3 days ofincreased dyspnea and purulent sputum. She has received twoalbuterol/ipratropium nebulizers, oral prednisone and doxycycline. She is usingaccessory muscles but is awake, oriented and following commands, and ismanaging her secretions. Vital signs: HR 108, RR 28, BP 148/86, T 37.8 C, SpO290% on 2 L nasal cannula. Arterial blood gas: pH 7.29, PaCO2 66 mm Hg, PaO2 62mm Hg, HCO3 31 mEq/L. Chest radiograph shows hyperinflation withoutpneumothorax.

Question:

Which ofthe following is the MOST appropriate next step in management?

A. Rapid sequence intubationand mechanical ventilation

B. Nonrebreather mask at 15L/min to raise SpO2 above 96%

C. Continue current therapyand repeat the blood gas in 2 hours

D. Bilevel noninvasive positive-pressure ventilation

CORRECT ANSWER: D. Bilevel noninvasive positive-pressureventilation

RATIONALE:

This patient has an acute COPDexacerbation with acute-on-chronic hypercapnic respiratory acidosis: theelevated bicarbonate indicates chronic retention, but a pH of 7.29 shows anacute rise in PaCO2 beyond her compensated baseline. GOLD and ERS/ATS guidancerecommend bilevel NIV for COPD exacerbations with pH 7.35 or less and PaCO2above 45 mm Hg, or for severe dyspnea with signs of respiratory muscle fatigue.NIV augments tidal volume through inspiratory pressure support, offsetsintrinsic PEEP with expiratory pressure, and unloads fatigued muscles. In thispopulation it reduces intubation rates, ICU length of stay and mortality. Sheis an ideal candidate: awake, cooperative, protecting her airway,hemodynamically stable and without facial trauma or vomiting. Response shouldbe reassessed clinically and with a repeat blood gas within 1-2 hours, andoxygen should be titrated to SpO2 88-92%.

WHY THE OTHER ANSWERS ARE INCORRECT:

A. Intubation is reserved for NIV failure orcontraindications: inability to protect the airway, severe agitation orsomnolence, hemodynamic instability, copious secretions or respiratory arrest.An alert, cooperative patient should first receive a trial of NIV.

B. High-flow oxygen targeting high saturations inchronic hypercapnic COPD worsens CO2 retention through V/Q mismatch and theHaldane effect. The oxygen target is 88-92%, and oxygen does not address herventilatory failure.

C. Watchful waiting delays proven therapy. With pH7.29 and accessory muscle use, she already meets NIV criteria, and she risksprogressive fatigue and CO2 narcosis while waiting.

D. Correct answer (see rationale above).

CLINICALPEARL: In COPD exacerbation, start bilevel NIV when pH is 7.35 orless with PaCO2 above 45 mm Hg, provided the patient is alert enough to protectthe airway.

REDFLAG / CANNOT-MISS POINT: Over-oxygenating a CO2 retainer canprecipitate hypercapnic narcosis; titrate oxygen to SpO2 88-92%.

DIFFICULTY:Moderate

COGNITIVELEVEL: Clinical Decision-Making

AANPCBDOMAIN I (PRACTICE): 01 Medical Screening — Establish patient acuitylevel to determine need for rapid intervention

AANPCBDOMAIN II (PATIENT CONDITION): Thoracic-Respiratory Disorders

CLINICALDOMAIN: Respiratory emergencies

POPULATION:Adult

PRIMARYDIAGNOSIS OR CONCEPT: NIV indications in acute hypercapnic COPDexacerbation

AANPCBENP PROCEDURE: Noninvasive ventilation

REFERENCES:

Tintinalli,J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D.M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: Acomprehensive study guide (9th ed.). McGraw Hill. Topic: Chronic ObstructivePulmonary Disease.

Walls, R.M., Hockberger, R. S., Gausche-Hill, M., Erickson, T. B., & Wilcox, S. R.(Eds.). (2023). Rosen's emergency medicine: Concepts and clinical practice(10th ed., Vols. 1-2). Elsevier. Topic: Chronic Obstructive PulmonaryDisease.

A 34-year-old man with asthma presents to an urban ED with 2 days of wheeze and dyspnea after a cold. For the past month he has used his albuterol inhaler 3-4 times daily; he has no controller inhaler. He has never been intubated or admitted to an ICU. On arrival his peak expiratory flow (PEF) was 45% of predicted. Over the first hour he received three albuterol/ipratropium nebulizers and oral prednisone 50 mg. Now, 60 minutes after the last nebulizer, he speaks in full sentences with minimal end-expiratory wheeze. Vital signs: HR 96, RR 18, BP 132/80, SpO2 96% on room air. PEF is 78% of predicted. He has a primary care clinician and can fill prescriptions today.

Question:

Which discharge plan is MOST appropriate?

A. Prednisone for 5 days plus a daily inhaled corticosteroid-containing controller

B. As-needed albuterol only, with primary care follow-up in 1 month

C. Prednisone for 5 days plus oral azithromycin for 5 days

D. Observation unit admission for 24 hours of scheduled nebulizers

CORRECT ANSWER: A. Prednisone for 5 days plus a daily inhaled corticosteroid-containing controller

RATIONALE:

His exacerbation was moderate to severe on arrival, but he has responded well: PEF is above 70% of predicted and sustained 60 minutes after the last bronchodilator, he has minimal symptoms, normal oxygenation and no risk factors for fatal asthma such as prior intubation or ICU care. NAEPP and GINA criteria support discharge. A short course of systemic corticosteroid (prednisone 40-50 mg daily for about 5-7 days) reduces relapse after an ED visit. Just as important, his month of daily reliever use without a controller shows uncontrolled asthma; current GINA guidance advises that every adult or adolescent discharged after an exacerbation start or step up inhaled corticosteroid (ICS)-containing therapy, either daily ICS or ICS-formoterol as maintenance and reliever, because SABA-only treatment increases the risk of severe exacerbations and asthma death. Discharge should also include inhaler technique review, a written action plan and follow-up within about 1 week.

WHY THE OTHER ANSWERS ARE INCORRECT:

A. Correct answer

B. SABA-only treatment is no longer recommended for adults or adolescents, and heavy reliever use signals poor control and higher risk of a fatal exacerbation. Follow-up should occur within days, not a month. As-needed ICS-formoterol, not albuterol alone, is the reliever-only option for mild asthma.

C. Antibiotics do not improve outcomes in asthma exacerbations, which are usually viral. They are appropriate only with evidence of bacterial infection such as pneumonia or bacterial sinusitis. The steroid component is correct, but the missing controller leaves him at high relapse risk.

D. Observation or admission suits patients with an incomplete response (PEF about 40-69%), persistent hypoxemia, or high-risk features such as prior intubation, recent ICU care or poor access to follow-up. A sustained PEF above 70% with minimal symptoms supports safe discharge.

PEARL: After an ED asthma exacerbation, discharge with a short systemic corticosteroid course and start or step up ICS-containing controller therapy; SABA-only treatment is no longer recommended.

CANNOT-MISS : Discharging a patient with frequent reliever use on albuterol alone misses uncontrolled asthma and leaves him at risk for recurrent severe or fatal exacerbations.

COGNITIVE LEVEL: Clinical Decision-Making

AANPCB DOMAIN I: Transitions of Care

AANPCB DOMAIN II: Respiratory Disorders

CLINICAL DOMAIN: Resp emergency

REFERENCES: Tintinalli, J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D. M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: A comprehensive study guide (9th ed.). McGraw Hill. Topic: Acute Asthma in Adults.

Walls, R. M., Hockberger, R. S., Gausche-Hill, M., Erickson, T. B., & Wilcox, S. R. (Eds.). (2023). Rosen's emergency medicine: Concepts and clinical practice (10th ed., Vols. 1-2). Elsevier. Topic: Asthma.

Clinical vignette:

A 29-year-old woman at 30 weeks' gestation with moderate persistent asthma presents with 2 days of worsening wheeze after a viral illness. She has received three back-to-back albuterol/ipratropium nebulizers and IV methylprednisolone. She now speaks in short phrases. Vital signs: HR 118, RR 30, BP 118/70, SpO2 97% on 2 L nasal cannula. Peak expiratory flow is 60% of her personal best. Diffuse expiratory wheezes are present bilaterally. Arterial blood gas: pH 7.38, PaCO2 40 mm Hg, PaO2 88 mm Hg. Fetal heart tones are 150/min.

Question:

Which finding is MOST concerning for impending respiratory failure in this patient?

A. Heart rate of 118/min after repeated beta-agonist therapy

B. Peak expiratory flow of 60% of personal best

C. Arterial PaCO2 of 40 mm Hg

D. Diffuse bilateral expiratory wheezing on auscultation

CORRECT ANSWER: C. Arterial PaCO2 of 40 mm Hg

RATIONALE:

Pregnancy produces a progesterone-driven chronic respiratory alkalosis; normal maternal PaCO2 is roughly 28-32 mm Hg with renal compensation. In any acute asthma exacerbation, the expected finding is hypocapnia from tachypnea. A PaCO2 that has risen into the 'normal' nonpregnant range signals that ventilation can no longer keep pace with work of breathing and that the patient is tiring. In pregnancy, a PaCO2 of 40 mm Hg is therefore equivalent to significant hypercapnia and should prompt escalation: ICU-level monitoring, continued aggressive bronchodilator therapy, adjuncts such as IV magnesium, early obstetric involvement with continuous fetal monitoring, and preparation for airway management by the most experienced operator. Maternal oxygenation should be kept at SpO2 of 95% or higher to protect fetal oxygen delivery. Delay in recognizing fatigue risks sudden maternal decompensation and fetal hypoxia, which is why arterial or venous CO2 must be interpreted against pregnancy-specific norms rather than standard reference ranges.

WHY THE OTHER ANSWERS ARE INCORRECT:

A. Tachycardia is expected from both beta-agonist therapy and the physiologic increase in maternal heart rate. Worsening tachycardia or new bradycardia would be more alarming; bradycardia in severe asthma is a preterminal sign.

B. A PEF of 60% indicates an incomplete response and moderate severity, supporting continued treatment and observation. A PEF below 40% or inability to perform the maneuver would indicate severe disease requiring escalation.

C. Correct answer (see rationale above).

D. Audible wheezing reflects ongoing airflow through narrowed airways. A 'silent chest' with diminishing wheezes and poor air movement is the ominous finding; diffuse wheezing alone does not predict imminent failure.

CLINICAL PEARL: Normal PaCO2 in pregnancy is about 28-32 mm Hg, so a 'normal' PaCO2 of 40 in a pregnant asthmatic represents CO2 retention and fatigue.

RED FLAG / CANNOT-MISS POINT: Falsely reassuring 'normal' blood gas values in a pregnant patient can delay ICU care and airway preparation, jeopardizing both mother and fetus.

TINTINALLI REFERENCE: Tintinalli's Emergency Medicine, 9th ed. — topic: Acute Asthma in Adults. Exact chapter citation should be verified against Tintinalli's Emergency Medicine, 9th Edition.

REFERENCES:

Tintinalli, J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D. M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: A comprehensive study guide (9th ed.). McGraw Hill. Topic: Acute Asthma in Adults.

Tintinalli, J. E., Ma, O. J., Yealy, D. M., Meckler, G. D., Stapczynski, J. S., Cline, D. M., & Thomas, S. H. (Eds.). (2020). Tintinalli's emergency medicine: A comprehensive study guide (9th ed.). McGraw Hill. Topic: Comorbid Diseases in Pregnancy.

Walls, R. M., Hockberger, R. S., Gausche-Hill, M., Erickson, T. B., & Wilcox, S. R. (Eds.). (2023). Rosen's emergency medicine: Concepts and clinical practice (10th ed., Vols. 1-2). Elsevier. Topic: Asthma.