A 68-year-old woman comes to the emergency department reporting severe difficulty breathin… — USMLE Step 2 CK

A $68$ -year-old woman comes to the emergency department reporting severe difficulty breathing and wheezing for the past two days. She has a history of type 2 diabetes, hypertension, and severe chronic obstructive pulmonary disease (COPD). She reports a recent upper respiratory tract infection. Her home medications include metformin, lisinopril, and a tiotropium inhaler. She has been using her rescue albuterol inhaler multiple times today with minimal relief.

She reports an increase in breathlessness, but states her sputum remains clear and sparse. She denies chest pain, orthopnea, paroxysmal nocturnal dyspnea, or swelling in her legs. Temperature is $37.2^\circ\text{C}$ ( $99.0^\circ\text{F}$ ), pulse is $118\text{/min}$ , blood pressure is $138/86\text{ mmHg}$ , and respiratory rate is $28\text{/min}$ . Pulse oximetry shows $88\%$ on room air.

Physical examination reveals an anxious woman using accessory muscles of respiration. Lung auscultation demonstrates diffuse, bilateral expiratory wheezing with a prolonged expiratory phase. Jugular venous pressure is estimated at $6\text{ cm H}_2\text{O}$ . Trace bilateral pedal edema is noted, which the patient states is chronic.

Laboratory studies:

Test	Result	Reference Range
Leukocyte count	$9,200\text{/mm}^3$	$4,000-11,000\text{/mm}^3$
B-type natriuretic peptide (BNP)	$65\text{ pg/mL}$	$< 100\text{ pg/mL}$
Procalcitonin	$0.03\text{ ng/mL}$	$< 0.1\text{ ng/mL}$

Arterial blood gas (room air):

Parameter	Result	Reference Range
pH	$7.32$	$7.35-7.45$
PaCO $_2$	$56\text{ mmHg}$	$35-45\text{ mmHg}$
PaO $_2$	$58\text{ mmHg}$	$75-105\text{ mmHg}$
HCO $_3^-$	$28\text{ mEq/L}$	$22-28\text{ mEq/L}$

A rapid multiplex respiratory polymerase chain reaction (PCR) panel is positive for rhinovirus. Chest radiograph shows lung hyperinflation with flattened hemidiaphragms. There is no focal consolidation, pleural effusion, or cardiomegaly.

Which of the following interventions are indicated for the initial management of this patient? (Select 2)

Administer nebulized short-acting bronchodilator therapyAnswer
Administer systemic glucocorticoid therapyAnswer
C
Initiate diuresis with a loop diuretic
D
Start empiric therapy with cefepime and vancomycin
E
Use Winter's formula to evaluate expected respiratory compensation

Answer

The correct initial management steps are administering nebulized short-acting bronchodilator therapy and administering systemic glucocorticoid therapy.

The correct interventions are administering nebulized short-acting bronchodilator therapy and systemic glucocorticoid therapy. This patient is experiencing a severe acute COPD exacerbation, indicated by her accessory muscle use, tachypnea, acute-on-chronic respiratory acidosis, and failure of outpatient therapy. The standard of care in the emergency department includes immediate nebulized short-acting beta-agonists (often combined with muscarinic antagonists like ipratropium) to reverse bronchoconstriction, alongside early administration of systemic glucocorticoids (oral or intravenous) to treat underlying inflammation and expedite recovery.

Step-by-Step Solution

Analyze the clinical presentation and physical exam.

The patient has an acute exacerbation of COPD, characterized by increased dyspnea, diffuse wheezing, accessory muscle use, and hyperinflation on the chest radiograph.

To establish the primary diagnosis and rule out alternative causes of dyspnea such as acute decompensated heart failure or pneumonia.

Interpret the laboratory and arterial blood gas (ABG) data.

Normal BNP and procalcitonin rule out heart failure and bacterial pneumonia, respectively. The ABG demonstrates an acute-on-chronic respiratory acidosis (pH 7.32, PaCO2 56 mmHg, HCO3 28 mEq/L) consistent with severe airway obstruction.

To appropriately stage the severity of the exacerbation and verify that the primary derangement is respiratory.

Determine the appropriate evidence-based bundle of interventions.

Standard protocol for a severe COPD exacerbation requires immediate inhaled short-acting bronchodilators, systemic glucocorticoids, and supplemental oxygen. Antibiotics are withheld because she lacks purulent sputum and has a confirmed rhinovirus infection.

Bronchodilators relieve acute bronchospasm, glucocorticoids reduce underlying airway inflammation, and targeted therapy prevents unnecessary antibiotic exposure.

Key Concept

The initial pharmacological management of moderate-to-severe acute COPD exacerbations includes inhaled short-acting bronchodilators and early administration of systemic glucocorticoids. Antibiotics are reserved for patients with purulent sputum or those requiring mechanical ventilation.

Estimated Time:1m 30s

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