An 8-year-old girl with a history of homozygous sickle cell anemia (HbSS) is brought to th… — USMLE Step 2 CK

An $8$ -year-old girl with a history of homozygous sickle cell anemia (HbSS) is brought to the pediatric emergency department due to a two-day history of progressive shortness of breath, right-sided chest pain, and fever. Her temperature is $38.9^\circ \text{C}$ ( $102.0^\circ \text{F}$ ), blood pressure is $100/60\text{ mmHg}$ , heart rate is $128/\text{min}$ , and respiratory rate is $34/\text{min}$ . Oxygen saturation is $89\%$ on room air. Physical examination reveals shallow breathing and crackles over the right lower posterior lung fields. Laboratory studies show:

* Hemoglobin: $7.1\text{ g/dL}$
* Leukocyte count: $19,500/\mu \text{L}$
* Reticulocytes: $11\%$

Chest radiography demonstrates a new alveolar infiltrate in the right lower lobe. The patient is immediately started on supplemental oxygen, pain control, and intravenous normal saline. Which of the following is the most appropriate additional pharmacologic therapy for this patient?

Intravenous ceftriaxone and oral azithromycinCevap
B
Nebulized albuterol and oral dexamethasone
C
Oral amoxicillin monotherapy
D
Intravenous furosemide
E
Intravenous sodium bicarbonate

Cevap

Intravenous ceftriaxone and oral azithromycin

The correct answer provides the standard empiric antibiotic therapy for Acute Chest Syndrome (ACS). ACS is characterized by fever, chest pain, tachypnea, hypoxemia, and a new pulmonary infiltrate on chest radiography in a patient with sickle cell disease. Because atypical pathogens (e.g., Mycoplasma pneumoniae, Chlamydia pneumoniae) and encapsulated organisms (e.g., Streptococcus pneumoniae) frequently trigger or complicate ACS, patients require broad-spectrum coverage. Intravenous ceftriaxone provides excellent coverage for typical encapsulated organisms, while azithromycin covers the atypical pathogens.

Adım Adım Çözüm

Identify the patient's acute complication based on her underlying disease and clinical presentation.

The patient has sickle cell anemia and presents with fever, chest pain, hypoxemia, and a new pulmonary infiltrate, which defines Acute Chest Syndrome (ACS).

Recognizing ACS is critical because it is a life-threatening emergency in sickle cell patients requiring immediate, specific interventions.

Determine the standard medical management for Acute Chest Syndrome.

Standard management includes supplemental oxygen, cautious intravenous fluids, pain control, and empiric broad-spectrum antibiotics.

Infection is a major trigger for ACS, and distinguishing between pulmonary infarction and pneumonia is clinically difficult. Coverage for both encapsulated organisms and atypical bacteria is required.

Select the appropriate antibiotic regimen from the given options.

A third-generation cephalosporin (ceftriaxone) covers encapsulated organisms (e.g., Streptococcus pneumoniae), and a macrolide (azithromycin) covers atypical pathogens (e.g., Mycoplasma pneumoniae).

This dual-therapy approach ensures comprehensive coverage for the most common bacterial triggers of ACS in the pediatric population.

Anahtar Kavram

Management of Acute Chest Syndrome in Sickle Cell Disease

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Konular

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