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Zorluk: OrtaRheumatology and Immunology

A 42-year-old man is hospitalized for community-acquired pneumonia. He has a 15-year history of ankylosing spondylitis. On admission two days ago, a sputum Gram stain and culture grew *Streptococcus pneumoniae* that is pan-sensitive to all standard antimicrobial agents, and he was appropriately started on targeted intravenous ceftriaxone. Over the past 48 hours, he has received 4 liters of intravenous crystalloid fluids. Today, he develops acute-onset severe shortness of breath and orthopnea. His temperature is 37.1∘37.1^\circ C (98.8∘98.8^\circ F), blood pressure is 150/50150/50 mm Hg, pulse is 110/min, and respirations are 26/min. Pulse oximetry shows 86% on room air. Physical examination reveals an early blowing diastolic murmur best heard at the left lower sternal border. Pulmonary auscultation reveals bilateral crackles in the middle and lower lung fields. Laboratory studies show:

Thyroid-stimulating hormone (TSH): 2.52.5 mU/L
Total T4: 4.14.1 μ\mu g/dL (Normal: 5.05.0 - 12.012.0 μ\mu g/dL)

Arterial blood gas (room air):
pH: 7.487.48
pCO 2_2: 3030 mm Hg
pO 2_2: 5555 mm Hg

Which of the following is the most appropriate next step in the management of this patient?

  1. A
    Escalate antibiotic therapy to intravenous vancomycin and piperacillin-tazobactam
  2. B
    Administer inhaled albuterol and intravenous methylprednisolone
  3. Administer intravenous furosemideCevap
  4. D
    Initiate oral levothyroxine
  5. E
    Calculate the expected carbon dioxide level using Winter's formula

Cevap

The most appropriate next step is to administer intravenous furosemide to treat acute pulmonary edema.
This patient with a long-standing history of ankylosing spondylitis has developed acute pulmonary edema secondary to volume overload. Ankylosing spondylitis is associated with several extra-articular manifestations, most notably anterior uveitis, restrictive lung disease, and cardiovascular involvement. Cardiovascular complications often manifest as aortitis, which causes aortic root dilation and subsequent aortic regurgitation (AR). AR presents clinically with a widened pulse pressure (e.g., 150/50150/50 mm Hg) and an early blowing diastolic murmur best heard along the left sternal border.

While treating his pneumonia, the administration of 4 liters of intravenous crystalloid fluids acutely increased his intravascular volume. In the setting of chronic aortic regurgitation, this sudden increase in preload overwhelmed the left ventricle, resulting in elevated left ventricular end-diastolic pressure, backward failure, and acute cardiogenic pulmonary edema (evidenced by orthopnea, severe dyspnea, and bilateral crackles). The most appropriate next step in management is diuresis with intravenous furosemide to reduce preload, clear the pulmonary edema, and improve oxygenation.

Adım Adım Çözüm

1
Analyze the new physical examination findings.
The patient has a widened pulse pressure (150/50150/50 mm Hg) and an early diastolic murmur at the left sternal border, which are classic signs of aortic regurgitation.
Identifying the structural heart lesion explains the underlying cardiovascular vulnerability.
2
Connect the structural heart lesion to the patient's rheumatologic history.
Ankylosing spondylitis is known to cause extra-articular manifestations, including aortitis that leads to aortic root dilation and subsequent aortic regurgitation.
Understanding the systemic complications of ankylosing spondylitis is required to establish the correct etiology.
3
Determine the cause of the acute respiratory deterioration.
The administration of 4 liters of intravenous fluids in a patient with chronic aortic regurgitation precipitated volume overload, leading to acute decompensated heart failure and pulmonary edema (manifesting as crackles, orthopnea, and hypoxemia).
The fluid challenge disrupted the hemodynamic balance, shifting the patient into heart failure rather than worsening pneumonia.
4
Select the appropriate therapeutic intervention.
Intravenous furosemide is indicated to induce diuresis, decrease preload, and resolve the pulmonary edema.
Loop diuretics are the first-line therapy for volume-overloaded states causing acute decompensated heart failure.

Anahtar Kavram

Extra-articular manifestations of ankylosing spondylitis include aortitis and aortic regurgitation, which can precipitate acute decompensated heart failure when patients receive large volumes of intravenous fluids.
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Rheumatology and Immunology

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