HIV pulmonary complications

Background

• Pulmonary disease is the most common reason for hospitalization in HIV/AIDS patients
• Most common cause of pneumonia in HIV: Streptococcus pneumoniae (not PCP)
• Risk of opportunistic infections increases as CD4 count declines:
  • CD4 >200: Bacterial pneumonia, tuberculosis
  • CD4 <200: Pneumocystis jirovecii pneumonia (PCP)
  • CD4 <100: Fungal infections (histoplasmosis, coccidioidomycosis), Mycobacterium avium complex
  • CD4 <50: CMV pneumonitis

Clinical Features

• Varies by organism:
  • Bacterial: Acute onset, productive cough, fever, focal consolidation
  • PCP: Subacute (weeks), dry cough, progressive dyspnea on exertion, hypoxia out of proportion to exam, bilateral diffuse infiltrates
  • TB: Chronic cough, night sweats, weight loss; may have upper lobe cavitary disease or atypical patterns with low CD4
  • Kaposi sarcoma (pulmonary): Dyspnea, hemoptysis; skin/mucosal lesions often present

Differential Diagnosis

HIV associated conditions

• HIV neurologic complications
  • Toxoplasmosis
  • Cryptococcosis
  • AIDS Dementia
  • Seizures in patients with HIV-AIDS
  • Primary CNS lymphoma
• HIV pulmonary complications
  • Pneumocystis jirovecii pneumonia (PCP)
  • Tuberculosis (TB)
  • CMV pneumonia
• Ophthalmologic complications
  • CMV Retinitis
  • Herpes Zoster Ophthalmicus
• Other
  • AIDS fever of unknown origin
  • Immune reconstitution inflammatory syndrome
  • HIV diarrhea
  • Esophageal candidiasis
  • Kaposi's sarcoma
  • Pruritic papular eruption of HIV
  • Hairy oral leukoplakia
• HAART medication side effects
  • HAART-induced lactic acidosis
  • Neuropyschiatric effects
  • Hepatic toxicity
  • Renal toxicity
  • Steven-Johnson's
  • Cytopenias
  • GI symptoms
  • Endocrine abnormalities

Evaluation

• CXR — essential first step:
  • Lobar consolidation → bacterial
  • Bilateral diffuse interstitial/ground-glass → PCP
  • Upper lobe cavitary disease → TB
  • Nodules, pleural effusions → fungal, TB, lymphoma, Kaposi sarcoma
• ABG/SpO2 — resting and with exertion (PCP may show desaturation only with ambulation)
• Labs: CBC, LDH (elevated in PCP), CD4 count, blood cultures, sputum (Gram stain, culture, AFB)
• Induced sputum for PCP (silver stain or DFA)
• CT chest if CXR non-diagnostic
• Cannot use PORT score to disposition HIV patients (not validated in this population)

Management

• Treat based on suspected organism; see individual disease pages for antibiotic templates
• Always isolate until TB ruled out (negative AFB × 3 or clinical exclusion)
• Start empiric antibiotics for bacterial pneumonia per standard CAP guidelines while workup pending
• Low threshold for ICU admission — HIV patients decompensate rapidly

Disposition

• Low threshold for admission; most HIV patients with pneumonia require inpatient treatment
• ICU for respiratory failure, severe hypoxia, hemodynamic instability

See Also

• HIV - AIDS (Main)
• PCP
• Tuberculosis
• Community acquired pneumonia
• Neutropenic fever