Rosen & Barkin's 5-Minute Emergency Medicine Consult (176 page)

• Chronic hypoxia
  
  • COPD
    
  • High-altitude dwellers
    
  • Sleep apnea
    
  • Chest deformities
    
    • Kyphoscoliosis
      
• Pulmonary embolism
  
• Interstitial lung disease
  
  • Scleroderma
    
  • Systemic lupus erythematosus
    
  • Mixed connective tissue disease
    
  • Sarcoidosis
    
  • Pulmonary Langerhans cell histiocytosis
    
  • Neurofibromatosis type
    
  • Lymphangioleiomyomatosis
    
• Cystic fibrosis
  
• Severe anemia
  
• Obesity
  
• Pulmonary veno-occlusive disease
  
• Pulmonary vascular obstruction secondary to tumors or adenopathy
  
• Increased blood viscosity:
  
  • Polycythemia vera
    
  • Leukemia
    
• Increased intrathoracic pressure:
  
  • Mechanical ventilation with positive end-expiratory pressure
    
• Idiopathic primary pulmonary HTN
  

DIAGNOSIS

• Exertional dyspnea
  
• Easy fatigability
  
• Weakness
  
• Exertional syncope
  
• Cough
  
• Hemoptysis
  
• Exertional angina even in the absence of coronary disease
  
• Anorexia
  
• Right upper quadrant discomfort
  
• Wheezing
  
• Hoarseness
  
• Weight gain
  
• Hepatomegaly
  
• Ascites
  
• Peripheral edema
  

End-stage cor pulmonale

• Cardiogenic shock
  
• Oliguria
  
• Cool extremities
  
• Pulmonary edema secondary to intraventricular septum impairing left ventricular diastolic function
  

• Exercise intolerance
  
• Palpitations
  
• Chest pain
  
• Lightheadedness
  
• Syncope
  
• Swelling of the lower extremities
  

• Jugular venous distention:
  
  • Prominent A- and V-waves
    
• Increase in chest diameter
  
• Crackles and/or wheezes
  
• Left parasternal heave on cardiac palpation
  
• Splitting of the 2nd heart sound or murmurs of the pulmonary vasculature may be heard.
  
• Hepatojugular reflex and pulsatile liver
  
• Pitting edema of the lower extremities
  

• Pulse oximetry or ABG:
  
  • Resting PO
    ₂
    40–60 mm Hg
    
  • Resting PCO
    ₂
    often 40–70 mm Hg
    
• Hematocrit:
  
  • Frequently elevated
    
• B-natriuretic peptide:
  
  • When elevated, is sensitive for moderate to severe pulmonary HTN, and may be an independent predictor of mortality
    
  • Elevated level alone is not enough to establish diagnosis of cor pulmonale.
    
• Other lab tests are not generally useful.
  

• CXR:
  
  • Signs of pulmonary HTN:
    
    • Large pulmonary arteries (>16–18 mm)
      
    • An enlarged RV silhouette
      
    • Shows abnormalities in >90% of patients in the detection of cor pulmonale, but does not indicate the severity of disease
      
    • Pleural effusions do not occur in the setting of cor pulmonale alone.
      
• EKG:
  
  • Right-axis deviation
    
  • Right bundle branch block
    
  • RVH
    
    • Dominant R-wave in V1 and V2
      
    • Prominent S-wave in V5 and V6
      
    • Small R-waves and deep S-waves across the precordium
      
  • Right atrial enlargement
    
    • Tall, peaked P-waves (P pulmonale)
      
  • S1Q3 pattern with acute cor pulmonale
    
  • Transient changes due to hypoxia
    
  • Right precordial T-wave flattening
    
• Echocardiography
  
  • The noninvasive diagnostic method of choice
    
  • RV dilation or RVH
    
  • Assessment of tricuspid regurgitation
    
  • Doppler quantization of pulmonary artery pressure, RV ejection fraction
    
• Chest CT, ventilation/perfusion scans, or pulmonary angiography:
  
  • Useful in the setting of acute cor pulmonale
    
• Magnetic resonance imaging
  
  • Superior to echocardiography for assessment of right ventricular size and function
    
• Pulmonary function tests
  
  • Impaired diffusion capacity due to pulmonary HTN
    
• Right-heart catheterization:
  
  • The most precise estimate of pulmonary vascular hemodynamics
    
  • Gives accurate measurements of pulmonary arterial pressure and pulmonary capillary wedge pressure
    

• Primary disease of the left side of the heart
  
  • Mitral stenosis
    
• Congenital heart disease
  
  • Eisenmenger syndrome
    
    • Left to right shunt caused by a congenital heart defect in the fetal heart causes increased flow through the pulmonary vasculature, causing pulmonary HTN
      
• Hypothyroidism
  
• Cirrhosis
  

TREATMENT

• Supportive therapy:
  
  • Supplemental oxygen
    
    • To an endpoint of 90% arterial saturation
      
• • IV access
    
  • Cardiac monitoring
    
  • Pulse oximetry
    
• Treat bronchospasm from associated respiratory disease:
  
  • β-Agonist nebulizers
    
• Caution:
  
  • Vasodilators and diuretics do not have a role in the field.
    
  • Severely hypoxic patients may require endotracheal intubation.
    

ED therapy is directed at the underlying disease process and reducing pulmonary HTN.

• Supplemental oxygen sufficient to raise arterial saturation to 90%:
  
  • Improving oxygenation reduces pulmonary arterial vasoconstriction and RV afterload.
    
  • The improved cardiac output enhances diuresis of excess body water.
    
  • Care must be taken to monitor the patient’s ventilatory status and PCO
    ₂
    , as hypercapnia may reduce respiratory drive and cause acidosis.
    
• Diuretics, such as furosemide, may be added cautiously to reduce pulmonary artery pressure by contributing to the reduction of circulating blood volume:
  
  • Be wary of volume depletion and hypokalemia
    
• Patients should be maintained on salt and fluid restriction.
  
• There is no role for digoxin in the treatment of cor pulmonale.
  
• Bronchodilators:
  
  • Bronchodilator therapy is particularly helpful for those patients with COPD
    
  • Selective β-adrenergic agents such as terbutaline 0.25 mg SC may be useful.
    
  • Bronchodilator affects and reduces ventricular afterload.
    
  • Theophylline may play a role to improve diaphragmatic contractility and reduce muscle fatigue.
    
  • Anticoagulation may be considered for those at high risk for thromboembolic disease.
    
• Acutely decompensated COPD patients:
  
  • Early steroid therapy
    
  • Antibiotic administration
    
• In general, improvement in the underlying respiratory disease results in improved RV function.
  

• Furosemide: 20–60 mg IV (peds: 1 mg/kg may increase by 1 mg/kg/q2h not to exceed 6 mg/kg)
  
• Terbutaline: 0.25 mg SC
  

FOLLOW-UP

• New-onset hypoxia
  
• Anasarca
  
• Severe respiratory failure
  
• Admission criteria for the underlying disease process
  

Patients without hypoxia or a stable oxygen requirement

• Close follow-up as long as the underlying etiology has responded to acute management
  
• The need for a sleep study to assess for sleep apnea should be coordinated by the patient’s physician.
  

Ensure home oxygenation in patients with chronic hypoxia

• The physical exam is unreliable for detecting cor pulmonale in patients with COPD, as hyperinflation of the chest obscures the classic findings.
  
• Vasodilator therapy should only be considered after conventional therapy and oxygenation have failed.
  

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  . 2008;52(21):1683.
  
• Chaouat A, Naeije R, Weitzenblum E. Pulmonary hypertension in COPD.
  Eur Respir J
  . 2008;32:1371–1385.
  
• Han MK, McLaughlin VV, Criner CJ, et al. Pulmonary diseases and the heart.
  Circulation
  . 2007;116:2992–3005.
  
• Jardin F, Vieillard-Baron A. Acute cor pulmonale.
  Curr Opin Crit Care
  . 2009;15:67–70.
  
• Luks AM. Can patients with pulmonary hypertension travel to high altitude?
  High Alt Med Biol
  . 2009;10:215–219.
  

CODES