Pulmonary Hypertension
Pulmonary Hypertension: Excerpt from The 5-Minute Pediatric Consult
Richard M. Kravitz, MD
Pulmonary Hypertension - BASICS
Pulmonary Hypertension - description
Increased pulmonary vascular resistance
Pulmonary Hypertension - epidemiology
Pulmonary Hypertension - incidence
Incidence in children is unknown.
Pulmonary Hypertension - pathophysiology
Structural alterations in pulmonary vessel architecture (remodeling)
- Smooth muscle hypertrophy
- Extension of blood vessel’s smooth muscle into smaller vessels
- Inflammation
Pulmonary Hypertension - etiology
- Hypoxemia-induced pulmonary hypertension
- Chronic lung disease
- Cystic fibrosis
- Bronchopulmonary dysplasia
- Interstitial lung disease
- Upper airway obstruction:
- Tonsillar and/or adenoid hypertrophy
- Obesity
- Hypoventilation:
- Neurologically mediated process
- Secondary to muscular weakness
- High pulmonary blood flow secondary to left-to-right shunting (seen in congenital heart disease):
- Patent ductus arteriosus
- Atrial septal defect
- Ventricular septal defect
- Left-sided cardiac disorders that increase pulmonary venous pressure:
- Left ventricular failure
- Mitral valve stenosis
- Obstructed anomalous pulmonary veins
- Occlusion of pulmonary vessels:
- Sickle cell disease
- Veno-occlusive disease
- Thromboembolism
- Pulmonary vasculitis:
- Systemic lupus erythematosus
- Rheumatoid arthritis
- Scleroderma
- Persistent pulmonary hypertension of the newborn
- Idiopathic cases (primary pulmonary hypertension)
Pulmonary Hypertension - DIAGNOSIS
Pulmonary Hypertension - signs & symptoms
Pitfalls:
- Signs and symptoms of pulmonary hypertension are not specific and can easily be missed.
- Consider obstructive sleep apnea as a possible cause of pulmonary hypertension (ask about snoring if suspecting pulmonary hypertension in the absence of overt cardiac or pulmonary disease).
Pulmonary Hypertension - history
- Dyspnea (usually earliest complaint reported)
- Fatigue:
- Seen early in course of illness with exercise or exertion (but not at rest)
- Seen at rest in the later stages of the illness or in severe cases
- Exercise intolerance
- Feeding intolerance
- Failure to thrive
- Excessive sleeping
- Diaphoresis
- Chest pain
- Syncope
- Palpitations (late finding)
Pulmonary Hypertension - physical exam
- Typically governed by the signs and findings related to underlying lung or heart disease
- Tachypnea
- Arrhythmias
- Narrowed splitting of S2 heart sound
- Increased P2 heart sound
- Presence of S3 and/or S4 heart sounds
- Murmur of pulmonary or tricuspid insufficiency; tricuspid insufficiency more common
- Jugular venous distention
- Peripheral edema
- Hepatomegaly
Pulmonary Hypertension - tests
- EKG:
- Can be normal if cor pulmonale has not yet developed
- If cor pulmonale present, electrocardiography can demonstrate:
- Right QRS axis deviation
- Right ventricular hypertrophy
- Right atrial hypertrophy
- Echocardiogram with Doppler flow:
- Increased pulmonary artery pressure
- Right ventricular hypertrophy
- Paradoxic movement of the intraventricular septum
- Pulmonic and tricuspid valve regurgitation
- Right-to-left shunting via an open foramen ovale
- Cardiac catheterization:
- Most accurate measurement of pulmonary artery pressure is accomplished by right heart catheterization.
- Criteria for pulmonary hypertension in children:
- Mean pulmonary arterial pressure exceeds 25 mm Hg (at rest)
- Mean pulmonary arterial pressure exceeds 30 mm Hg (with exercise)
- Pulmonary vascular resistance exceeds 3 U/m2
- Pressures should be measured before and after various vasodilators to assess potential reversibility of pulmonary hypertension.
- Caution: In patients with severe disease, catheterization is associated with increased risk of complications.
Pulmonary Hypertension - lab
Arterial blood gases:
- Measurement of pOEvaluation of pCO
Pulmonary Hypertension - imaging
Chest x-ray:
- Will vary according to the underlying disorder and extent of pulmonary hypertension
- Degree of pulmonary hypertension correlates poorly with chest x-ray findings.
- In primary pulmonary hypertension:
- Cardiomegaly
- Enlarged pulmonary artery
- Peripheral lung appears underperfused (“pruning” of pulmonary vessels)
Pulmonary Hypertension - differencial diagnosis
- Pulmonary:
- Asthma
- Cystic fibrosis
- Chronic obstructive pulmonary disease
- Emphysema
- Pulmonary arteriovenous malformations
- Miscellaneous:
- CHF
- Noncardiogenic pulmonary edema
- Fatigue
Pulmonary Hypertension - TREATMENT
Pulmonary Hypertension - general measures
- Provide for patient stabilization
- Need to treat the primary disease process
- Treat underlying hypoxia (supplemental OTreat underlying hypoventilation:
- Useful for correcting hypoxia and hypercarbia secondary to hypoventilation
- Available methods:
- Noninvasive positive pressure ventilation (bilevel ventilation)
- Mechanical ventilation (tracheostomy with mechanical ventilation)
Pulmonary Hypertension - medication
- Oxygen:
- Acts as a vasodilator
- Keep SaOSupplemental OCaution: Supplemental oxygen can sometimes cause hypercapnia by blunting the hypoxia-driven respiratory drive.
- Anticoagulation therapy (i.e., Coumadin):
- Prevents clot formation in the narrowed pulmonary vessels
- Helpful even in the absence of thromboembolic disease
- Vasodilators:
- Methods of action:
- Decreases pulmonary arterial pressures
- Improves right-sided cardiac function
- Available agents:
- Oxygen
- Calcium-channel blocker (i.e., nifedipine)
- Nitric oxide (continuous inhalation)
- Prostacyclin (continuous IV infusion) (i.e., epoprostenol)
- Endothelin receptor antagonist, PO (i.e., bosentan)
- Phosphodiesterase inhibitor PO (i.e., sildenafil)
- Caution: Vasodilators should be used under close supervision because of their effect on systemic BP (systemic hypotension can be a significant problem).
Pulmonary Hypertension - surgery
- Tonsillectomy and/or adenoidectomy if obstructive sleep apnea is the underlying etiology
- Transplantation (lung or heart-lung transplantation): Reserved for patients with refractory, severe pulmonary hypertension
Pulmonary Hypertension - FOLLOW UP
Pulmonary Hypertension - prognosis
- Depends on underlying disease, but generally poor
- In cases of primary pulmonary hypertension, improvement of pulmonary hypertension with administration of vasodilators during initial catheterization is associated with a better survival rate than if no response occurs.
- 10–40% mortality in treated patients
- Near 100% mortality if patient is untreated
- Treatment can be lifelong unless the primary cause of the pulmonary hypertension can be corrected.
- In acute pulmonary hypertension, response to most treatment modalities is almost immediate.
- Oxygen has been shown to reverse hypoxia-related remodeling of the airways after 1 month of therapy.
Pulmonary Hypertension - complications
- Chronic hypoxia
- Exercise intolerance
- Right-sided heart failure (cor pulmonale)
- Death
Pulmonary Hypertension - bibliography
- Barst RJ. Recent advances in the treatment of pediatric pulmonary hypertension. Pediatr Clin North Am. 1999;46:331–345.
- Chatterjee K, De Marco T, Alpert JS. Pulmonary hypertension: Hemodynamic diagnosis and management. Arch Intern Med. 2002;162:1925–1933.
- Klings ES, Farber HW. Current management of primary pulmonary hypertension. Drugs. 2001;61:1945–1956.
- Ravishankar C, Tabbutt S, Wernovsky G. Critical care in cardiovascular medicine. Curr Opin Pediatr. 2003;15:443–453.
- Rosenzweig EB, Widlitz AC, Barst RJ. Pulmonary arterial hypertension in children. Pediatr Pulmonol. 2004;38:2–22.
- Widlitz A, Barst RJ. Pulmonary arterial hypertension in children. Eur Respir J. 2003;21:155–176.
- Yeh TF. Persistent pulmonary hypertension in preterm infants with respiratory distress syndrome. Pediatr Pulmonol. 2001;23(suppl):103–106.
Pulmonary Hypertension - CODES
Pulmonary Hypertension - icd9
416.0 Primary pulmonary hypertension
Pulmonary Hypertension - FAQ
- Q: How many hours per day should supplemental oxygen be used?
- A: Studies have shown decreased mortality in patients using oxygen 24 hours per day compared with patients using supplemental oxygen for only part of the day.
- Q: Should the dosage of oxygen be adjusted during the day according to the patient’s activity?
- A: Increasing supplemental oxygen should be considered for activities that require increased oxygen consumption (i.e., exercise, eating, sleeping).
Book Source Details
- Book Title: The 5-Minute Pediatric Consult
- Author(s): M. William Schwartz MD; et al.
- Year of Publication: 2008
- Copyright Details: The 5-Minute Pediatric Consult, Copyright © 2008 Lippincott Williams & Wilkins.
More About Cor pulmonale
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Copyright notice for book excerpts: Copyright © 2008 Lippincott Williams & Wilkins. All rights reserved.
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More About This Book:
Title: The 5-Minute Pediatric Consult
Authors: M. William Schwartz MD; et al.
Publisher: Lippincott Williams & Wilkins
Copyright: 2008
ISBN: 0-7817-7577-9
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