Pulmonary hypertension

Background

Pulmonary Hypertension = mean PA pressure >25mmHg assessed by right heart cath

• can be divided into:
  • precapillary PH (normal PCWP)
    • Includes Pulmonary arterial hypertension (PAH), PH due to due to lung disease, and chronic thromboembolic PH
  • postcapillary PH (elevated PCWP)
    • PH due to left heart disease

Etiology

• PAH can be heritable, idiopathic, or associated with connective tissue disease, HIV, portal HTN, congenital heart dz, schistosomiasis, chronic hemolytic anemia
• PH can be due to lung disease, left heart disease, chronic exposure to high altitudes, chronic thromboembolic disease, myeloproliferative disorders, sarcoidosis, vasculitis, glycogen storage disease, Gaucher disease, chronic renal failure on dialysis

Diagnosis

• Consider in undifferentiated patients with dyspnea, fatigue, syncope, chest pain, palpitations
• Look for JVD, hepatomegaly, ascites, edema, stigmata of liver failure or CTD
• ECG shows signs of RHD (RAE, RAD, RVH)
• CXR with vascular congestion, PA dilation, RA enlargement
• TTE shows elevated PAP
• Need RH cath to diagnose

Chronic Therapies

• Prostacyclins - vasodilatation, inhibit platelet aggregation
  • Epoprostenol, Iloprost, Treprostinil, Beraprost
  • Complications include acute decompensation if stopped abruptly, diarrhea, edema, headache
• Phosphodiesterase Type 5 (PDE5) Inhibitors - vasodilation, increases RV contractility
  • Sildenafil
  • Complications include hypotension with administration of nitrates, flushing, epistaxis, headache
• Endothelin receptor antagonists - vasodilation
  • Bosentan, Ambrisentan
  • Complications include liver failure, supratherapeutic INR,
• Patients also usually taking digoxin, coumadin, diuretics, home O2. RARELY are they on CCB only if responsive during cath. Consider line infections as complication to chronic infusions.

Acute Treatment for PAH crisis

1. No fluids, consider diuretics
2. O2
3. Treat relative bradycardia
   1. atropine, pace, low dose dobutamine <5mcg/kg/min to increase contractility
   2. Consider norepinephrine prior to dobutamine if hypotensive
4. Cardiovert tachycardias - NO CCB or BB
   1. Electrical cardioversion or amiodarone
5. Pulm vasodialate
   1. sildenafil, bostantan, epoprostenol (2ng/kg/min), inhaled NO if intubated
6. Check INR, dig level and correct
7. Empiric abx
8. If intubated, low PEEP, low tidal volumes

Source

4/07 DONALDSON (adapted from Sarver)