Pulmonary · Topic 13 of 28

Pulmonary Hypertension & RV Failure

Pulmonary · pulmonary vascular disease

Pulmonary Hypertension & RV Failure

Mean PA pressure above 20 mmHg, confirmed by right heart catheter. When the RV fails, keep systemic pressure up and don't drown it with fluid.

Key numbers

Mean PA pressure above 20 mmHgmPAP > 20 mmHg

01 · Defined byMean PA pressure above 20 mmHg

Pulmonary hypertension = mean pulmonary artery pressure > 20 mmHg at rest on right heart catheterization; pulmonary arterial hypertension adds PA wedge pressure ≤ 15 mmHg and pulmonary vascular resistance > 2 Wood units.

02 · CauseMost PH: left heart or lung disease

Five WHO groups: 1 PAH, 2 left heart disease, 3 lung disease/hypoxemia (COPD, ILD, sleep-disordered breathing), 4 chronic thromboembolic obstruction, 5 multifactorial. Groups 2 and 3 are by far the most common.

03 · FirstFluid can worsen a pressure-overloaded RV

Volume loading a dilated, pressure-overloaded RV shifts the septum into the LV and lowers output; give fluid only if preload is low, and diurese (or dialyze) when CVP is high.

Presentation

What you'll see

Loud P2, RV heave, tricuspid regurgitationProgressive exertional dyspnea, fatigue and presyncope; signs of RV strain: loud P2, RV heave, tricuspid regurgitation murmur, raised JVP, hepatic congestion and edema. ECG shows right axis deviation and RV hypertrophy.

Do right now

In this order

First moves

Correct hypoxemia, hypercapnia and acidosis

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Norepinephrine for hypotension in RV failure

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Fluid can worsen a pressure-overloaded RV

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Inhaled nitric oxide unloads the RV

Why each step

Correct hypoxemia, hypercapnia and acidosisLower RV afterload first by correcting alveolar hypoxia, hypercapnia and acidemia — each causes pulmonary vasoconstriction and raises pulmonary vascular resistance.

Norepinephrine for hypotension in RV failureIn acute RV failure with hypotension, raise systemic pressure with norepinephrine to restore RV coronary perfusion; add dobutamine or milrinone for low cardiac output.

Fluid can worsen a pressure-overloaded RVVolume loading a dilated, pressure-overloaded RV shifts the septum into the LV and lowers output; give fluid only if preload is low, and diurese (or dialyze) when CVP is high.

Inhaled nitric oxide unloads the RVUse an inhaled pulmonary vasodilator (nitric oxide or prostacyclin) to unload the RV in the ICU; systemic vasodilators cause hypotension and worsen V/Q matching.

Management

Orders

Right heart catheterization confirms the diagnosis must knowEchocardiography estimates PA systolic pressure and RV function, but right heart catheterization is required to confirm PH, classify it (wedge pressure, PVR, cardiac output) and test vasoreactivity.

PAH: start ERA plus PDE5 inhibitorGroup 1 PAH that is not vasoreactive: initial combination therapy, eg ambrisentan or macitentan plus tadalafil; high-risk or functional class IV disease adds IV/subcut prostacyclin (epoprostenol, treprostinil).

Calcium channel blocker only if vasoreactiveOnly the few PAH patients who respond to acute vasoreactivity testing at catheterization are treated with a calcium channel blocker.

CTEPH: pulmonary endarterectomy can cureScreen unexplained PH for chronic thromboembolic disease (V/Q scan or CT angiography); pulmonary endarterectomy is first-line and often curative, with balloon angioplasty or riociguat when inoperable.

Red flags & don'ts

Avoid harm

Intubation can precipitate RV collapse complicationPositive-pressure ventilation impedes RV filling and deep sedation can precipitate hemodynamic collapse in RV failure; avoid intubation when possible and support blood pressure first if it is unavoidable.

Never combine a PDE5 inhibitor with riociguat interactionPDE5 inhibitors (sildenafil, tadalafil) and riociguat both raise cGMP — combining them causes dangerous hypotension.

Never abruptly stop an epoprostenol infusion avoidDo not interrupt or abruptly lower IV epoprostenol: its half-life is ≤ 6 minutes, so even brief interruptions cause rebound pulmonary hypertension; change the rate only in small steps.

The rules

Know these

Groups 2 and 3: treat the underlying diseasePAH drugs are not recommended for PH from left heart disease; treat the heart. In lung disease give oxygen for hypoxemia; inhaled treprostinil helps PH-ILD, while endothelin antagonists and riociguat are avoided there.

More detail

Reference

Show 6 reference facts

Sotatercept, an activin-signaling inhibitor added to background PAH therapy, improves 6-minute walk distance, PVR, NT-proBNP and functional class.

Heritable PAH is usually a BMPR2 mutation; drug and toxin causes include methamphetamine and amphetamines, fenfluramine and dasatinib.

Poor prognosis markers: low 6-minute walk distance, high NT-proBNP, TAPSE < 1.6 cm, pericardial effusion, high right atrial pressure and low cardiac output.

Pulmonary vasodilators are avoided in pulmonary veno-occlusive disease because they can cause catastrophic pulmonary edema.

Phenylephrine raises pulmonary vascular resistance without improving RV contractility; low-dose vasopressin may vasodilate the pulmonary circulation but higher doses constrict it.

Patients with PAH should avoid pregnancy, smoking, high altitude and sympathomimetics; lung transplantation is reserved for class IV disease despite maximal therapy.

Pearl

The failing RV lives on coronary perfusion and a low afterload: treat hypotension, hypoxemia, hypercapnia and acidosis before they spiral.

Sources · Merck Manual Professional — Pulmonary Hypertension · Ventetuolo CE, Klinger JR. Management of Acute Right Ventricular Failure in the Intensive Care Unit. Ann Am Thorac Soc 2014 · emDocs — 2026 Guideline: Evaluation and Management of Acute PE (summary of the AHA/ACC guideline) · Epoprostenol for injection prescribing information — DailyMed · Acute Right Ventricular Failure in the Medical ICU. Lung 2025 (narrative review) · Starter sheet built from the verified AGACNP fact map (facts reviewed 2026-10-15).