By Dr. Abdolghader Pakniyat, peer-reviewed by Dr. Sabrina Berouk.
The Central Problem: The Overwhelmed Right Ventricle
The pressure-loaded right ventricle can fail despite plenty of circulating volume. As it dilates, wall stress and oxygen demand rise. Higher intramyocardial pressure and falling systemic pressure reduce coronary perfusion. Septal displacement and pericardial constraint then impair LV filling, further lowering output. Venous congestion adds renal and hepatic dysfunction. This explains why both hypotension and indiscriminate fluid loading can worsen the same patient. AHA scientific statement.
First identify the PH phenotype. Pulmonary arterial hypertension (PAH, group 1) differs from PH associated with left-heart disease (group 2), lung disease/hypoxia (group 3), pulmonary artery obstruction including CTEPH (group 4), and multifactorial disease (group 5). Treating the cause matters; an elevated pulmonary pressure is not permission to start PAH drugs. 2024 WSPH classification.
Applying RV Physiology at the Bedside
Assess perfusion, congestion and the cause together: mental status, skin perfusion, urine output, lactate, ECG, blood gas and bedside echocardiography. Examine RV size/function, septal motion, LV disease and pericardial fluid. A D-shaped LV supports RV loading; it does not establish acute PE. A dilated IVC alone does not decide fluid treatment. Compare prior studies. Echocardiography estimates PH probability; right-heart catheterization defines its hemodynamic phenotype when indicated. Diagnostic framework.
Airway Risk and Escalation
Induction can remove sympathetic support and lower arterial pressure. Apnea adds hypoxemia and hypercapnia; positive pressure can reduce venous return and increase RV load. Use oxygen or HFNC when suitable. A monitored NIV trial may help selected patients, but must not delay intubation for failing oxygenation, ventilation or airway protection. Prepare an experienced airway team, vasoactive support and rescue options before induction when time permits. ESC consensus.
No induction drug or awake technique guarantees stability. In Hong et al.’s retrospective cohort, emergently intubated patients with group 1 or 3 PH had more early vasopressor use, acute kidney injury and gas-exchange disturbance than matched controls. This association supports close post-intubation surveillance; it does not prove that withholding a necessary airway improves survival. Hong et al., 2023.
Circulation: Managing Preload, Afterload, and Squeeze
Fluids: decide whether additional preload will improve forward flow and whether the circulation can tolerate it. In suspected hypovolemia, consider a small, closely reassessed challenge; stop if output fails to improve or RV distension/congestion worsens. Avoid routine large boluses in a dilated, pressure-loaded RV. A preload response alone does not establish a need for more fluid. ESC consensus.
Dynamic indices also need context. In a 282-patient septic-shock study, RV dilatation with congestion was associated with reduced fluid responsiveness despite pulse-pressure variation; TAPSE often remained normal. These findings warn against single-number decisions, but are not a PAH-specific fluid protocol. If feasible, use a reversible preload test with measured stroke-volume change and assess congestion separately. Vieillard-Baron et al., 2020.
Pressure and output: norepinephrine is commonly used for hypotensive RV failure. A small perioperative PH study favored its hemodynamic effects over phenylephrine, which lacks direct inotropy and may increase pulmonary resistance. This does not establish a survival advantage or make phenylephrine universally contraindicated. Kwak et al., 2002.
Do not treat MAP 65 mmHg as proof of adequate perfusion. Individualize pressure to output, venous pressure and organ response. Vasopressin can be an adjunct. If congested, use monitored diuresis; poor perfusion may require vasoactive support while decongesting. Neither fluids nor pressors follow a fixed sequence. 2024 WSPH guidance.
Persistent low output may need dobutamine or selected use of milrinone. Both can cause hypotension and arrhythmia; milrinone persists longer and accumulates with renal impairment. A pressor may be needed concurrently. Reassess flow and perfusion rather than escalating solely because RV contraction looks poor. AHA statement.
Breathing & Afterload Reduction
Correct hypoxemia and significant hypercapnic or metabolic acidosis while treating their cause. During ventilation, balance recruitment against overdistension, limit tidal volumes and driving pressures, and reassess hemodynamics after PEEP changes. Both collapsed and overinflated lungs can increase RV load; no single PEEP fits every patient. ESC consensus.
Inhaled pulmonary vasodilators are specialist-directed rescue options. The 2026 PHiNO trial randomized 30 patients with PAH or CTEPH and severe right-heart failure. Inhaled nitric oxide improved PVR at 30 minutes; no participant was invasively ventilated. This small physiological-endpoint trial does not establish a survival benefit, efficacy in every PH group, or equivalent benefit from inhaled epoprostenol. Ogo et al., 2026.
Monitor response and harms. Inhaled nitric oxide can cause hypotension, methemoglobinemia and rebound deterioration with abrupt withdrawal. LV dysfunction may precipitate pulmonary edema when pulmonary flow increases. Pulmonary edema with vasodilator therapy also raises concern for pulmonary veno-occlusive disease. Adult rescue use is outside the cited US neonatal indication; follow specialist protocols and local regulatory guidance. INOmax prescribing information; epoprostenol safety information.
The Three Needs of the Failing RV
The bedside priorities are connected: preserve coronary and systemic perfusion, reduce reversible RV afterload, and find a filling pressure that supports flow without worsening congestion. A better blood pressure with worsening urine output, lactate or venous congestion is not enough. WSPH intensive-care statement.
Do less — but do the right things
Treat the trigger in parallel. Look for infection, acute PE, arrhythmia, ischemia, bleeding and interrupted therapy rather than attributing all deterioration to chronic PH. Sepsis needs source-directed treatment; suspected high-risk PE needs urgent PE-team assessment for reperfusion; a causative unstable tachyarrhythmia needs emergency rhythm treatment. PH-specific rescue therapy cannot substitute for these actions. WSPH intensive-care framework; 2026 PE guideline.
Reassess after each intervention. Follow blood pressure, perfusion, oxygenation, blood gases, urine output and repeat echocardiography. In complex or refractory shock, invasive hemodynamics may distinguish persistent RV afterload, inadequate flow and a left-sided filling-pressure problem. 2024 WSPH guidance.
Protect continuous prostacyclin delivery. Verify the drug, concentration, dose, pump and dedicated line with the PH team and pharmacy. Do not abruptly stop epoprostenol: even a brief delivery failure can cause rebound PH and rapid deterioration. Plan backup delivery immediately when the pump or line fails. Epoprostenol label.
Treprostinil also must not be abruptly withdrawn or sharply reduced. Its longer half-life does not make interruption acceptable. Oral or inhaled PAH therapy needs a specialist plan if hypotension, contraindications or inability to swallow prevent normal dosing; avoid an unplanned gap or empiric route conversion. Treprostinil label; WSPH statement.
Escalate before multiorgan failure. Involve PH and critical-care specialists early. Persistent shock, rising lactate, worsening renal/hepatic function or escalating respiratory/vasoactive support should prompt discussion with a PH/ECMO-capable center. VA-ECMO is a selected bridge to recovery, definitive intervention or transplantation, with an agreed exit strategy. It is not automatic rescue for every patient. 2024 WSPH guidance.
Most acute PH resuscitation choices remain guided by physiology, small studies and expert consensus. Match treatment to the patient’s PH group and current hemodynamics, then check whether perfusion and congestion actually improve.
