Pulmonary Hypertension (PH) is defined as mean pulmonary artery pressure (mPAP) ≥20 mmHg at rest, measured by right heart catheterisation (RHC). This threshold was revised downward from 25 mmHg in the 2022 ESC/ERS guidelines.
mPAP ≥20 mmHg, PAWP ≤15 mmHg, PVR ≥2 WU. Groups 1, 3, 4, 5.
mPAP ≥20 mmHg, PAWP >15 mmHg. Group 2 (left heart disease). Most common overall.
mPAP ≥20 mmHg, PAWP >15 mmHg, PVR ≥2 WU. Mixed aetiology — worse prognosis.
Idiopathic (IPAH), Heritable (BMPR2 mutations), Drug/toxin-induced (anorexigens, methamphetamine), Associated: connective tissue disease (systemic sclerosis most common in GCC), HIV, portal hypertension, congenital heart disease, schistosomiasis.
Left ventricular systolic/diastolic dysfunction, valvular disease (mitral stenosis, aortic stenosis). PAWP >15 mmHg. Management targets underlying cardiac disease. PAH-specific therapy NOT indicated here.
COPD, interstitial lung disease (ILD), OSA, obesity hypoventilation syndrome. Hypoxia-driven vasoconstriction. Treat underlying lung disease and correct hypoxia. LTOT may reduce PAP progression.
Unresolved PE leading to organised thrombus obstructing pulmonary vasculature. Potentially curable by pulmonary endarterectomy (PEA). V/Q scan is investigation of choice. Riociguat approved for inoperable CTEPH.
Haematological disorders (sickle cell, thalassaemia), systemic disorders (sarcoidosis, Langerhans cell histiocytosis), metabolic disorders, fibrosing mediastinitis. Management is disease-specific.
GCC Context: Higher prevalence of systemic sclerosis-associated PAH (Group 1) and sickle-cell/thalassaemia-related PH (Group 5) across Gulf populations. Congenital heart disease-related PAH is also more prevalent given less historical access to paediatric cardiac surgery in some regions.
PH diagnosed but no limitation of physical activity. Ordinary activity does not cause symptoms.
Slight limitation. Comfortable at rest. Ordinary activity causes undue dyspnoea, fatigue, chest pain or presyncope.
Marked limitation. Comfortable at rest. Less than ordinary activity causes undue symptoms. Most patients on therapy.
Unable to carry out any physical activity without symptoms. Signs of RV failure at rest. May be near death.
Complications to watch: pneumothorax (jugular approach), haematoma, arrhythmias, pulmonary artery perforation (rare but serious — sudden haemoptysis).
Submaximal exercise test. Walk distance (metres) correlates with WHO FC and prognosis. Serial measurements track disease progression and treatment response.
Record: distance walked, SpO2 (start and nadir), heart rate, Borg dyspnoea scale (0–10), reason for stopping, symptoms during test.
SpO2 drop >4% or nadir <85% — significant oxygen desaturation; flag to physician.
Echocardiography is the key screening tool for PH, but cannot replace right heart catheterisation for definitive diagnosis. It provides estimated RVSP via TR jet velocity and assesses RV function.
TR velocity ≤2.8 m/s AND no other signs of PH.
TR velocity ≤2.8 m/s with other signs, OR TR velocity 2.9–3.4 m/s.
TR velocity >3.4 m/s regardless of other signs. Refer for RHC.
Right heart strain biomarker. Secreted by ventricular myocytes in response to wall stress and pressure overload.
Trend is more important than single values. Rising BNP/NT-proBNP on therapy = treatment failure or disease progression — escalate to treating team. Check timing relative to fluid shifts (renal function affects clearance).
Identifies acute or chronic PE, pulmonary artery dilation, parenchymal lung disease (Group 3). Main role: rule out CTEPH (Group 4) and underlying lung pathology. May show enlarged main PA (>29mm).
Note: CTPA is less sensitive than V/Q scan for CTEPH — V/Q preferred for CTEPH diagnosis.
Investigation of choice for CTEPH (Group 4). Shows mismatched perfusion defects. More sensitive than CTPA for CTEPH. Normal V/Q virtually excludes CTEPH. Segmental or larger perfusion defects with normal ventilation = CTEPH pattern.
Identifies underlying lung disease: ILD (UIP/NSIP pattern in systemic sclerosis), emphysema (COPD/Group 3), lymphangioleiomyomatosis. Key for differentiating Group 1 from Group 3 PH.
DLCO (Diffusing Capacity for CO) is reduced in PAH — often the only abnormality on PFTs. Sensitive early marker.
Spirometry typically normal or mild restriction in Group 1 PAH. Obstructive pattern suggests Group 3 (lung disease).
DLCO <45% predicted in systemic sclerosis — high risk for PAH development; triggers annual echo screening.
OSA is a treatable cause of Group 3 PH. Overnight oximetry or full polysomnography as clinically indicated. CPAP treatment may reduce PA pressures.
PAH-specific therapies are indicated ONLY for Group 1 PAH (pre-capillary). They are NOT appropriate for Group 2 (left heart disease) PH where they may cause harm. Always confirm WHO group before PAH therapy initiation.
| Class | Drugs | Mechanism | Route | Key Nursing Monitoring |
|---|---|---|---|---|
| PDE5 Inhibitors | Sildenafil, Tadalafil | cGMP ↑ → pulmonary vasodilation | Oral | Hypotension, flushing, headache. ABSOLUTE CI with nitrates. |
| sGC Stimulators | Riociguat | Directly stimulates soluble guanylate cyclase | Oral | Hypotension, dizziness, haemoptysis. CI with PDE5i and nitrates. Teratogenic. |
| ERA (Endothelin RA) | Bosentan, Macitentan, Ambrisentan | Blocks endothelin-1 → vasodilation + anti-proliferative | Oral | Hepatotoxicity (Bosentan), fluid retention, teratogenic — double contraception required. |
| Prostanoids | Epoprostenol (IV), Iloprost (inhaled), Treprostinil (SC/IV/inhaled) | Prostacyclin analogue → vasodilation, anti-platelet, anti-proliferative | IV/Inhaled/SC | Central line care, rebound crisis if stopped, cold chain, pump alarms. |
ABSOLUTE CONTRAINDICATION: Nitrates
Sildenafil + nitrates (GTN, isosorbide) = profound hypotension, potentially fatal. Must be documented clearly. Patients must carry alert card. Never administer GTN to a patient on sildenafil for PH.
Dual ERA (blocks ET-A and ET-B receptors). Oral BD dosing. Monthly LFT monitoring mandatory — 10% risk of elevated transaminases; dose reduction or cessation if >3× ULN. Teratogenic — double contraception for women of childbearing age.
Improved tissue penetration. Once-daily dosing. Lower hepatotoxicity risk than bosentan. Monitor: haemoglobin (anaemia), LFTs, fluid retention. Also teratogenic — double contraception required.
Once daily. Lower hepatotoxicity profile than bosentan (LFT monitoring still required). Peripheral oedema is common — monitor daily weight, fluid balance. Teratogenic.
All ERAs are TERATOGENIC (Category X). Document contraception counselling. Women of childbearing age require pregnancy test before initiation and monthly thereafter with two forms of contraception.
NEVER abruptly stop IV epoprostenol. Sudden discontinuation causes rebound pulmonary hypertensive crisis — can be rapidly fatal. Always have backup cassette/pump available. Patients and families must be educated about this.
6–9 inhalations per day (every 2–3 hours during waking hours). 5–10 min per inhalation. Teach inhaler device technique. Side effects: cough, flushing, jaw pain. Portable nebuliser for active patients.
Continuous subcutaneous infusion via small pump. Site pain is the main side effect (rotation every 3–7 days). Less infection risk than IV. Teach site care and pump management.
Current guidelines recommend upfront combination therapy in most newly diagnosed PAH patients (unless low-risk). The AMBITION trial established ERA + PDE5i as standard initial combination.
Oral dual combination: ERA + PDE5i (e.g., ambrisentan + tadalafil). Reassess at 3–6 months.
Oral dual or triple combination. Consider adding prostanoid (inhaled iloprost or SC treprostinil). Target low-risk profile at 3–6 months.
Triple therapy: ERA + PDE5i + IV prostanoid (epoprostenol). Transplant referral should be initiated. ICU-level monitoring.
PH Crisis = acute severe elevation of PAP leading to acute RV failure and haemodynamic collapse. Medical emergency requiring immediate specialist involvement. Mortality is very high without rapid intervention.
AVOID in PH Crisis:
Systemic vasodilators that reduce SVR more than PVR (e.g., GTN, hydralazine) — cause systemic hypotension without relieving pulmonary pressure, worsening RV perfusion. High PEEP. Aggressive fluid loading (RV is preload-dependent but excess fluid worsens ventricular interdependence).
The right ventricle is the primary determinant of prognosis in PAH. Progressive RV failure follows longstanding pressure overload.
Furosemide for volume overload. Use cautiously — RV is preload-dependent; over-diuresis reduces CO. Monitor daily weights, urine output, electrolytes (K+ and Mg2+). Target euvolaemia.
Noradrenaline first-line — maintains systemic pressure and coronary perfusion to RV. Vasopressin second-line. Avoid pure beta-agonists (tachycardia worsens RV filling).
Dobutamine (beta-1 + mild vasodilation) for acute RV support. Milrinone (PDE3 inhibitor) — inotrope and pulmonary vasodilator; use cautiously (may cause systemic hypotension).
Target SpO2 >90% in PAH (contrast with COPD). Hypoxia causes direct pulmonary vasoconstriction, worsening PH. LTOT for ambulatory desaturation.
PH carries significant peri-operative risk. Mortality from elective surgery in severe PAH can be 5–25%. Key principles:
Palliative intervention: creates a controlled right-to-left atrial shunt. Reduces RA pressure and improves cardiac output — at the cost of systemic oxygen saturation. Used as bridge to transplant in severe refractory PAH.
Bilateral lung transplantation preferred for PAH — single lung associated with reperfusion injury risk. Refer when high-risk features emerge despite maximal therapy. Pre-transplant nursing assessment includes exercise capacity, psychosocial readiness, adherence, social support.
Exercise rehabilitation is beneficial and recommended in PAH but must be supervised and moderate intensity. The EXPERT consensus (2019) supports supervised exercise in stable PAH.
Cabin pressure in commercial aircraft is equivalent to 6,000–8,000 feet altitude (PaO2 drops). PH patients may desaturate significantly.
Desert travel and highland areas (Asir mountains, Saudi Arabia): hypoxia at altitude worsens PH. Extreme heat increases cardiac demand. Advise avoidance of high-altitude locations and outdoor exertion in summer months (>40°C).
GCC summer temperatures (>45°C outdoors, high humidity in coastal areas) significantly increase cardiovascular demand. PH patients should stay in air-conditioned environments during peak heat hours.
Pregnancy in PAH carries 30–50% maternal mortality. ESC guidelines advise against pregnancy in all women with PAH. This applies to Group 1 PAH regardless of functional class or therapy.
Practice varies. Historically warfarin (INR target 1.5–2.5) was recommended for IPAH based on observational data suggesting improved survival. Current ESC 2022 guidelines:
All PH patients should carry a card or digital document stating:
Depression and anxiety are highly prevalent in PAH (30–50%). Contributing factors: chronic life-limiting illness, physical disability, complex treatment regimens, uncertainty about prognosis, social isolation, and financial burden of medications.
Mental health stigma remains a barrier to help-seeking in many GCC populations. Nurses should frame psychological support as part of holistic disease management. Family-centred approach preferred.
| Group | Name | Mechanism | Key Example | PAH Therapy? |
|---|---|---|---|---|
| 1 | Pulmonary Arterial Hypertension | Pulmonary arterial remodelling | IPAH, Systemic Sclerosis, CTD | YES |
| 2 | Left Heart Disease | Elevated PAWP (post-capillary) | LV failure, Mitral stenosis | NO |
| 3 | Lung Disease / Hypoxia | Hypoxic vasoconstriction | COPD, ILD, OSA | NO (treat cause) |
| 4 | CTEPH | Organised thrombus obstructing PA | Chronic PE | Riociguat only |
| 5 | Miscellaneous | Multifactorial | Sickle cell, Sarcoidosis | Disease-specific |
| Drug | Class | Route | Key Monitoring | Danger |
|---|---|---|---|---|
| Sildenafil | PDE5i | Oral BD/TID | BP, flushing, headache | NEVER with nitrates |
| Tadalafil | PDE5i | Oral OD | BP, flushing | NEVER with nitrates |
| Riociguat | sGC stimulator | Oral TID | BP, haemoptysis | NEVER with PDE5i/nitrates; teratogenic |
| Bosentan | ERA (dual) | Oral BD | Monthly LFTs, Hb | Hepatotoxic; teratogenic |
| Macitentan | ERA (dual) | Oral OD | LFTs, Hb, oedema | Teratogenic; anaemia |
| Ambrisentan | ERA (ET-A) | Oral OD | Oedema, weight, LFTs | Teratogenic; fluid retention |
| Epoprostenol | Prostanoid | IV continuous | Line care, BP, pump | NEVER stop suddenly — rebound crisis |
| Iloprost | Prostanoid | Inhaled 6–9x/day | BP, cough, jaw pain | Inconvenient frequency |
| Treprostinil | Prostanoid | SC/IV | Site pain, BP | Site pain (SC); do not stop |
Sildenafil + Nitrates = ABSOLUTE CONTRAINDICATION
Combination causes severe, potentially fatal hypotension. A patient on sildenafil for PH must NEVER receive GTN, isosorbide mononitrate, or isosorbide dinitrate for any reason.
Sudden cessation of IV epoprostenol causes rebound PH crisis
Never stop IV epoprostenol abruptly. Always have backup supply. This is the most dangerous acute event in PAH management.
V/Q scan — preferred over CTPA for CTEPH diagnosis
V/Q is more sensitive for CTEPH. A normal V/Q scan virtually excludes CTEPH. CTPA may miss organised thrombus.
Group 2 PH — PAH-specific therapy is CONTRAINDICATED
PAH therapies (ERA, PDE5i, prostanoids) are not indicated and can be harmful in left heart disease PH (Group 2). Identifying the correct WHO group is essential before any treatment.
Pregnancy in PAH — strongly advised against (30–50% mortality)
Highest risk of maternal death among cardiac diseases in pregnancy. ESC Class III indication against pregnancy. Requires urgent specialist and obstetric team co-management if it occurs.
Right heart catheterisation (RHC) = gold standard for PH diagnosis
Echocardiography is screening only. RHC confirms the diagnosis, determines haemodynamic type (pre/post-capillary), guides therapy, and allows vasoreactivity testing in IPAH.
DLCO reduction — may be the only PFT abnormality in early PAH
Spirometry may be normal. DLCO is sensitive for vascular changes. Reduced DLCO in systemic sclerosis warrants annual echo screening for PAH.
Avoid high PEEP in ventilated PH patients
High PEEP increases intrathoracic pressure → compresses pulmonary vasculature → increases RV afterload → precipitates or worsens RV failure in PH.