See also: [[Right heart failure]] > [!key points] > - management is intrinsically linked with management for [[Right heart failure#haemodynamic management for severe right heart failure|right heart failure]], as RV failure is the hallmark of decompensated pulmonary hypertension > - *normal* pulm artery pressure ~ 15 mmHg; > - *pulm HTN if ≥ 25 mmHg* at rest > - if pulm artery pressure is > systemic pressure, RV cannot be perfused and becomes ischaemic , leading to catastrophic spiral of RV failure > - **Exertional dyspnea** is the most common symptom attributable to pulmonary hypertension. ~ 19% of patients with a CTPA -ve for PE but with persistent dyspnea have an ECHO with RV dysfunction or overload > - **Syncope** in pulm HTN, especially pulm arterial HTN, is very concerning and requires inpatient **admission** and evaluation > - in resus, **avoid hypoxia and hypercaponea**, **avoid hypotension** aiming systemic BP > pulm art pressure. judicious fluids if hypovolaemia; if hypervolaemia then diuresis. > - The ideal hemodynamic medication would augment cardiac output, maintain SVR, decrease pulmonary vascular resistance, and not increase tachycardia or dysrhythmias > - *norad* first line vasopressor > - [[BNP]] ∝ degree of RV failure > [!references]- > - [Pulmonary Hypertension and Right Ventricular Failure in Emergency Medicine - 2015 Wilcox](bookends://sonnysoftware.com/ref/DL/230990) -- [cubox link](cubox://card?id=7247211468771296586) -- [online link](https://www.sciencedirect.com/science/article/pii/S0196064415011154) : source for many of these notes > - [Dunn - Pulmonary Hypertension](x-devonthink-item://A569FFA7-EBE9-4997-89E5-ED38F149B1B3) > - [Management of Crashing Patients with Pulmonary Hypertension - Greenwood 2015](bookends://sonnysoftware.com/ref/DL/207779) > - [Pulmonary hypertension and right ventricular failure - first10em](cubox://card?id=6826101067164420621) > - [Getting it 'Right': Pulmonary Hypertension in the ED - EMOttawa Blog](https://emottawablog.com/2017/08/getting-right-pulmonary-hypertension-ed/) > - [cardiac Intensive Care David Brown - 32. pulmonary hypertension](x-devonthink-item://C5BE7A05-6B49-44F9-A896-007551DBE78A?page=441) > - [European Respiratory Journal 2022 ESC/ERS Guidelines for pulmonary Hypertension](https://erj.ersjournals.com/content/early/2022/08/25/13993003.00879-2022.full) -- [bookends PDF](bookends://sonnysoftware.com/ref/DL/231145) > - [Biomechanics of the Right ventricle 2014](https://onlinelibrary.wiley.com/doi/10.1086/677354) - [bookends pdf](bookends://sonnysoftware.com/ref/DL/220139) > - [Airway management and perioperative decision making in the patient with severe pulmonary hypertension who requires emergency noncardiac surgery. 2012](bookends://sonnysoftware.com/ref/DL/164860) > Pts with pulm artery hypertension are at a high risk of sudden cardiac death. CPR is highly unsuccessful in patients with pulmonary arterial hypertension and right ventricular failure. 2000 survey of pulm artery HTN pts found that resuscitation after cardiac arrest was unsuccessful in 79% of patients, and only 6% survived for longer than 3 months. ## Definition elevated pressures in the pulmonary vascular bed *Pulmonary Artery Pressure ≥ 25 mmHg* ## Classification - Group 1 -- Pulmonary artery hypertension - Group 1' -- pulmonary venoocclusive disease and/or pulm capillary haemangiomatosis - Group 2 -- Pulm HTN caused by left heart disease - Group 3 -- Pulm HTN caused by lung diseases and/or hypoxia - Group 4 -- chronic thromboembolic pulm HTN ![[Pasted image 20241019205021.png]] **Pulmonary arterial hypertension** (group 1) is a group of diseases characterized by vascular remodeling of the small pulmonary arteries - pulmonary artery vasodilators for this group **Group 2 pulm HTN: LV heart disease** - There is no specific treatment for group 2 disease because the focus of care is to treat the underlying left-sided heart failure - Treatment often relies heavily on diuretics to manage volume overload, systemic afterload reduction, and treating reversible causes of left-sided heart disease **Group 3 pulmonary hypertension: lung disease or hypoxemia** - COPD and obstructive sleep aponea common causes **Group 4 chronic pulm VTE** (CTEPH) - 4% of pts after acute [[Pulmonary Embolism|PE]] - develops in patients with chronic PE as a result of persistent macrovascular obstruction that causes small vessel arteriopathy, leading to persistent small vessel pulmonary vasoconstriction and thrombosis in situ - need [anticoagulation](bookends://sonnysoftware.com/annotation/DL/207779/1729321998/13/-51/-149) of course - may need pulmonary endarterectomy **Group 5** - multifactorial ## Physiology - The pulmonary circulation is a low-pressure, low-resistance system, with thin-walled vessels and a large reserve of unperfused vessels - The RV is usually a thin-walled structure and can accommodate large changes in volume, or preload, but acutely has a limited contractile reserve to tackle increased impedance to ejection, or afterload - ↑ pressure in pulm system → ↓ RV stroke volume and RV output and increase RV volume - When the right ventricle is overloaded, the interventricular septum may bulge into the left ventricle (LV), leading to decreased LV filling and decreased cardiac output, a relationship known as *interventricular dependence* - ↑ RV pressure and volume → ↑ tricuspid regurgitation → ↓ Cardiac output and end-organ perfusion - the [[Right heart failure|RV can fail]] in both acute and chronic pulm HTN - Normally, RV ejection fraction *depends on right ventricular preload* and wall tension increases by the Frank-Starling mechanism. - Beyond a certain point of myocardial distention, ventricular function will fail, with a *reduced cardiac output* and ↑ RV filling pressure - Unlike the LV, which is fed by the coronaries during diastole, the **right ventricle is perfused during both diastole and systole** because of low right ventricular wall tension - ==in pulm HTN, RV perfusion by the coronary arteries decreases in proportion to increases in right ventricular pressure== - If the pulmonary artery pressure surpasses the systemic pressures, the right ventricle cannot be well perfused and will become ischaemic! - this worsens RV conractility → worse RV overload → catastrophic spiral - Hypoxemia is one of the major determinants of pulmonary hypertension - ↓ oxygenation → pulmonary arterioles constrict (*hypoxic pulmonary vasoconstriction*) → pulm HTN ![[Pasted image 20241025233356.png]] ## Clinical presentation - symptoms are non-specific - ==dysponea on exertion== and gradual exercise intolerance most common presenting symptom. - unexplained dysponea (eg CTPA negative) has a [20-30%](bookends://sonnysoftware.com/annotation/DL/230990/1729323307/4/-22/-436) rate of ECHOs showing RV dysfunction - generally progressive with time, resulting in steady decline of functional capacity and worsening in dyspnea - easy fatigability, cough, haemoptysis, hoarsness (from compression of left recurrent laryngeal nerve by large pulm artery) are also known symptoms - symptoms of [[Right heart failure]] begin to manifest later in disease - lower extremity oedema - abdo distension - shortness of breath at rest - chest pain from demand ischaemia (↓ coronary perfusion to RV - [[Syncope]] (usually exertional syncope or pre-syncope as cardiac output becomes fixed and eventually decreases as RV failure progresses) - ==patients with chronic pulm htn are at a high risk for acute [[Pulmonary Embolism]] caused by reduced pulm vascular flow== - CTPA any pt with known pulm HTN with interval change in symptoms > In patients presenting to the ED with dyspnea, [elevated BNP](http://refhub.elsevier.com/S0196-0644(15)01115-4/sref9) levels correlate with echocardiography and provide prognostic information > - \> 1500 ∝ ↓ survival ; < 300 low risk mortality **physical exam** - widened S2 heart sound - elevated JVP > check walking O2 saturation before d/c ## Diagnosis > many of these patients need a CTPA a) because they have unexplained dysponea and evidence of right heart strain, b) pulm htn is a risk factor for PE, and c) chronic PE can cause pulm HTN ### POCUS pulm hypertension #pocus measurement of [[Right Ventricle POCUS#RVSP|RVSP]] other ECHO features: - Thickened RV free wall >5mm on the subcostal view - RV dilatation with a RV end-diastolic/ LV end-diastolic Ratio > 0.9 on the apical 4 chamber view - Flattening of the interventricular septum with a “D” Sign on the parasternal short axis - Other advanced findings include: right atrial enlargement, tricuspid regurgitation, TAPSE < 15mm - can detect ↑ pulm pressures from Doppler flow across the tricuspid valve and detail abnormalities of the interventricular septum, including septal bowing into the LV and paradoxic movement of the septum into the LV during systole note: Because of tricuspid regurgitation and chronically elevated right-sided pressures, central venous pressure is *not an accurate indicator of LV preload* in patients with pulmonary hypertension (AKA ==don't look at IVC to try and establish volume status==) | POCUS finding | example | | ------------------------- | ------------------------------------ | | thickened RV free wall | ![[Pasted image 20241025232359.png]] | | RV dilation | ![[Pasted image 20241025232550.png]] | | "D sign"<br>septal bowing | ![[Pasted image 20241025232615.png]] | ### ECG and CT chest diagnostics **ECG features:** - right axis deviation - incomplete RBBB - tall R in v1 - tall P wave in inferior leads (right atrial enlargement) - ST depressions and T inverions in inferior and R precordial lead (RV strain) - AVNRT, AF, a flutter **CT Chest features** - RV enlargement - main pulm artery diameter > 30 mm - Pulmonary artery dilatation on CT correlates well with pulmonary artery pressure - may help show underlying cause of pulm HTN (eg PE, pneumonia, ground glass from chronic pulm oedema) ![[Pasted image 20241019212959.png|Chest CT scan showing signs of PH, including vascular pruning and a main pulmonary artery diameter greater than the proximal ascending aorta]] ## Management see also: [[Right heart failure#haemodynamic management for severe right heart failure|Right heart failure management]] > [!danger] Management overview > - pre-load and volume status > - Optimise RV systolic function > - Maintain right coronary artery perfusion > - Reduce RV afterload eg avoid hypoxia (aim O2 >90%) and ↑ CO2. nitric oxide if indicated > - treat atrial dysrhythmias -- no β-blockers or CCB > - treat anaemia target 10 g/dL > - anticoagulate PAH or chronic embolism > - consider [[ECMO]] if in extremis | issue | ED mgmt | | ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | pain/anxiety | judicious narcotics and sedatives to avoid hypoventilation and ↑ CO2, ↓ O2 | | optimise preload | - BNP is good test for degree of RV dysfunction and overload<br>- usually have excessive preload; ∴ IVF can cause ↓ cardiac output from RV bowing into LV (interventricular dependence)<br>- if overloaded, may need diuresis. avoid IVF if RAP > 10 - 15 mmHg<br>- if no overload, likely no diuresis<br>- *if hypovolaemia, judicious IVF in 250 - 500 mL aliquots* | | hypotension | - avoid hypotension; *need systemic pressure > pulm artery pressure* to avoid RV ischaemia from ↓ RV coronary perfusion <br>- The cardiac output in most patients with advanced pulmonary hypertension cannot be augmented because of “fixed” pulmonary vascular resistance. Therefore, any reduction in systemic vascular resistance (SVR) will not be followed by a compensatory increase in cardiac output, thus magnifying the degree of hypotension.<br>- The ideal hemodynamic medication would augment cardiac output, maintain SVR, decrease pulmonary vascular resistance, and not increase tachycardia or dysrhythmias; likely need to combine to achieve this effect<br>- ==vasopressors== can prevent RV ischaemia (see below) | | vasopressors | - [[Noradrenaline]] [first line](bookends://sonnysoftware.com/annotation/DL/230990/1729323307/5/-24/-425) (although possible slight ↑ pulm vascular resistance from alpha effects)<br>- *vasopressin* may also decrease pulm vascular resistance <br>- avoid phenylepherine (metaraminol inferior to norad) | | ionotropes | - [[Dobutamine#Right heart failure / pulm HTN\|dobutamine]] can ↑ CO, but causes tachy and ↓ SVR (likely needs norad to prevent systemic hypotension). Often used for acute RV infarct if PA pressure normal to ↑ contractility. <br>- [[Milrinone#Right heart failure / pulm HTN\|Milrinone]] good pulm vasodilator, causes more hypotension, used more if PA pressures ↑ *and need to reduce RV afterload*. | | arrhythmias | - need to treat because pts depend on atrial contraction for adequate filling to maintain CO<br>- *avoid beta blockers and CCB* → ↓ RV f(x)<br>- consider [[Cardioversion]] if AF | | pulm vasodilators | - *only for known Group 1* (pulm artery hypertension)<br>- not helpful for group 2 (LV failure) as can worsen APO, and may worsen V/Q mismatch in COPD<br>- inhaled nitric oxide may be used in severe RV failure, massive PE. will ↓ PVR ; no change in SVR. improve VQ<br>and prostacyclins (Epoprostenol)<br>- Phosphodiesterase-5 inhibitors eg such as sildenafil and tadalafil often taken by outpatients, minimal ED use | | Ventilation failure | - given risks of sedation, vasodilation, ↑ interthoracic pressure, avoid intubation in pts with RV failure <br>- however, significant haemodynamic risks of hypoxia, hypercarbia, and metabolic acidosis | | NIV | - Positive-pressure ventilation will ↓ preload but will also ↑ RV afterload, ∴ *worsening systemic hypotension*<br>- if resp failure can do NIV judiciously to avoid intubation | | intubation | - consider [awake fibreoptic intubation](bookends://sonnysoftware.com/annotation/DL/164860/1729863625/2/-68/-545) with mucosal topicalization and reassurance to avoid ↑ anxiety, coughing or gagging, and ↑ sympathetic tone<br>- if RSI, use **ketamine** or high dose fentanyl | | Ventilation | - maintain low pulm vascular resistance to systemic vascular resistance ration (PVR/SVR)<br>- atelectasis increases PVR, as does over-inflated lung; under-ventilation does as well due to ↑ CO2 and hypoxia<br>- similar to *ARDS* (low tidal volumes, low plateau pressures, low PEEP), but *NO permissive hypercaponea or hypoxia* | --- ## Congenital heart disease-associated Pulm artery HTN ### Eisenmenger Syndrome This category includes all large intracardiac and extracardiac defects that begin as systemic-to-pulmonary shunts and progress with time to severe elevation of PVR and to reversal (pulmonary-to-systemic) or bidirectional shunting. Cyanosis, secondary erythrocytosis, and multiple organ involvement are usually present ### PAH a/w systemic-to-pulm shunt This category includes moderate to large defects, in which PVR is mildly to moderately increased, systemic-to-pulmonary shunting is still prevalent, and cyanosis at rest is not a feature. They are divided into correctable (surgically or with intravascular percutaneous procedure) and noncorrectable. ### PAH with small defects This category includes PAH with significant PVR elevation in the presence of small cardiac defects (usually ventricular septal defects <1 cm and atrial septal defects <2 cm of effective diameter as assessed by echocardiography), which themselves do not account for the development of the PVR elevation. The clinical picture is very similar to idiopathic PAH and closing the defects is contraindicated. ### PAH after defect correction This category includes persisting PAH after congenital heart disease repair, either immediately after correction or developing within months to years after correction. This is in the absence of any significant postoperative hemodynamic lesions.