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Prostacyclin (prostaglandin I) is commonly considered the most effective treatment for PAH. Epoprostenol (synthetic prostacyclin) is given via continuous infusion that requires a semi-permanent central venous catheter. This delivery system can cause sepsis and thrombosis. Prostacyclin is unstable, and therefore has to be kept on ice during administration. Since it has a half-life of 3 to 5 minutes, the infusion has to be continuous, and interruption can be fatal. Other prostanoids have therefore been developed. Treprostinil can be given intravenously or subcutaneously, but the subcutaneous form can be very painful. An increased risk of sepsis with intravenous Remodulin has been reported by the CDC. Iloprost is also used in Europe intravenously and has a longer half life. Iloprost was the only inhaled form of prostacyclin approved for use in the US and Europe, until the inhaled form of treprostinil was approved by the FDA in July 2009.
The dual (ET and ET) endothelin receptor antagonist bosentan was approved in 2001. Sitaxentan (Thelin) was approved for use in Canada, Australia, and the European Union, but not in the United States. In 2010, Pfizer withdrew Thelin worldwide because of fatal liver complications. A similar drug, ambrisentan is marketed as Letairis in the U.S. by Gilead Sciences.
Standard medical treatment consists of anticoagulants (blood thinners), diuretics, and oxygen. Lifelong anticoagulation is recommended, even after PEA. Routine inferior vena cava filter placement is not recommended.
In patients with non-operable CTEPH or persistent/recurrent PH after PEA, there is evidence for benefit from pulmonary vasodilator drug treatment. The microvascular disease component in CTEPH has provided the rationale for off-label use of drugs approved for PAH. Currently, only riociguat (a stimulator of soluble guanylate cyclase) is approved for treatment of adults with inoperable CTEPH or persistent or recurrent CTEPH after surgical treatment. Other drug trials are ongoing in patients with inoperable CTEPH, with macitentan recently proving efficacy and safety in MERIT
Decision making for patients with CTEPH can be complex and needs to be managed by CTEPH teams in expert centres. CTEPH teams comprise cardiologists and pulmonologists with specialist PH training, radiologists, experienced PEA surgeons with a significant caseload of CTEPH patients per year and physicians with percutaneous interventional expertise. Currently, there are three recognised targeted treatment options available: pulmonary endarterectomy (PEA), balloon pulmonary angioplasty (BPA) and pulmonary vasodilator drug treatment for inoperable patients.
Specialist imaging using either magnetic resonance or invasive PA is necessary to determine risks and benefits of interventional treatment with PEA or BPA.
In general, the treatment of PPH is derived from the treatment of pulmonary hypertension. The best treatment available is the combination of medical therapy and liver transplantation.
The ideal treatment for PPH management is that which can achieve pulmonary vasodilatation and smooth muscle relaxation without exacerbating systemic hypotension. Most of the therapies for PPH have been adapted from the primary pulmonary hypertension literature. Calcium channel blockers, b-blockers and nitrates have all been used – but the most potent and widely used aids are prostaglandin (and prostacyclin) analogs, phosphodiesterase inhibitors, nitric oxide and, most recently, endothelin receptor antagonists and agents capable of reversing the remodeling of pulmonary vasculature.
Inhaled nitric oxide vasodilates, decreasing pulmonary arterial pressure (PAP) and pulmonary vascular resistance (PVR) without affecting systemic artery pressure because it is rapidly inactivated by hemoglobin, and improves oxygenation by redistributing pulmonary blood flow to ventilated areas of lung. Inhaled nitric oxide has been used successfully to bridge patients through liver transplantation and the immediate perioperative period, but there are two significant drawbacks: it requires intubation and cannot be used for long periods of time due to methemoglobinemia.
Prostaglandin PGE1 (Alprostadil) binds G-protein linked cell surface receptors that activate adenylate cyclase to relax vascular smooth muscle. Prostacyclin – PGI2, an arachadonic acid derived lipid mediator (Epoprostenol, Flolan, Treprostenil) – is a vasodilator and, at the same time, the most potent inhibitor of platelet aggregation. More importantly, PGI2 (and not nitrous oxide) is also associated with an improvement in splanchnic perfusion and oxygenation. Epoprostenol and ilioprost (a more stable, longer acting variation) can and does successfully bridge for patients to transplant. Epoprostenol therapy can lower PAP by 29-46% and PVR by 21-71%., Ilioprost shows no evidence of generating tolerance, increases cardiac output and improves gas exchange while lowering PAP and PVR. A subset of patients does not respond to any therapy, likely having fixed vascular anatomic changes.
Phosphodiesterase inhibitors (PDE-i) have been employed with excellent results. It has been shown to reduce mean PAP by as much as 50%, though it prolongs bleeding time by inhibiting collagen-induced platelet aggregation. Another drug, Milrinone, a Type 3 PDE-i increases vascular smooth muscle adenosine-3,5-cyclic monophosphate concentrations to cause selective pulmonary vasodilation. Also, by causing the buildup of cAMP in the myocardium, Milrinone increases contractile force, heart rate and the extent of relaxation.
The newest generation in PPH pharmacy shows great promise. Bosentan is a nonspecific endothelin-receptor antagonist capable of neutralizing the most identifiable cirrhosis associated vasoconstrictor, safely and efficaciously improving oxygenation and PVR, especially in conjunction with sildenafil. Finally, where the high pressures and pulmonary tree irritations of PPH cause a medial thickening of the vessels (smooth muscle migration and hyperplasia), one can remove the cause –control the pressure, transplant the liver – yet those morphological changes persist, sometimes necessitating lung transplantation. Imatinib, designed to treat chronic myeloid leukemia, has been shown to reverse the pulmonary remodeling associated with PPH.
In those with underlying heart disease, effective control of congestive symptoms prevents pulmonary edema.
Dexamethasone is in widespread use for the prevention of high altitude pulmonary edema. Sildenafil is used as a preventive treatment for altitude-induced pulmonary edema and pulmonary hypertension, the mechanism of action is via phosphodiesterase inhibition which raises cGMP, resulting in pulmonary arterial vasodilation and inhibition of smooth muscle cell proliferation. While this effect has only recently been discovered, sildenafil is already becoming an accepted treatment for this condition, in particular in situations where the standard treatment of rapid descent has been delayed for some reason.
The initial management of pulmonary edema, irrespective of the type or cause, is supporting vital functions. Therefore, if the level of consciousness is decreased it may be required to proceed to tracheal intubation and mechanical ventilation to prevent airway compromise. Hypoxia (abnormally low oxygen levels) may require supplementary oxygen, but if this is insufficient then again mechanical ventilation may be required to prevent complications. Treatment of the underlying cause is the next priority; pulmonary edema secondary to infection, for instance, would require the administration of appropriate antibiotics.
It is sometimes treated with surgery, which involves rerouting blood from the right atrium into the left atrium with a patch or use of the Warden procedure. However, interest is increasing in catheter-based interventional approaches, as well as medical therapy for less severe cases.
Treatment aims to increase the amount of oxygen in the blood and reverse any causes of hypoxia.
- oxygen therapy
- mechanical ventilation
- Nitrous Oxide (NO·) Inhalation
- Prostaglandins (intravenous)
The therapies available to manage PPHN include the high frequency ventilation, surfactant instillation, inhaled nitric oxide, and extracorporeal membrane oxygenation. These expensive and/or invasive modalities are unavailable in the developing countries where the frequency and mortality of PPHN is likely to be much higher due to higher incidence of asphyxia and sepsis. In developing countries, the medical facilities are usually supplied with outdated equipment that was initially donated. "For people in developing countries, basic medical supplies are luxuries that are simply not available or not affordable. Doctors and nurses must constantly make do - washing and reusing "disposable" gloves and syringes, or substituting inappropriate materials such as fishing line or sewing thread for suture- or patients must go without needed care. In many countries patients must bring their own supplies, even acquire their own medicines, before treatment can be given." The limitations made it necessary to search for cheaper therapies, assuring quick effectiveness and stabilization of the patient going through a very high-risk situation. The treatments are chosen on the basis of low cost, low-tech, wide availability, and safety in the hands of non-professionals. Therefore, oral sildenafil citrate, has been the alternative way of therapy. The cost comparison shows that sildenafil is lower in cost than iNO and more readily available. There is improvement in oxygenation when oral sildenifal is administered according to the studies found in the Official Journal of the American Academy of Pediatric. The positive research results for varies studies indicates that oral sildenifal is a feasible source to improve oxygenation and survival in critical ill infants with PPHN secondary to parenchymal lung disease in centers without access to high-frequency ventilation, iNO, or ECMO.
Treatment is aimed at controlling symptoms and improving the interrupted blood flow to the affected area of the body.
Medications include:
- Antithrombotic medication. These are commonly given because thromboembolism is the major cause of arterial embolism. Examples are:
- Anticoagulants (such as warfarin or heparin) and antiplatelet medication (such as aspirin, ticlopidine, and clopidogrel) can prevent new clots from forming
- Thrombolytics (such as streptokinase) can dissolve clots
- Painkillers given intravenously
- Vasodilators to relax and dilate blood vessels.
Appropriate drug treatments successfully produces thrombolysis and removal of the clot in 50% to 80% of all cases.
Antithrombotic agents may be administered directly onto the clot in the vessel using a flexible catheter ("intra-arterial thrombolysis"). Intra-arterial thrombolysis reduces thromboembolic occlusion by 95% in 50% of cases, and restores adequate blood flow in 50% to 80% of cases.
Surgical procedures include:
- Arterial bypass surgery to create another source of blood supply
- Embolectomy, to remove the embolus, with various techniques available:
- Thromboaspiration
- Angioplasty with balloon catheterization with or without implanting a stent Balloon catheterization or open embolectomy surgery reduces mortality by nearly 50% and the need for limb amputation by approximately 35%.
- Embolectomy by open surgery on the artery
If extensive necrosis and gangrene has set in an arm or leg, the limb may have to be amputated. Limb amputation is in itself usually remarkably well tolerated, but is associated with a substantial mortality (~50%), primarily because of the severity of the diseases in patients where it is indicated.
Currently the only definitive treatment is liver transplantation. Alternative treatments such as supplemental oxygen or somatostatin to inhibit vasodilation remain anecdotal.
With liver transplantation, the 5 year survival rate is 74%, which is comparable to patients who undergo liver transplants who do not suffer from hepatopulmonary syndrome.
Treatments for primary pulmonary hypertension such as prostacyclins and endothelin receptor antagonists can be fatal in people with PVOD due to the development of severe pulmonary edema, and worsening symptoms after initiation of these medications may be a clue to the diagnosis of pulmonary veno occlusive disease.
The definitive therapy is lung transplantation, though transplant rejection is always a possibility, in this measures must be taken in terms of appropriate treatment and medication.
Warfarin and vitamin K antagonists are anticoagulants that can be taken orally to reduce thromboembolic occurrence. Where a more effective response is required, heparin can be given (by injection) concomitantly. As a side effect of any anticoagulant, the risk of bleeding is increased, so the international normalized ratio of blood is monitored. Self-monitoring and self-management are safe options for competent patients, though their practice varies. In Germany, about 20% of patients were self-managed while only 1% of U.S. patients did home self-testing (according to one 2012 study). Other medications such as direct thrombin inhibitors and direct Xa inhibitors are increasingly being used instead of warfarin.
Following diagnosis, mean survival of patients with PPH is 15 months. The survival of those with cirrhosis is sharply curtailed by PPH but can be significantly extended by both medical therapy and liver transplantation, provided the patient remains eligible.
Eligibility for transplantation is generally related to mean pulmonary artery pressure (PAP). Given the fear that those PPH patients with high PAP will suffer right heart failure following the stress of post-transplant reperfusion or in the immediate perioperative period, patients are typically risk-stratified based on mean PAP. Indeed, the operation-related mortality rate is greater than 50% when pre-operative mean PAP values lie between 35 and 50 mm Hg; if mean PAP exceeds 40-45, transplantation is associated with a perioperative mortality of 70-80% (in those cases without preoperative medical therapy). Patients, then, are considered to have a high risk of perioperative death once their mean PAP exceeds 35 mm_Hg.
Survival is best inferred from published institutional experiences. At one institution, without treatment, 1-year survival was 46% and 5-year survival was 14%. With medical therapy, 1-year survival was 88% and 5-year survival was 55%. Survival at 5 years with medical therapy followed by liver transplantation was 67%. At another institution, of the 67 patients with PPH from 1652 total cirrhotics evaluated for transplant, half (34) were placed on the waiting list. Of these, 16 (48%) were transplanted at a time when 25% of all patients who underwent full evaluation received new livers, meaning the diagnosis of PPH made a patient twice as likely to be transplanted, once on the waiting list. Of those listed for transplant with PPH, 11 (33%) were eventually removed because of PPH, and 5 (15%) died on the waitlist. Of the 16 transplanted patients with PPH, 11 (69%) survived for more than a year after transplant, at a time when overall one-year survival in that center was 86.4%. The three year post-transplant survival for patients with PPH was 62.5% when it was 81.02% overall at this institution.
This has a good prognosis if it is reversible. Causes include polycythemia and hyperfibrinogenemia.
The standard and most important treatment is to descend to a lower altitude as quickly as possible, preferably by at least 1000 metres. Oxygen should also be given if possible. Symptoms tend to quickly improve with descent, but more severe symptoms may continue for several days. The standard drug treatments for which there is strong clinical evidence are dexamethasone and nifedipine. Phosphodiesterase inhibitors such as sildenafil and tadalafil are also effective but may worsen the headache of mountain sickness.
Mechanical clot retrieval and catheter-guided thrombolysis are used in certain situations.
How well a patient does depends on the location of the clot and to what extent the clot has blocked blood flow. Arterial embolism can be serious if not treated promptly.
Without treatment, it has a 25% to 30% mortality rate. The affected area can be permanently damaged, and up to approximately 25% of cases require amputation of an affected extremity.
Arterial emboli may recur even after successful treatment.
In treating pulmonary insufficiency, it should be determined if pulmonary hypertension is causing the problem to therefore begin the most appropriate therapy as soon as possible (primary pulmonary hypertension or secondary pulmonary hypertension due to thromboembolism). Furthermore, pulmonary insufficiency is generally treated by addressing the underlying condition, in certain cases, the pulmonary valve may be surgically replaced.
Oxygen first aid treatment is useful for suspected gas embolism casualties or divers who have made fast ascents or missed decompression stops. Most fully closed-circuit rebreathers can deliver sustained high concentrations of oxygen-rich breathing gas and could be used as an alternative to pure open-circuit oxygen resuscitators. However pure oxygen from an oxygen cylinder through a Non-rebreather mask is the optimal way to deliver oxygen to a decompression illness patient.
Recompression is the most effective, though slow, treatment of gas embolism in divers. Normally this is carried out in a recompression chamber. As pressure increases, the solubility of a gas increases, which reduces bubble size by accelerating absorption of the gas into the surrounding blood and tissues. Additionally, the volumes of the gas bubbles decrease in inverse proportion to the ambient pressure as described by Boyle's law. In the hyperbaric chamber the patient may breathe 100% oxygen, at ambient pressures up to a depth equivalent of 18 msw. Under hyperbaric conditions, oxygen diffuses into the bubbles, displacing the nitrogen from the bubble and into solution in the blood. Oxygen bubbles are more easily tolerated. Diffusion of oxygen into the blood and tissues under hyperbaric conditions supports areas of the body which are deprived of blood flow when arteries are blocked by gas bubbles. This helps to reduce ischemic injury. The effects of hyperbaric oxygen also counteract the damage that can occur with reperfusion of previously ischemic areas; this damage is mediated by leukocytes (a type of white blood cell).
If the inciting defect in the heart is identified "before" it causes significant pulmonary hypertension, it can normally be repaired through surgery, preventing the disease. After pulmonary hypertension is sufficient to reverse the blood flow through the defect, however, the maladaptation is considered irreversible, and a heart–lung transplant or a lung transplant with repair of the heart is the only curative option.
Transplantation is the final therapeutic option and only for patients with poor prognosis and quality of life. Timing and appropriateness of transplantation remain difficult decisions. 5-year and 10-year survival ranges between 70% and 80%, 50% and 70%, 30% and 50%, respectively. Since the average life expectancy of patients after lung transplantation is as low as 30% at 5 years, patients with "reasonable functional status" related to Eisenmenger syndrome have "improved survival with conservative medical care" compared with transplantation.
Various medicines and therapies for pulmonary hypertension are under investigation for treatment of the symptoms.
The infant will continue to see a cardiologist on a regular basis. Although these appointments are required less frequently as time goes on, they will continue throughout the lifetime of the individual, and may increase in the event of complications or as the individual approaches middle age.
The cardiology exam may include an echocardiogram, EKG, and/or cardiac stress test in addition to consultation.
Additionally, some individuals may require ongoing medication therapy at home, which may include diuretics (such as furosemide or spironolactone), analgesics (such as paracetamol), cardiac glycosides (such as digoxin), anticoagulants (such as heparin or aspirin), or other medications. If the individual has undergone stenting, an anticoagulant will be a necessity to prevent build-up around the stent(s), as the body will perceive the foreign body as a wound and attempt to heal it.
Some patients who had alternate corrective surgery, such as the Mustard or Senning procedure, may have issues with SA and VA nodal transmissions in later life. Typical symptoms include palpitations and problems with low heart rates. This is commonly solved with a Pacemaker unit, providing scar tissue from the original operation does not block its functionality.
More recently, ACE inhibitors have been prescribed to patients in the hope of relieving stress on the heart.
As previously stated, management of HFpEF is primarily dependent on the treatment of symptoms and exacerbating conditions. Currently treatment with ACE inhibitors, calcium channel blockers, beta blockers, and angiotensin receptor blockers are employed but do not have a proven benefit in HFpEF patients. Additionally, use of Diuretics or other therapies that can alter loading conditions or blood pressure should be used with caution. It is not recommended that patients be treated with phosphodiesterase-5-inhibitors or digoxin.
Antimineralocorticoid is currently recommended for patients with HFpEF who show elevated brain natriuretic peptide levels. Spironolactone is the first member of this drug class and the most frequently employed. Care should be taken to monitor serum potassium levels as well as kidney function, specifically glomerular filtration rate during treatment.
Beta blockers play a rather obscure role in HFpEF treatment but appear to play a beneficial role in patient management. There is currently a deficit of clinical evidence to support a particular benefit for HFpEF patients, with most evidence resulting from HFpEF patients' inclusion in broader heart failure trials. However, some evidence suggests that vasodilating beta blockers, such as nebivolol, can provide a benefit for patients with heart failure regardless of ejection fraction. Additionally, because of the chronotropic perturbation and diminished LV filling seen in HFpEF the bradycardic effect of beta blockers may enable improved filling, reduced myocardial oxygen demand and lowered blood pressure. However, this effect also can contribute to diminished response to exercise demands and can result in an excessive reduction in heart rate.
ACE inhibitors do not appear to improve morbidity or mortality associated with HFpEF alone. However, they are important in the management of hypertension, a significant player in the pathophysiology of HFpEF.
Angiotensin II receptor blocker treatment shows an improvement in diastolic dysfunction and hypertension that is comparable to other anti-hypertensive medication.
When PGE is administered to a newborn, it prevents the ductus arteriosus from closing, therefore providing an additional shunt through which to provide the systemic circulation with a higher level of oxygen.
Antibiotics may be administered preventatively. However, due to the physical strain caused by uncorrected d-TGA, as well as the potential for introduction of bacteria via arterial and central lines, infection is not uncommon in pre-operative patients.
Diuretics aid in flushing excess fluid from the body, thereby easing strain on the heart.
Analgesics normally are not used pre-operatively, but they may be used in certain cases. They are occasionally used partially for their sedative effects.
Cardiac glycosides are used to maintain proper heart rhythm while increasing the strength of each contraction.
Sedatives may be used palliatively to prevent a young child from thrashing about or pulling out any of their lines.