PLATYPNEA: SYMPTOMS, CAUSES AND TREATMENTS - ANATOMY AND PHYSIOLOGY - 2024

The platypnea is a rare respiratory disorder characterized by the presence of dyspnea people sitting or standing, lying down significantly improving. It is the opposite of orthopnea, a more common condition that usually affects patients with heart failure, in which there is dyspnea when lying down that is relieved when standing up.

Coming from the ancient Greek platys, which means "flat", it refers to the fact that adequate breathing occurs when the person lies down or in a horizontal position. I would literally translate "flat breath" or "flat breath."

Although it can also occur in patients with heart failure, as in the case of orthopnea, most of the time it is related to intracardiac, pulmonary and hepatic circulatory problems.

Symptoms

From a strictly semiological point of view, platypnea is a syndromic sign, so it does not have its own symptoms but is part of the clinical manifestations of some disease.

However, platypnea does have particular characteristics that allow it to be detected, among which are:

- It occurs only in an upright position, both in a standing position (standing or standing) and in a sitting position (sitting).

- It is basically observed as intercostal pulling or retraction of the thoracic muscles, which are drawn under the skin with each breath.

- It is also possible to detect nasal flutter in the patient when examining standing or sitting. This rhythmic opening of the nostrils appears in severe cases.

- Although it seems paradoxical, platypnea is not always accompanied by an increase in respiratory rate. There may be an adaptive phenomenon that prevents an increase in respiratory rate.

Causes

As previously mentioned, there are several diseases that present with platypnea within their clinical manifestations. Some of the most important are mentioned below:

Platypnea-orthodeoxia syndrome

It is a rare condition characterized by positional dyspnoea and hypoxemia (decreased oxygen concentration in the blood). It is the only clinical picture described to date that has the word "platypnea" in its name.

As it is a syndrome, it can have several causes, which can be summarized as: intracardiac blood shunts, pulmonary blood shunts, ventilation-perfusion imbalances or a combination of the above.

Intracardiac shorts

Only right-to-left shorts can cause platypnea. The most important examples are congenital heart diseases such as patent artery trunk, tetralogy of Fallot, univentricular heart or transposition of the great arteries.

It is possible to find right-to-left shunts in patients born with a pathology that shunts from left to right but changes direction over time and adaptation. The classic example is Eisenmenger syndrome.

In adult patients it is possible to find some cases of patent foramen ovale or wide defects of the atrial septum. These can manifest with platypnea when the heart no longer tolerates the increase in blood volume that these pathologies cause.

Intrapulmonary shunts

It occurs mainly in the lung bases and has been associated with hepatopulmonary syndrome, which is a complication of chronic liver diseases and hereditary hemorrhagic telangiectasia.

Due to the proximity of the liver to the lower region of the lungs, when it becomes diseased and increases in size, it compresses the lung bases, or when it becomes cirrhotic, it can favor the passage of fluid towards them, which compromises the ventilation of the area and favors the short circuit.

Ventilation-perfusion imbalances

Any abnormality in the air intake or blood supply to the lung can compromise the ventilation-perfusion rate, resulting in hypoxemia.

For this to generate platypnea, the lung bases or the entire lung must be affected.

Treatment

Platypnea management involves treating the disease that causes it, some of which can be definitively cured through certain surgical procedures, which would make platypnea disappear.

Most right-to-left intracardiac shunts caused by congenital malformations can be resolved with open or minimally invasive surgery.

Major surgeries

Open heart surgery can resolve large defects of the interatrial or interventricular heart walls, severe valvular heart disease, and congenital malformations, but they are often high-risk, and the failure and mortality rates remain high despite advances in medicine.

Minimally invasive surgery

It is performed endovascularly or percutaneously, and in both cases special catheters are used that reach the heart and perform a specific job for which they were designed.

In most cases, these procedures are carried out to close small or medium-sized septal defects and only when they are symptomatic or life-threatening. Also cures for valvular heart disease and electrical disorders of the heart.

Pharmacotherapy

Some of the diseases that cause platypnea cannot be cured through surgery and can only be controlled with medications. The best example of this is the cause of the platypnea-orthodeoxia syndrome: the hepatopulmonary syndrome.

Lactulose continues to be one of the most widely used treatments in liver failure and has been shown to greatly improve the quality of life of those who receive it. The decrease in respiratory symptoms (such as platypnea) and hypoxemia is notable, especially in pediatric patients.

Also certain cardiovascular diseases that cause platypnea can be managed pharmacologically, such as heart failure, in which diuretics play a fundamental role as well as angiotensin converting enzyme inhibitors, beta-blockers and calcium antagonists.

Pneumonectomy

Pneumonectomy deserves a separate section. Despite its infrequency, one of the causes of platypnea-orthodeoxia syndrome is surgical removal of the lung or pneumonectomy.

It seems to be related to an increase in pulmonary vascular resistance, a decrease in the compliance of the right ventricle and rotation of the heart through the space left free by the extracted lung, which distorts the blood flow from the inferior vena cava and causes a right shunt to the left.

Sometimes these patients must be reoperated to try to solve the problem or repair the damage caused with the first surgery.

References

1. McGee, Steven (2018). Respiratory Rate and Abnormal Breathing Patterns. Evidence-based Physical Diagnosis, Fourth Edition, Chapter 19, Pages 145-156.
2. Heusser, Felipe (2017). Intracardiac short circuits. Notes, Pontificia Universidad Católica de Chile, recovered from: Medicina.uc.cl
3. Sáenz Gómez, Jessica; Kram Bechara, José and Jamaica Balderas, Lourdes (2015). Hepatopulmonary syndrome as a cause of hypoxemia in children with liver disease. Medical Bulletin of the Hospital de Niños de México, volume 72 (2), 124-128.
4. Davies, James and Allen, Mark (2009). Pneumonectomy. Surgical Pitfalls, Chapter 67, Pages 693-704.
5. Niculescu, Z. et al. (2013). Clinical manifestations of hepatopulmonary syndrome. European Journal of Internal Medicine, 24 (1), e54-e55.
6. Henkin, Stalinav et al. (2015). Platypnea-Orthodeoxia Syndrome: Diagnostic Challenge and the Importance of Heightened Clinical Suspicion. Texas Heart Institute Journal, October; 42 (5), 498-501.