Pulmonary stenosis: Nursing

The heart can be divided into a right and left side. The right side of the heart is responsible for pumping poorly oxygenated blood to the lungs, and the left side of the heart is responsible for pumping highly oxygenated blood out to the entire body.

Now, there are conditions that can affect the right side’s ability to pump effectively. These conditions, or heart defects, obstruct or decrease pulmonary blood flow, which ultimately leads to inadequately oxygenated blood.

These types of heart defects are primarily congenital, which means they were present at birth. Such defects include pulmonary stenosis, tetralogy of Fallot and tricuspid atresia.

Pulmonary stenosis, sometimes called pulmonic stenosis, occurs when there is narrowing of the pulmonic valve.

Though little is known about what causes it, genetic and environmental factors may play a role in its development.

Now, the narrowing of the valves obstructs normal blood flow through the pulmonary artery. This means less blood is making its way to the lungs.

Depending on the severity of the disease, this could cause no symptoms at all, like in mild cases; or dyspnea, fatigue and syncope in moderate cases; and cyanosis in severe cases. These symptoms also tend to worsen with exertion.

In moderate to severe cases of pulmonary stenosis, the right ventricle muscle can enlarge.

This happens because the right ventricle has to work harder to pump blood past the stiff, narrowed valve, and the harder that muscle has to work, the bigger it becomes.

This is known as hypertrophy. Now, a bigger ventricle muscle doesn’t mean a stronger pump. In fact, a hypertrophied ventricle actually doesn’t pump as effectively.

And over time, it can no longer pump enough blood to meet the body’s demand; we call this “heart failure.”

So this means even less blood is getting to the lungs and the symptoms associated with pulmonary stenosis worsen, coupled with new symptoms of right sided heart failure; like jugular vein distention, abdominal distention, peripheral edema and heart murmur.

Now in some cases, a client with pulmonary stenosis may have an additional defect, such as an atrial-septal or a ventricular-septal defect, most often called ASD and VSD.

If an ASD or VSD is present, these openings between the atria or ventricles can allow blood to shunt from side to side.

Normally, the pressure on the left side of the heart is greater than the right side. If we look at this a little closer, it makes lots of sense!

The left side of the heart is responsible for pumping blood out to the entire body, so it’s got to work harder to move all that blood out to all of the body.

The right side of the heart is responsible for pumping blood to the neighboring lungs. Since that’s not a very long distance for the blood to travel, the pressure on the right side of the heart is normally lower than the left side.

So, if a client with pulmonary stenosis also has an ASD or VSD, a right to left shunting of blood will occur.

Because the right side of the heart in a client with pulmonary stenosis has to work extra hard to pump blood past that stenotic valve, the pressure on this side is abnormally higher than the left side.

So when the heart contracts, blood shunts over from the right side, through the ASD or VSD, to the left side, and now there’s a mix of blood from both sides; the poorly oxygenated blood on the right side and the highly oxygenated blood on the left side.

With the left side of the heart pumping this desaturated mix of blood out to the entire body, this leads to poorly oxygenated systemic circulation, which is why clients with these defects could present with pale or cyanotic skin color and mucous membranes.

Pulmonary stenosis can be diagnosed through physical examination and diagnostic tests.