What is Pulsus Paradoxus: All About the Causes and How to Measure It

Photo by Gerald Oswald from Pixabay

Aug 25, 2020 02:00 PM

What is pulsus paradoxus?

Pulsus paradoxus is the drop in blood pressure when someone takes a breath. Another name for pulsus paradoxus is paradoxis pulse or paradoxical pulse.

The normal fall in pressure is below 10 mm Hg. If the mild and brief drops are greater than 10 mmHg, then it is called pulsus paradoxus. This condition is noticeable.

Pulsus paradoxus is a sign of several health conditions such as cardiac tamponade, chronic sleep apnea, obstructive lung disease including asthma AND COPD. The condition is not related to pulse rate or heart rate.

This article will explain more about pulsus paradoxus, what causes the condition, as well as how it can be measured. Besides, if you questioned asthma can cause pulsus paradoxus, this reading is where you should read.

Pulsus Paradoxus Causes

Photo by Gerald Oswald from Pixabay

Several factors appear as the causes of pulsus paradoxus. Those include asthma attacks, and heart and lung condition.

Furthermore, Hypovolemia also can be a factor that can cause pulsus paradoxus to become more serious. This condition occurs when there is not enough blood in someone's body, dehydration, surgery, or injury.

Below are more detailed explanation regarding heart condition that can cause pulsus paradoxus

1. Constrictive pericarditis

This happens when pericardium, the membrane surrounding the heart began to thicken. When someone breathes, the heart will unable to open up as usual. Pulsus paradoxus can be seen in constrictive pericarditis, even though it not often than that seen in tamponade

2. Pericardial Temponade

When someone experiences pericardial tamponade, extra fluid will build up in the pericardium. This occurs for several reasons such as enhanced ventricular chamber interaction. The other name for this is cardiac tamponade. Symptoms of pericardial tamponade can be recognized with low blood pressure and large, and neck veins.

Besides, pulsus paradoxus can be caused by several lung conditions such as:

1. COPD exacerbations

Other causes of pulsus paradoxus are Chronic obstructive pulmonary disease (COPD). This condition will damage the lungs.  COPD exacerbations occur when there is something that worsens the symptoms of COPD such as smoking cigarettes. The effect of COPD exacerbations is sometimes close to those of asthma.

2. Obstructive Sleep Apnea

Sleep apnea is a condition that makes people stop breathing during their sleep. While obstructive sleep apnea happens when the airways are blocked because of relaxed throat muscles.

3. Pectus Excavatum

Pectus excavation occurs a person's breastbone is sunken into the chest. It can increase pressure on the lungs and heart. In a more serious case, pectus excavatum looks like the chest cooped out and leaving such dent.

4. Massive Pulmonary Embolism

It is defined as the condition when a thrombus (blood clot) becomes lodged in the lung and blocks blood to flow to the lung. Pulmonary metabolism can damage someone's ability to breathe and the mortality rate for this is between 30 - 60%.

Other causes are not related to lung and heart conditions (pulmonary and cardiac). Those include:

  • Pregnancy
  • obesity
  • hypovolemia
  • anaphylactic shock
  • superior vena cava obstruction

Pulses Paradoxus Asthma

Pulsus Paradoxus - Photo by Victoria_Borodinova from Pixabay

Asthma can be one of the factors that cause pulses paradoxus. In a severe condition of an asthma attack, part of the airways in the human body began to tighten and swell.

Besides, the lungs will overinflate in response. This gives multiple pressure on the veins that carry unoxygenated blood from the heart to the lungs.

Consequently, blood will return to the right ventricle located in the lower right part of the heart. When it happens, there is extra pressure on the right side of the heart.

Moreover, asthma can increase negative pressure in the human lung. Therefore, it also gives more pressure to the left ventricle.

How to Measure Pulsus Paradoxus

Pulsus Paradoxus - Photo by Gerald Osward from Pixabay

Several ways can be done to measure pulsus paradoxus. The simplest one is checking it using manual blood pressure cuff to listen for differences in the heart sound. You should note that using manual blood pressure is highly suggested since it can not be detected by using automatic blood pressure.

The second is inserting a catheter into the artery, usually the radial artery located in the wrist or femoral artery in the groin. The catheter can measure blood pressure from beat to beat.

So, that's all about pulsus paradoxus, including what causes the condition, as well as how to measure pulsus paradoxus.


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