We will discuss a bit about the two main reasons why acute respiratory failure occurs.
Acute respiratory failure (ARF) of the lungs is not to be confused with acute renal failure (ARF) of the kidneys, and it is significantly different from acute respiratory distress syndrome (ARDS).
In retrospect, acute respiratory failure simply means that the respiratory tract is malfunctioning for one reason or another. First, we will do a bit of pathophysiology of mainly what happens when your respiratory tract becomes faulty. And second, what causes ARF.
So, let’s start.
The Two Causes
Remember, whenever you’re talking about the respiratory tract, two major elements are involved – ventilation and quality. In breaking that down, it would be the mechanics of breathing and oxygenation; therefore, there two most common causes of acute respiratory failure are mechanics and oxygenation.
When you take a deep breath, what happens is air flows into the lungs, so oxygen comes in. Oxygen then goes into the alveoli, and the alveolar sacs exchanges oxygen for carbon dioxide, then carbon dioxide is breathed out.
Oxygen should be transported to different parts of the body, for this to happen, oxygen should be placed on “oxygen buses” or the oxygen carriers which is what we know as hemoglobin.
Hemoglobin, which is found in red blood cells, carries oxygen and transports it from the lungs to the different tissues and organs of the body.
Mechanism versus Oxygenation
If there is not enough hemoglobin in the body, oxygen will not be transported around appropriately, even if there’s no problem with your breathing.
On the other hand, there might be sufficient amount of hemoglobin inside the body, but the breathing becomes obscured or problematic; for example, someone punched you, hitting your diaphragm and breaking your ribs. When that happens, your breathing mechanism becomes faulty, and the oxygen-carbon dioxide exchange gets impaired.
How Mechanism is Affected
Affectation of breathing mechanics is mainly due to external and internal reasons; these are the following:
- A muscular problem wherein your diaphragm (breathing muscles) or respiratory muscles have suffered trauma or injury.
- Since the brain stimulates and controls the respiratory tract, any form of neurologic dysfunction severely affects the respiratory drive. Some examples of neurological disorders are:
- Myasthenia Gravis – decompression of the central nervous system
- Guillain-Barre Syndrome – an autoimmune disorder
One primary example of breathing mechanism failure due to CNS injury is the actor who played Superman, who just passed away. He fell off a horse and broke his neck, damaged his spinal cord, got paralyzed, and was subjected to a wheelchair for the rest of his life.
- Medications like opioid analgesic (Morphine) and narcotics depress the central nervous system (CNS) that can immediately debilitate the respiratory tract.
- Chronic obstructive pulmonary disorder
- Pulmonary emboli
- Pulmonary edema
These diseases have one thing in common – they all mess up with the structure of the lungs which cripple proper functioning because they mainly affect the lungs’ absorption abilities.
You can interpret mechanism versus quality with eating. When you eat food, you swallow it, and it goes right down to the stomach; therefore, you don’t have a problem with your chewing capacity which is your mechanics. The problem lies inside your stomach whether you have an infection or stomach flu. So, you can still chew and swallow but cannot absorb.
On the other hand, if you cannot chew or swallow because you have experienced trauma like hitting your head and affecting that part of the brain which is responsible for swallowing, food is unable to enter the body through your mouth.
So, not getting food in due to mechanism and absorption is same with not getting oxygen in due to mechanism and oxygenation. In normal breathing, there has to be a mechanical factor that enables oxygen exchange – these two has to work succinctly to maintain perfusion.
If the problem is internal and there would be an obstruction that is considered as a mechanical ventilation problem due to impaired oxygen exchange. Pulmonary emboli or a clot in the lungs is a typical example of blocking oxygen exchange. Pulmonary edema, which is increased lung fluid or edematous lungs, also poses a threat in oxygen exchange.
So, on our next discussion, we will be focusing on the major problems on how quality, the second common cause of ARF, becomes affected.
See you there!