Respiratory Disease: An SLP’s Understanding

Last week you read a (very brief) overview of the respiratory system. This week we are going to get into the different types of disease processes and how the lungs respond to those diseases. For the most part, our lungs work without a hitch. Which is why you barely ever think about them (unless you’re like me and you think about them way too much- hence this blog series). But for a growing number, respiratory disease is changing people’s lives in a myriad of negative ways that will make it impossible not to notice.

Lung disease can be broken up into three main categories:

1. Airway disease where the air that moves through the lungs’ tubes or “airways” is restricted because of a narrowing or blockage (i.e. COPD).

2. Restrictive lung disease where the tissues of the lungs have become damaged and are less compliant or stretchy (i.e. pulmonary fibrosis).

3. Pulmonary vascular disease (PVD) where the blood flow through the pulmonary capillaries is restricted (i.e. pulmonary hypertension).

These conditions often occur in combination with each other and can present in a combination of disease processes (with different severities).

Airway Disease

Airway disease can feel to the patient like they are breathing through a small straw. This is because the airways aren’t fully open. The clinical presentation can range, but may include wheezing, tightness, dyspnea (difficulty breathing), and excess mucus with increased coughing (things get stuck in small straws, right?). Remember that mucociliary elevator I discussed in my first blog about ARDS with Dr. Coyle and Kelsey Day? That transit will slow down in airway disease causing mucus plugging in an already narrow track. Remember all the nonsense that makes its way down into the lungs at times? This stuff gets stuck on the elevator along with all that sticky mucus (a claustrophobic nightmare). This decreases airflow even more and also increases the likelihood of microbials sticking around and making lots of babies (thick, warm, moist mucus is a microbial Caribbean vacation). This is why patients with airway disease are at a particularly high risk for pneumonia. You know what else can stick around? Aspirated contents. Which is why seeing the diagnosis for airway disease such as COPD in our chart review should hit us in the face with a bright, red flag.

Restrictive Lung Disease

Restrictive lung disease on the other hand can feel to the patient like a sumo wrestler is sitting on their chest. This is because the lungs are no longer able to hold onto a sufficient amount of air while breathing either due to reduced lung elasticity (intrinsic) or a reduced mobility of the chest wall (extrinsic). This in turns reduces lung ventilation leading to reduced vital capacity (maximum air inhaled and exhaled) and in severe cases may lead to respiratory failure. There are many examples of restrictive lung disease, but what’s important from an SLP standpoint is understanding that aspiration can be both a cause and an effect. With aspiration comes inflammation and with inflammation comes reduced flexibility of mobility, making ventilation even more difficult and aspiration more likely. How? Well, The only way to compensate for this reduction in ventilation is to increase respiratory rate (tachypnea). With tachypnea comes an increased likelihood of aspiration (the more breaths you take per minute, the more likely you are to inhale during the swallow or before clearing penetration/residue) and a vicious cycle spins round and round.

Pulmonary Vascular Disease (The other PVD)

Last, but not least, we have PVD. PVD covers a wide array of conditions, but always has to do with the way blood is moving between the heart and the lungs. For example, if there is an abnormal connection between a pulmonary artery and vein one could develop an arterio-venous malformation (AVM) which may lead to pulmonary hypertension, and ultimately poor o2/co2 exchange. If the blood vessels in the lungs become restricted, this could also cause cardiac issues as the blood gets backed up into the heart from reduced blood flow to the lungs. The heart then has to pump harder to try to get the blood to flow through which may lead to cardiomegaly and heart failure. That same blood flow can also clot in the lungs causing an embolism. PVD is serious stuff, but the symptoms that arise from the disease process may occur slowly and quietly. This insidious harm becomes most apparent in the most severe cases, such as with a pulmonary embolism or when it has resulted in heart failure and/or respiratory failure (less oxygen flow or co2 elimination = respiratory insufficiency = respiratory failure and possible vent dependence). That’s when the problem is so obvious that it smacks us over the head and we have to manage the changes in swallow physiology directly (i.e. increased respiratory rate, dyspnea, and increased fatigue during meals). Though even in those patients without severe illness, PVD is an important concept to understand from an SLP perspective so we know the increased risk for a precipitous downturn in this population; especially if it is accompanied with other medical complications.

Respiratory Disease in Nutshell

While this was only a brief and surface-level intro to respiratory disease, my hope is that it helps you understand how it can impact our scope of practice and why we should be paying attention to it. In my next and final blog on the subject I’m going to get into how we can help with and what we should be paying attention to. We are valuable practitioners to our patients with respiratory disease and our value doesn’t stop abruptly at the throat. Instead it extends to the whole body. Which is why we should go beyond the swallow and seek to understand the whole patient. Stay tuned.

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