Chronic obstructive pulmonary disease: Clinical sciences

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Introduction0:00–1:08

Chronic obstructive pulmonary disease or COPD refers to a heterogeneous usually progressive lung condition that results in airflow obstruction and breathing difficulties.
Often due to long term exposure to irritants such as tobacco smoke over time. COPD can lead to irreversible lung damage, making breathing difficult and limiting everyday activities such as physical exercise.
Some patients with COPD may 1st show up with chronic breathing difficulties and no prior history of CO PD. While others might come in with CO PD flare ups, which are also known as COPD exacerbations.
Now, if your patient presents with signs and symptoms, suggestive of CO PD, you should perform an ABCD E assessment to determine if they are unstable or stable if unstable, stabilize the airway breathing and circulation.
Next, obtain IV access and put your patient on continuous vital sign monitoring, including heart rate, BP and pulse oximetry.
Most of the time these individuals will present with severe respiratory distress that requires supplemental oxygen or even mechanical ventilation.

Unstable branch1:08–2:06

Now, here's a clinical pearl. To keep in mind when treating individuals with severe respiratory distress, always be on the lookout for signs of life threatening respiratory failure.
These include altered mental status the use of accessory respiratory muscles and a respiratory rate greater than 24 breaths per minute.
It's also important to recognize abnormal arterial blood gas analysis results that suggest impaired alveolar gas exchange such as acidosis hypercarbia and hypoxemia.
Now, let's get back to the ABCDE assessment and take a look at stable individuals start by obtaining a focused history and physical exam as well as pulse oximetry.

Stable branch2:06–6:43

First, let's focus on individuals with no previous diagnosis of COPD who are reporting persistent and slowly progressive shortness of breath which worsens with exercise.
In this case, history typically reveals fatigue, chest tightness, recurrent wheezing and chronic cough that could be either productive or nonproductive.
It's also helpful to ask about frequent winter colds or recurrent lower respiratory infections as these can be signs of COPD.
Finally check for risk factors like tobacco use and exposure to occupational hazards such as dust, asbestos, chemicals or fumes.
On the flip side, the physical exam could be entirely normal especially in the early stages of the disease. However, as the disease progresses, you might hear wheezing particularly during forced expiration due to airway obstruction.
In most cases, pulse oximetry will show normal oxygen saturation. But in more severe cases, saturation might drop to 92% or below indicating significant impairment in respiratory function.
With these findings, you should suspect CO PD. Your next step is to obtain spirometry.
Start with the pre bronchodilator spirometry, meaning the patient shouldn't use any bronchodilators beforehand, this will give you a baseline measurement of lung function.
Next, calculate the F EV one to F VC ratio F VC or forced vital capacity refers to the total amount of air the patient can exhale during the forced breath while fev one or forced expiratory volume in one second is the amount of air exhaled during the 1st 2nd of this forced exhalation.
If the F EV one over F VC ratio is equal to or greater than 0.7 consider an alternative diagnosis. On the other hand, values below 0.7 suggest an airflow obstruction.
So the next step is post bronchodilator, spirometry. First, give your patient an inhaled bronchodilator like albuterol, wait 15 minutes and then repeat the spirometry.
Next, calculate the F EV one to F VC ratio to see if the obstruction is reversible. If the ratio goes up to 0.7 or above the obstruction is reversible.
So you should think of alternative diagnoses, but if the ratio stays below 0.7 the obstruction is not reversible, confirming the diagnosis of CO PD.
Now, here's a clinical pearl to keep in mind when evaluating individuals with suspected COPD, be sure to obtain chest imaging to rule out comorbidities such as interstitial lung disease and heart failure.
Once you confirm the diagnosis, the next step is to initiate management which covers lifestyle modifications, vaccination, initial pharmacotherapy and sometimes supplemental oxygen therapy.
First, you should encourage lifestyle modifications like smoking cessation and physical exercise. In severe cases.
A patient might also benefit from a pulmonary rehabilitation program which focuses on endurance, strength, flexibility, and inspiratory muscle training.
Next. Be sure to provide vaccinations such as influenza COVID-19, pneumococcal zoster R SV and Pertussis vaccines.
In line with local guidelines. Moving on to initial pharmacotherapy for individuals who have had one or fewer COPD exacerbations per year and experience only mild symptoms like shortness of breath during intense exercise or when rushing up a hill, start with a single inhaled long acting bronchodilator, either a long acting beta agonist or laba or a long acting muscarinic antagonist or LMA.
For those who have had one or fewer exacerbations per year, but report significant symptoms such as walking slower than others, their age or stopping to catch their breath when walking at a normal pace, go with a Laba llama combination on the flip side for patients with two or more exacerbations per year or who have been hospitalized at least once a year due to breathing difficulties, start with the laba lama combination, but consider adding inhaled corticosteroids.

Stable patient6:43–11:07

Finally, you may need to provide supplemental oxygen therapy if the oxygen saturation is below 88% be sure to provide long term supplemental oxygen therapy to keep it above 90%.
Now, let's go back to our focused history and physical exam. Next, we'll look at patients with a history of COPD exacerbations.
These are usually associated with a positive history of COPD and worsening of respiratory symptoms over the past 14 days.
These symptoms typically include shortness of breath, chest tightness, cough and increased sputum production. On a physical exam.
You'll notice increased respiratory rate, heart rate and wheezing. In severe cases, the patient will use accessory respiratory muscles to help with breathing pulse, oximetry might also show a drop in oxygen saturation below 92% with these findings diagnose CO PD exacerbation.
Now, here's a clinical pearl to keep in mind when approaching a patient with a known history of COPD, be sure to rule out other conditions that could trigger the exacerbation such as pneumonia, heart failure and pulmonary embolism.
Also remember that some patients may not have a previous COPD diagnosis and present with their first COPD exacerbation. In these cases, you'll typically confirm the diagnosis after treating the patient's acute exacerbation by performing spirometry testing a few weeks after discharge.
Once you identify AC O PD exacerbation, the next step is to move on to labs. Labs include an arterial blood gas analysis to assess the alveolar gas exchange along with c reactive protein to determine the level of inflammation in the body.
After that assess the severity of the respiratory distress. Using the dyspnea visual analog scale or VA S.
This scale is a subjective tool that allows patients to rate the severity of respiratory distress on a scale from 0 to 10, a score of zero means no shortness of breath while a score of 10 indicates the worst shortness of breath the patient has ever experienced.
Let's start with mild COPD exacerbations. In this case, the dyspnea V score is below five.
The respiratory rate is under 24 breaths per minute and the heart rate is below 95 BPM. Oxygen saturation is 92% or higher and CRP levels are below 10 mg per liter.
Lastly, arterial blood gas analysis will reveal normal partial pressure of carbon dioxide and normal PH values meaning between 7.35 and 7.45.
With these findings diagnose a mild COPD exacerbation and proceed with management. The main approach involves inhaled short acting beta two agonists or saba with or without short acting muscarinic antagonists or sama.
You can also consider oral corticosteroids such as predniSONE. If there's increased sputum production, that's more purulent.
Suggesting a potential bacterial infection, consider adding oral antibiotics to the treatment plan. Next up are moderate co PD exacerbations which are associated with a dyspnea va S score of five or greater, a respiratory rate of 24 breaths per minute or more and a heart rate of at least 95 BPM.
Also, oxygen saturation might drop below 92% and CRP levels could be 10 mg per liter or greater. Finally, arterial blood gas analysis will typically show an elevated partial pressure of carbon dioxide, greater than 45 millimeters of mercury within normal Ph values if three out of the first five criteria are present, diagnose a moderate COPD exacerbation.
Start treatment with an inhaled saba with or without saba. Next, prescribe oral corticosteroids to manage inflammation and oral antibiotics.

Recap11:07–13:37

If you suspect a bacterial infection, be sure to provide supplemental oxygen to improve oxygen saturation. Finally, let's go over severe COPD exacerbations which are like moderate exacerbations but with one key difference in severe cases, the arterial blood gas analysis will reveal respiratory acidosis, meaning elevated partial pressure of carbon dioxide over 45 millimeters of mercury and decreased ph with values below 7.35.
With these findings diagnose a severe COPD exacerbation for management. Again.
Be sure to start your patient on an inhaled saba with or without sa next to reduce inflammation. Give intravenous corticosteroids such as methylprednisolone and don't forget intravenous antibiotics to fight possible bacterial infections.
Finally begin noninvasive ventilation to support the patient's breathing and help the alveolar gas exchange. Now, here's one last clinical pearl to remember, key indications for noninvasive mechanical ventilation include respiratory acidosis, which as mentioned is arterial ph below 7.35 with a partial carbon dioxide pressure, greater than 45 millimeters of mercury also consider noninvasive mechanical ventilation.
If the respiratory symptoms are accompanied by paradoxical motion of the abdomen and retractions of intercostal spaces. Lastly, if oxygen saturation remains below 88%.
Despite supplemental oxygen therapy, it's time to start noninvasive mechanical ventilation to ensure proper ventilation and oxygenation All right.
It's a quick recap. Chronic obstructive pulmonary disease refers to a progressive lung condition that results in airflow obstruction and breathing difficulties.
Often due to long term exposure to irritants if your patient hasn't been diagnosed with COPD, but reports gradually worsening, shortness of breath, chest tightness, wheezing and a chronic cough.
Consider COPD. On the other hand, if they have a positive history of CO PD and there's worsening of their symptoms over the past 14 days.
Think of CO PD exacerbation.
Chronic obstructive pulmonary disease: Video | Osmosis