BEYOND THE BASICS: COPD
Chronic obstructive pulmonary diseases are common and potentially serious calls.
While it isn't within our realm to diagnose new cases of COPD in the field, there are certain items in the history that help point to COPD. The most significant is a 20 or more pack/year history of smoking, defined as smoking one pack per day for a year. This method allows the EMS provider to get a relatively accurate assessment of potential harm to the lungs. To obtain a pack/year history, multiply the number of packs smoked per day by the number of years the patient has smoked. A patient who smoked two packs/day for 10 years would have the same potential for pulmonary damage as the patient who smoked one pack/day for 20 years. Both would be reported as 20 pack/year smokers.
COPD exacerbations are frequently caused by respiratory infection. Exacerbations are the significant and relatively sudden worsening of the patient's condition. COPD usually worsens slowly and progressively over a period of years. This is different from an exacerbation, which occurs over a day or days. A recent history of respiratory infection, including increased cough and mucus production, fever and malaise, may be present.
Note the color of any respiratory secretions. Patients with a long history of COPD will watch for a change in color of sputum or mucus and will be happy to show you the results of a productive cough in the multitude of tissues near their chair or bed.
As with all patients suspected of having cardiac and respiratory conditions, it is important to determine the progression of symptoms and the relation of signs and symptoms to exertion and rest. All patients with respiratory complaints should be asked about chest pain, chest discomfort, fatigue and other signs and symptoms of cardiac conditions.
Depending on the course and severity of the patient's COPD, a variety of medications ranging from bronchodilators and steroids to home oxygen may be in use. It is important to note all of the patient's medications as part of your history, but perhaps even more important to note which medications have been taken in response to this acute condition and how the patient responded to them.
Physical Exam Findings
The patient with a history of COPD and potential exacerbation will exhibit some of the classic signs of respiratory distress, including shortness of breath and wheezing--especially on expiration--in conjunction with prolonged expiratory times, which are necessary to help the patient exhale gases trapped in the lower airways.
The patient may also experience increased coughing, with or without producing mucus. The tripod position is common. You may also see other signs and symptoms including:
- JVD. This may be present because of increased pressure as a result of right heart failure. Kussmaul's sign (increasing JVD with inspiration) may occur in severe cases.
- Increased A-P chest diameter (barrel chest) as a result of increased pulmonary hyperinflation.
- Clubbing, a condition where chronic hypoxia has caused vasodilation and enlargement of the distal portion of the fingers. The clubbed appearance is defined by a greater than 165-degree angle between the proximal nail and the cuticle (it becomes more convex), resulting from a general thickening of the distal finger.
- Pursed-lip breathing. Patients exhale against partially closed (pursed) lips to help reduce lung hyperinflation by providing a back-pressure similar to PEEP (positive end-expiratory pressure).
- Mucus color. Changes in mucus color, especially to yellows, greens and brown/rust colors, may indicate infection.
The pulse oximetry reading of a COPD patient may be routinely low. COPD patients on home oxygen have experienced 88% (PaO2 of 55 mmHg or less, or 55–59 mmHg in the presence of right heart failure) or less to qualify for that oxygen, so assume that the room air pulse ox reading will be fairly low. However, in an early stage of the disease, it is possible to get a 100% pulse ox reading on a patient with supplemental O2 because of oxygen retention.
Differential Diagnosis
While it is important to use a differential diagnostic approach to all patients, in the COPD patient, the differentials frequently overlap (e.g., emphysema with chronic bronchitis or chronic bronchitis with right heart failure). Additionally, a respiratory infection that exacerbates a patient with COPD is treated by treating the signs and symptoms of COPD.
The most significant differential in assessing the COPD patient is congestive heart failure. Complicating matters is the fact that it is common to have COPD and congestive heart failure concomitantly. In this case, treatment will differ between congestive heart failure and COPD, depending on which is believed to be the primary cause of the patient's respiratory distress.
