Differentiating Causes of Respiratory Distress

“Township Medic 303, Engine 311 responding to 345 Jamesway Avenue, Apartment D as in ‘David’ for a 69-year-old male with difficulty breathing. Time out 10:29.”

Upon arrival, the crew finds an elderly male in respiratory distress sitting in a tripod position on a kitchen chair. He is able to speak only in short sentences and has a dusky appearance. From this point forward, an assessment is continuously made and a differential diagnosis for respiratory distress is considered.

Respiratory emergencies make up a large percentage of calls answered by any EMS agency. The following is a review of possible causes for respiratory distress and a challenge for us to become better at performing patient assessments. Assessment skills for patients with respiratory complaints are something every EMS agency should focus on during training.

Scene Size-Up

As you approach your patient, begin a scene size-up, being alert for clues in the home that can add to your assessment. Is the patient on home oxygen? Is there a metered dose inhaler on the bedstand or end table? Does the home smell like cigarette smoke? Review the patient’s medications. First and foremost, find out if the patient is taking them and is following the prescribed directions. Lasix (furosemide) and nitroglycerin are used in CHF. Antibiotics indicate some infectious process such as bronchitis or pneumonia. Steroids can indicate a chronic condition like asthma or COPD. Always ask if your patient takes any anticoagulants like Coumadin, Plavix or aspirin.

Focused History and Exam

When you are listening for breath sounds, think of common conditions first. Wheezing does not always indicate bronchospasm or asthma, but it usually does. Rales or crackles can represent pulmonary edema or pneumonia. Look for other clues to help differentiate why your patient is in respiratory distress. Has there recently been fever, or is he/she producing purulent sputum? Check for edema in the lower extremities or ascites fluid in the abdomen. Is there chest pain? Could the CHF be the result of an acute MI? In patients older than 80 years with acute pulmonary edema, a frequent cause is myocardial infarction, even in the absence of chest pains. Remember that each element in the SAMPLE survey has value. Document all pertinent positive and negative findings such as: mental status, skin color and temperature, presence or absence of JVD and capillary refill.

Establishing a Differential Diagnosis

Organize your thinking in terms of major body systems: airway, respiratory, cardiac, vascular, neuromuscular and metabolic. Anxiety and panic attack, or some other mental health disorder, may be responsible for respiratory distress, but your primary focus must be on treatable organic causes in the prehospital setting. Remember to be systematic in your assessment. Then you can direct treatment accordingly.

Airway

Listen for stridor, grunting or snoring. Remember, stridor can occur during both phases of ventilation. Is it croup season? Is there any possibility of foreign body airway obstruction? Always be mindful of epiglottitis, especially in children with high fever and drooling. Laryngospasm can be triggered by allergens, infections or your manipulation. Evaluate the size of your patient’s tongue and the posterior landmarks of his oropharynx. Would this patient be a difficult intubation? Remember that preplanning for a difficult intubation can be the difference between passing the tube or not.

Respiratory

Common clinical encounters include asthma, emphysema, bronchitis, pneumonia, pleural effusion and pulmonary embolism. Talk with your patient. See if he has had similar symptoms in the past, or are these new? Give lots of oxygen, and don’t hold back in emphysema if the patient is in distress. Hypoxia demands treatment before we worry about retained carbon dioxide. Get comfortable with auscultation of abnormal breath sounds, primarily crackles (rales), ronchi and wheezes.

Dyspnea (shortness of breath) with exertion may also be the product of deconditioning or fatigue, even in younger patients.

Vascular

A unique clinical entity that is difficult to assess in the prehospital environment is an acute pulmonary embolism (PE). Symptoms of a PE include: dyspnea, pleuritic chest pain, apprehension, cough, hemoptysis, sweating and syncope. Clinical signs of a PE include: tachypnea, crackles/rales, tachycardia, fever, diaphoresis, lower extremity edema, cyanosis and wheezes. Risk factors to look for in your patient include: prolonged immobilization (particularly patients in an extended-care facility), those with a history of a deep venous thrombosis (DVT), smoking, malignancy, pregnancy, obesity, recent fractures, clotting disorders and oral contraceptive use.

Cardiac

A range of clinical conditions can create CHF. Remember, CHF is a sign, not a final diagnosis. Risk factors for CHF include: high blood pressure, history of MI, fluid overload, valvular heart disease, obesity, advanced age, noncompliance with medications and cardiomyopathy. Most protocols allow paramedics to give a diuretic, nitroglycerin and morphine for CHF. Cardiac dysrhythmias may also cause respiratory distress. With atrial fibrillation and a rapid ventricular response, the left ventricular filling time is reduced, resulting in a lower ejection fraction and subsequent pulmonary edema. The same is true for SVT and ventricular tachycardia with a pulse. Agencies with 12-lead EKG capability would definitely want to obtain a tracing during transport.

Neuromuscular

Several disorders can lead to respiratory distress, including: cerebrovascular disease, ALS (Lou Gehrig’s disease), myasthenia gravis and muscular dystrophy. Always get the SAMPLE history. Talk with the patient’s family about chronic disorders. Look at other body systems and assess for neurological or muscular abnormalities. Take the time to see if the patient has a DNR-CC or DNR-CC Arrest. Many chronically ill patients do not want to be intubated and maintained on life support.

Metabolic

Think diabetic ketoacidosis if you see Kussmaul’s respirations or smell acetone on the breath. Ascertain a history of hypo- or hyperthyroidism. Thyroid storm is a true medical emergency marked by tachycardia, hypertension and pulmonary edema. Anemia and sickle cell disease can produce high- output CHF and hypoxia. Look at the mucous membranes and conjunctiva. Is there pallor? Are there any signs of hemorrhage? Be alert for signs and symptoms compatible with recreational drug abuse. Alcohol and toxic ingestions must always be considered as well.

Summary

Respiratory emergencies will continue to make up a large percentage of our EMS calls. Many of these conditions will be managed in the same fashion early on with a focus on oxygenation and adequate ventilation. Once the ABCs have been stabilized, use your assessment skills to create a differential diagnosis for respiratory distress. Once a field impression has been made, you can better direct a specific treatment. As always, follow your local treatment protocols established by your medical director. Practice your assessment skills and attend as much training as you can on airway and respiratory emergencies. ?