A 70-year-old male presents to EMS complaining of shortness of breath for the past hour. He hasn’t been ill recently and has never smoked. His blood pressure is 240/118, respiratory rate is 24, pulse is 118 and irregular, temperature is 98.9_ F, and his O2 saturation on room air is 86%.
On exam, he has diffuse wheezing, JVD and 3+ pitting pretibial edema. His medications include Lasix and digoxin. His past medical history is significant for myocardial infarction (MI) with stent placement and congestive heart failure (CHF). He also admits non-compliance with his physician’s recommended low-salt diet.
When I was a paramedic, we would have instinctively treated this patient with albuterol. The teaching at the time was to treat wheezing with albuterol, and rales with Lasix. Although we’ve a come long way in differentiating CHF from chronic obstructive pulmonary disorder (COPD) in the field, it’s still a commonly confused differentiation that may require review.
The Sounds of CHF
Rales are the sounds we hear when the alveoli are partially filled with fluid. The sounds are similar to when a child (or an adult) blows through a straw into their drink. But why don’t we hear rales when a patient is in severe pulmonary edema? A better question is: Why do we hear wheezing in the patient we’re confident has severe pulmonary edema?
The answer is that when the alveoli are completely filled with fluid, there isn’t enough room for those bubbles to form, giving us the sounds we hear as rales. In severe pulmonary edema, that fluid has no other place to go and the bronchi become swollen and constricted, giving us the sounds of wheezing. This wheezing is called