12- Orthopnea

KYJ12- Orthopnea
In "knowing your Jargon", we tackle those funky terms, abbreviations and conditions that we use, but don't always understand.

Today's pearl is Orthopnea.
This is a symptom of heart failure, and other respiratory distress causing diseases. Literally, Orthopnea is Latin for "position breath", and it refers to someone who gets breathless when lying flat.

Functionally, it is a good piece of respiratory assessment.  A skilled clinician will ask the patient, "how many pillows do you sleep on at night?"
For those who experience Orthopnea, the answer will be more than two.  Some patients will claim they sleep in an arm chair or recliner. This is severe orthopnea.

Physiologically, the majority of alveoli that contribute to gas exchange are in the large bases of the lungs. These are located in the back, not on top of the diaphragms like your intuition suggests. As a consequence, lying flat allows more blood to gravitationally occupy the vascular beds of the bases, and air to occupy the apex and middle/upper lobes. With less air contacting the majority of the basal avleoli, less gas exchange occurs, giving rise to dyspnoea when lying flat.

Sitting someone up allows those big bases to fill with air and thus improve oxygenation and CO2 excretion.

Next time your breathless patient is struggling, try sitting them up... Then you can high five yourself all the way down the hallway!!

Know your jargon and share this post!!  Because that is what cool nurses do!