Cyanosis is also discussed in Chapter 13, The Chest. The important questions regarding cyanosis are indicated in that chapter.

On occasion, cyanosis is noted only in the lower extremities. This is termed differential cyanosis. It is related to a right-to-left shunt through a patent ductus arteriosus (PDA). In a right-to-left shunt resulting from pulmonary hypertension, blood in the pulmonary artery crosses the PDA, which is located below the level of the carotid and left subclavian arteries; deoxygenated blood is pumped only to the lower extremity, producing cyanosis in only that location. Some blood does get to the lungs for oxygenation and is ultimately pumped out through the aorta to produce normal skin color in the upper extremity.

The patient whose feet are shown in Figure 14-11 is a 30-year-old immigrant who was evaluated in the United States for cyanosis. Until the age of 20 years, he had marked ''bluish discoloration'' of his lower extremities and relatively normal color in his upper extremities. Over the next 10 years, there was a gradual darkening of his upper extremities. Note the marked cyanosis of the extremities and nail beds of the fingers and toes. The patient had a PDA with marked pulmonary hypertension.

Differential Cyanosis
Figure 14-11 Differential cyanosis of the extremities: patent ductus arteriosus.
Reducing Blood Pressure Naturally

Reducing Blood Pressure Naturally

Do You Suffer From High Blood Pressure? Do You Feel Like This Silent Killer Might Be Stalking You? Have you been diagnosed or pre-hypertension and hypertension? Then JOIN THE CROWD Nearly 1 in 3 adults in the United States suffer from High Blood Pressure and only 1 in 3 adults are actually aware that they have it.

Get My Free Ebook

Post a comment