WILTYIMS #241: Pulmonary grab bag

TYesterdayIL: Whispered pectoriloquy, literally "breast speaking," is a term for when you can hear a whisper through the stethoscope while listening to a person's lungs. Normally, the sounds of a whisper are nearly entirely made from the scratchy passage of air through the mouth and upper throat, unlike with normal speech, where the bulk of the sound is from the vibrations of the vocal cords resonating through the whole upper airway. If a whisper is resonating, then it is a sign that there is fluid and/or swelling in the upper airways of the respiratory tract, changing the normal conduction of sound through the tissues of the chest.

Jim Henson died of a Strep pyogenes pneumonia. This is unusual for Group A Strep, as this bacterium is sometimes called, since it is better known for causing strep throat, rheumatic fever, scarlet fever and glomerulonephritis (kidney infection), among others.

An uncorrected left-to-right cardiac shunt can progress to a right-to-left shunt; this process is termed Eisenmenger syndrome.The left side of the heart is under higher pressures and facing greater resistance than the right side. This pushes blood through any hole in the central wall, or septum, of the heart. In small amounts, this isn't a big deal because the blood from the left is already oxygenated. But all the blood that leaks through the hole is essentially extra pressure for the lungs to deal with and after a while they learn to fight back by constricting the pulmonary arteries. This increases the resistance and pushes blood from the right to the left. Now deoxygenated blood is leaking through to the systemic circulation, causing what is termed a shunt. No bueno.

The progression of Eisenmenger syndrome (http://www.medscape.org/viewarticle/557721)

Every 10 mmHg increase in PaCO2 (partial pressure of carbon dioxide in the pulmonary arteries) explains approximately .08 of a decrease in pH. You can use this calculation to see if there is a chronic acidosis or alkalosis hidden underneath an acute pH change.