WILTIMS #479-82: Nephrology - Part I

Sorry for falling behind again! I have been taking notes in my little black book (spoiler-free example page on the right), and I'm hoping to do a crazy series of catch-up posts over the next day or so.

A few weeks ago week I started my second two-week elective, nephrology. Taking a detour south from the lungs, I turned my currently myopic gaze to the kidneys. One of the reasons that nephrology was on my elective list was that kidney pathology is very physiology-heavy. You have to really know how the organ functions on a biochemical level to diagnose and treat kidney diseases. I like this connection with the basic sciences and the similar reliance on physiology in intensive care is part of why I'm leaning that way career-wise.

MIL: Dialysis machines measure the sodium concentration indirectly by measuring the conductivity of the dialysis solution. Pure water conducts electricity poorly, while salty water conducts very well. By measuring how conductive the water is, you can determine how salty the water must be. The predominant cation (positively charged molecule) in the dialysate broth is sodium, so conductivity ≈ saltiness ≈ sodium concentration. Who says high school chemistry was never useful!?

TuIL: Acute kidney injury (AKI) is classified by several systems. The older model is based around the RIFLE acronym,

WIL: Wednesday was our last class meeting of the year. We finally learned how we are going to sign up for our various fourth-year courses! Kind of... We subsequently had a lottery for our required courses and are still waiting for open enrollment for our electives. I also learned that there are over 20 people in my class planning on going into pediatrics, which is a huge increase over previous years. This made our required fourth-year course work difficult to schedule, because the simply aren't enough spots for everyone to do everything at convenient times.

ThIL: ACE inhibitor drugs decrease the filtration rate of the kidneys in the short-term. This is generally a bad thing for an already stressed kidney. But, in the long-term, the decrease in blood flow decreases the rate of glomerular damage. Think of it like an old car that is always parked under a bird-filled, pollen-generating tree. If you wash it every day, it gets clean, but eventually the paint is going to wear off. So wash it less often; that way it still gets cleaned regularly but, in the long-term, you avoid damaging your paint job.

Sunitinib is a chemo drug that has a side effect of dramatically increasing blood pressure. The effect is so consistent that blood pressure is often used as a marker for how well the chemo is working.

Many drugs break down in the body into active and inactive metabolites. If a patient has severe kidney disease, though, the inactive metabolites can build up to such high levels that they actually start causing side effects. Enough of anything is poisonous.