Preconditioning

It was the first Saturday morning after my return from an overseas conference. There's no denying that it takes a bit of time to adjust ourselves to the working mode after a holiday. But I did it. I went back to the hospital and my routines.

Saturday routines have been many things to many people: a morning to sleep in and have brunch, a holiday to recover after long working hours, and tutorial time for students. According to my Saturday routines, I first pick up a topic to read, followed by an one-hour teaching of remedial class students, and then morning round at 9.

Here's what I read this morning: remote ischaemic preconditioning and kidneys, and it's a promising way to save our patients' kidneys from being knocked out by contrast dye (as used in a lot of imaging in hospitals). Such cases are common. In order to show the blood vessels in the heart, for example, doctors need to inject dye. Just as remarkable as the dye's power to outline the blood vessels, is how powerful the dye can damage the kidneys. So how do doctors get around the problem? The idea for such a protective drug to safeguard the kidneys has been around for close to 20 years, but none had pulled off a miracle. Easy to say, hard to do.

Last year, news broke that a trick called remote ischaemic preconditioning could cut the odds of kidney damage by 80 percent after dye injection in the heart.

An unusual trick.

What they did was to inflate a blood pressure cuff on the arm for four cycles, five minutes on and then five minutes off. The action of the inflated cuff, of course, is to apply brakes on the blood flow, and if short-lived, won't suffocate anybody. It's hard to think of any tool, any drug, any machine in history with which so many can afford so easily. It's a form of rehearsal or disaster drill, to the point that our patients' kidneys get better prepared before the real attack.

Which makes me wonder: Just how similar can I apply the concept of preconditioning to prepare my medical students for their examination?