On the Knee Chest Position

There are certain heart conditions where the patient would turn blue, what we call cyanotic heart disease. But of course, the mainstay treatment would be surgery. But there are also simple measures where the patient are asked to squat down or maybe curl up in lying position as long as the flex their hips and knees and keep their knees to their chest, what was called as the 'knee chest position.'

But if you askED me, I would have told you I have no idea why. For all I know, I may actually answer that they are asked to do so to lower their centre of gravity perhaps, reduce the work of the heart pumping enough blood to the rest of the body, and hence less blue. Lucky me I didn't tell the professor what was in my mind that day, or else I'd be screwed upside down.

Only came to know the reason why when another colleague explained about it.

Apparently when they are asked to hold their knees close to their chest, they are (1) constricting the femoral artery, and hence (2) increasing the peripheral resistence, and hence (3) increasing the workload of the left ventricle, (4) reversing the right to left shunt, so there would be more blood pumped into the pulmonary circulation rather than straight into the systemic circulation, and hence... less cyanotic.

Eureka!

Don't get me?

Nehmind. I'm just mumbling....