Wednesday, April 18, 2012

Day of Fast

Think of this as more of a Public Service Announcement from your friendly ( though a tad disgruntled ) neighbourhood anaesthetist.

And it concerns the directive to fast before surgery. Used to think it was common knowledge known to even the most ill-informed layperson but obviously I keep making that same unfortunate mistake. Again and again. Repeatedly I keep finding patients who think that the preoperative fasting order is just a silly little exhortation to be flouted at will.

Paul : And when did you have your last meal?
Patient : Two hours ago.
Paul : What did you have? You mean you had breakfast at 5 in the morning?
Patient : I was hungry. I had fried rice.
Paul : Fried rice?!
Patient : And instant noodles too.
Paul : Really? Such a solid breakfast. And did you miss the directive to fast before surgery?
Patient : Oh I know all about it. I thought it was more of a suggestion rather than a necessity. Thought it wasn't that important.
Paul : Well if you don't want to die from pulmonary aspiration, I would think it terribly important.
Patient : Really ah?

Seriously, if you've already taken solids right before an elective surgery, you might as well just call up an accompanying buffet. Since only the most foolhardy anaesthetist would dare prep a patient for surgery right after a full meal of rice and noodles.

David Gandy
Paul : Waitaminute, why do I smell fried rice in the room?

Worst case scenario - that entire carbohydrate-fibre laden meal - rice, noodles, fish, meat, etc - would go hurling out into your vulnerable lungs during general anaesthesia. Not a pretty picture.

But let's get technical here. The main reason for preoperative fasting is to prevent pulmonary aspiration of the stomach contents while under the effects of general anaesthesia. Oh yes, we might be able to avoid general anaesthesia with the use of regional blocks but there's no 100% guarantee that a block would definitely work. At least no sane, responsible anaesthetist would offer that particular promise. Most regional anaesthetic techniques, even in expert hands, have a failure rate of 1–10%.

So main point is unless you enjoy that debilitating bout of pneumonia, bloody hell stick to the fasting hours as mentioned. We repeat it often enough after all.


Vincent~ said...

so can you stop the surgery?

I guess not, but still...

DeluSion said...

I sense you lost your zen from the introduction.

But thanks for the public education!

savante said...

Yes, the surgery is usually postponed, Vincent.

Yeah, delusion, one of my pet peeves haha...

Tempus said...

unless you wanna kill the patient!

And we were like, oh we are supposed to ear before blood donation?

Medical students pffft.

Sometimes patients just don't get it do they? Autonomy ma.