I’m not asking for medical advice, I’m just curious. I’ve had surgery that required general anesthetic twice, and both times was instructed not to eat after midnight the night before. Both times I got incredibly sick a few hours after I woke up. My understanding is that the reason they tell you not to eat beforehand is to lessen the chance that you’ll barf while you’re under and asprate your vomit.
Is there another reason that you shouldn't eat before surgery? What happens if you eat a big meal, and suddenly have an appendix attack or something and need emergency surgery? Is there a different anesthetic that they give you, or do they do it with local, or just watch you really carefully to make sure you don't puke? What happens if you show up at the hospital for your surgery and tell them that you forgot and had nachos at 4 a.m.?
IANAD, but I’ve had general anesthesia lots of times. Usually, with emergency surgery, they’ll try to put it off until you’ve been food-free for six hours; if they can’t, they’ll just take their chances because the chances of you dying from vomiting during surgery are lower than the odds of you dying from whatever you need operated on. The frequent nausea/vomiting post surgery isn’t a result of you eating, but a result of the anesthesia itself. It’s my understanding that, during surgery, some fairly strong anti-nausea drugs are put in your IV to try to minimize your chances of vomiting during surgery; it’s also my understanding that, in part due to these drugs, the chances of this happening, even if you’ve eaten, are fairly small. But why take the risk if it can be avoided? I mean, imagine your surgeon tells you “Oh, you’re probably not gonna puke during surgery and choke to death, so go ahead and have dinner”, and then it happens. The malpractice lawyers would be all over that!
Oh, also, the not eating pre-surgery reduces the quantity of puke post-surgery, which is generally considered desirable.
I thought the point of not eating or drinking 6-7 hours before is so the anesthesiologist is working with a body free of unknowns.
I would think eating something with lots of salt for breakfast before having a general would make judging a heart rate more difficult then a heart running on an empty belly.
Norinew is right, if you eat before surgery they will postpone your surgery if possible. IANAD but my mother is, and she says it is to reduce the chances of food refluxing up your oesophagus and down your windpipe while you’re unconscious, which would definitely be unpleasant.
The reason not to eat or drink before receiving a general anesthetic is to lessen the likelihood of aspiration at the time of induction, i.e. as the patient loses consciousness and just before he/she gets intubated[sup]*[/sup] by the anesthetist.
So, if someone’s in a car crash after his/her dinner, they will not have an empty stomach. But they may still need urgent, life-saving surgery. They will be at high risk for aspiration at the time of induction of anesthesia as described above. To try to offest this increased risk, the anesthetist will employ what’s called a “crash induction”.
AFAIK, the nil by mouth business, has nothing to do with post-op nausea and vomiting.
BTW, the link above seems to look like a good source regarding, “why you shouldn’t eat before getting a general anesthetic”.
*intubation = the insertion of a tube into the windpipe, with the breathing usually done by a machine after that
Out of curiousity, and since it’s semi-related: I know that practically all general anesthetic is given in a gaseous form. But is the ‘jam a tube down someone’s throat’ really what’s done? I had eye surgery requiring general anesthesia once (technically twice, but the first time I was only a few months old). It’s a bit fuzzy because A) anesthetic, of course, and B) I was about seven at the time.
But I distinctly remember them giving me a series of drugs first - I think first it was a dose of some vile-tasting liquid medication, which I think might have been equivilent to Valium, just to chill me out. Then, they started an IV line (this is the point where I get really vague), which I think was in the (IMO) improbably location of the back of my hand. Next memory: waking up afterwards and someone taking a mask off my face. For all I know it was oxygen, but for some reason I was under the belief that the anesthetic gas was administered through a mask just held over the mouth and nose. It seems to me that, if this were a viable option, it would be much more preferable, as ‘mask over the face’ isn’t going to, say, accidentally end up tearing someone’s larynx out or something.
Alternately, I’m just entirely confused about my drug-addled 12-year-old memories. Anyone?
Actually on topic question: What is it about the anesthetic that seems to so universally cause at least nausea, if not puking?
three times. one was a trauma patient of a normal healthy guy who was in an auto accident and was walking around after the accident then passed out. took a chest xray on him and one of his lungs was not showing on the xray due to aspiration. another time in a different trauma the doctors were having trouble intubating a patient so they suctioned his trachea and out comes an entire beef dinner, looked like thick vegetable beef soup coming out of his lungs, lots of it. and the last and most tragic was a woman undergoing a c section and she aspirated under anesthesia, she eventually recovered after a few months but the baby didnt. so i do know for a fact its quite important to follow instructions from your doctor before and after a medical procedure.
On average, it takes about 6 hours for the stomach to empty.
General anesthetics stop the intestines from moving food along. Therefore, not only is there a increased chance of vomiting and aspiration if the stomach isn’t empty prior to surgery, but the length of time that danger exists is prolonged.
When surgery can’t wait, after the patient is asleep, a tube is passed through the nose to the stomach to empty it. This is also done for any patient undergoing especially long surgery.
For most surgeries under general anesthesia, a breathing tube is gently passed throught the mouth into the trachea (the beginning of the respiratory system.) The anesthesiologist is in charge of the breathing tube so he/she can adminster the right mix of oxygen and anesthesia. He/she is also incharge of and lines going into veins and arteries.
This was most likely Versed, which is, as you’ve guessed, a benzodiazapine (hope I spelled that right). An anesthesiologist once told me that Versed is like Valium on steroids. It never did anything for me, but my middle daughter had surgery about a year and a half ago (she was about 13 at the time), and they gave her liquid Versed (mine was always given via IV); red, nasty stuff. Stoned her right on out. Laying in the hallway, ready to go into surgery, she looked up at the wallpaper border, then looked at me, giggled, and said “Mommy. I’m pretty sure the wallpaper isn’t supposed to be moving”. By the time surgery was over, she didn’t remember anything about that conversation; one of the benefits of Versed is it tends to make you forget everything (that part never worked for me, either).
Your memories aren’t false…that’s what they do before they intubate you (put a tube down your windpipe so you can breathe artificially). They give you a bunch of special drugs and give you a lot of oxygen, and they make sure you are OUT before they put that tube in (it’s a traumatic procedure if you’re awake). When you are under general anesthesia you always have that tube down, because under those drugs you can’t breathe on your own. That’s why just a mask wouldn’t work.
As a side note, there was once an entire movie based on a hospital error regarding food before surgery. A woman was brought in for emergency surgery, the admitting nurse filled out a form and indicated she had eaten just 1 hour before. The doctor overlooked it, operated anyway, the patient aspirated vomit and ended up in a coma. Afterwards the doctor coerced the nurse into changing the form so the 1 became a 9 (IIRC) so that he couldn’t be blamed.
picunurse-Are you sure it’s as long as 6 hours for the stomach to empty?
I was always taught that there was no point in a gastric lavage 2 or 3 hours post ingestion of poisons/overdose, as not enough would be left in the stomach to make it worthwhile.
6 is maximum, and used prior to surgery, for safety. Although, stress can delay gastric emptying.
For all practicial perposes, 2-3 is about right. I guess you could say 6 hours is the lawyers’ gastric emptying time.
The nausea on the table can happen even without general anaesthesia. For my c-section, I was awake, and felt pretty good, until suddenly I felt awfully bad. *So *nauseous. The anaestheseologist asked me if I felt nauseous, and I nodded. He turned a knob or valve on something I couldn’t see, and it went away immediately. What relief! My husband got to hold the vomit catcher (aka “emesis basin”), although I only needed it to spit in, luckily.
No one asked me when I had last eaten, as I had been admitted through the ER about 8 hours earlier. They knew I had nothing at all. But given that ooginess, I’d expect them to order nil by mouth for c-sections with spinals as well.
When I was nine, I had major back surgery, and they left the tube in until after I was awake. Plenty awake enough to remember it, though I was still pretty drugged. It’s…unpleasant. They did take it once I was awake enough; I’d been under for six hours, and that’s a lot of anesthesia. I’d been warned about that; I know somebody who had a tube after surgery but hadn’t been warned. That was mean of whoever did it unless they didn’t know they were going to leave it until after she was out. But they don’t normally put them in you awake unless it’s some horrible emergency or something, and even then I think they drug you up some.
All my IVs have been in the back of my hand, and this is at about three different hospitals, one just over a month ago. It’s awkward, but I can’t figure out a place for those things that wouldn’t be. I hate them.
I’ve had dozens of IVs over the years, and have to get them wherever the nurse/anesthesiologist/IV specialist can find a vein. The back of the hand hurts, but not as much as the inside of the wrist. Once, when I was scheduled for surgery and they couldn’t find a vein anywhere else, I ended up with one in my foot! :eek:
I have been blessed with good veins. This makes people who are looking to stick sharp things in them very happy. It also makes me happy since it’s really hard to screw up, say, a blood draw on me (it’s only happened like twice in my life, once when I was little and uncooperative, and the other time by some tech in a hospital at 5:30 AM and even then I don’t know how she messed up but it hurt a lot and I had an enormous bruise afterwards). The next time I have to get an IV (it will happen eventually) I’m going to ask if they can put it in my arm instead so I can use my hand!
I absolutely hate the food restriction, but I’ve always understood there are good reasons for it. I’ve never had to have unplanned surgery, which is good, since planned is bad enough!
