Whenever I’ve had surgery, I’ve been told to not eat anything after midnight so I have an empty stomach for the anesthesia, which will prevent me choking in case I vomit.
I’ve been watching ER reruns on PopTV and it occurred to me that with emergency surgery, the patient may likely have eaten fairly recently. How does the OR work with that? Is the stomach pumped? Or does the surgeon go for it and hope they can handle any vomiting that may happen?
2008 India study on emergency anesthesia - PDF
Thanks for the link. It’s a little dense and I’m not a doctor, but from what I can tell, they treat the emergency and worry about a full stomach if and when it becomes an issue during surgery?
It depends on the procedure, but gastric lavage (i.e. stomach pumping) is often performed to empty the stomach when minimum fasting times have not (or couldn’t) be observed. In some cases the patient will be given an emetic instead.
IANAD. I am an RN in an emergency department. I don’t know if we currently have any surgeons, anesthesiologists, or CRNAs posting.
The reason you should have nothing to eat or drink (NPO-Nil Per Os-nothing by mouth) prior to surgery
is to reduce both stomach contents and acidity. Anesthesia, resulting unconsciousness, and to an extent, drugs used during these procedures, all result in the inability to protect your airway (keep your trachea open and keep stomach contents out). It takes very little acidic liquid to damage your lungs. As little as 50 ml or 3.5 tablespoons. Solid matter in your stomach also damages and blocks your lung function in addition to introducing possible bacterial infection.
So reduce contents and acidity. Drugs to reduce acidity are also usually given.
Next a tube (an ET endotracheal) is placed. This has a cuff that blocks aspiration of stomach fluids. It protects your airway. There are some other devices such as a LMA that are sometimes used. The problem is that a patient can aspirate before or during this procedure. Thus the NPO instruction.
Of course, as noted, emergencies make this impossible. So procedures then depend on how much of an emergency it is. For instance, appendicitis can be acute enough for *immediate *surgery, or more often, surgery in the very near future, after time for gastric emptying. For a real life or death emergency, we intubate you immediately using a procedure called RSI, Rapid Sequence Intubation. We then place an NG, Naso Gastric, tube to decompress your stomach. NOT lavage. To the OP and RNTB I don’t believe actual lavage (which requires a larger esophageal tube is done).
And the NPO times have been shortened.
I have never seen an emetic used for ANY purpose in 20 years of practice.
Gastric lavage involves adding fluid to the stomach and then suctioning it out, repeatedly, until the fluid returns ‘clean’. Stomach suctioning (formally nasogastric aspiration), on the other hand, just involves suction to try to remove gas and liquid from the stomach. The NG tube has a side channel open to air so that the suction can run continuously without having the ports on the end or side of the tube glom onto the stomach lining and cause an injury that way.
Gastric lavage increases the risk of vomiting/inhaling vomit over simple NG suction, and I haven’t seen it used outside of ingestion of poisons or toxins, where the continued presence of the poison in the stomach is a greater risk than that of aspiration. It can also be used to rewarm or cool patients with major body temperature problems, but I haven’t seen that done in practice.
Giving emetics is a terrible idea, since it causes the very thing you are hoping to avoid: vomiting.
If the patient already has an NG tube in, it’s generally left in place while the patient is anesthetized and intubated. Pressure can be placed on the cricoid cartilage (just below the adam’s apple) to compress the esophagus between the cricoid and spine to limit the backflow of stomach contents while the endotracheal tube is being placed. Once the ET tube is placed and the cuff inflated, it is easier to manage any subsequent reflux or vomiting - but it’s not a guarantee of safety.
OP - thank you for asking this. I wonder about this every time I have a procedure and never get around to finding out. 
Anesthesiologist here…
Pretty much what brossa and **steatopygia **said, with some comments.
Re the OP, the risk is not exactly “choking on your vomit”, which to me implies a blockage of the trachea, but rather aspiration of gastric contents, which results in chemical damage to the lungs which may required prolonged intubation and ventilation, or can be permanent or even fatal.
Also, the surgeon has nothing to do with handling any vomiting that may happen" That’s our job. I recently heard my job described as “keeping patients alive while surgeons do things that may otherwise kill them”.
Really Not All That Bright - to agree with the other posters here, gastric lavage and emetics are not used.
An NG tube is often placed and suctioned in cases where the patient has an extremely high risk of aspiration, beyond the standard risks of having a full stomach, specifically, if the surgery is to repair a bowel obstruction. There is some controversy about whether the NG tube should be left in place after suctioning or whether it sort of stents open the esophagus and should be removed before inducing anesthesia. The evidence probably supports leaving the NG tube on suction and applying cricoid pressure during induction. As brossa mentioned, cricoid pressure is supposed to compress the esophagus and prevent regurgitation of stomach contents. Whether or not it accomplishes this is unclear. Some studies seem to show that it merely displaces the esophagus to one side. This probably varies with the amount of pressure applied, which in turn varies with the skill and experience of the person applying the pressure.
Other precautions to reduce aspiration risk include preoperative oral administration of a non-particulate antacid such as sodium citrate which makes the consequences of aspiration less severe, an H2 receptor blocker such as pepcid for the same purpose, and administration of promotility drugs such as metoclopramide which should help empty the stomach. Of course, this all depends on how emergent the surgery/need for intubation is.
Last, an explanation about RSI/rapid sequence induction. A standard induction involves giving the patient pure oxygen to greatly increase the amount of time they can go without breathing (apneic time), then giving one or a combination of several hypnotic drugs such as propofol, etomidate, fentantyl, etc, then confirming your ability to mask ventilate the patient, giving a paralytic agent, continuing to ventilate the patient with oxygen and possibly anesthetic gas while the paralytic agent takes effect, and then intubating the patient. Since the patient’s protective airway reflexes are greatly diminished once the initial hypnotic drugs are given, they are at risk for aspiration of regurgitated stomach contents during this time, especially with mask ventilation which may insufflate air into the stomach and increase the likelihood of regurgitation. Therefore, RSI involves preoxygenating the patient, giving the hypnotic and rapid acting paralytic drugs together, and then letting the patient remain apneic until the paralytic has taken effect, at which point they can be intubated.
I had emergency surgery many years ago, just 3-4 hours after lunch. The doctors told me that because of this, they could do it under local anesthesia, but I didn’t want to be awake.
So they said that as soon as I was under, they would be placing a tube down my throat to provide a clear airway. And that the tube would be left in until I was clearly awake again. Thus when I woke up, there would be a tube down my throat, which would be disturbing. They would then pull it out in the recovery room, so I should try not to panic when I awoke with this strange thing down my throat.
I said I still wanted general anesthesia. So they did that.
So I did wake up with it in my throat, but before I was alert enough to panic they removed it. They said I might have a sore throat for a couple of days, but I was sore in so many other places I never noticed that.
t-bonham, that sounds awful. I’ve had emergency surgery under general anesthesia. No one told me anything except “breathe deeply.” By the time I woke up there was nothing down my throat.
I had to have an emergency c-section, and I was intubated. I don’t remember the tube-- last thing I remember was the mask coming down over my face after I told the doctor that yeah, I could feel the knife; restarting the epidural wasn’t working fast enough. Then I woke up to my husband telling me that the baby was fine, and thinking there was a but, and not being able to talk. The tube was out, but my throat hurt like hell.
The “but” was that they had to aspirate him, and there was a lot of meconium in his throat, so as a precaution, he was in an isolette, and had gotten an antibiotic. I knew someone whose baby had gotten pneumonia from aspirating meconium, so I was fine with the precautions, which was all they were.
Thanks so much for the answers and the clarification. So just in case the patient has recently eaten, there are ways around that if needed.
tl;dr
1970 - acute appendicitis. Immortal words: “enema until clear”.
Surgeon estimated time-to-rupture at 3 hours.
I was in the ER at 06:00, OR at 09:30.
They found the time to wash me out as well as they could.
You really do not want feces in close proximity to an open incision.