Thursday, October 26, 2006

NPO after midnight

NPO = nothing by mouth. No food. No beverages - not even water. Standard instructions for adults and older children having surgery. As it turns out, that may be rather more strict than is absolutely necessary.

I already knew that pediatric anesthesiologists don't recommend long fasts for NICU babies prior to elective surgeries. I started researching the actual recommendations for adults last summer when my 20-something son was scheduled for elective surgery. 8 days prior to his surgery, almost a full page in the Baltimore Sun was devoted to the subject. The clinical director of anesthesia at University of Maryland Medical Center and several other anesthesiologists were quoted extensively in the article stating that clear liquids can usually be safely consumed up to 2 hours prior to surgery. If a patient asks, these physicians will even say so to the patient.

Not trusting the newspaper to get it right, I went on a hunt for more information and found that the reporter had been accurate. See the links at the bottom for more.

I presented all this to my son and asked what he'd been told, since all his printed information said quite clearly "NPO after midnight" for his 11:30 am surgery. It seems his surgeon was up to speed on the research and had OK'd water or other clear liquids 4-6 hours prior to surgery. My son opted not to take advantage of that information, but he was aware of it.

There is another reason surgeons prefer that their patients fast for longer than the mandatory minmum times. It makes rescheduling that much easier if it becomes necessary. Sometimes it does. While we were in the holding area about half an hour prior to my son's scheduled OR time, we heard another patient very profanely complaining that his procedure had been cancelled because certain necessary records were not available. He wasn't a bit happy. My son's OR time wasn't impacted, but someone else's probably was. I'm sure things like that happen all the time. Maybe not missing records, but changes in the OR schedule for a multitude of reasons.

I would never recommend that anyone disregard his or her physician's advice regarding preoperative fasting. There are too many variables and each case is different. It is worth asking, though, if your procedure is scheduled later in the day, whether it is safe for you to drink water and perhaps other clear liquids. You may be pleasantly surprised by the answer.

Food? Don't even go there! Depending on the reason for surgery and the nature of the food consumed, your stomach may not be empty many hours later. I was kept in the ER for nearly 12 hours prior to my appendectomy many years ago. I still threw up in the recovery room and woke up looking at an X-ray machine. Fortunately I didn't aspirate any of my stomach contents and end up in intensive care. It happens.

If your doctor wants you to eat, he or she will tell you to do that. Don't count on that happening and if you slip up and nibble on something in the morning, for goodness sake, ADMIT IT. Your life might depend on it.

Studies about fluid intake preoperatively:

Evidence Based Nursing 2004: Literature review "evidence is lacking that adults given liquids 1.5-3 hours preoperatively have a greater risk of aspiration or regurgitation than those given a standard fast"

Abstract from British Journal of Surgery on Ingenta Preoperative Fasting Findings recommend 2 hour fast from clear liquids for elective surgery for most healthy adults undergoing elective procedures.

Cochrane Collaboration -- another abstract which clarifies that pregnant, obese, elderly, and those with stomach disorders are more likely to regurgitate, but that healthy adults with none of the above may be able to drink water or other clear liquids up to 2 hours prior to surgery.

I think it's important to note the recommendations from the American Society of Anesthesiologists web site: (emphasis mine)

Why are patients not allowed to eat or drink anything before surgery?
For most procedures it is necessary for you to have an empty stomach so that the chances of regurgitating any undigested food or liquids is greatly reduced. Some anesthetics suspend your normal reflexes so that your body's automatic defenses may not be working. For example, your lungs normally are protected from objects, such as undigested food, from entering them. However, this natural protection does not occur while you are anesthetized. So for your safety you may be told to fast (no food or liquids) before surgery. Your doctor will tell you specifically whether you can or cannot eat and drink and for how long. In addition, the anesthesiologist may instruct you to take certain medications with a little water during your fasting time. For your own safety, it is very important that you follow these instructions carefully about fasting and medications; if not it may be necessary to postpone surgery.

Some degree of fast is clearly necessary. Fasting from food will almost certainly be recommended from midnight the night before. Ask your doctor his or her recommendations about liquid intake -- and then follow them.


PJ said...

My grandmother is told she can have minimal amounts of yellow jelly (gello) before her procedures (throat and stomach) due to troubles with fasting. Hope this is of interest.

Clark Bartram said...

Great post for the peds grand rounds. Mind if I pass it along to next edition's host?

Judy said...

Jello is generally considered to be a clear liquid, so I am not surprised that your grandmother has been given permission to consume this. Yellow is doubtless a better choice than red, orange, or purple, since all those have red dye in them. Blood isn't quite the same color, but no need offering even the potential for confusion.

Thanks! Please feel free.

Ex Utero said...

Definately Ped.s Grand Rounds material. Will include, thanks!


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Anonymous said...

This is a great and informative post. Thanks!

steven palter, MD said...

it's all realtive. In general NPO after MN, reality 6 hrs usually acceptable --on the Ob service with crash sections galore and laboring women-- no NPO and do a rapid sequence intubation. It's all about rsk benefits..

muse said...

Interestingly this has been a point of discussion recently in my workplace. Nurses tend to be rather draconian, not allowing patients anything much for hours before a procedure. One patient was brought in far too early the other day, and it was discovered that our hospital protocol states a patient can drink up to 2 hours before a meal, so we gave them jelly and a drink. They felt better, but we felt nervous. Somehow that 6 hour guidelines seems so much more safe! What if the list was started early or the first case cancelled - then they were sunk!! But I'll try and be nicer to patients from now on and let them drink.

Judy said...

It really can be hard to change your way of doing things -- even when the evidence supports the change. I'm old enough to have taught many parent NOT to put babies on their backs to sleep. Makes me queasy just thinking about that now, because we have enough hard evidence that the change was beneficial, but it was a struggle to make that change too.