Let them eat: Emergency department patients should be encouraged to eat and drink

Are patients allowed to eat in your department? Do you field endless phone calls from nurses asking whether a patient is allowed to eat? Have you ever witnessed a confrontation between a nurse and a patient or family member over NPO status? The concept of forcing emergency patients to remain “nil by mouth” on the off chance that they might need surgery or an airway intervention is one of the most nonsensical, evidence-uninformed, harmful myths in modern emergency medicine.

Do we even need evidence?

Before we get to the evidence, it is worth considering the logic behind the current state of our emergency departments, where nurses are constantly in conflict with patients, knocking food and drink out of their hands “just in case”.

Let’s assume that having a full stomach increases a patient’s risk of aspiration during induction of anesthesia. If true, it would make sense to keep a patient NPO if they were imminently going to the operating room. But how many of your patients end up in the operating room on the same day that you see them? This will depend somewhat on the system, but everywhere that I have worked (in Canada, New Zealand, and Australia), the vast majority of patients are taken to the operating room the next day. Appendicitis is a next day operation. A hip fracture is a next day operation. Of the patients who have a same day surgery, the majority are too sick to even consider eating. I have never met a patient with an intestinal perforation who was asking for a cheeseburger. The patient with an operative brain bleed is not asking for food. Even a patient with a testicular torsion is not usually in the mood to eat. Although there are a few exceptions – the intoxicated patient with an open fracture is a common one – the vast majority of patients who require surgery are either NPO naturally or won’t have their surgery until the next day. 

Furthermore, for every one patient who is ultimately diagnosed with surgical pathology, dozens will have negative workups, and dozens more will present with conditions that clearly don’t require surgery or airway management. The vast majority of our patients will never need to be NPO, but for some reason the status quo of most emergency departments seems to be to force all patients not to eat or drink, just in case one might need surgery.

The departments that I work in see more than 300 patients every day. Only a handful of patients will be brought to the operating room urgently every week. For the sake of keeping 5 patients adequately NPO, we forcefully starve 2095 patients every week. Does that make any sense?

Not only is it inhumane to tell someone that they can’t eat, it is dangerous. Many of our patients present with dehydration. Their specific management plan is eating and drinking, and yet because of blanket bans on oral intake in emergency departments, I have even seen these patients denied water. Even if it wasn’t your presenting complaint, a 6 hour emergency department wait while being denied food and water will certainly cause a lot of dehydration. Patients miss important scheduled medications. Patients have important procedures delayed because they cheated on our NPO rules. We cause significant harm and generate significant conflict enforcing these NPO policies.

Before we even tackle the evidence, it seems clear that the logic for keeping the entire emergency department NPO rests on shaky ground.

Some history

Where did this practice even come from? As every emergency physician knows, massive regurgitation and aspiration is a rare but horrible complication of airway management. This was recognized very early after the development of anesthesia. However, in the early years it was recognized that there is a big difference between solid foods and liquids. For example, in 1853 Joseph Lister wrote “while it is desirable that there should be no solid matter in the stomach when chloroform is administered, it will be found very salutary to give a cup of tea or beef-tea about two hours previously.” (Rüggeberg 2024) Similarly, it was long recognized that “‘several hours of preoperative fasting aggravate existing states of exhaustion’, tea with red wine or cognac up to 45 min before induction of anaesthesia was recommended at the beginning of the 20th century, especially for alcoholics.” (Rüggeberg 2024)

Things seemed to change after a 1946 publication that described 66 cases of aspiration during obstetric anesthesia, including 2 deaths from airway obstruction from solid food. (Mendelson 1946) This led to the recommendation to withhold oral intake (abandoning the distinction between solids and liquids), and over a decade or so morphed into the standard “NPO after midnight” recommendation. This study actually included 44,016 women, and so the aspiration risk was only 0.15%. Furthermore, there did seem to be any discussion of the harms of such a recommendation. Thus, the NPO after midnight recommendation is based on a very rare (but real) risk of aspiration, but with no real consideration of the overall harm/benefit ratio. 

The evidence

Instead of relying on logic and conjecture, let’s look at some evidence. Unfortunately, the evidence moves us beyond the slightly sketchy logic and makes it very clear that we are causing a lot of unnecessary harm. The entire logic for keeping everyone in the emergency department NPO was based on the benefit to the small few that will need surgery. It turns out that there is good evidence that strict fasting is harmful even if patients are going to the operating room.

Some basic physiology

The idea of keeping patients fasted for 6 or 8 hours, or even more, has never made any sense. We know not to give activated charcoal more than 1-2 hours after ingestion, because by then the stomach has mostly emptied. Why do we consider the stomach empty at 2 hours in the overdose patients, but still worry at 6 hours in the elective surgery patient? It doesn’t make sense, but what does science actually say?

The rate of stomach emptying is impacted by a number of factors, but liquids almost all drain rapidly. Chug a 500 mL glass of water, and it will be almost completely gone by 30 minutes. The biggest individual factor in gastric emptying is caloric density (the intestines can only absorb so many calories per hour, so the stomach has receptors that limit the number of calories delivered). However, essentially all normal drinks, from milk to juice to coca-cola, will be out of the stomach by 90 minutes. (Rüggeberg 2024)

When considering whether you should let your patient drink, I think the single most important fact I encountered is that increased fluid volume in the stomach exponentially increases stomach emptying. Therefore, drinking water actually speeds up the rate of gastric emptying. (Rüggeberg 2024) In other words, drinking water is likely protective against aspiration, rather than dangerous.

Obviously, everything in the human body is complex. There are many factors that can delay gastric emptying, including age, medications, diabetes, and trauma, but these factors only seem to apply to solids and do not delay the emptying of liquids. (Rüggeberg 2024)

Although you will find that many guidelines still treat milk as a separate entity, this does not seem to be evidence based. Gastric emptying is proportional to the caloric content of liquids rather than the nature of the drink. (Okabe 2015; Hillyard 2014)

The numbers for gastric emptying of solids are far more variable, and solids are also much more likely to be harmful if aspirated. However, barring medications or pathology that causes delayed gastric emptying, you can expect 90% or more of solid food to be out of the stomach by 4 hours, and with reasonable sized meals it is usually quicker than that. (Singh 2006; Abell 2008; Hansrod 2020)

Procedural sedation

I previously covered the evidence around procedural sedation at some length. Essentially, aspiration is very rare, and there is no evidence in the observational data available of an association between NPO status and aspiration risk. On the flip side, there is obvious harm to fasting, where patients with painful procedures are made to wait unnecessarily, increasing pain, making the ultimate procedure more difficult, and utilizing scarce emergency department resources. I think the ACEP guideline does an adequate job summarizing this literature: “Do not delay procedural sedation in adults or pediatrics in the ED based on fasting time. Preprocedural fasting for any duration has not demonstrated a reduction in the risk of emesis or aspiration when administering procedural sedation and analgesia.” (Godwin 2014)

Operating room data

I will touch on some of the individual trials for details, but there is a 2023 Cochrane review where we can start. (Brady 2023) The big problem is that most of the trials rely on surrogate outcomes (gastric volume or pH) rather than clinical outcomes like aspiration. (That makes sense when you consider that the aspiration risk is way less than 1%, so massive trials would be required. However, when the potential benefit is way less than 1% you really have to question whether it could possibly be worth the harm. Furthermore, aspiration itself is really a surrogate, as many aspiration events are trivial with no patient oriented outcomes.) They find that “there was no evidence that the volume or pH of participants’ gastric contents differed significantly depending on whether the groups were permitted a shortened preoperative fluid fast or continued a standard fast. Fluids evaluated included water, coffee, fruit juice, clear fluids and other drinks (e.g. isotonic drink, carbohydrate drink).” Interestingly, although perfectly consistent with the physiologic evidence, patients allowed to drink water actually have lower volumes of gastric content than those held to a standard fasting regimen. The major caveat to the studies they found is that most excluded patients thought to be at high risk for aspiration.

One small RCT randomized 300 adult patients with elective morning surgeries to either their standard rules (NPO at 21:00) or prescribed oral rehydration solution (500 mL to drink overnight, and 500 mL to drink from wakening until 2 hours before surgery). (Itou 2012)  Sadly, the primary outcome was gastric volume, but it was identical between the groups. There were no aspiration or vomiting events in either group. Unsurprisingly the oral hydration group had significantly less thirst, dry mouth, and hunger. The big problem with this trial are that adverse events (both hypotension from dehydration and aspiration events) are rare, and so a 300 person trial was never going to capture them. 

There are numerous small RCTs that replicate the results seen in Itou, demonstrating no differences in stomach volume or pH when fasting times of 2 hours were compared to those of 6 hours or more. Of course, they all suffer from the same limitation of being far too small to comment on clinically important outcomes. (Maltby 1988; Maltby 1991; Phillips 1993; Søreide 1993; Schmidt 2015; Schmidt 2018)

There is an RCT with 210 patients undergoing laparoscopic gynecologic surgery which demonstrated that carbohydrate loading at 2 hours prior to surgery improved gastrointestinal function, decreased pain, and shortened hospital length of stay. (Wang 2024)

I am not sure that it requires RCT data to prove, but a small RCT demonstrated that patients allowed to drink until 2 hours prior to surgery had less hunger, less thirst, and increased satisfaction as compared to those required to remain NPO from midnight. (Bopp 2011)

Given that almost all guidelines now suggest permitting clear fluids until 2 hours prior to surgery, most of the modern data is actually focused on shortening that time frame. “Sip til send” is a practice that has been championed in anesthesia, which allows patients to sip on clear fluid (up to 170 mL per hour) right until they are sent for the procedure. One author described their experience, covering 12,000 patients, in which fluid fasting times decreased from 6 hours to a median of 17 minutes, with no observable change in adverse events, but significantly improved patient satisfaction. (Checketts 2022) Another QI study of the “sip til send” intervention found no incidents of aspiration, with increased patient satisfaction and decreased patient thirst. (Wiles 2024)

A pediatric institution implemented a “6-4-0” rule, with fasting of 6 hours for solids, 4 hours for breast milk, and 0 hours for clear fluids. They retrospectively identified 10,015 cases, and there were 3 documented aspirations (0.03%), which is equal to or lower than historical controls using longer fasting regimens. There were no significant clinical outcomes from the aspirations. (Andersson 2015) 

A large prospective cohort of 12,093 children from Germany found no difference in the incidence of regurgitation among patients with clear fluid fasting from 1-2 hours (0.2%), 2-4 hours (0.4%), or >4 hours (0.4%). There was a possible increase in regurgitation in patients fasted less than 1 hour (0.6%). Rates of suspected or confirmed pulmonary aspiration are an order of magnitude lower than regurgitation (not a patient oriented outcome itself). (Beck 2020)

In another very large before-after quality improvement study from the Netherlands, they moved 4 hospitals from “standard fasting” (which was clear fluids until 2 hours before the start of anesthesia) to a liberal policy which allowed clear fluids until the arrival at the operating room, with a maximum of 1 glass per hour. They include data on 76,451 patients, and document a clear decrease in fasting time by about 3 hours, with a post-implementation median fast of 1 hour and 20 minutes. There was no difference in regurgitation (0.2%), aspiration (0.02%), or aspiration pneumonia (0.02%). There was a statistical (but very marginal) decrease in postoperative nausea, vomiting and use of antiemetics (about 1% less with the liberal fasting policy). Preoperative reports of thirst decrease by 9%. (Marsman 2023)

As far as I can tell, all of the available research has focused on decreasing fasting from fluids, with essentially no evidence around solids. I can understand why, given physiologic data that solids take longer to leave the stomach, and the fact that aspiration of solids is far more clinically significant than aspiration of liquids. However, it leaves us with an unfortunate knowledge gap. Considering that there is no association between fasting time and adverse events or aspiration in all of the procedural sedation literature, I think it is reasonable to question whether even prolonged solid fasting is necessary. (There is a difference between residual stomach volume and true patient outcomes). However, for now, all we can really say is that we don’t know. 

Emergency department data

Change is possible. One emergency department described their transition from the standard “NPO at midnight” order to the actual ASA 1999 guidelines (which are probably still too strict), allowing solids until 6 hours before surgery and clear liquids until 2 hours before surgery. (Denton 2015) Based on survey results of the nursing and medical staff, they believe there were no adverse outcomes as a result of the change, but that there was a decrease in nursing frustration, decreased patient thirst and hunger complaints, better glucose control, and a decreased overall workload for nursing staff. (This is a huge selling point: no more phone calls about whether a patient is allowed to eat!)

Sadly, although I know there are at least a handful of emergency departments that have adopted a “nobody needs to be NPO” policy, or in the case of Reuben Strayer’s hospitals, and “everyone eats” policy, I couldn’t find any published literature on these experiences. I can guess, from everything above, that there has been tremendous benefit with no harm, but it would be amazing to see data from some of those centres published.

The harms

I shouldn’t really have to describe the harms. Eating and drinking are basic human functions. You could probably call them human rights. Depriving human beings of food and water is the kind of thing that could get you charged with war crimes. That being said, I think we routinely underestimate the amount of harm these policies cause in the emergency department. 

There are the obvious things like hunger, thirst, dehydration, and irritability. (Anyone who has raised a toddler knows that hunger can lead to some horrible behaviour. How many of our angry patients are actually just ‘hangry’? How many people leave AMA because of our silly rules?) Patient satisfaction is worse when we deprive patients of their ability to eat and drink at their leisure. (Denton 2015; Checketts 2022) 

However, if patient comfort and satisfaction is not enough for you, there are a number of obvious medical harms. Patients become dehydrated and hypoglycemic over time, especially with wait times of 6 hours or more. Patients skip doses of medications that probably shouldn’t be skipped because they are told nothing can enter their mouths.

Even for the patients who ultimately do need surgery, there are significant harms from fasting. Longer duration of preoperative liquid fasting is directly associated with post-operative delirium (with an odds ratio of 10.5). (Radtke 2010; Rüggeberg 2024) Preoperative dehydration quadruples the risk of complications after hip surgery. (Rüggeberg 2024) Longer pre-operative fasting is also associated with more postoperative nausea and vomiting. (McCrackenm 2018; Huang 2024) Children who deviated from the 2 hour liquid fasting guideline (with a mean fasting time of 6 hours) had a higher incidence of perioperative hypotension. (Dennhardt 2016) Prolonged fasting has been correlated with longer postoperative hospital stays. (Huang 2024) Prolonged peri-operative fasting is also associated with a host of metabolic changes such as insulin resistance, hyperglycemia, acute kidney injury, increased inflammation, and impaired wound healing. (Diks 2005; Carvalho 2020; Rüggeberg 2024) Although more tenuous, some studies have also seen associations with increased infection rates and even mortality. (Diks 2005; Rüggeberg 2024)

Although all of these observational findings require the caveat that the quality of data is low, the point is that essentially every observational association points to harm rather than benefit from increased fasting. The direction of the effect is consistent. Considering that we are talking about withholding food and drink – a basic human right – I don’t think the data needs to be incredibly high quality to be convincing. 

The demand that patients don’t eat and drink probably also degrades the doctor patient relationship. A significant percentage of patients ignore these recommendations, and this might be increasing overall risk. (Rüggeberg 2024) (If we allowed patients to drink, they might not consume the more dangerous solids.) We also cause a tremendous amount of harm in medicine by cancelling required surgeries and procedures because patients ignored these guidelines, despite the fact that the risk is incredibly low. 

Unfortunately, the harms are worse than the guidelines make them seem. A consistent theme in all the literature is that we starve patients for way longer than the guidelines recommend, because it is never clear when exactly a patient will go to surgery, and so the fear of having a surgery cancelled results in patients being kept NPO for very long (and unnecessary) lengths of time.

Quick evidence summary

“In the era of evidence based medicine however, there are no scientific reasons to keep a patient in prolonged preoperative fasting.” (de Aguilar-Nascimento 2010)

There are substantial harms from the practice of keeping all emergency department patients fasting. Even among patients headed to the operating room, oral intake until shortly before surgery is important. The risk of aspiration, although real and important, is incredibly rare. Liquids leave the stomach within 1-2 hours, and increased liquid intake results in faster gastric emptying. Solids take longer, in the realm of 4-6 hours, but it is not clear that longer fasting actually decreases aspiration risk or improves clinical outcomes. All available data shows no correlation between length of fasting and aspiration risk. There is a lot of surgical data that demonstrates decreasing fasting times improves outcomes, with no increase in aspiration risk, although the data is mostly limited to liquids, and aspiration is so rare that massive trials would be required to be definitive. Conversely, prolonged fasting is strongly associated with a long list of harms, and is just cruel. 

At this point, the evidence suggests that all emergency department patients should be encouraged to drink, and should be allowed to eat, although if you wanted to encourage light snacking over heavy meals, that would make sense.

Current guidelines

Anesthesia

The 2017 ASA guideline suggests clear liquids (water, and fruit juices without pulp, carbonated beverages, carbohydrate rich nutritional drinks, clear tea, and black coffee) until 2 hours before surgery. (ASA 2017) They allow a light meal up until 4 hours before elective surgery requiring general anesthesia. 

There is a 2023 update to the ASA guideline that reaffirms the recommendation to allow carbohydrates containing clear fluids until 2 hours before surgery, but notes that most facilities are failing at this and causing harm, and so really emphasizes that hospitals need to do a better job following this guideline. (Joshi 2023) They hint that 1 hour may also be appropriate, although there is insufficient evidence. They acknowledge that although they previously made different recommendations for protein containing liquids (mild) there is actually insufficient evidence to make such a recommendation. 

The European Society of Anaesthesiology says “adults and children should be encouraged to drink clear fluids (including water, pulp-free juice and tea or coffee without milk) up to 2 h before elective surgery… Drinking carbohydrate-rich fluids before elective surgery improves subjective well being, reduces thirst and hunger and reduces postoperative insulin resistance.” (Smith 2011) Their cutoff for solid foods is 6 hours.

Canadian Anesthesiologists’ Society state “unless contraindicated, adults and children should be encouraged to drink clear fluids (including water, pulp-free juice, complex carbohydrate beverages, and black tea or coffee) up to two hours before elective surgery. Pediatric patients should also be encouraged to consume clear fluids, as defined, up to one hour before elective procedures.” (Dobson 2024)

Pediatric anesthesia

The European Society of Anaesthesiology and Intensive Care recommends 1 hour of clear fluid fasting and 3 hour breast milk fasting preoperatively. (Frykholm 2022) They say “prolonged fasting should be avoided whenever possible”. Solid food should be allowed until 6 hours before anesthesia induction, but a light breakfast of solids may be allowed up to 4 hours prior to induction. 

Emergency medicine

ACEP: “Do not delay procedural sedation in adults or pediatrics in the ED based on fasting time. Preprocedural fasting for any duration has not demonstrated a reduction in the risk of emesis or aspiration when administering procedural sedation and analgesia.” (Godwin 2014)

Summary of the guidelines

The guidelines all say essentially the same thing, and although I think they might still be too conservative based on the real risk represented, it is clear that most emergency departments have policies (whether official or unofficial) that result in way too many patients being fasted way too long. Even if all of our patients ended up having surgical conditions, we are not following the anesthesia guidelines that tell us to encourage drinking until 2 hours before surgery. After making the diagnosis of a life threatening surgical condition, once you include the time to page the surgeon, have them assess the patient, and get the patient to the operating room, it is pretty clear that the patient should be allowed to drink even as their CT scan is being performed. Of course, the vast majority of surgical diagnoses result in next day, rather than same day, surgery. Furthermore, NPO status is irrelevant when there is a truly life threatening surgical diagnosis, as the benefit of surgery far outweighs the miniscule aspiration risk. (Not that any of these patients really want to eat or drink.) Therefore, the anesthesia guidelines are consistent with the idea that everyone should be allowed to eat and drink while their workup is being performed in the emergency department, and then even after a surgical diagnosis has been made, no one should be made “NPO at midnight”. Instead we need to adopt strategies that allow clear fluids until far closer to the actual procedure. In fact, “allow” is not the correct verb. Patients should be encouraged to drink. 

How do we change practice?

Although it is clear that we need to change practice, this is not going to be an easy change to make. Culture trumps evidence over and over again in medicine. This is not something you can change alone. You can’t just decide to practice following the evidence for your own patients. You need to start with a departmental policy. Luckily the policy is very easy to write: “Let them eat: everyone is allowed to eat and drink in the emergency department, unless there is a specific medical order written to keep the patient NPO”. 

Realistically, some departments are easier to change than others. I think the “everyone eats” is the correct policy, but if you want to ease your department into this, perhaps start with just “everyone drinks”. There should never be a question that patients are allowed to drink water or other clear fluids. Even patients scheduled for the operating room are OK to drink water. If the people in your department are nervous about solid food, start with drinking (and make sure patients have clear fluid options that include carbohydrates). Once people are comfortable with that practice, you can readdress the food later.

To really help patients, we are also going to have to make infrastructure changes. Because of long standing NPO rules, most emergency departments make it very hard for patients to access water. That needs to change. Water dispensers and cups need to be easily accessible in all waiting rooms. Signage needs to encourage patients to drink if thirsty. If you are at all civilized (like the hospitals I worked at in Australia and New Zealand), you can have tea and coffee options for patients as well (but that would be a dramatic change in Canada). 

Ideally, you will get buy-in from the departments of anesthesia and surgery. An angry consultant could really derail this initiative, and not all consultants practice perfectly evidence based medicine. Drinking until 2 hours (or less) before surgery is already part of anesthesia guidelines, so despite strong historical inertia, this really shouldn’t be a difficult practice change. We just need to ask specialists to follow their own guidelines. (For all we know, they might be aghast to find that we are depriving patients of food and water based on our misunderstanding of their desires.) 

Throughout the anesthesia literature, it was noted that long standing culture is very hard to change. Passive interventions, such as simply changing the rules, generally had little to no effect on actual fasting rates. They found active interventions and nursing campaigns are required. Similarly, language such as “patients are allowed to drink” is not nearly as effective as language like “patients are encouraged to drink”. The culture around eating is somewhat different, but I imagine we will relearn some of the same lessons. I, for one, am all for encouraging (rather than simple “allowing”) emergency department patients to eat and drink, because a well hydrated and well fed patient is better in almost every scenario. 

Final summary

Let them eat.

The historical practice of depriving patients of basic necessities of life “just in case” has clear significant harm with no clear benefit at all. Even if there is a small decrease in aspiration risk, the evidence and guidelines all say that patients should be allowed to drink clear fluids until at least 2 hours prior to general anesthesia. If you just made that your target, it would mean that 99.9% of all patients in the department are allowed to drink. 

Our current fasting policies are cruel. They clearly cause harm, from patient discomfort, to dehydration, to physician distractions and inefficiencies (with repeated phone calls asking if patients are allowed to eat). There is no doubt: everyone drinks.

The evidence and guidance around solid food is a little more uncertain. There is reason to be concerned about very large high caloric meals. In general, people aren’t eating quadruple cheeseburgers and cheese fries in the emergency departments, but if that is common practice where you work it might be reasonable to discourage (although not ban) eating. For most of us, just allowing snacking without encouraging full meals is probably enough. However, considering that sick patients need food, and almost none of our patients require same day surgery, the emergency department policy is actually very easy: everyone eats (unless there is a specific order to the contrary). 

Allow the physicians to use clinical judgement. We don’t want our patients to have an overly distended stomach during airway management if we can help it, but very few of our patients are going to need airway management. Let the physicians identify the highest risk patients. Let them sort out the few medical patients (such as a bad stroke with a high aspiration risk) that need to be NPO. Let them figure out the patients that might need same day surgery. Let them write fasting orders. But for everyone else, let them eat.

Of course, even if a patient is identified as high risk for surgery, the order should never be “NPO”. At most, based on the evidence and guidelines, it should be “clear fluids”. However, allowing patients to snack while preventing them from eating full meals is a very reasonable approach even on the day of surgery. If a patient is starving and wants to eat a granola bar, we probably shouldn’t be denying them. Unfortunately, you will probably need to develop new terminology to allow that to happen, as I have never seen an EMR that allows me to order “light snacking only”. However, this is such a niche case that it should not distract us from the overall message. Almost no one needs same day surgery. Starving patients is cruel. Let them eat.

Don’t just let them, encourage them. Drinking patients are healthy patients; happy patients. We want our patients to be encouraged to eat and drink.

Other FOAMed

NPO for sedation? Don’t swallow the myth

The Harms of Fasting

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