The start of a new academic medicine year reminds me of the initial shock of being a 'tern. My first rotation was ambulatory medicine and I had recurrent waking nightmares about a patient presenting to the clinic with chest pain. That initial day in ambulatory clinic the first patient simply wanted his medication explained and the second a refill. Feeling saucy I was ready for the third until he said, "I have chest pain". With that I ran from the room, forgetting further history or physical, and called my attending to staff, which sounded something like this: "The patient has chest pain. In the thorax. You know, in the chest area. It is painful, in his chest." Awed by this clinical marvel, my attending sighed and took over, tempted to administer a benzodiazepine or a swift slap to the back of the head of the hyperactive intern.
My next rotation was the ICU, where experienced nurses carefully took us by the hand and shepherded the "intensivist interns" away from too much stupidity, tactfully paging me when they needed a critical intervention of acetaminophen or an antiemetic while deferring the more mundane ventilator adjustments and anxiolysis to the attending.
My third month was on the floors at the VA. On-call. With a suboptimally motivated or interested senior resident. The resident had vanished before shift change leaving me to face a barrage of sign-offs and nursing shift change. My first solo decision was...the diet order. Never has a physician faced such consternation and mental gymnastics as I did when making this pivotal decision. I thought back to my clinical nutrition rotation and pondered the need for enteral versus parenteral nutrition. I weighed his medical problems, each one indicating a specific diet. The nurse, patience fraying as the minutes ticked by finally threw me a clue with the infamous, "Well last time he was here he had a regular diet". Sold! One regular diet order coming up.
In medicine you need a system for making decisions, all of them are important but some are more important than others. Some of them need to be made right now and some of them can be made later. Americans are obsessed with food. Obesity epidemic being corpulent evidence of the same. Patients with intractable abdominal pain or who have just been told that a myocardial infarction has destroyed the pumping ability of their heart are more concerned with getting that next megaburger with ubër fries and a diet Coke then the next diagnostic and therapeutic step. Been vomiting all day after eating? Family says feed her. Had a stroke and with each meal starts hacking and turning cyanotic? Family says he can't get well if he doesn't eat.
This oral fixation drives nursing to page as soon as the diseased hit the floor, regarding the diet order. Regardless of the vital signs, presenting complaint, operative or procedural needs the first thing I usually hear is "Can they eat?" Despite a chronic history of "just say no" I still get the question. Patients are usually blessedly monosyllabic while they eat, making it a perfect time to get a history or for nursing to get done. However, food or withholding of the same is a therapeutic decision and should be made after the physician has determined the problem and the solution for the same. If there is no aspiration risk consider limited ice chips, patients are much happier if they don't have a dry mouth. Unless they have been given a large dose of insulin or other anti-hyperglycemic medications, skipping one meal or even a whole days worth (as long as they are adequately intravenously hydrated) has never killed anyone. If they did you would have a case report of hyperstarvation.
So how do you decide the diet order?
First decide if they can or cannot eat. They cannot eat if they have a condition that will be worsened with intake or they will have a procedure the next day. Typically they can eat up until midnight if they are having a procedure or operation. Conditions that preclude intake are neurological insults (e.g. stroke, aspiration pneumonia) that have caused or increase the chance of aspiration, nausea ± emesis, abdominal pain of suspected gastrointestinal origin, blood coming out of the esophagus or rectum, a blood glucose > 400 mg/dL, and recent surgery or procedure until cleared by the surgeon/proceduralist.
Next choose their diet, basically look at their health problems and choose, e.g. hypertension = 2 g sodium, heart disease history = cardiac (trumps hypertension), diabetes = diabetic, both = cardiac diabetic, on dialysis = renal, hyperkalemia = restrict their potassium (which there is an abundance of in salt substitute, tomatoes, oranges, and bananas). If they forgot their dentures, puree it. If they have diet restrictions from the nursing home continue them. If they have been losing weight, no liver disease, and cancer has been excluded or if they have low serum protein and albumin add some CIB shakes. When in doubt about the calories ask a dietician to see them, when in doubt about the consistency ask the speech therapist to see them. The longer you think they are going to live the stricter the diet needs to be. The octogenarian with advanced cancer probably doesn't need to worry as much about her A1c as the newly diagnosed type I diabetic.
If they cannot eat you will need to come up with some form of nutrition other than the meager benefits of D5*. As a rule of thumb, three days without food should be the temporal trigger for initiating some form of nutrition. Always use the gut first if you can, consider a Dobhof for tube feeding if they cannot swallow with consideration for a PEG-tube (G-tube) if they are still deemed unable to swallow. Be aware that neither tube decreases aspiration risk. Sometimes the stomach needs to be bypassed and a GJ-tube can be used. If the etiology of the NPO status precludes enteral feeding, i.e. a gastrointestinally-based intraabdominal etiology, consideration toward parenteral nutrition via a PICC or central line must be undertaken. With either tube feeding (TF) or total parenteral nutrition (TPN) a dietician consultation is highly recommended.
*The amount of kcal (Cal) per liter of D5W = 5000 mg/dL x 3.4 kcal / g x 1 g / 1000 mg x 10 dL/1 L = 170 kcal/L. Thus a patient receiving 150 mL/hr of D5 NS would receive 170 kcal/L x 150 mL/hr x 1 L/1000 mL x 24 hours = 612 kcal per day. As the average caloric intake per day ~2000 kcal this is a starvation "diet" and catabolic.