Chapter 2.9 covers drugs acting on the gastro-intestinal tract that are relevant to anaesthesia. We include antiemetic drugs, with detail on the vomiting centre and the mechanisms of action of commonly used antiemetics. We then discuss gastric acid secretion and drugs used to control this. Finally we discuss drugs used in diabetes – oral hypoglycaemic agents. Here we include detail on the diagnosis of diabetes mellitus, commonly used drugs and the perioperative management of such drugs.

Dehydration is a frequent diagnosis made in the emergency department (ED) and a common pathway in the observation unit (OU). Gastroenteritis and vomiting are two common causes of dehydration. Patients at the extremities of age are particularly vulnerable to dehydration yet still can be managed effectively in an observation setting. The evaluation of dehydration includes physical and laboratory assessment though both can be nonspecific. Management includes non-invasive versus invasive rehydration as well as electrolyte correction. The first-line therapy of intravenous rehydration is isotonic crystalloid solution. The management of dehydration in an OU is straightforward, typical and effective.

OU patients will be on track to better outcomes, reduced length of stay, all while reducing health care costs.

Hyperemesis gravidarum is considered the severe end of the spectrum of nausea and vomiting of pregnancy. While there is no agreed upon strict definition for this condition, the criteria include persistent vomiting not related to other causes, a measure of acute starvation, and documented weight loss, most often at least 5% of pre-pregnancy weight. Electrolyte, thyroid, and liver abnormalities also may be present. The incidence of hyperemesis gravidarum is approximately 0.3–3% of pregnancies, but the reported incidence varies because of different diagnostic criteria and ethnic variation in study populations. Risk factors include patients with increased placental mass (molar gestation or multiple gestation), a history of motion sickness, migraine headaches, a family history, and a history of hyperemesis gravidarum in a previous pregnancy. Daughters and sisters of patients who had hyperemesis gravidarum are more likely to have the same condition, as are patients carrying a female fetus. The workup involves ruling out other causes, and the treatment focuses on relieving symptoms and preventing serious morbidity. Hyperemesis gravidarum can significantly impact the quality of life of patients and their families and may be challenging to treat.

Clinicians begin the Explosions! with familiar routines: a Henry Heartbeat activity, reviewing homework and adding data to the Body Map, and a new ritual: checking in with our energy and seeing if we need a snack. New characters related to processes of eating and digesting food are introduced: Victor Vomit, Gaggy Greg, Gordon Gotta Go. Investigations explore activities that may induce gagging. Equipped with garbage cans and paper towels, families are prepared for any result of these disgusting but fun investigations. Body Brainstorms explore questions such as who passes the most gas in the family and what foods produce the smelliest farts. Clinicians introduce a decision-tree in the Body Clues Worksheet that helps family members notice their body sensations, figure out what those sensations may mean (e.g., is Betty the Butterfly telling me I am excited?), and design a corresponding investigation (e.g., what happens to Betty the Butterfly if I take some deep breaths while facing my fears?). Families practice using their Body Clues Worksheet to review the highs and lows of the day or to explore the meaning of an intense moment. Armed with these new investigative tools, families are prepared for any intense situation even if it’s disgusting!

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

Overview of gastrointestinal complications including constipation, diarrhea, nausea, and vomiting, feeding tube complications, bowel perforation and obstruction, and neutropenic enterocolitis

This chapter describes the primary interventions for the fear of aversive consequences presentation of ARFID, including:

• Examples of how avoidance of feared food or eating situations keeps the problem going

• Examples of how facing fears through exposure can actually reduce anxiety

• Creating a hierarchy of feared food and eating situations

• How to design and implement at-home exposures to these feared food and eating situations

Antiemetic choice is dictated by the mechanism of vomiting, whether from gastric distension (prokinetic), poisoning (centrally acting) or vestibular disturbance (targeting acetylcholine or H2 receptors). Readers are provided with information on the most commonly used antiemetics and their clinical use to help guide therapy.