Chapter 039. Nausea, Vomiting, and Indigestion (Part 3)

Disordered gut sensorimotor function also commonly causes nausea and vomiting. Gastroparesis is defined as a delay in emptying of food from the stomach and occurs after vagotomy, with pancreatic adenocarcinoma, with mesenteric vascular insufficiency, or in systemic diseases such as diabetes, scleroderma, and amyloidosis. Idiopathic gastroparesis occurring in the absence of systemic illness may follow a viral prodrome, suggesting an infectious etiology. Intestinal pseudoobstruction is characterized by disrupted intestinal and colonic motor activity and leads to retention of food residue and secretions, bacterial overgrowth, nutrient malabsorption, and symptoms of nausea, vomiting, bloating, pain, and altered defecation. ...
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Chapter 039. Nausea, Vomiting, and Indigestion (Part 3) Chapter 039. Nausea, Vomiting, and Indigestion (Part 3) Disordered gut sensorimotor function also commonly causes nausea andvomiting. Gastroparesis is defined as a delay in emptying of food from thestomach and occurs after vagotomy, with pancreatic adenocarcinoma, withmesenteric vascular insufficiency, or in systemic diseases such as diabetes,scleroderma, and amyloidosis. Idiopathic gastroparesis occurring in the absence ofsystemic illness may follow a viral prodrome, suggesting an infectious etiology.Intestinal pseudoobstruction is characterized by disrupted intestinal and colonicmotor activity and leads to retention of food residue and secretions, bacterialovergrowth, nutrient malabsorption, and symptoms of nausea, vomiting, bloating,pain, and altered defecation. Intestinal pseudoobstruction may be idiopathic orinherited as a familial visceral myopathy or neuropathy, or it may result fromsystemic disease or as a paraneoplastic complication of a malignancy such assmall cell lung carcinoma. Patients with gastroesophageal reflux may reportnausea and vomiting, as do some individuals with functional dyspepsia andirritable bowel syndrome. Three other functional disorders without organic abnormalities have beencharacterized in adults. Chronic idiopathic nausea is defined as nausea withoutvomiting occurring several times weekly, whereas functional vomiting is definedas one or more vomiting episodes weekly in the absence of an eating disorder orpsychiatric disease. Cyclic vomiting syndrome is a rare disorder of unknownetiology that produces periodic discrete episodes of relentless nausea andvomiting. The syndrome shows a strong association with migraine headaches,suggesting that some cases may be migraine variants. Cyclic vomiting is mostcommon in children, although adult cases have been described in association withrapid gastric emptying and with chronic cannabis use. Extraperitoneal Disorders Myocardial infarction and congestive heart failure are cardiac causes ofnausea and vomiting. Postoperative emesis occurs after 25% of surgeries, mostcommonly laparotomy and orthopedic surgery, and is more prevalent in women.Increased intracranial pressure from tumors, bleeding, abscess, or obstruction tocerebrospinal fluid outflow produces prominent vomiting with or without nausea.Motion sickness, labyrinthitis, and Ménières disease evoke symptoms vialabyrinthine pathways. Patients with psychiatric illnesses including anorexianervosa, bulimia nervosa, anxiety, and depression may report significant nauseathat may be associated with delayed gastric emptying. Medications and Metabolic Disorders Drugs evoke vomiting by action on the stomach (analgesics, erythromycin)or area postrema (digoxin, opiates, anti-Parkinsonian drugs). Emetogenic agentsinclude antibiotics, cardiac antiarrhythmics, antihypertensives, oralhypoglycemics, and contraceptives. Cancer chemotherapy causes vomiting that isacute (within hours of administration), delayed (after 1 or more days), oranticipatory. Acute emesis resulting from highly emetogenic agents such ascisplatin is mediated by 5-HT3 pathways, whereas delayed emesis is 5-HT3-independent. Anticipatory nausea often responds better to anxiolytic therapy thanto antiemetics. Several metabolic disorders elicit nausea and vomiting. Pregnancy is themost prevalent endocrinologic cause of nausea, occurring in 70% of women in thefirst trimester. Hyperemesis gravidarum is a severe form of nausea of pregnancywhich can produce significant fluid loss and electrolyte disturbances. Uremia,ketoacidosis, and adrenal insufficiency, as well as parathyroid and thyroid disease,are other metabolic causes of emesis. Circulating toxins evoke symptoms via effects on the area postrema.Endogenous toxins are generated in fulminant liver failure, whereas exogenousenterotoxins may be produced by enteric bacterial infection. Ethanol intoxicationis a common toxic etiology of nausea and vomiting. Approach to the Patient: Nausea and Vomiting History and Physical Examination The history helps define the etiology of unexplained nausea and vomiting.Drugs, toxins, and gastrointestinal infections commonly cause acute symptoms,whereas established illnesses evoke chronic complaints. Pyloric obstruction andgastroparesis produce vomiting within 1 h of eating, whereas emesis fromintestinal obstruction occurs later. In severe cases of gastroparesis, the vomitusmay contain food residue ingested hours or days previously. Hematemesis raisessuspicion of an ulcer, malignancy, or Mallory-Weiss tear, whereas feculent emesisis noted with distal intestinal or colonic obstruction. B ...