Wk 4: Nausea and Vomiting
Overview and Core Definitions of Nausea and Vomiting
Nausea: Defined as an unpleasant sensation characterized by a feeling of the imminent need to vomit. It may or may not ultimately lead to the act of vomiting. From an evolutionary perspective, nausea served as a survival mechanism to prevent the ingestion of toxic or unfamiliar plants.
Vomiting (Emesis): The forceful oral expulsion of gastric contents. It is associated with the coordinated contraction of the abdominal musculature and diaphragm.
Chronic Nausea and Vomiting: Defined as symptoms lasting for a duration of more than month.
Early Satiety: A sensation of feeling full after consuming an unusually small amount of food. While often appearing as a nausea mimic, it is specifically concerning for gastric pathology, particularly raising the suspicion of gastric cancer.
Regurgitation: The simple, retrograde, and passive flow of esophageal contents into the mouth. It occurs without the muscular effort associated with vomiting and without antecedent nausea. A common example is Gastroesophageal Reflux Disease (GERD).
Retching: Also known as "dry heaves." These are spasmodic respiratory movements conducted against a closed glottis, involving contractions of the abdominal muscles without the actual expulsion of gastric contents.
Rumination: A condition where patients chew and swallow food that has been regurgitated into the mouth. This may involve a voluntary increase in intra-abdominal pressure to induce regurgitation. The term is derived from "ruminants" (e.g., cows), which possess complex multi-stomach digestive processes.
Physiology and Saftey of the Vomiting Reflex
The Vomiting Center: Located in the medulla of the brain. It coordinates the simultaneous contraction of the diaphragm and abdominal muscles.
Mechanical Process:
The stomach and upper intestine are squeezed.
The lower esophageal sphincter (LES) relaxes.
The glottis closes to protect the airway.
Aspiration Risks: If the glottis fails to close (common in alcohol or drug intoxication), the patient may aspirate vomitus. This can lead to fatal obstruction of the respiratory passages.
Safety Positioning: To prevent aspiration in an unconscious or intoxicated patient, they should be placed on their left side. This positioning encourages the expulsion of vomitus from the body rather than allowing it to settle in the airway.
Acute Causes of Nausea and Vomiting
Infections and Toxins:
Gastroenteritis.
Food poisoning.
Hepatitis.
Medications and Substances:
Chemotherapeutics: High association with acute and delayed nausea.
Antibiotics.
Analgesics: Excessive use of Ibuprofen can cause gastric irritation; Acetaminophen (Tylenol) is generally well-tolerated but can cause nausea in toxic doses.
Visceral Pain: Intense localized pain from abdominal organs can trigger vomiting:
Pancreatitits.
Appendicitis.
Renal colic (kidney stones) is a very frequent cause of significant vomiting.
Central Nervous System (CNS) Conditions:
Vertigo-inducing conditions such as Labyrinthitis.
Motion sickness.
Strokes (if they involve vestibular pathyways).
Increased intracranial pressure (ICP).
Head trauma: Vomiting following a head strike is a significant indicator of potential severity.
Meningitis.
Statistically, of adults and of children with skull fractures will experience vomiting.
Metabolic and Systemic Issues:
Pregnancy.
Diabetic Ketoacidosis (DKA).
Uremia (kidney failure).
Radiation: Specifically when directed at the abdomen.
Chronic and Recurrent Vomiting Syndromes
Gastric Causes:
Gastroparesis: Injury to the nerves (often due to diabetes) preventing the stomach from emptying normally.
Dyspepsia or chronic reflux.
Gastric outlet obstruction.
Small Intestinal Dysmotility: Related to conditions like pseudo-obstruction or Scleroderma (an autoimmune condition).
Metabolic Disorders: Chronic hyperthyroidism or adrenal insufficiency.
CNS Disorders: Chronic increased ICP due to tumors, pseudotumor cerebri, cerebral edema, or encephalopathy. Nausea from CNS causes is always considered potentially dangerous.
Psychogenic and Idiopathic Disorders:
Disordered eating.
Cyclic Vomiting Syndrome: An idiopathic condition characterized by recurrent, discrete episodes of vomiting.
Cannabinoid Hyperemesis Syndrome: Associated with chronic, widespread marijuana use.
Rumination Syndrome: Characterized by regurgitation followed by re-chewing and re-swallowing.
Chemotherapy-Induced Nausea
Acute: Occurring shortly after administration.
Delayed: Occurring more than hours after the dose.
Anticipatory: Nausea that occurs before the next dose is administered; believed to be a learned behavioral response.
Emergency "Alarm Symptoms" and Dangerous Conditions
Gastrointestinal Emergencies:
Large volume hematemesis (bloody vomit): Especially critical in patients with a history of ulcers, liver disease, or cirrhosis.
Obstruction, perforation, or peritonitis.
Right lower quadrant pain or pain migrating from the umbilicus: Suggestive of appendicitis.
Abdominal pain worsening with jolting movements: Suggestive of peritonitis.
Pregnancy Complications:
Hyperemesis Gravidarum: Frequent, severe vomiting in pregnancy that becomes dangerous (distinct from standard morning sickness).
HELLP Syndrome: A severe complication involving Hemolysis, Elevated Liver enzymes, and Low Platelets.
Neurological Emergencies:
Nausea and vomiting following head injury.
Headache with nausea/vomiting: Could indicate a bleed, mass, infection, or migraine.
Neck stiffness and fever: High suspicion for meningitis.
Altered mental status.
Cardiovascular: Inferior myocardial infarction (heart attack) can present with nausea/vomiting due to the heart's proximity to the diaphragm.
Systemic: Dehydration and hypovolemia, especially if the patient (particularly a child) cannot retain liquids.
Diagnostic Clues from Vomitus and Timing
Characteristics of Vomitus:
Bilious (contains bile): Suggestive of small bowel obstruction.
Feculent (contains stool): Indicative of large bowel obstruction.
Hematemesis (Blood): Can indicate esophageal varices (common in liver disease), ulcers, or a Mallory-Weiss tear (a small esophageal tear caused by the force of retching).
Undigested Food: Suggestive of gastroparesis, gastric outlet obstruction, or esophageal issues like stenosis or achalasia.
Projectile Vomiting: In infants, suggests pyloric stenosis. In adults, can indicate increased ICP (masses, bleeds, or infections).
Timing of Episodes:
In the morning (pre-breakfast): Pregnancy or increased ICP.
Immediately after eating: Gastroparesis, gastric outlet obstruction, gastric ulcers, or eating disorders.
Intermittent/Recurrent: Cyclic vomiting syndrome or cannabinoid hyperemesis.
Toxin and Foodborne Illness Specifics
Staphylococcus aureus or Bacillus cereus: Rapid onset of vomiting shortly after ingestion.
Vibrio: Associated with shellfish.
Paralytic Shellfish Poisoning: Vomiting accompanied by numbness and tingling around the mouth.
Botulism: Associated with poorly canned foods; presents with paresthesias, blurred vision, difficulty swallowing, and muscle weakness.
Ciguatera: A fish-borne infection causing vomiting and neurological symptoms.
Anisakiasis: Caused by the ingestion of raw fish.
Scombroid Poisoning: Occurs from cooked fish; involves a food-poisoning picture plus high histamine release (burning, itchy rash).
Heavy Metals: Vomiting associated with drinking from metal containers or a metallic taste.
Toxic Ingestions: Including accidental ingestion of poisonous mushrooms or medication overdoses (e.g., Ibuprofen).
Pediatric Considerations
Ear Infection: Sick children with ear pain may experience nausea/vomiting.
Reye Syndrome: A dangerous condition caused by giving aspirin to children.
Pyloric Stenosis: Causes projectile vomiting in infants.
Metabolic Disorders: Should be considered if there is a family history of early death.