What You Should Know about the Gastrointestinal System for the EMT Exam

By Arthur Hsieh

Make sure you know about the gastrointestinal system for the EMT exam. The abdomen contains most of the major structures and organs of digestion. In general, they’re divided into two categories: hollow organs such as the stomach, gallbladder, and intestines, and solid organs such as the liver, kidneys, and pancreas.

If injured or breached, hollow organs tend to spill their contents into the abdominal cavity, possibly causing infection and cell tissue damage. Solid organs contain a lot of blood vessels and tend to bleed if injured.

Food is mechanically broken down by the teeth and chemically taken apart by stomach acid. It eventually becomes a slurry that is moved slowly through the small and large intestines through rhythmical motions known as peristalsis. Nutrients and water are absorbed by the walls of the intestines and circulated throughout the body.

Eventually all that is left are feces. They’re excreted out the rectum through the anus.

[Credit: Illustration by Kathryn Born, MA]
Credit: Illustration by Kathryn Born, MA

Covering the different organs are two layers of tissue: the visceral and parietal membranes. The visceral membrane lies on top of the organs; the parietal lies against the walls of the abdominal cavity. They slide past each other, allowing the organs to move as people move, yet still maintain their relative positions.

Know the general locations of the abdominal organs. Pain in those areas may be a clue to which organ is involved and whether the patient has a potentially serious medical condition that requires immediate assessment by emergency department staff.

Illness or Disease Signs and Symptoms Specific Treatment
Appendicitis Pain centered in right lower quadrant or beginning around the
navel and moving downward over a few hours. Fever, body aches,
chills. May feel nauseous, vomit. If appendix ruptures, may cause
peritonitis.
Treat for shock if needed by keeping patient supine,
administering oxygen, and maintaining body temperature.
Cholecystitis: Inflammation of the gallbladder; often caused by
gallstones that block the gallbladder, causing it to swell
Rapid onset of sharp, severe pain in right upper quadrant,
radiates to back, right shoulder, or flank 30–60 minutes
after a meal rich in fat. May experience nausea, vomiting,
indigestion, gas.
Place patient in position of comfort. Avoid anything by
mouth.
Esophageal varices/Mallory-Weiss Syndrome A weakness in the wall of the esophagus may suddenly burst,
causing massive bleeding. Patient vomits large amounts of bright
red blood. Shock is likely.
If possible, lay patient in left lateral recumbent position to
help keep the airway open. Suction any blood in the airway. Provide
supplemental high-flow oxygen using a nonrebreather mask. Maintain
body temperature. Rapid transport is needed.
Gastroenteritis: Infection of the GI tract by virus or
bacterium
Caused by ingestion of contaminated food or water. Causes
nausea, vomiting, and diarrhea. May also cause dehydration, which
results in signs of shock.
Treat for shock if needed by keeping patient supine,
administering oxygen, and maintaining body temperature.
GI hemorrhage Depending on where the bleeding site is, patient may vomit
blood or, more likely, have blood in stool. If enough blood is
lost, signs of early shock may be seen — tachycardia,
tachypnea, worsening weakness.
Measure orthostatic vital signs (pulse and blood pressure when
laying supine, repeated when sitting, and then standing). Treat for
shock if necessary by keeping patient supine, administering oxygen,
and maintaining body temperature.
Pancreatitis: Caused by gallstones, alcohol abuse, and other
diseases
Deep-set pain in mid-upper abdomen. May experience nausea,
vomiting. In severe cases, may cause sepsis or the pancreas to
begin bleeding.
Place patient in position of comfort. Avoid anything by
mouth.
Peritonitis: Irritation of the membranes lining the abdominal
cavity caused by a rupture in the GI tract
Intestinal contents leaking into the abdominal cavity can cause
very serious infections. Patient may have fever, nausea, vomiting.
Abdomen may become distended, painful to palpitation. In severe
cases, may cause septic shock.
Transport patient with knees flexed, may help reduce pain.
Treat for shock if needed by keeping patient supine, administering
oxygen, and maintaining body temperature.
Ulcers: Small erosions of the stomach lining or duodenum Burning, pressure, or gnawing discomfort in the upper abdomen
or upper back. Comes on shortly after a meal, lasts 2–3
hours. May have nausea, vomiting. May cause bleeding resulting in
bloody vomit (hematemesis) and/or dark, tarry stool
(melena).
If bleeding is significant, there may be signs of shock that
you must manage by keeping patient supine, administering oxygen,
and maintaining body temperature.

There are also non-GI system causes of abdominal pain. For example:

  • An abdominal aortic aneurysm (AAA, or triple A) is a sudden weakening of the aorta causing it to bulge out or, in the worst cases, suddenly rupture. An AAA causes severe abdominal pain. The patient’s blood pressure may fall quickly, and pedal pulses may be absent. This is a life-threatening emergency that requires rapid but gentle movement of the patient to a hospital.

  • Pain from a myocardial infarction may be centered around the epigastric region, midway between the two upper abdominal quadrants. A patient may mistake the discomfort for indigestion. Carefully evaluate the rest of the history of the present illness to see whether an MI may be happening.

A 41-year-old male is complaining of a sudden onset of abdominal pain that began 30 minutes after eating a spicy meal. He describes the pain as feeling sharp, just below his ribcage in the middle of his abdomen. He felt nauseous and vomited, which did not relieve the pain. He is awake and anxious, and his skin is pale, cool, and diaphoretic.

He has a faint, fast radial pulse and is tachypneic. You cannot feel his femoral pulse. Which of the following conditions best explains your findings?

  • (A)Appendicitis

  • (B)Gastroenteritis

  • (C)Aortic abdominal aneurysm

  • (D)Ulcers

The correct answer is Choice (C). Even though this episode came on after a meal, all other signs point to a serious, potentially life-threatening condition.