Gastrointestinal and Urologic Emergencies

Chapter 19: Gastrointestinal and Urologic Emergencies
Peritonitis (Inflammation of the Peritoneum)

Peritonitis is when the peritoneum (the lining of the abdominal cavity) becomes inflamed, often due to various issues with the digestive system or injuries.

Key aspects of Peritonitis:

  • Symptoms:

    • Abdominal Distention: The belly swells because feces accumulate when the bowel stops moving properly.
    • Emesis (Vomiting): This is the only way the stomach can empty its contents when food cannot pass through the bowel normally.
    • Nausea and Vomiting: While common, these are general symptoms that can occur with almost any digestive problem.

  • Fluid Shifts:

    • Fluids can leak from the bloodstream into the abdominal cavity.
    • This loss reduces the amount of blood circulating, which can lead to:
      • Lowered blood pressure (BPBP).
      • Potentially, a state of low blood flow (shock).

  • Vital Signs:

    • Initially, vital signs might appear normal.
    • As the condition worsens, patients often develop a fast heart rate (tachycardia) and low blood pressure (hypotension).

  • Hemorrhage: If there's bleeding (hemorrhage), the signs of shock will become much more severe.

  • Fever: Whether a fever is present depends on the specific underlying cause.

    • Conditions Leading to Fever:
      • Diverticulitis: Inflammation of small pouches in the intestinal walls typically causes a noticeable fever.
      • Cholecystitis: Inflammation of the gallbladder can also lead to an elevated body temperature.
      • Acute Appendicitis: A fever might not develop until the appendix actually ruptures and contaminates the abdominal cavity.
Abdominal Pain: Understanding Why It Feels Different

The way abdominal pain is perceived depends on which part of the peritoneum is affected because different types of nerves supply them.

  • Parietal Peritoneum (Outer Layer):

    • This part is supplied by somatic nerves from the spinal cord.
    • These nerves are excellent at localizing sensations like pain, touch, pressure, heat, and cold.
    • Result: Patients can usually point precisely to where the irritation or pain is occurring.

  • Visceral Peritoneum (Inner Layer, Covering Organs):

    • This part is supplied by autonomic nerves.
    • These nerves are not very good at localizing sensations.
    • Result: Pain here is often described as deep, vague, and difficult for patients to pinpoint an exact location.

  • Stimulation of Visceral Peritoneum:

    • This pain commonly arises when hollow abdominal organs (like the intestines) are stretched (distended) or contract, stimulating special stretch receptors.
    • The sensation from visceral pain is distinctly different from the sharper, more localized parietal pain due to the nature of its nerve supply.