Chapter 19: Gastrointestinal and Urologic Emergencies - Study Notes
Anatomy and physiology
The abdominal cavity contains solid and hollow organs that make up the gastrointestinal, genital, and urinary systems.
Solid organs: liver, spleen, pancreas, kidneys, and ovaries in women.- Retroperitoneal (behind the peritoneum) for kidneys, ovaries, and pancreas, yet they lie next to the peritoneum and can cause abdominal pain when injured.
Injury to a solid organ can cause shock and bleeding due to rich vascular supply.
Hollow organs: gallbladder, stomach, small intestine, large intestine, and urinary bladder.
Peritoneum: the abdominal space is lined by peritoneum (parietal peritoneum lines the cavity walls; visceral peritoneum covers the organs).- Normally contains a small amount of peritoneal fluid for lubrication.
Irritation by foreign material (blood, pus, bile, pancreatic juice, amniotic fluid) causes peritonitis.
Peritonitis and acute abdomen are life-threatening conditions requiring prompt recognition and treatment.
The gastrointestinal system
Main function: digestion.
Digestion process:- Food intake and mastication in the mouth; salivary glands secrete saliva to begin digestion.
Food travels down the esophagus to the stomach.
The stomach is the main organ of digestion; absorption occurs along the GI tract; sugars begin absorption in the mouth.
The liver secretes bile to aid fat digestion.
Liver: filters toxic substances from digestion, stores glucose, and produces factors for blood clotting and immune function.
Gallbladder: hollow pouch beneath the liver; stores bile.
Small intestine: duodenum, jejunum, ileum.
Duodenum: where pancreatic and biliary secretions mix; digestion continues.
Pancreas: secretes enzymes to digest starches, fats, proteins; also secretes bicarbonate, insulin, glucagon.- Amylase: breaks down starches into sugar.
Bicarbonate neutralizes stomach acid entering the duodenum.
Insulin and glucagon regulate blood glucose.
Jejunum: large surface area; major site of nutrient absorption.
Ileum: absorbs remaining nutrients; reabsorbs bile acids for recycling to the liver; absorbs vitamin B12 for nerve cells and red blood cells.
Large intestine (colon): water absorption and stool formation; stools pass through the rectum to the anus.
Peristalsis: wave-like contractions move waste through the intestines.
Spleen (additional organ): located in the abdomen; part of the lymphatic system; filters blood, removes old red blood cells, recycles iron, serves as a blood reservoir, and helps produce antibodies.
The genital and urinary systems (overview)
Genital system (reproductive):- Male: testicles, epididymis, vasa deferentia, seminal vesicles, prostate gland, and penis.
Female: ovaries, fallopian tubes, uterus, cervix, and vagina.
Urinary system: filters waste from blood via kidneys; ureters, bladder, and urethra are hollow components.- The genitourinary system: often discussed together because they share organs and can affect one another.
Two kidneys are present (one on each side) and lie on the posterior abdominal wall behind the peritoneum (retroperitoneal).
Kidneys regulate acid-base balance, body pH, and blood pressure; they remove sodium chloride and other wastes from the body.
Kidney disease is a common cause of secondary hypertension; chronic kidney disease often coexists with hypertension.
Blood flow through kidneys is high:
Approx. of cardiac output passes through the kidneys each minute, reflecting high perfusion (expressed as ).
Kidney structure: nephrons filter blood; water reabsorption occurs along a tubular system; urine collects in the renal pelvis and drains through the ureters to the bladder.
Ureters: narrow, about in diameter; peristalsis moves urine to the bladder.
Urinary bladder: located behind the pubic symphysis; smooth muscle; stores urine until excretion via the urethra.
Male urethra: passes through the penis; female urethra opens at the front of the vagina.
Normal urine production in a healthy adult: .
Pathophysiology in the abdomen
Peritoneum and peritoneal irritation:- Visceral peritoneum is supplied by autonomic nerves; pain is poorly localized and described as deep or vague.
Parietal peritoneum is supplied by somatic (spinal) nerves; pain is well localized to the abdominal wall.
Referred pain can occur when visceral peritoneum stimulation is perceived at a distant surface site due to nerve connections (e.g., acute cholecystitis causing right shoulder pain).
Acute abdomen: sudden onset of abdominal pain often with progressive severity; may require urgent medical attention; peritonitis often causes ileus and abdominal distension.
Peritonitis can cause fluid shifts, leading to decreased circulating blood volume and potential shock; fever may or may not be present depending on cause.
Early abdominal pain is often vague due to visceral peritoneum irritation; parietal peritoneum irritation leads to more specific pain.
Causes of acute abdomen (high-yield overview)
Ulcers (peptic ulcer disease):- Protective mucus layers erode; ulcers caused by Helicobacter pylori infection or chronic NSAID use (e.g., aspirin, ibuprofen).
Alcohol and smoking can worsen acidity.
Classic pain: burning/gnawing in the stomach; relieves briefly after eating, then returns 2–3 hours later.
Location: upper abdomen; could be below the sternum.
Associated: nausea, vomiting, belching, heartburn.
Complications: gastric bleeding (hematemesis) or melena; perforation leading to peritonitis and acute abdomen.
Gallstones and cholecystitis:- Gallstones can block the gallbladder outlet, causing cholecystitis (inflammation of the gallbladder wall).
Severe cases may involve rupture, irritation of diaphragm/bowel, and constant severe pain in the RUQ or mid abdomen; may refer to right upper back, shoulder, or flank.
Typical timing: about 30 minutes after fatty meals; may occur at night.
Risk factors: women, older adults, obesity; ancestry factors (Scandinavian, Native American, Hispanic).
Elderly may have minimal classic symptoms; localized tenderness may be the only finding.
Pancreatitis:- Pancreas produces digestive juices and hormones (insulin, glucagon).
Causes include gallstones and alcohol use; other diseases.
Pain: upper left and right quadrant, often radiating to the back; may worsen after eating.
Associated: nausea, vomiting, abdominal distension, tenderness; fever or tachycardia if septic or hemorrhagic.
Appendicitis:- Inflammation of the appendix; potentially progresses to abscess, peritonitis, or shock if rupture.
Initial pain is generalized and may be around the umbilicus; later localizes to right lower quadrant.
Symptoms: nausea, vomiting, anorexia, fever; rebound tenderness is classic.
In pregnancy, rebound tenderness may be absent.
Positioning: patients often adopt fetal position due to pain.
Gastrointestinal hemorrhage:- Upper GI bleeding (esophagus to upper small intestine): hematemesis; melena can occur due to digestion of blood; causes include esophagitis, esophageal varices (portal hypertension from liver failure), and Mallory-Weiss tear (from forceful vomiting).
Lower GI bleeding (from lower small intestine to anus): often bright red or maroon stools; causes include bowel inflammation, diverticulosis/diverticulitis, cancer, and hemorrhoids.
Esophagitis and GERD:- GERD = gastroesophageal reflux disease; stomach acid refluxes into esophagus due to incompetent lower esophageal sphincter.
High prevalence: about , roughly of the population.
Treatments: antacids, proton pump inhibitors.
Symptoms: heartburn, pain with swallowing, chest discomfort; may include mouth sores.
Esophageal varices:- Portal hypertension-related dilation of esophageal veins; risk with liver disease and cirrhosis.
Rupture causes massive upper GI bleeding and hematemesis; can be life-threatening with rapid blood loss.
Presentation: signs of liver disease (fatigue, weight loss, jaundice, edema, abdominal pain) progress over months to years; rupture presents abruptly with severe epigastric/sternal pain, severe dysphagia, hematemesis, and shock.
Mallory-Weiss tear:- Tear at esophagogastric junction from forceful vomiting or retching; risk factors include alcoholism and eating disorders; pregnancy-related vomiting can contribute.
Bleeding ranges from minor to life-threatening with shock in extreme cases.
Gastroenteritis:- Infection (bacterial or viral) causing diarrhea, nausea, and vomiting; can be infectious or noninfectious (drug reactions, toxins, chemotherapy).
Diarrhea may be large-volume or frequent, possibly with blood or pus; dehydration risk increases with volume loss; potential for shock with severe dehydration.
Diverticulitis/diverticulosis:- Diverticulosis: pouches (diverticula) form along colon due to low fiber diet; bleeding is the most common cause of lower GI bleeding in the U.S. and is usually painless and bright red.
Diverticulitis: infection/inflammation of diverticula; LLQ abdominal pain; fever, malaise, nausea, vomiting; bleeding is less common.
Complications: scar tissue leads to narrowing (strictures) and possibly constipation or bowel obstruction; severe infection can perforate and cause peritonitis and septic shock.
Hemorrhoids:- Swollen rectal vessels; common in about half of people by age 50.
Types: internal (high in rectum; often painless; bright red bleeding) and external (low in rectum; may be painful).
Symptoms: bright red blood during defecation; itching; potential palpable mass.
Urinary system disorders and gynecologic considerations:- Cystitis (bladder infection) is common in women; symptoms include midline lower abdominal pain, urinary urgency/frequency, blood in urine, and bladder tenderness.
If infection spreads to kidneys, symptoms can worsen; do not miss urinary tract involvement.
Gynecologic emergencies: lower quadrant pain in women may involve ovaries, fallopian tubes, or uterus; Chapter 24 covers gynecologic emergencies in depth.
Kidneys and stones:- Kidney function and stones:
Stones can form from mineral buildup; if a stone obstructs the ureter, pain radiates to the groin and is often intense and accompanied by nausea/vomiting.
Some stones pass spontaneously; others require intervention.
Hematuria may be present around stone passage.
Acute kidney injury (AKI): sudden decrease in function; reversible with prompt treatment.
Chronic kidney disease (CKD): irreversible, progressive; often due to diabetes or hypertension; may require dialysis or transplant; late-stage CKD can involve seizures, coma, edema, and electrolyte disturbances.
Dialysis emergencies (special considerations for EMS):- Dialysis modalities:
Hemodialysis: blood is filtered through a machine; access via shunt/fistula usually in the forearm or upper arm; home hemodialysis is increasingly common.
Peritoneal dialysis: dialysis fluid infused into the peritoneal cavity and drained; home-based option; catheter in abdomen.
Peritonitis risk with peritoneal dialysis; signs include abdominal pain, hypotension, fever, nausea, diarrhea, and cloudy dialysis effluent.
Dialysis complications (acute): hypotension, dysrhythmias, chest pain, cramps, nausea/vomiting, electrolyte imbalance, hemorrhage at access site, and infection.
EMS approach:
Always assess airway, breathing, circulation first (ABC).
For dialysis patients, start with life threats; administer high-flow oxygen if needed.
Position: sit up for pulmonary edema; supine if in shock.
Do not place a blood pressure cuff on the arm with a shunt/fistula to avoid damage or clots; use the other arm if possible.
If extended transport is needed, consider air medical transport.
Catheters used in peritoneal dialysis may be a source of infection; leave catheter in place if present during transport.
Transport to a dialysis-capable facility when feasible and appropriate.
Patient assessment framework
Scene size-up:- Ensure scene safety; follow standard precautions (gloves, eye protection; consider face shield, gown, shoe covers due to possible feces, urine, and vomiting).
Determine number of patients; request additional resources early when needed.
Look for clues to illness mechanism; GI bleeds may have distinctive odors.
Primary assessment (life threats first):- Airway, breathing, circulation assessment and management.
Treat life-threatening issues immediately; provide high-flow oxygen as needed.
If life threats are present, transport promptly with ALS support as needed.
For suspected internal bleeding or shock, position and transport carefully; avoid rough handling if thoracic or abdominal trauma.
For patients with dialysis shunts, avoid BP on the shunt arm.
History taking (OPQRST-based prompts and beyond):- Signs/symptoms: nausea, vomiting (frequency, appearance like red blood or coffee-ground), changes in bowel habits, urination changes, weight loss, belching, or flatulence, pain characteristics (quality, onset, provocation/palliation, region, radiation, severity, duration).
Chest pain: evaluate onset, provocation/palliation, quality, region, radiation, severity, timing.
Medications: antibiotics, NSAIDs, analgesics taken recently.
Alcohol use.
If female of childbearing age: determine last menstrual period to assess pregnancy risk or obstetric emergencies.
Ingested substances that could cause acute abdomen; avoid giving food or drink as it may worsen symptoms or risk aspiration.
Events leading up to illness; check for recent trauma or injuries.
Secondary assessment (abdominal-focused exam):- Patient positioning: some patients prefer certain positions to relieve pain (e.g., right knee drawn up in appendicitis; pancreatitis patients may lie on side).
Abdominal exam steps:
Explain the exam procedure to the patient.
Position supine with knees flexed to relax abdominal wall unless trauma dictates otherwise.
Visually inspect for distension, pulsating masses (possible AAA), bruising, and surgical scars.
Ask patient where pain is most intense; palpate in a clockwise sequence away from the painful area to avoid guarding that obscures findings.
Palpate gently; avoid touching a pulsating mass; do not palpate if a ruptured aneurysm suspected.
Palpate all four quadrants to assess tone (tense/guarded/soft) and localization of pain.
Observe patient response to palpation; look for grimace or verbal “ouch.”
Assess for rebound tenderness (pain upon release after pressing); use extreme caution because of peritoneal irritation.
Determine if patient can relax abdominal wall on command (guarding could indicate peritoneal irritation).
Note respiratory pattern; a high respiratory rate with normal blood pressure may indicate poor ventilation due to pain; however, a high RR with tachycardia and signs of shock indicates significant illness.
Reassessment and transport decisions- Reassess patient frequently; abdominal conditions can deteriorate rapidly.
Compare vitals to baseline; monitor changes en route to hospital.
Be prepared to adjust management if condition worsens.
Gentle transport; avoid jostling the patient to prevent worsening pain.
Interventions to comfort and support- Provide reassurance and emotional support; manage pain and nausea where appropriate without delaying transport.
Treat shock symptoms early: high-flow oxygen, warm blanket, place supine or position of comfort as needed.
If vomiting, keep airway patent; protect from aspiration with appropriate positioning and suction as needed.
Use biohazard precautions to contain vomitus and clean equipment after transport.
Wash hands after glove removal.
Emergency care special considerations- If signs of shock or life threats are present, do not delay transport.
For suspected abdominal aortic aneurysm, handle with extreme care; avoid abdominal palpation that could precipitate rupture.
In suspected internal bleeding, rapid transport and ALS support if available.
Summary of key clinical indicators to watch for
Peritonitis indicators: rebound tenderness, rigid guarding, shallow rapid breathing, persistent pain even at rest.
Signs of shock: pallor, diaphoresis, tachycardia, hypotension, altered mental status, cool/clammy skin; may be masked in elderly or pediatric patients.
Red flags: acute onset severe abdominal pain with shock signs, rigid abdomen, pulsatile abdominal mass, signs of GI bleeding with hematemesis or melena, cast-iron neck or back pain suggesting AAA rupture, sudden severe pain with radiating back or flank pain, persistent vomiting with signs of dehydration.
When to escalate: escalate to advanced life support for IV fluids, pain control, antiemetics, and rapid transport; consider air transport if time-to-treatment is prolonged.
Quick reference: common numerical/hard facts
Ureters diameter:
Kidney perfusion: per minute
Urine production:
Number of kidneys:
Esophageal varices cause acute upper GI bleeding and hematemesis in severe cases of portal hypertension.
GERD prevalence: people in the U.S.; ≈ of the population.
Connections to broader practice and ethics
Recognize that many abdominal emergencies require rapid assessment to identify life threats rather than precise diagnosis.
Use nonjudgmental communication to maintain patient comfort and reduce anxiety.
Ensure infection control and personal protective equipment when dealing with vomiting or diarrhea to prevent contagion.
Understand that elderly and pediatric patients may present atypically; maintain a high index of suspicion for serious conditions.
Ethical considerations: do not delay transport in suspected life-threatening conditions; provide appropriate pain relief while balancing risks of masking symptoms that could inform diagnosis.
Links to related topics
Chapter 24: Gynecologic emergencies (relevant for female patients of childbearing age).
Chapter 31: Abdominal and genitourinary injuries (traumatic causes of acute abdomen).
General principles of shock management and airway/breathing/circulation support in emergency care.
Definitions
Abdominal Cavity: The body space containing solid and hollow organs of the gastrointestinal, genital, and urinary systems.
Solid Organs: Organs like the liver, spleen, pancreas, kidneys, and ovaries, which are densely packed and can cause significant bleeding when injured.
Hollow Organs: Organs such as the gallbladder, stomach, intestines, and urinary bladder, which can spill their contents and cause irritation when injured.
Peritoneum: The membrane lining the abdominal cavity (parietal peritoneum) and covering the abdominal organs (visceral peritoneum).
Peritonitis: Inflammation of the peritoneum, often caused by irritation from foreign material like blood, pus, or bile within the abdominal cavity.
Acute Abdomen: A sudden onset of abdominal pain with progressive severity, often requiring urgent medical attention due to underlying serious conditions.
Peristalsis: Wave-like muscular contractions that move food and waste through the gastrointestinal tract.
Visceral Peritoneum: The inner layer of the peritoneum that covers the abdominal organs, supplied by autonomic nerves leading to poorly localized pain.
Parietal Peritoneum: The outer layer of the peritoneum that lines the abdominal cavity walls, supplied by somatic nerves leading to well-localized pain.
Referred Pain: Pain perceived at a location distant from the actual source of the stimulus, due to shared nerve pathways.
Ileus: Paralysis of the bowel, often caused by peritonitis, leading to abdominal distension.
Hematemesis: Vomiting of blood, which can appear red or like coffee grounds, indicating upper gastrointestinal bleeding.
Melena: Black, tarry stools resulting from the digestion of blood in the gastrointestinal tract, indicating upper GI bleeding.
Gastroesophageal Reflux Disease (GERD): A condition where stomach acid flows back into the esophagus due to an incompetent lower esophageal sphincter, causing heartburn and pain.
Esophageal Varices: Dilated veins in the esophagus, typically caused by portal hypertension in individuals with liver disease, which can rupture and cause life-threatening bleeding.
Mallory-Weiss Tear: A tear in the esophageal lining, usually at the junction with the stomach, caused by forceful vomiting or retching, leading to bleeding.
Gastroenteritis: Inflammation of the stomach and intestines, often caused by infection, leading to diarrhea, nausea, and vomiting.
Diverticulosis: A condition characterized by the formation of small pouches (diverticula) in the colon wall, often due to a low-fiber diet.
Diverticulitis: Inflammation or infection of the diverticula, typically causing lower left quadrant abdominal pain.
Hemorrhoids: Swollen and inflamed veins in the rectum or anus, which can cause bleeding and pain.
Cystitis: An inflammation of the urinary bladder, commonly known as a bladder infection, with symptoms like lower abdominal pain, urgency, and frequency.
Acute Kidney Injury (AKI): A sudden and often reversible decrease in kidney function.
Chronic Kidney Disease (CKD): An irreversible and progressive loss of kidney function, often due to diabetes or hypertension, potentially requiring dialysis or transplant.
Hemodialysis: A medical procedure where a machine filters waste products and excess fluid from the blood, typically via an access point (shunt/fistula) in an arm.
Peritoneal Dialysis: A dialysis method where a special fluid is flushed into and out of the peritoneal cavity (abdomen) through a catheter to remove waste products.
Portal Hypertension: Elevated blood pressure in the portal venous system, often due to liver disease, which can lead to complications like esophageal varices.
Guarding: Involuntary muscle spasms of the abdominal wall, a protective response to pain or peritoneal irritation.
Pulsating Mass (possible AAA): A noticeable pulsation within the abdomen, which could indicate an abdominal aortic aneurysm, a serious condition requiring extreme caution during examination.
Shunt/Fistula: A surgical connection, usually in the forearm, to create an access point for hemodialysis, which should be protected from blood pressure cuffs to prevent damage.