The Acute Abdomen

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The Acute Abdomen
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Outline

• Definitions
• What causes an acute abdomen
• Differential Diagnosis
• History and physical
• Labs
• Diagnostic imaging

• High Risk Patients with Acute Abdomen

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Acute Abdomen

• Symptoms and signs of acute intra- abdominal
  disease processes, usually treated best by
  surgical operation

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The Epidemiology of Acute Abdominal Pain

• 5-10 of all ED visits.
• Among them, 14-40 patients need surgical
  intervention.
• Challenge for emergency physician (EP)
• About 1/3 have an atypical presentation.
• If misdiagnosis, mortality rate 2.5 times higher
  than correct diagnosis in the elderly.

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Three Types of Abdominal Pain

• Visceral Pain
• Somatic (Parietal) Pain
• Referred Pain

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The Physiology and Mechanisms of Abdominal Pain

• Visceral Pain
• Within the muscular walls of hollow organs and
  the capsules of solid organs.
• Stimulated primarily by stretching, distension,
  and excessive contractions.
• Characteristically deep, dull, aching or
  cramping, and poorly localized.
• Usually felt in the midline, unaccompanied by
  tenderness.

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The Physiology and Mechanisms of Abdominal Pain

• Somatic (Parietal) Pain
• Afferent fibers from T6 to L1, more localized.
• Characteristically sharper, aggravated by
  stimulation of the parietal peritoneum with
  movement, coughing, or walking.
• True parietal pain surgical cause of
  abdominal pain.

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The Physiology and Mechanisms of Abdominal Pain

• Referred Pain
• Pain felt a site other than that of the primary
  noxious stimulus.
• Occurs in an area supplied by the same
  neurosegment as the involved organ.
• Most visceral pain is of this type.
• Usually intense and most often secondary to an
  inflammatory lesion.
• Subdiaphragm disordershoulder pain
• Biliary tract disorderright shoulder pain
• Small bowel disorderback pain

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Causes of Acute Abdomen (DDx)

• Appendicitis
• Peritonitis
• Bowel Perforation
• Pancreatitis
• Diverticular disease
• Cholecystitis
• Perforating Gastric/Duodenal ulcer
• Ruptured Ectopic Pregnancy
• Ruptured or hemorrhagic ovarian cyst
• Pelvic Inflammatory Disease
• Abdominal Aortic Aneurysm
• Tubo-ovarian abscess

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Acute Abdominal Pain in Patients Under and Over
Age 50
Under 50 (6317 cases),
Over 50 (2406 cases),

• Nonspecific abd. pain 39.5
• Appendicitis 32.5
• Cholecystitis 6.3
• Obstruction 2.5
• Pancreatitis 1.6
• Diverticular disease lt0.1
• Cancer lt0.1
• Hernia lt0.1
• Vascular lt0.1

• Cholecystitis 20.5
• Nonspecific abd. Pain
  15.7
• Appendicitis 15.2
• Obstruction 12.5
• Pancreatitis 7.3
• Diverticular disease
  5.5
• Cancer 4.1
• Hernia 3.1
• Vascular 2.3

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Important Extra-abdominal Causes of Abdominal Pain

• Systemic
• DKA
• Alcoholic ketoacidosis
• Uremia
• Sickle cell disease
• Porphyria
• SLE
• Vasculitis
• Glaucoma
• Hyperthyroidism
• Toxic
• Methanol poisoning
• Heavy metal toxicity
• Scorpion bite
• Black widow spider bite
• Thoracic
• Myocardial infarction/ Unstable angina

• Pneumonia
• Pulmonary embolism
• Herniated thoracic disc (neuralgia)
• Genitourinary
• Testicular torison
• Renal colic
• Infectious
• Strep pharyngitis (more often in children)
• Rocky Mountain Spotted Fever
• Monocucleosis
• Abdominal wall
• Muscle spasm
• Muscle hematoma
• Herpes zoster

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History of Present Illness

• O nset
• P recipitating/ relieving
• Q uality
• R adiation
• S everity
• T iming
• Matched to clinical condition
• Emerges over time and then concentrates (acute
  appy)
• Sudden onset (perforated viscous)

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High-Yield Historical Questions

• How old are you? (Advanced age mean increased
  risk)
• 2. Describe the position, character,and migration
  of the pain
• sudden coupled with weakness or fainting,
  less acute but still abrupt onset ,or begin
  gradually and maximize slowly
• Is the pain constant or intermittent?
  (Constant pain is worse)
• Have you ever had this before? (No prior
  episodes is worse)
• Did the pain start centrally and migrate to
  the right lower quadrant? (High specificity for
  appendicitis)
• 3. Have you noticed specific aggravating or
  relieving factors? (Eating, defecation or
  flatus)
• 4. Have you ever had abdominal surgery? (Consider
  obstruction in patients who report previous
  abdominal surgery)

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High-Yield Historical Questions

• 5. Do you have nausea, vomiting, diarrhea or
  bowel habit change? (D/D true diarrhea, overflow
  incontinence or tenesmus)
• 6. Do you have HIV? (Consider occult and unusual
  infection, 30 mortality of surgical treatment)
• 7. How much alcohol do you drink per day?
  (Consider pancreatitis, hepatitis, or cirrhosis)
• 8. Are you pregnant? (Test for pregnancy-consider
  ectopic pregnancy, menstrual history, sexual
  exposure history)
• 9. Are you taking antibiotics or steroids? (These
  may mask infection)
• 10. Do you have a history of vascular or heart
  disease, hypertension, or atrial fibrillation?
  (Consider mesenteric ischemia and abdominal
  aneurysm)

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Physical Examination

• Overall appearance ( Facial expression,
  diaphoresis, pallor, and degree of agitation)
• Walking and recumbent
• Vital signs
• Temperature (T gt 40 C or lt 35 C ? consider
  abdominal sepsis)
• Tachycardia
• Hypotension
• Inspection scars, hernias, masses
• Auscultation ( Hyperactive BS, hypoactive BS or
  silent BS, Pulsatile bruit)
• Percussion
• Palpation The most critical step
• Tenderness
• Rigidity and guarding (Only 21 gt 70 y patients
  with PPU present with epigastria rigidity)
• Board-like abdomen
• Rectal digital examination
• rebounding pain

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Laboratory Examination

• CBC differential
• Serum electrolyte ( K, Bicarbonate )
• Urinalysis
• ß-HCG woman of childbearing age
• Bilirubin, Alk-p, ALT, AST, G-GT RUQ pain,
  jaundice
• Amylase, lipase epigastralgia
• PT, APTT
• EKG, CK epigastralgia with aged patient

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Five Major Categories of Acute Abdomen (BIOPI)

• Bleeding or rupture of vessels or tumor
• Ischemia or Infarction
• Obstruction
• Perforation
• Inflammation

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Emergency Department Evaluation of Acute Abdomen

• History
• Menstruation history (LMP, ovulation, sexual
  exposure)
• Rapid pregnancy test women of childbearing age.
• Lab CBC, liver panel, EKG for elderly.
• Plain KUB helpful in obstruction 40 patients
  invisible free air.
• Ultrasound and CT scan aneurysm, cholelithiasis,
  ectopic pregnancy, and ureterolithiasis.

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Diagnostic Imaging
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Important Imaging Studies for Acute Abdomen

• Standing CXR and KUB
• Ultrasound for solid organs.
• CT of abdomen for abscess, free air, vessel,
  tumor and ischemia bowel.( gold standard for
  finding acute appendicitis)
• Angiography Especially in non-diagnostic
  ischemia bowel.

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Indications for Abdominal Plain Films

• Suspected Diagnosis Clinical
  Findings
• Perforated viscus Sudden-onset
  pain
• Rigid abdomen
• Decreased bowel sounds
• Bowel obstruction Prior abdominal surgery
• Abdominal distension
• Abnormal bowel sounds
• High risk for obstruction or volvulus
• Foreign body Mental retardation
• Psychosis
• Suspicion of rectal foreign body

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Plain Films

• Upright CXR
• Free air
• KUB (kidney/ureter/bladder)
• Calcifications
• Air/ Fluid levels
• Reactive bowel patterns
• Foreign bodies

Lateral Decubitus Film
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Ultrasound

• Rapid, safe, low cost
• Operator dependent
• Fluid, inflammation, air in walls, masses
• Liver, GB, CBD, Spleen, Pancreas, Appendix,
  Kidney, Ovaries, Uterus

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CT Scans

• Better than plain films and US for evaluation of
  solid and hollow organs
• Intravenous contrast
• Oral contrast
• Per rectal contrast
• High use in appendicitis, diverticulitis,
  abscess, pancreatitis

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The Identification of High Risk Patients with
Acute Abdomen

• Elderly gt 65 y
• S/S of Shock
• Peritoneal sign ()
• silent bowel sound
• Pulsatile mass
• Refractory pain post Tx
• The immunocompromised. (e.g. HIV)
• Women of childbearing age.

• Elevation of Band WBC
• Fever cause
• Hypothermia
• Acute renal failure
• Not post-surgical obstruction

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Emergency Department Management of Acute Abdomen

• IV volume replacement and NG decompression
• Antibiotics indicated if infection is suspected.
• Narcotic analgesia (?) Timing (?)
• Pro Permit a more accurate history and PE.
  Morphine (2-5 mg IV)
• Con Surgeon is hostile to this approach,
  consultation immediately.

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When to Operate ?

• Peritonitis
• Excluding primary peritonitis
• Abdominal pain/tenderness sepsis
• Acute intestinal ischemia
• Pneumoperitoneum
• Make sure pancreatitis is excluded

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When NOT to Operate ?

• Cholangitis
• Appendiceal abscess
• Acute diverticulitis abscess
• Acute pancreatitis or hepatitis
• Ruptured ovarian cysts
• Long standing perforated ulcers?

• MI, Acute pericarditis
• PN, pulmonary infarction
• GE reflux, DKA, Adrenal Insufficiency
• Acute Porphyria
• Rectus muscle hematoma
• Pyelonephritis, Sickle cell crisis

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Thank you