DESCRIPTION

• Parietal pain:
  • Irritating material causing peritoneal inflammation
  • Pain transmitted by somatic nerves
  • Exacerbated by changes in tension of the peritoneum
  • Pain is sharp, well localized with abdominal, rebound tenderness and involuntary guarding
• Visceral pain:
  • Afferent impulses result in poorly localized pain based on the embryologic origin rather than true location of an organ.
    • Pain of foregut structures to the epigastric area
    • Pain from midgut structures to the periumbilical area
    • Pain from hindgut structures to the suprapubic region
  • Distention of a viscous or organ capsule or spasm of intestinal muscularis fibers
    • Pain is constant and colicky
  • Inflammation:
    • Focal tenderness develops once the inflammation extends to the peritoneum
  • Ischemia from vascular emergencies:
    • Pain is severe and diffuse
• Referred pain:
  • Felt at distant location from diseased organ
  • Due to an overlapping supply by the affected neurosegment
• Abdominal wall pain:
  • Constant, aching with muscle spasm
  • Involvement of other muscle groups

ETIOLOGY

• Peritoneal irritants:
  • Gastric juice, fecal material, pus, blood, bile, pancreatic enzymes
• Visceral obstruction:
  • Small and large intestines, gallbladder, ureters and kidneys, visceral ischemia, intestinal, renal, splenic
• Visceral inflammation:
  • Appendicitis, inflammatory bowel disorders, cholecystitis, hepatitis, peptic ulcer disease, pancreatitis, pelvic inflammatory disease, pyelonephritis
• Abdominal wall pain
• Referred pain: (e.g., intrathoracic disease)

[Outline]

• DESCRIPTION
• ETIOLOGY

SIGNS AND SYMPTOMS

History

• Pain
  • Nature of onset of pain
  • Time of onset and duration of pain
  • Location of pain initially and at presentation
  • Extra-abdominal radiations
  • Quality of pain (sharp, dull, crampy)
  • Aggravating or alleviating factors
  • Relation of associated finding to pain onset
• Anorexia
• Nausea
• Vomiting (bilious, coffee-ground emesis)
• Malaise
• Fainting or syncope
• Cough, dyspnea, or respiratory symptoms
• Change in stool characteristics (e.g., melena)
• Hematuria
• Changes in bowel or urinary habits
• History of trauma or visceral obstruction
• Gynecologic and obstetric history
• Postoperative (e.g., cause ileus)
• Family history (e.g., familial aortic aneurysm)
• Alcohol use and quantity
• Medications: (e.g., aspirin and NSAIDs)

Physical Exam

• General:
  • Anorexia
  • Tachycardia
  • Tachypnea
  • Hypotension
  • Fever
  • Yellow sclera (icterus)
  • Distal pulses and pulse amplitudes between lower and upper extremities
• Abdominal:
  • Distended abdomen
  • Abnormal bowel sounds:
    • High-pitched rushes with bowel obstruction
    • Absence of sound with ileus or peritonitis
  • Pulsatile abdominal mass
  • Rebound tenderness, guarding, and cough test for peritoneal irritation (e.g., appendicitis, peritonitis)
  • Rovsing sign, suggestive of appendicitis:
    • Palpation of left lower quadrant causes pain in right lower quadrant (RLQ).
  • Psoas sign suggests appendicitis (on right)
    • Pain on extension of thigh
  • Obturator sign suggests pelvic appendicitis (on the right only)
    • Pain on rotation of the flexed thigh, especially internal rotation
  • McBurney point tenderness associated with appendicitis:
    • Palpation in RLQ 2/3 distance between umbilicus and right anterior superior iliac crest causes pain.
  • Murphy sign, suggestive of cholecystitis:
    • Pause in inspiration while examiner is palpating under liver
  • Carnett sign indicates abdominal wall pain
    • Pain when a supine patient tenses the abdominal wall by lifting the head and shoulders.
  • Tender or discolored hernia site
  • Rectal and pelvic examination:
    • Tenderness with pelvic peritoneal irritation
    • Cervical motion tenderness
    • Adnexal masses
    • Rectal mass or tenderness
    • Guaiac positive stool
• Genitourinary:
  • Flank pain
  • Dysuria
  • Costovertebral angle tenderness
  • Suprapubic tenderness
  • Tender adnexal mass on pelvis
  • Testicular pain:
    • May be referred from renal or appendiceal pathology
• Referred pain:
  • Kehr sign (diaphragmatic irritation due to blood or other irritants) causes shoulder pain.
• Extremities:
  • Pulse deficit or unequal femoral pulses
• Skin:
  • Jaundice
  • Liver disease (caput medusa)
  • Hemorrhage
    • Grey Turner sign of flank ecchymosis
    • Cullen sign is ecchymotic area round the umbilicus
  • Herpes zoster
  • Cellulitis
  • Rash (Henoch–Schönlein purpura [HSP])

ESSENTIAL WORKUP

• For a woman in reproductive age group a pregnancy test is essential
• Where applicable for majority of cases, ultrasonography should be done with CT used in cases of negative or inconclusive ultrasonography.

DIAGNOSIS TESTS & INTERPRETATION

Lab

• CBC
• Serum electrolytes, creatinine, and glucose
• ESR
• LFTs
• Lactic acid
• Serum lipase:
  • More sensitive and specific than amylase
• Urinalysis
• Stool analysis and culture
• Pregnancy testing (age reproductive women)

Imaging

• EKG:
  • Consider if risk factors for coronary artery disease are present
• Abdominal radiograph: Supine and upright
  • CT is superior for suspected visceral perforation and bowel obstruction.
• Upright CXR:
  • Pneumoperitoneum
  • Intrathoracic disease causing referred abdominal pain
• US:
  • Biliary abnormalities
  • Hydronephrosis
  • Intraperitoneal fluid
  • Aortic aneurysm
  • Intussusception
• US (Doppler ultrasonography)
  • Volvulus and malrotation
  • Testicular and ovarian torsion
  • Hepatitis, cirrhosis, and portal vein thrombosis
• Abdominal CT:
  • Spiral CT without contrast:
    • Renal Colic
    • Retroperitoneal hemorrhage
    • Appendicitis
  • CT with intravenous contrast only:
    • Vascular rupture suspected in a stable patient (e.g., acute abdominal aortic aneurtsn [AAA], aortic dissection)
    • Ischemic bowel
    • Pancreatitis
  • CT with IV and oral contrast:
    • Indicated when there is a suspicion of a surgical etiology involving bowel
    • History of inflammatory bowel disease
    • Thin patients (low BMI)
    • Diverticulitis
  • CT angiography:
    • Mesenteric ischemia
    • AAA
• IVP:
  • CT has replaced the use of intravenous urography in detection of ureteral stones
• Barium enema:
  • Intussusception
  • Treatment and confirmation of intussusception is with air contrast enema.
• MRI:
  • If concerns for radiation exposure or nephrotoxicity
  • Contraindicated in patients with metallic implants

Pregnancy Considerations

Ultrasonography and MRI should be preferred to prevent exposure of ionizing radiation to the fetus.

DIFFERENTIAL DIAGNOSIS

• AAA
• Abdominal epilepsy or abdominal migraine
• Boerhaave syndrome
• Adrenal crisis
• Early appendicitis
• Bowel obstruction
• Cholecystitis
• Constipation +/– fecal impaction
• Diabetic ketoacidosis
• Diverticulitis
• Dysmenorrhea
• Ectopic pregnancy
• Esophagitis
• Endometriosis
• Fitz-Hugh–Curtis syndrome
• Gastroenteritis
• Hepatitis
• Incarcerated hernia
• Infectious gastroenteritis
• Inflammatory bowel disease
• Irritable bowel syndrome
• Ischemic bowel
• Meckel diverticulitis
• Neoplasm
• Ovarian torsion
• Ovarian cysts (hemorrhagic)
• Pancreatitis
• Pelvic inflammatory disease
• Peptic ulcer disease
• Renal/ureteral calculi
• Renal Infarction
• Sickle cell crisis
• Spider bite (Black widow)
• Splenic infarction
• Spontaneous abortion
• Testicular torsion
• Tubo-ovarian abscess
• UTI
• Volvulus
• Referred pain:
  • Myocardial infarction
  • Pneumonia
• Abdominal wall pain:
  • Abdominal wall hematoma or infection
  • Black widow spider bite
  • Herpes zoster

Pediatric Considerations

• Under 2 yr:
  • Hirschsprung disease
  • Incarcerated hernia
  • Intussusception
  • Volvulus
  • Foreign body ingestion
• 2–5 yr:
  • Appendicitis
  • Incarcerated hernia
  • Meckel diverticulitis
  • Sickle cell crisis
  • HSP
  • Constipation

[Outline]

• SIGNS AND SYMPTOMS
• ESSENTIAL WORKUP
• DIAGNOSIS TESTS & INTERPRETATION
• DIFFERENTIAL DIAGNOSIS

ED TREATMENT/PROCEDURES

• Nasogastric tube decompression and bowel rest
• IV fluids and electrolyte repletion
• Antiemetics are important for comfort.
• Narcotics or analgesics should not be withheld.
• Send for blood type and cross-match for unstable patient
• Surgical consultation based on suspected etiology

MEDICATION

• Fentanyl: 1–2 µg/kg IV qh
• Morphine sulfate: 0.1 mg/kg IV q4h PRN
• Ondansetron: 4 mg IV
• Prochlorperazine: 0.13 mg/kg IV/PO/IM q6h PRN nausea; 25 mg PR q6h in adults
• Promethazine: 25–50 mg/kg IM/PO/PR

[Outline]

• ED TREATMENT/PROCEDURES
• MEDICATION

DISPOSITION

Admission Criteria

• Surgical intervention
• Peritoneal signs
• Patient unable to keep down fluids
• Lack of pain control
• Medical cause necessitating in-house treatment (MI, DKA)
• IV antibiotics needed

Discharge Criteria

No surgical or severe medical etiology found in patient who is able to keep fluid down, has good pain control, and is able to follow detailed discharge instructions

FOLLOW-UP RECOMMENDATIONS

The patient should return with any warning signs:

• Vomiting
• Blood or dark/black material in vomit or stools
• Yellow skin or in the whites of the eyes
• No improvement or worsening of pain within 8–12 hr
• Shaking chills, or a fever > 100.4°F (38°C)

[Outline]

• DISPOSITION
• FOLLOW-UP RECOMMENDATIONS

• Elderly patients are more likely to present with atypical presentations and life threatening etiologies requiring admission.
• Do not consider constipation if stool is absent in the rectal vault.
• Etiology requiring surgical intervention is less likely when vomiting precedes the onset of pain.

ICD9

• 789.00 Abdominal pain, unspecified site
• 789.06 Abdominal pain, epigastric
• 789.07 Abdominal pain, generalized

ICD10

• R10.9 Unspecified abdominal pain
• R10.13 Epigastric pain
• R10.84 Generalized abdominal pain

[Outline]

• ICD9
• ICD10

• Flasar MH, Cross R, Goldberg E. Acute abdominal pain. Prim Care. 2006;33(3):659–684.
• McNamara R, Dean AJ. Approach to acute abdominal pain. Emerg Med Clin North Am. 2011;29(2):159–173.
• Ross A, LeLeiko NS. Acute abdominal pain. Pediatr Rev. 2010;31(4):135–144.
• Yeh EL, McNamara RM. Abdominal pain. Clin Geriatr Med. 2007;23(2):255–270.

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