GO-EM: An Approach: ABDOMINAL PAIN-causes, symptoms, management

Abdominal Pain

Description

Parietal pain:
- Irritating material causing peritoneal inflammation
- Pain transmitted by somatic nerves
- Exacerbated by changes in tension of the peritoneum
- Pain characteristics:
  - Sharp
  - Well localized
  - Abdominal tenderness
  - Involuntary guarding
  - Rebound tenderness
  - Exacerbated by movement and coughing
Visceral pain:
- Distention of a viscous or organ capsule or spasm of intestinal muscularis fibers:
  - Pain is generally poorly localized.
  - Colicky with intestinal distention
  - Constant with a distended gallbladder or kidney
- Inflammation:
  - Initially, the pain is poorly localized.
  - Focal tenderness develops as the inflammation extends to the peritoneum or localizers.
- Ischemia from vascular disturbances:
  - Pain is severe and diffuse with catastrophic vascular emergencies
  - Pain is disproportional to the abdominal examination
Referred pain:
- Felt at distant location from diseased organ
- Due to an overlapping supply by the affected neurosegment to the perceived location of pain
Abdominal wall pain:
- Constant
- Aching
- Muscle spasm
- Involvement of other muscle groups

Etiology

Peritoneal irritants:
- Gastric juice
- Fecal material
- Pus
- Blood
- Bile
- Pancreatic enzymes
Visceral obstruction:
- Small intestines
- 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:
- The possibility of intrathoracic disease must be considered in every patient with abdominal pain.

Diagnosis

Signs and Symptoms

General:
- Anorexia
- Malaise
- Tachycardia
- Hypotension
- Fever
- Nausea
- Vomiting:
  - Etiology requiring surgical intervention is less likely when vomiting precedes the onset of pain
Abdominal:
- Diarrhea
- Constipation
- Distended abdomen
- Abnormal bowel sounds:
  - High-pitched rushes with bowel obstruction
  - Absence of sound with ileus or peritonitis
  - Often unreliable
- Pulsatile abdominal mass
- Rovsing sign:
  - Palpation of left lower quadrant causes pain in right lower quadrant (RLQ)
  - Suggestive of appendicitis
- McBurney point tenderness associated with appendicitis:
  - Palpation in RLQ two-thirds distance between umbilicus and right anterior superior iliac crest causes pain
- Murphy sign:
  - Pause in inspiration while examiner is palpating under liver
  - Suggestive of cholecystitis
- Psoas sign:
  - Pain on extension of the thigh
  - Suggests inflammation around psoas muscle
- Obturator sign
  - Pain on rotation of the flexed thigh, especially internal rotation
  - Inflammation around internal obturator muscle
- Tender or discolored hernia site
- Rectal and pelvic examination:
  - Tenderness with pelvic peritoneal irritation
  - Cervical motion tenderness
  - Adnexal masses
  - Rectal mass or tenderness
Genitourinary:
- Flank pain
- Dysuria
- Hematuria
- Vaginal bleeding
- Tender adnexal mass on pelvis
- Testicular pain
  - May be referred from renal or appendiceal pathology
- Testicular swelling
- High-riding testes
- Transverse lie of testis
Extremities:
- Shoulder pain:
  - Referred pain from diaphragmatic involvement
- Pulse deficit or unequal femoral pulses
Skin:
- Jaundice
- Herpes zoster
- Cellulitis

Essential Workup

Historical characteristics define the type of pain and suggest underlying causes:

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 (e.g., sharp, dull, crampy)
Palliative or provocative factors
Relation of associated finding to onset of pain
Changes in bowel habits
History of trauma
Gynecologic history
Visceral obstruction

Tests

Lab

CBC:
- WBC is a poor predictor of surgical disease
Urinalysis
Serum lipase:
- More accurate than a serum amylase in diagnosing pancreatic disorders
hCG
Serum electrolytes and glucose
Liver function tests
Gonorrhea and chlamydia cultures should be obtained if a pelvic examination is performed.

Imaging

ECG:
- Indicated in patients with epigastric pain with risk factors for coronary artery disease
Kidney, ureter, and bladder (KUB) and upright:

Indicated primarily if bowel obstruction is suspected
Air-fluid levels and intestinal distention:
- Bowel obstruction
- Ileus
- Volvulus
- Intussusception

Upright chest radiograph:
- Pneumoperitoneum
  - Perforated viscus
  - Extra-abdominal causes
Ultrasound:

Biliary abnormalities
Hydronephrosis
Intraperitoneal fluid
Aortic aneurysm
Pelvic ultrasound

Abdominal CT:

- Spiral CT without contrast:
  - Determines location and size of stone in patients with renal colic
- CT with IV contrast only:
  - Vascular rupture suspected in a stable patient
- CT with IV and oral contrast:
  - Indicated when there is a suspicion of a surgical etiology involving bowel or intraperitoneal hemorrhage
- CT with rectal contrast only:
  - High accuracy reported in detecting appendicitis
IVP:
- Indicated in patients with suspected ureteral calculi
- More time-consuming than spiral CT
Barium enema:

- Intussusception
- Volvulus

Differential Diagnosis

Parietal pain:
- Abdominal arterial aneurysm
- Appendicitis
- Diverticulitis with perforation or abscess
- Ruptured ectopic pregnancy
- Ruptured ovarian cyst
- Pancreatitis
- Perforated peptic ulcer
- Perforated viscus
- Splenic rupture
Visceral pain:
- Abdominal epilepsy
- Abdominal migraine
- Adrenal crisis
- Early Appendicitis
- Bowel obstruction
- Cholecystitis
- Constipation
- Depression
- Diabetic ketoacidosis
- Diverticulitis
- Dysmenorrhea
- Ectopic pregnancy
- Esophagitis
- Fecal impaction
- Fitz-Hugh-Curtis syndrome
- Gastroenteritis
- Hepatitis
- Hirschsprung disease
- Incarcerated hernia
- Inflammatory bowel disease
- Intussusception
- Irritable bowel syndrome
- Ischemic bowel
- Lactose intolerance
- Lead poisoning
- Meckel diverticulitis
- Neoplasm
- Ovarian torsion
- Pancreatitis
- Pelvic inflammatory disease
- Peptic ulcer disease
- Renal/ureteral calculi
- Sickle cell crisis
- Splenic infarction
- Spontaneous abortion
- Testicular torsion
- Urinary tract infection
- Volvulus
Referred pain:
- Myocardial infarction
- Pneumonia
Abdominal wall pain:
- Abdominal wall hematoma or infection
- Black widow spider bite
- Herpes zoster

Pediatric Considerations

<2 years:
- Hirschsprung disease
- Incarcerated hernia
- Intussusception
- Neoplasm
- Sickle cell crisis
- Volvulus
2-5 years:
- Appendicitis
- Incarcerated hernia
- Meckel diverticulitis
- Neoplasm
- Sickle cell crisis
>5 years:
- Appendicitis
- Ectopic pregnancy
- Inflammatory bowel disease
- Pelvic inflammatory disease