The Acute Abdomen Jason E. Davis, MD

Abdominal Pain A leading cause for hospital admissions Most self-limited and of little consequence Subset of serious acute pathology may require acute medical and/or surgical intervention This latter group referred to as ‘acute abdomen’ Not all acute abdomens = surgical abdomen Renal colic, gastroenteritis, infectious colitis*, PID Mesenteric ischemia, ruptured AAA, appendicitis, perforated bowel, perf’d peptic ulcer, inc’d hernia

Broad Differential Dx

Anatomic Considerations Embryonic origin & Blood supply Foregut: esophagus, stomach, proximal duodenum, pancreas, liver, biliary tract, spleen Celiac artery Midgut: distal duodenum, jejunem, ileum, cecum, appendix, proximal 2/3 transverse colon Superior mesenteric artery Hindgut: remaining colon and rectum Inferior mesenteric artery

Anatomic Considerations Innervation Visceral pain: autonomic, dull, cramping, poorly localized, often assoc with nausea and diaphoresis Often midline secondary to embryonic origin Parietal pain: somatic, sharp, severe, persistent, loc Referred visceral sensation Foregut pain: Epigastric Midgut pain: Peri-umbilical Hindgut pain: Hypogastrium

Anatomic Considerations

Anatomic Considerations

Approach to Acute Abdomen Age Location and character of pain Pain duration and progression Associated symptoms Nausea Emesis Anorexia Constipation/Diarrhea

Approach to Acute Abdomen Most important symptom is PAIN. Accordingly, history should include all of the following: 1. Onset 2. Severity 3. Type of pain 4. Radiation of pain 5. Change in nature of pain 6. Associated bowel or urinary symptoms 7. Aggravating or relieving factors

Approach to Acute Abdomen Diagnosis according to onset of pain: Sudden Rapid Gradual Chronic (exacerbation) Sudden onset (full pain in seconds) Perforated ulcer Mesenteric infarction Ruptured AAA Ruptured ectopic pregnancy Ovarian torsion or ruptured cyst Pulmonary embolism Acute myocardial infarction Rapid onset (initial sensation to full pain over minutes or hours) Strangulated hernia Volvulus Intussusception Acute pancreatitis Biliary colic Diverticulitis Ureteral and renal colic Gradual onset (hours) Appendicitis Strangulated hernia Chronic pancreatitis Peptic ulcer disease Inflammatory bowel disease Mesenteric lymphadenitis Cystitis and urinary retention Salpingitis and prostatitis Stereotypes of Pain Onset and Associated Pathology Position of patient (motionless vs. writhing in pain vs. rolling restlessly  appendicitis/peritonitis vs. mesentary ischemia vs. ureteral/intestinal colic)

Approach to Acute Abdomen Diaphragmatic Supraclavicular area (Kehr’s sign) Ureteral Hypogastrium, groin, inner thigh Cardiac pain Epigastrium, jaw, shoulder Appendix Periumbilical via T10 nerve Duodenum Umbilical region via greater thoracic splanchnic nerve Hiatal hernia Epigastrium via T7 and T8 nerves Pancreas or gallbladder Epigastrium Gallbladder and bile duct Epigastric pain, wraps around scapula Structure irritated Location of referred pain

Named Exam Findings Sign Finding Association Cullen's sign Bluish periumbilical discoloration Retroperitoneal hemorrhage (hemorrhagic pancreatitis, abdominal aortic aneurysm rupture) Kehr's sign Severe left shoulder pain Splenic rupture Ectopic pregnancy rupture McBurney's sign Tenderness located 2/3 distance from anterior iliac spine to umbilicus on right side Appendicitis Murphy's sign Abrupt interruption of inspiration on palpation of right upper quadrant Acute cholecystitis Iliopsoas sign Hyperextension of right hip causing abdominal pain Obturator's sign Internal rotation of flexed right hip causing abdominal pain Grey-Turner's sign Discoloration of the flank Chandelier sign Manipulation of cervix causes patient to lift buttocks off table Pelvic inflammatory disease Rovsing's sign Right lower quadrant pain with palpation of the left lower quadrant Sign Finding Association

Imaging and Laboratory Studies Laboratory examinations CBC with differential, type & screen Chem-10, amylase, LFT’s, urinanalysis X-rays of the chest and abdomen (upright/supine) Distended loops of bowel, kidney stones, perf  free gas Ultrasound: cholelithiasis, bile duct obstruction, AAA Abdominal CT: AAA, abdominal abscess, severe diverticulitis Endoscopy: perforated peptic ulcer, SBO, gastric cancer Colonoscopy: carcinoma of the colon Angiography: mesenteric ischemia Radionuclide scans

Appendiceal Disease Appendicitis Constipation: “the great imitator” 7% lifetime risk of appendicitis Most common cause of acute abdominal surgery in the U.S. Though living in Lehigh Valley appears to be risk for gallbladder disease Must be considered in every patient with acute abdomen Especially common during pregnancy (also important to consider ectopic pregnancy in women of reproductive age) Constipation: “the great imitator” Less common among differential diagnoses Mucocele, carcinoid, appendiceal carcinoma

Special Considerations Elderly patients May not mount febrile response Atypical pain presentation (severity/location) Immunosuppressed patients Opportunistic infections, lymphomas Corticosteroids may mask pain Obese patients May be more difficult to palpate Patients taking pain medications Opioids may cause constipation and mask/distort pain Pregnant women Distorted abdomen & pregnancy may mimic Sx’s

Beyond Appendicitis

Beyond Appendicitis Appendiceal Neoplasms Carcinoid Marjority of appendiceal neoplasms Derived from neural crest cells <2cm (90%)  appendectomy >2cm (10%)  right hemicolectomy Slow mets, 5 yr survival >50% w/ mets Primary Adenocarcinoma Mucinous more favorable than Colonic Assoc with colon and ovarian CA (15 – 30%) Lymphoma (often AIDS-associated)

Acute Abdomen Algorhithm adopted from Vanderbilt Medical Center

RLQ Pain Adopted from Vanderbilt Medical Center

Case 1: Ms. Jones 27 years old, pregnant female ED presentation Crampy peri-umbilical pain Nausea, emesis and anorexia x 12 hours Pain has ‘migrated’ to RLQ over past several hours, becoming constant and intense Urinanalysis: mild hematuria and pyuria CT scan – deferred for preg

Case 1: Ms. Jones revisited Appendicitis Classic chronologic presentation Especially common during pregnancy 1 out of every 1750 pregnancies! May be in RUQ due to enlarged uterus Mild hematuria and pyuria are common in appendicitis with pelvic inflammation Radiopaque fecalith present only 5% x’s Open or Laparoscopic appendectomy

Case 2: Mr. Smith 42 year-old male ED presentation Fever, vomiting and diarrhea Constant abdominal pain 4hrs, radiates to back Last bowel movement yesterday, flatus unsure FUA: non-specific bowel gas pattern

Case 2: Mr. Smith revisited Gastroenteritis Classic presentation Pain often follows N/V Non-surgical, medical management

Summary Differential diagnosis for acute abdomen is lengthy Many presentations will not require admission or surgery Ischemic colitis, ruptured AAA, intestinal or ulcer perforation, and ectopic pregnancy are important causes not to be missed Common differentials include appendicitis, cholecystitis, obstruction, and ischemia, but will vary per population

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