Acute Abdominal Pain

Some important cause of abdominal pain

Pain originating in the abdomen:

    • Parietal peritoneal inflammation

      • Bacterial contamination

        • Perforated appendix or other perforate viscus

        • PID

      • Chemical irritation

        • PUD

        • Pancreatitis

        • Mittelschmerz

    • Mechanical obstruction of hollow viscera

      • SBO

      • Obstruction of the biliary tree

      • Ureteric obstruction

    • Vascular

      • embolism or thrombosis

      • vascular rupture

      • pressure or torsional occlusion

      • sickle cell anemia

    • Abdominal wall

      • Distortion or traction of mesentery

      • Trauma or infection of muscles

    • Distension of visceral surfaces, e.g., by H'ge

      • hepatic or renal capsules

    • Inflammation of viscus

      • appendicitis

      • typhoid fever

      • typhlitis

Pain referred from Extraabdominal source:

    • Cardiothoracic

      • AMI

      • myocarditis, pericarditis, endocarditis

      • CHF

      • Pneuomonia

      • PE

      • pleurodynia

      • PTx

      • empyema

      • esophageal disease, spasm, rupture, inflammation

    • Genitalia

      • torsion of testis

Metabolic causes:

    • DKA

    • Uremia

    • Hyperlipidemia

    • hyperparathyroidism

    • AI

    • Familial Mediterranean fever

    • Prophyria

    • C'1 esterase inhibitor deficiency (angioneurotic edema)

Neurologic/Psychiatric causes:

    • Herpes zoster

    • Tabes dorsalis

    • Causalgia

    • Radiculitis from infection or arthritis

    • Spinal cord or nerve root compression

    • Functional d/o

    • Psychiatric d/o

Toxic causes:

    • Lead poisoning

    • Insect or animal envenomations

      • black widow spiders

      • snake bites

Uncertain mechanisms:

    • narcotic withdrawal

    • heat stroke

Abdominal pain by region:

    • RUQ: hepatitis, liver abscess, perihepatitis (Fitz-Hugh Curtis - gonococcal), cholecystitis, cholangitis, choledocholithiasis. Check for Charcot's triad and Reynold's pentad.

    • RLQ: appendicitis, appendicular abscess, ovarian torsion, ruptured ovarian cyst, ovarian carcinoma.

    • LUQ: splenic rupture, splenic infarct, splenic abscess, splenic flexure - colon obstruction.

    • LLQ: diverticulitis, ischemic colitis, ovarian torsion, ruptured ovarian cyst, ovarian carcinoma.

    • Epigastrium: MI, pericarditis, aortic dissection, AAA, pneumonia, pleurisy, subphrenic abscess, GERD, PUD, pancreatitis, pyelonephritis, renal colic.

    • Hypogastrium: renal colic, psoas abscess, IBD, SBO, infectious gastroenteritis, ovarian torsion, ovarian cyst, ovarian carcinoma, ectopic pregnancy, salpingitis, endometriosis, cystitis, distended bladder.

    • Generalized abdominal pain: appendicitis, gastroenteritis, SBO, IBD, peritonitis, DKA, SCC, acute intermittent porphyria, acute adrenal insufficiency due to steroid withdrawal, mesenteric ischemia.

    • Major threat to life: perforated or ruptured viscus, ascending cholangitis, necrosis of viscus, AAA rupture - exsanguinating H'ge.

    • Abdominal pain in AIDS or immunosuppressed patient:

      • Fever: take BC x 2

      • Enteric inf: Cryptosporidium, Shigella, Salmonella, CMV, and Campylobacter enteritis.

      • Even a Normal WBC count with slight left shift = poss. Inf

      • Neutopenic colitis (typhlitis) common.

      • Drug induced pancreatitis from NRTIs.

      • Hepatic steatosis with lactic acidosis is rapidly fatal has ~50% mortality.

      • HIV-infected Pts are at risk for non-Hodgkin's lymphoma in GI tract.

      • Acalculous cholecystitis is common. Causes may include Cryptosporidium, CMV, or MAC inf.

History:

    • Check BP, pulse, resp, O2 sats, and temp.

    • Quickly look at the Pt, and review the chart.

    • Take a focussed history, including duration, location, character, intensity, radiation, periodicity, aggravating/relieving factors, nausea, vomiting (bilious, non-bilious), last bowel movt., diarrhea, constipation, hematemesis, melena, or hematochezia, genitourinary complaints, testicular swelling or pain, vagnial bleeding or discharge.

    • Mesenteric ischemia often has pain out of proportion to examination. Consider this, especially with a history of atrial fibrillation, vascular d/o, and in elderly patients.

    • Pain preceding vomiting, for example reflects a disease process which will likely need surgical intervention more commonly than abdominal pain that follows vomiting.

    • Past medical history of similar problems.

    • Any history of previous abdominal operations? (adhesions causing obstruction)

    • In patients with CAD and HTN, think AAA. Also mesenteric ischemia.

    • In patients with AF think embolization in the mesenteric vessels - bowel infarct.

    • Pancreatitis, and risk factors, including drugs and iatrogenic causes.

    • Pain of biliary colic is steady not colicky.

Focussed examination:

    • General: How sick and distressed does the patient look? Is patient able to stay still (peritonitis) or writhing in pain (ureteric colic)

    • Vitals: repeat now. Tachycardia, hypotension, orthostatic BP and pulse changes, pulse ox, tachypnea (metabolic acidosis - DKA, mesenteric ischemia, infection like pneumonia)

    • Skin: Herpes zoster, abnormal ecchymoses such as flank ecchymoses associated with retroperitoneal H'ge from H'gic pancreatitis (Grey-Turner's sign, Cullen's sign), stigamata of liver disease like spider nevi.

    • HEENT: Check for icterus, tonsils (Strep. pharyngitis in children can cause abdominal pain - mesenteric adenitis)

    • Chest: Check for skin lesions. Listen for murmur, rubs, or gallops. Assess jugular venous pulse

    • Lungs: Assess for crackles, absent breath sounds on one side, friction rub. Lower lobe pneumonia.

    • Abdomen: Inspect bowel sounds: high pitched with SBO, hypoactive or absent with lleus. Bruit of AAA, renal. Percussion: tympany, shifting tenderness. Palpate: Masses, hepatosplenomegaly, AAA pulsation. McBurney's sign, Rovsing's sign, Murphy's sign, psoas, and obturator signs. Assess for CVA tenderness. Ascites, shifting dullness, fluid wave. Umbilical hernia, other hernial orifices - inguinal, femoral. Check for surgical scars. Carnett's test: ask patient to place hands behind the head and try to do half sit up from a supine position, while you palpate the anterior abdominal wall. Increased pain with this maneuver suggests a disease process withing the abdominal wall. Also to check for anterior abdominal wall masses.

    • Rectal: Must be performed, guaiac for occult blood

    • Pelvic: If indicated by history. Check for CMT and adnexal tenderness. Vaginal discharge, CMT, adnexal tenderness, fever = acute PID. Ovarian cyst, ovarian torsion, or ectopic pregnancy. Enlarged, tender uterus with an irregular contour may implicate uterine leiomyoma or malignancy.

    • Scrotal swelling, tenderness, testicular postion, mass, or tenderness - torsion of testes, epididimytis

Laboratory Data:

    • Consider CBC, electrolytes, ABG, lactate, LFTs, amylase, lipase, B-hCG, and UA, Urine HCG. Films to consider include flat an upright abdominal films, CXR, and EEG. Abdominal CT, US, or both may be required.

    • AXR - air under diaphragm - ruptured viscus.

    • Helical noncontrast abdominal CT: urolithiasis, AAA, appendicitis, diverticulitis

    • US: AAA, gall stones.

    • TVUS: ectopic pregnancy

    • Serum beta-HCG of >1800 - 2000 to determine the US "Window" discriminating zone. TVUS should be able to see gestational sac in the uterus at this HCG level. If not think about ectopic pregnancy.

Management:

    • Initial goal is to determine if the patient has an acute abdomen and need surgical evaluation and treatment. Avoid any analgesics as this may mask the pain and obscure the evaluation. An acute abdomen includes rebound tenderness or guarding hemorrhage.

    • Other conditions can be managed using a more detailed and leisure approach, after the acute abdomen has been ruled out.

    • Keep the patient NPO. Ensure IV access, and run maintenance fluids.