Acute abdominal pain resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2], Amr Marawan, M.D. [3]

Overview

Abdominal pain (or stomach ache) is a common symptom associated with transient disorders or serious disease. Diagnosing the cause of abdominal pain can be difficult, because many diseases can cause this symptom. Most frequently the cause is benign and/or self-limiting, but more serious causes may require urgent intervention. Acute abdominal pain is a severe, persistent abdominal pain of sudden onset that is likely to require surgical intervention to treat its cause. The pain may frequently be associated with nausea and vomiting, abdominal distention, fever and signs of shock.

Definitions

Terms	Definitions
Acute abdominal pain	Severe, persistent abdominal pain of sudden onset that is likely to require surgical intervention to treat its cause. Duration of less than several days.
Acute abdomen	It is defined as a sudden, abrupt onset of severe localized or generalized abdominal pain with abdominal rigidity. It is less than 24 hours in duration and requires urgent evaluation and diagnosis because it may indicate a need for immediate surgical intervention.(also known as surgical abdomen)
Subacute abdominal pain	It's a type of abdominal pain that has a duration of more than several days but less than six months.
Chronic abdominal pain	It has a duration of more than six months, either constantly or intermittently.

Causes

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Abdominal aortic aneurysm
• Acute bowel obstruction
• DKA
• Ectopic pregnancy
• Mesenteric ischemia
• Myocardial infarction
• Perforated viscus (including peptic ulcer, bowel, esophagus, or appendix)
• Placental abruption
• Splenic rupture (It is usually secondary to trauma, EBV or leukemia)
• Volvulus

Common Causes

• Acute pancreatitis
• Adnexal pathology (cyst or tumor that caused torsion, bleeding or rupture)
• Appendicitis
• Biliary disease (Acute cholecystitis)
• Bladder distension
• Chronic heroin or morphine use
• Crohn's disease
• Diverticulitis
• Dyspepsia
• Endometriosis
• Endometritis
• Hemophilia
• Hiatus hernia
• High dose steroids
• HIV infection (affecting the GI and hepatobiliary systems)
• Kidney stones
• Mesenteric infarction
• Pelvic inflammatory disease
• Peritonitis
• Sickle cell disease (as a part of vasoocclusive crisis)
• Splenic abscess
• Splenic infarction
• Ulcerative colitis

Management

Diagnostic Approach

Shown below is an algorithm depicting the diagnostic approach of acute abdominal pain.

Characterize the pain: ❑ Onset (eg, sudden, gradual) ❑ Provocative and palliating factors (eg, Is the pain related to your meals?) ❑ Quality (eg, dull, sharp, colicky, waxing and waning) ❑ Radiation (eg, to the shoulder, back, flank, groin, or chest) ❑ Site (eg, a particular quadrant or diffuse) ❑ Pain location may change over time, reflecting progression of disease ❑ Intensity ❑ Time course (eg, hours versus weeks, constant or intermittent) Other symptoms ❑ Nausea & vomiting ❑ Diaphoresis ❑ Anorexia ❑ Fever ❑ Bloody stool ❑ Vaginal discharge ❑ Penile discharge ❑ Painful urination ❑ Shortness of breath ❑ Altered mental status ❑ Jaundice ❑ Mal-digestion ❑ Flatulence ❑ Fatigue ❑ Scrotal pain/swelling ❑ Recent trauma ❑ Mass in any of the quadrants ❑ Symptoms suggestive of sepsis ❑ Symptoms suggestive of common hepatic duct obstruction ❑ RUQ pain with fever & jaundice ❑ Symptoms suggestive of gallstone ileus ❑ Transient abdominal pain with nausea & vomiting ❑ Hematemesis Detailed history: ❑ Age (it is more likely to have sever diseases and atypical symptoms in patients above 50 years old) ❑ Past medical history (to exclude risk factors for cardiovascular diseases) ❑ Past surgical history (for previous abdominal surgeries) ❑ Menstrual and contraceptive history (pregnancy should be excluded in all women of childbearing age with abdominal pain) ❑ Occupational history ❑ Travel history ❑ Medications (for over the counter drugs as, acetaminophen, aspirin, and NSAIDs)

Examine the patient: ❑ Vital signs ❑ Temperature ❑ Heart rate (tachycardia) ❑ Blood pressure (hypotension) ❑ Respiratory rate (tachypnea) ❑ Skin ❑ Diaphoresis ❑ Pallor ❑ Jaundice ❑ Dehydration ❑ Inspection ❑ If the patient is curled up/agitated, this is suggestive of renal colic ❑ If the patient is lying still in bed with knees bent, this is suggestive of peritonitis ❑ Signs of previous surgery ❑ Abdominal pulsations ❑ Signs of systemic disease eg, ❑ Pallor, suggestive of bleeding ❑ Spider angiomata, suggestive of cirrhosis ❑ Auscultation ❑ Abdominal crepitations ❑ Reduced bowel sounds ❑ Increased bowel sounds ❑ Bruit, suggestive of abdominal aortic aneurysm ❑ Palpation ❑ Rigidity ❑ Guarding ❑ Abdominal tenderness ❑ Distension ❑ Detection of masses on palpating the abdomen ❑ McBurney's point tenderness ❑ Rovsing's sign ❑ Carnett's sign ❑ Psoas sign (suggestive of retrocecal appendix) ❑ Obturator sign ❑ Cullen's sign ❑ Grey-Turner's sign ❑ Digital rectal exam (tenderness may be present in retrocecal appendicitis) ❑ Pelvic exam in females ❑ Testicular examination in males ❑ Signs of sepsis ❑ Cardiovascular system ❑ Respiratory system ❑ Anorectal (bleeding)

Consider extraabdominal differential diagnosis: ❑ Abdominal epilepsy ❑ Alcoholic ketoacidosis ❑ Diabetic ketoacidosis ❑ Esophageal spasm or rupture (boerhaav's syndrome) ❑ Familial mediterranean fever ❑ Herpes zoster ❑ Lead poisoning ❑ Myocardial ischemia and infarction ❑ Myocarditis ❑ Pleurodynia (bornholm's disease) ❑ Pneumonia (involving the lower lobes) ❑ Porphyria ❑ Pulmonary embolus ❑ Radiculopathy ❑ Sickle cell anemia ❑ Tabes dorsalis ❑ Uremia

❑ Assess hemodynamic stability

If the patient is unstable, Stabilize the patient: ❑ Establish two large-bore intravenous peripheral lines ❑ NPO until the patient is stable ❑ Supportive care (fluids and electrolyes as required) ❑ Place nasogastric tube if there is bleeding, obstruction, significant nausea or vomiting ❑ Place foley catheter to monitor volume status ❑ Cardiac monitoring ❑ Supplemental oxygen as needed ❑ Administer early antibiotics if indicated

If the patient is stable, Order laboratory tests: ❑ Pregnancy test (required in women of child-bearing age) ❑ CBC ❑ Hematocrit ❑ Urinalysis ❑ Serum electrolytes ❑ ESR ❑ ABG ❑ D dimer ❑ Serum lactate ❑ BUN ❑ Creatinine ❑ Amylase ❑ Lipase ❑ Triglyceride ❑ Total bilirubin ❑ Direct bilirubin ❑ Albumin ❑ AST ❑ ALT ❑ Alkaline phosphatase ❑ GGT ❑ Stool for ova and parasites ❑ C. difficile culture and toxin assay Order imaging studies: ❑ Order urgent trans abdominal ultrasound (TAUSG) ❑ Abdominal CT ❑ ECG ❑ MRCP ❑ Abdominal x-ray ❑ Angiography ❑ Diagnostic paracentesis *Order the tests to rule in a suspected diagnosis or to assess a case of unclear etiology *In case of elderly patients, immunocompromised or those unable to provide a comprehensive history, order broader range of tests

Peritoneal signs, shock or toxic appearing

No

No

Yes

Symptoms, signs, risk factors or ECG suggestive of acute coronary syndrome

Symptoms, signs or risk factors suggestive of abdominal aortic aneurysm

❑ Initiate resuscitation ❑ Obtain immediate surgical consultation ❑ Perform bedside ultrasound (evaluate aorta, hemoperitoneum, pericardium and inferior vena cava) ❑ Obtain indicated tests and studies (e.g. x-ray, ECG, lactate, lipase and LFTs)

No

Yes

Appropriate management

❑ Surgical consultation ❑ Bedside ultrasound ❑ Abdominal CT

History, examination and risk factors suggest mesentric ischemia (pain out of proportion to exam)

Yes

No

❑ Surgical consultation ❑ Abdominal CT

History and examination suggest bowel obstruction (diffuse tenderness with distention and persistent vomiting) or perforation (rigidity with absent bowel sounds

Yes

No

Abdominal x-ray series

Where is pain localized

Presence of free air

Presence of obstruction

Absent free air and absent obstruction

Epigastric or upper right quadrant tenderness

Right lower quadrant tenderness

Left lower quadrant tenderness

Surgical consult

Abdominal CT

Abdominal CT

Left upper quadrant tenderness

Approach to a Female of Child-bearing Age

Peritoneal signs or shock

No

Yes

Pregnant

❑ Stabilize airway, breathing and circulation ❑ Obtain emergent surgical consultation ❑ Obtain pregnancy test ❑ Perform bedside ultrasound

No

Yes

Unilateral adnexal tenderness

Yes

❑ Perform ultrasound examination (consider ectopic pregnancy, appendicitis) ❑ Perform sterile pelvic examination (not in third trimester vaginal bleeding) ❑ Obtain quantitative HCG and other needed lab tests ❑ Obtain OB/Gyn and surgery consultation as indicated

No

US to rule out ovarian torsion or ovarian cyst

Intrauterine pregnancy

Ectopic pregnancy

Clinical pelvic inflammatory disease

❑ Assess appendix with US ❑ Obtain OB/Gyn and surgery consultation as indicated

Obtain OB/Gyn consultation

No

Yes

Predominant right lower quadrant tenderness

Toxic appearing or persistent vomiting

No

Yes

Administer antibiotics as an outpatient

Admit, start IV antibiotics and consult Gyn

Differentiating Common Causes of Abdominal Pain

Shown below is a table summarizing some clues that help to distinguish the presentation of different diseases.

Causes	Clues
Appendicitis	Gradual achy pain that starts as diffuse periumbilical pain, then becomes localized in the right lower quadrant.
Cholecystitis	Acute constricting pain that starts localized in the right upper quadrant and sometimes radiates to the scapula.
Pancreatitis	Acute boring pain that starts in the epigastrium and radiates to midback.
Diverticulitis	Gradual achy pain, localized in the left lower quadrant (called left sided appendicitis).
Perforated peptic ulcer	Sudden burning pain, presents as a diffuse pain in the periumbilical region.
Small bowel obstruction	Gradual crampy pain, presents as a diffuse pain in the periumbilical region.
Mesenteric ischemia or infarction	Sudden agonizing pain, presents as a diffuse pain in the periumbilical region.
Ruptured abdominal aortic aneurysm	Sudden tearing pain, presents as a diffuse pain in the abdomen, back and flanks.
Gastroenteritis	Gradual spasmodic pain, presents as a diffuse pain in the periumbilical region.
Pelvic inflammatory disease	Gradual achy pain, presents in either lower quadrants or pelvis and sometimes radiates to the upper thigh.
Ruptured ectopic pregnancy	Sudden sharp pain, presents in either lower quadrants or pelvis.

Do's

• Start the approach to acute abdominal pain by rapid assessment of the patient using the pneumonic "ABC:" airway, breathing and circulation, to identify unstable patients.
• Consider abdominal aortic aneurysm, mesenteric ischemia and malignancy in patients above 50 years as it is much less likely for younger patients.
• Perform pelvic and testicular examination in patients with low abdominal pain.
• Re-examine patients at high risk who were initially diagnosed with pain of unclear etiology.
• Taking careful history, characterizing the pain precisely and thorough physical examination is crucial for creating narrow differential diagnosis.
• Correlate the CD4 count in HIV positive patients with the most commonly occurring pathology.
• Order a pregnancy test before proceeding with a CT scan in females in the child bearing age.
• Order an ultrasound or magnetic resonance among pregnant females to avoid exposure to radiation. In case the previous tests were inconclusive and appendicitis is suspected, the next step in the management includes proceeding with either laparoscopy or limited CT scan.
• Consider peritonitis with cervical motion tenderness as it isn't specific for pelvic inflammatory disease.
• Suspect abdominal aortic aneurysm in old patients presenting with abdominal pain with history of tobacco use.
• Suspect acute mesenteric ischemia or acute pancreatitis in patients presenting with poorly localized pain out of proportion to physical findings.
• Recommend initial imaging studies based on the location of abdominal pain:

• Ultrasonography is recommended when a patient presents with right upper quadrant pain.
• Computed tomography (CT) with intravenous contrast media is recommended for evaluating adults with acute right lower quadrant pain.
• CT with oral and intravenous contrast media is recommended for patients with left lower quadrant pain.

• Order ECG for old patients with upper abdominal pain with high cardiac risk factors.
• Administer narcotic analgesia for patients who present to the ED with moderate or severe abdominal pain.
• Perform diagnostic paracentesis (cell count, differential count, gram stain, culture, bilirubin and albumin) in patients with ascites and abdominal pain to rule out spontaneous bacterial peritonitis.

Don'ts

• Fail to evaluate elder patients in the presence of overt clinical signs.
• Over rely on laboratory tests, they are only used as adjuncts.
• Do not delay the initial intervention.
• Do not order blood cultures routinely in all patients
• Don’t delay resuscitation or surgical consultation for ill patient while waiting for imaging.
• Don’t restrict the differential diagnosis of abdominal pain based on the location; for example, right-sided structures may refer pain to the left abdomen.