Right lower quadrant abdominal pain resident survival guide

# Overview
Right lower quadrant of the human abdomen, often abbreviated as RLQ, is used to refer to a portion of the abdomen that allows doctors to localise pain and tenderness, scars, lumps and other items of interest. The RLQ extends from the median plane to the right of the patient, and from the umbilical plane to the right inguinal ligament.

# Causes
- Adnexal pathology (cyst or tumor that caused torsion, bleeding or rupture)
- Appendicitis
- Cecum (intussusception, bowel obstruction)
- Colon cancer (ascending colon)
- Ectopic pregnancy
- Endometriosis
- Endometritis
- Hernia
- Inflammatory bowel disease
- Leiomyoma
- Mittelschmerz
- Pelvic inflammatory disease
- Testicular torsion
- Typhlitis

## Management

### Diagnostic approach
Shown below is an algorithm depicting the diagnostic approach of acute abdominal pain in the right lower quadrant.

# 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
- Dont delay resuscitation or surgical consultation for ill patient while waiting for imaging.
- Dont restrict the differential diagnosis of abdominal pain based on the location; for example, right-sided structures may refer pain to the left abdomen.