Acute Abdominal Pain

دکتر بهزاد بذخش فوق تخصص گوارش

• Abdominal pain • Common • Most benign • Up to 10% in the ER have a severe or life-threatening cause or require surgery • Very important to make an accurate Dx (as possible) • First R/O • serious e.g. aortic dissection and mesenteric ischemiaor • surgical conditions e.g. appendicitis, cholecystitis • also consider conditions of the abdominal wall • e.g. muscle strain or herpes zoster

• What helps? • A thorough history • Delineate • location, • radiation, and • movement (e.g., appendicitis-associated pain usually moves from the periumbilical area to the RLQ) • general information about • onset, • duration, • severity, and • quality of pain • exacerbating and remitting factors

• Location: RUQ • Biliary: cholecystitis, cholelithiasis, cholangitis • Colonic: colitis, diverticulitis • Hepatic: abscess, hepatitis, mass • Pulmonary: pneumonia, embolus • Renal: nephrolithiasis, pyelonephritis

• Location: Epigastric • Biliary: cholecystitis, cholelithiasis, cholangitis • Cardiac: myocardial infarction, pericarditis • Gastric: esophagitis, gastritis, peptic ulcer • Pancreatic: mass, pancreatitis • Vascular: aortic dissection, mesenteric ischemia

• Location: LUQ • Cardiac: angina, myocardial infarction, pericarditis • Gastric: esophagitis, gastritis, peptic ulcer • Pancreatic: mass, pancreatitis • Renal: nephrolithiasis, pyelonephritis • Vascular: aortic dissection, mesenteric ischemia

• Location: Periumbilical • Colonic: early appendicitis • Gastric: esophagitis, gastritis, peptic ulcer, smallbowel • mass or obstruction • Vascular: aortic dissection, mesenteric ischemia

• Location: RLQ • Colonic: appendicitis, colitis, diverticulitis, IBD, IBS • Gynecologic: ectopic pregnancy, fibroids, ovarian mass, torsion, PID • Renal: nephrolithiasis, pyelonephritis

• Location: Suprapubic • Colonic: appendicitis, colitis, diverticulitis, IBD, IBS • Gynecologic: ectopic pregnancy, fibroids, ovarian mass, torsion, PID, Mittelshmerz • Renal: cystitis, nephrolithiasis, pyelonephritis

• Location: LLQ • Colonic: colitis, diverticulitis, IBD, IBS • Gynecologic: ectopic pregnancy, fibroids, ovarian mass, torsion, PID • Renal: nephrolithiasis, pyelonephritis

• Location: Any • Abdominal wall: herpes zoster, muscle strain, hernia • Other: bowel obstruction, mesenteric ischemia, peritonitis, narcotic withdrawal, sickle cell crisis, porphyria, IBD, heavy metal poisoning, angioedema

• Associated symptoms • Bowel obstruction: constipation (the highest positive predictive value) • Appendicitis: RLQ pain (the highest PPV) • Migration from periumbilical to RLQ & fever also suggest appendicitis • Protracted vomiting • Of little use: • Anorexia (in pts w appendicitis)

• Quality • Colic: sharp, localized abdominal pain that increases, peaks, and subsides • associated with numerous diseases of hollow viscera • Due to smooth muscle contraction proximal to a partial or complete obstruction (e.g. gallstone, kidney stone, small bowel obstruction) • location helps • Absence of colic useful for ruling out diseases e.g. acute cholecystitis (< 25% of patients are without RUQ pain or colic)

• P/E • general appearance • Peritonitis: usually lie very still • Renal colic: unable to stay still • V/S • Fever: suggests infection • Absence does not rule it out, especially the elderly & immunocompromised • Tachycardia and orthostatic hypotension suggest hypovolemia • Tachypnea: PTE, sepsis • The location of pain: • pay close attention to the cardiac and lung examinations in patients with upper abdomen (Pneumonia, ACE)

• P/E: • Carnett’s sign • increased pain when a supine pt tenses the abdominal wall by lifting the head and shoulders off the examination table in patients with abdominal wall pain • Murphy’s sign in patients with cholecystitis • present in 65% of adults with cholecystitis • particularly unreliable in older patients • Psoas sign in patients with appendicitis • Nonspecific/important • Rigidity • Rebound tenderness

• P/E: • Carnett’s sign • increased pain when a supine pt tenses the abdominal wall by lifting the head and shoulders off the examination table in patients with abdominal wall pain • Murphy’s sign in patients with cholecystitis • present in 65% of adults with cholecystitis • particularly unreliable in older patients • Psoas sign in patients with appendicitis • Nonspecific/important • Rigidity • Rebound tenderness

• Rectal examination • Fecal impaction, • Palpable mass, or • Occult blood in the stool • Tenderness and fullness on the right side of the rectum: ? retrocecal appendix

• Pelvic examination • Vaginal discharge: vaginitis • Cervical motion tenderness and peritoneal signs: • increased likelihood of ectopic pregnancy or • other GYN complications, e.g. salpingitis or a tubo-ovarian abscess

• Lab • WBC • Good but not very helpful: • 1 in 4 pts w acute appendicitis has a nl WBC • Simultaneous amylase & lipase measurements • an elevated lipase with a nl amylase level is NOT likely to be caused by pancreatitis • Liver chemistries: very important in pts with RUQ pain • Do it at the time of pain (AST/ALT/ALP) • U/A • Urine pregnancy test

• Recommended Imaging Studies Based on Location of Abdominal Pain

• Special populations: Females of childbearing age

• The role of plain abdominal film • High usage, Low yield • ACR suggests it in: • suspected bowel obstruction or ileus, • constipation, or pneumoperitoneum • foreign body assessment; and • evaluation of urinary tract stones

• Use Imaging Appropriately

• Case-1 • A 64 Y/O man presents with LLQ pain that has progressively worsened over the past three days. • fat stranding adjacent to the sigmoid colon, with scattered colonic diverticula • Coronal reformatted image: the offending diverticulum at the epicenter of the inflammatory changes • Rx: Medical (antibiotics/hydration)

• Case-2 • A 44 Y/O man who was recently treated conservatively for diverticulitis presents with recurrent left LLQ pain and fever • pericolonic rim-enhancing gas and fluid collection consistent with a diverticular abscess (arrow). • stranding in the surrounding fat & adjacent colon wall thickening • Rx: PerQ drainage

• • A 76 Y/O man with recurrent sigmoid diverticulitis presents with LLQ pain and fever • contrast material extending into a diverticular abscess via a fistula tract (arrow). • Multiple sigmoid diverticula and free fluid in the pelvis • Axial image obtained just inferior to the fistula tract: full extent of the associated diverticular abscess (note the air-fluid level) • Rx: Sigmoidectomy

• Imaging: RLQ pain • 25 Y/O lady with RLQ pain of 8 hours duration • Sono: inconclusive • CT: small, rim-enhancing fluid collection surrounding the appendix (arrow), consistent with periappendiceal abscess • CT has better sensitivity and specificity (91% and 90%, respectively) than ultrasonography (78% and 83%, respectively) for acute appendicitis

• Take home message • Acute abdominal pain is common • Accurate Hx is the key (serious/surgical conditions vs. benign) • P/E • Astute clinical Dx (DDx) • Thoughtful interpretation of lab data • Appropriate use of imagings