2 Outline Definitions What causes an “acute abdomen” Differential DiagnosisHistory and physicalLabsDiagnostic imagingHigh Risk Patients with Acute Abdomen
3 Acute AbdomenSymptoms and signs of acute intra- abdominal disease processes, usually treated best by surgical operation
4 The Epidemiology of Acute Abdominal Pain 5-10% of all ED visits.Among them, 14-40% patients need surgical intervention.Challenge for emergency physician (EP):About 1/3 have an atypical presentation.If misdiagnosis, mortality rate 2.5 times higher than correct diagnosis in the elderly.
5 Three Types of Abdominal Pain Visceral PainSomatic (Parietal) PainReferred Pain
6 The Physiology and Mechanisms of Abdominal Pain Visceral PainWithin the muscular walls of hollow organs and the capsules of solid organs.Stimulated primarily by stretching, distension, and excessive contractions.Characteristically deep, dull, aching or cramping, and poorly localized.Usually felt in the midline, unaccompanied by tenderness.
7 The Physiology and Mechanisms of Abdominal Pain Somatic (Parietal) PainAfferent fibers: from T6 to L1, more localized.Characteristically sharper, aggravated by stimulation of the parietal peritoneum with movement, coughing, or walking.True parietal pain surgical cause of abdominal pain.
8 The Physiology and Mechanisms of Abdominal Pain Referred PainPain felt a site other than that of the primary noxious stimulus.Occurs in an area supplied by the same neurosegment as the involved organ.Most visceral pain is of this type.Usually intense and most often secondary to an inflammatory lesion.Subdiaphragm disorder~shoulder painBiliary tract disorder~right shoulder painSmall bowel disorder~back pain
10 Acute Abdominal Pain in Patients Under and Over Age 50 Under 50 (6317 cases), % Over 50 (2406 cases), %Nonspecific abd. painAppendicitisCholecystitisObstructionPancreatitisDiverticular disease <0.1Cancer <0.1Hernia <0.1Vascular <0.1CholecystitisNonspecific abd. PainAppendicitisObstructionPancreatitisDiverticular diseaseCancerHerniaVascular
11 Important Extra-abdominal Causes of Abdominal Pain SystemicDKAAlcoholic ketoacidosisUremiaSickle cell diseasePorphyriaSLEVasculitisGlaucomaHyperthyroidismToxicMethanol poisoningHeavy metal toxicityScorpion biteBlack widow spider biteThoracicMyocardial infarction/ Unstable anginaPneumoniaPulmonary embolismHerniated thoracic disc (neuralgia)GenitourinaryTesticular torisonRenal colicInfectiousStrep pharyngitis (more often in children)Rocky Mountain Spotted FeverMonocucleosisAbdominal wallMuscle spasmMuscle hematomaHerpes zoster
12 History of Present Illness O nsetP recipitating/ relievingQ ualityR adiationS everityT imingMatched to clinical conditionEmerges over time and then concentrates (acute appy)Sudden onset (perforated viscous)
13 High-Yield Historical Questions How old are you? (Advanced age mean increased risk)2. Describe the position, character,and migration of the painsudden coupled with weakness or fainting, less acute but still abrupt onset ,or begin gradually and maximize slowlyIs the pain constant or intermittent? (Constant pain is worse)Have you ever had this before? (No prior episodes is worse)Did the pain start centrally and migrate to the right lower quadrant? (High specificity for appendicitis)3. Have you noticed specific aggravating or relieving factors? (Eating, defecation or flatus)4. Have you ever had abdominal surgery? (Consider obstruction in patients who report previous abdominal surgery)
14 High-Yield Historical Questions 5. Do you have nausea, vomiting, diarrhea or bowel habit change? (D/D true diarrhea, overflow incontinence or tenesmus)6. Do you have HIV? (Consider occult and unusual infection, 30% mortality of surgical treatment)7. How much alcohol do you drink per day? (Consider pancreatitis, hepatitis, or cirrhosis)8. Are you pregnant? (Test for pregnancy-consider ectopic pregnancy, menstrual history, sexual exposure history)9. Are you taking antibiotics or steroids? (These may mask infection)10. Do you have a history of vascular or heart disease, hypertension, or atrial fibrillation? (Consider mesenteric ischemia and abdominal aneurysm)
15 Physical ExaminationOverall appearance ( Facial expression, diaphoresis, pallor, and degree of agitation)Walking and recumbentVital signsTemperature (T > 40 °C or < 35° C consider abdominal sepsis)TachycardiaHypotensionInspection: scars, hernias, massesAuscultation ( Hyperactive BS, hypoactive BS or silent BS, Pulsatile bruit)PercussionPalpation : The most critical stepTendernessRigidity and guarding (Only 21% > 70 y patients with PPU present with epigastria rigidity)“Board-like abdomen”Rectal digital examinationrebounding pain
17 Five Major Categories of Acute Abdomen (BIOPI) Bleeding or rupture of vessels or tumorIschemia or InfarctionObstructionPerforationInflammation
18 Emergency Department Evaluation of Acute Abdomen HistoryMenstruation history (LMP, ovulation, sexual exposure)Rapid pregnancy test: women of childbearing age.Lab: CBC, liver panel, EKG for elderly.Plain KUB: helpful in obstruction; 40% patients invisible free air.Ultrasound and CT scan: aneurysm, cholelithiasis, ectopic pregnancy, and ureterolithiasis.
20 Important Imaging Studies for Acute Abdomen Standing CXR and KUBUltrasound: for solid organs.CT of abdomen for abscess, free air, vessel, tumor and ischemia bowel.( gold standard for finding acute appendicitis)Angiography: Especially in non-diagnostic ischemia bowel.
21 Indications for Abdominal Plain Films Suspected Diagnosis Clinical FindingsPerforated viscus Sudden-onset painRigid abdomenDecreased bowel soundsBowel obstruction Prior abdominal surgeryAbdominal distensionAbnormal bowel soundsHigh risk for obstruction or volvulusForeign body Mental retardationPsychosisSuspicion of rectal foreign body
22 Plain Films Upright CXR KUB (kidney/ureter/bladder) “Free” air CalcificationsAir/ Fluid levelsReactive bowel patternsForeign bodiesLateral Decubitus Film
24 CT ScansBetter than plain films and US for evaluation of solid and hollow organsIntravenous contrastOral contrastPer rectal contrastHigh use in appendicitis, diverticulitis, abscess, pancreatitis
25 The Identification of High Risk Patients with Acute Abdomen Elderly > 65 yS/S of ShockPeritoneal sign (+)silent bowel soundPulsatile massRefractory pain post TxThe immunocompromised. (e.g. HIV)Women of childbearing age.Elevation of Band WBCFever causeHypothermiaAcute renal failureNot post-surgical obstruction
26 Emergency Department Management of Acute Abdomen IV volume replacement and NG decompressionAntibiotics: indicated if infection is suspected.Narcotic analgesia (?) Timing (?)Pro: Permit a more accurate history and PE. Morphine (2-5 mg IV)Con: Surgeon is hostile to this approach, consultation immediately.
27 When to Operate ? Peritonitis Abdominal pain/tenderness + sepsis Excluding primary peritonitisAbdominal pain/tenderness + sepsisAcute intestinal ischemiaPneumoperitoneumMake sure pancreatitis is excluded
28 When NOT to Operate ? Cholangitis Appendiceal abscess Acute diverticulitis + abscessAcute pancreatitis or hepatitisRuptured ovarian cystsLong standing perforated ulcers?MI, Acute pericarditisPN, pulmonary infarctionGE reflux, DKA, Adrenal InsufficiencyAcute PorphyriaRectus muscle hematomaPyelonephritis, Sickle cell crisis