A 22-year-old woman presents with severe lower abdominal pain. The differential diagnosis includes appendicitis, pelvic inflammatory disease, ovarian cyst, and ectopic pregnancy. Given her age, a pregnancy test and pelvic exam are important to evaluate for potential gynecologic causes of her pain.

1. Abdominal Pain Acute abdominal pain is the chief complaint in about 5% of ED visits Most patients are discharged after ED evaluation Only about 10% require urgent surgery

2. Causes of Acute Abdominal Pain Stratified by Age 8500 patients, 200 EDs in 17 countries over a 10-year period . [ Gallagher EJ, in Emergency Medicine , Tintinalli JE, p 490] 13% 13% Other 4% <0.1% Gynecologic <0.1% 2% Vascular <0.1% 3% Hernia <0.1% 4% Cancer <0.1% 6% Diverticular disease 2% 7% Pancreatitis 2% 12% Bowel obstruction 32% 15% Appendicitis 40% 16% Nonspecific abdominal pain (NSAP) 6% 21% Biliary Tract Disease <50 Years  50 Years FINAL DIAGNOSIS

3. Causes of Acute Abdominal Pain Stratified by Age In all large series of acute abdominal pain in adults, the largest groups are (in order): Nonspecific abdominal pain (NSAP) Appendicitis Biliary disease (usually cholecystitis) This accounts for 75% of cases In older patients, biliary disease is most common: Biliary disease Nonspecific abdominal pain (NSAP) Appendicitis

4. Immediately Life-Threatening 1 HOUR Abdominal aortic aneurysm (AAA) Intra-abdominal hemorrhage Myocardial infarction (MI) Ruptured ectopic pregnancy

5. Mesenteric ischemia Peritonitis Perforated viscus Volvulus / Intussusception Complicated hernia Diabetic ketoacidosis (DKA) Rapidly Life-Threatening BETWEEN 1 H AND 1 DAY

6. Serious Threat to Health or Life BETWEEN 1 DAY & 1 WEEK Appendicitis Cholecystitis Pancreatitis Pneumonia Rupture or torsion of ovarian cyst Small bowel obstruction (SBO) Pelvic inflammatory disease (PID) Intra-abdominal abscess

7. Mild-Moderate Morbidity > 1 WEEK Diverticulitis Ovarian cyst Endometriosis Prostatitis Biliary or Renal colic Hepatitis Inflammatory bowel disease (IBD) Undifferentiated abdominal pain (UDAP)

8. No Morbidity Gastroenteritis Mittelschmerz Musculoskeletal pain Herpes Zoster Dysmenorrhea Constipation Normal intrauterine pregnancy (IUP) Urinary tract infection (UTI)

9. Rapid Assessment/Stabilization Up to 7% of patients with abdominal pain may have a life-threatening process Physiologically compromised patients should be identified in triage and brought immediately to the treatment area for resuscitation

10. Your worst nightmare A 60 year old woman with Type II diabetes mellitus, hypertension, coronary artery disease, chronic renal insufficiency, two prior myocardial infarctions, Marfan’s syndrome, who is a smoker and drinker for >40 years, presents to the ED on Monday night with abdominal pain, fever, nausea, vomiting, vaginal bleeding, bloody diarrhea, and syncope. On exam, she is lethargic, tachypneic, hypotensive, with a barely palpable pulse. Her abdomen is distended and rigid. She’s deaf and mute. What do you do?

11. Rapid Assessment/Stabilization All critically ill patients require resuscitation before beginning a diagnostic assessment What is important is not to make a specific diagnosis, but to identify and treat life threatening conditions A irway Profound shock or protracted emesis may compromise airway and require intubation B reathing: Provide supplemental O 2 O 2 saturation monitoring

12. Rapid Assessment/Stabilization C irculation: IV access (2 large bore IV catheters) Cardiac rhythm monitoring Volume repletion with an isotonic crystalloid solution May require several liters of fluid Titrate volume to hemodynamic status and urine output Extreme conditions e.g. ruptured AAA, massive GI hemorrhage, ruptured spleen, and hemorrhagic pancreatitis  may require blood replacement 12-lead EKG Nasogastric tube (for bowel obstruction) Urinary catheter for critically ill patients (to monitor urine output)

13. Pivotal Findings: History How old are you? Advanced age means increased risk. Which came first--pain or vomiting? Pain first is more likely caused by surgical disease. How long have you had the pain? Pain < 48 hours is worse. Have you ever had abdominal surgery? Consider obstruction Is the pain constant or intermittent? Constant pain is worse. Have you ever had this before? No prior episodes is worse. Colucciello SA, et al. Emerg Med Pract 1:2, 1999.

14. Pivotal Findings: History Do you have a history of cancer, diverticulosis, pancreatitis, kidney failure, gallstones, or inflammatory bowel disease? All are suggestive of more serious disease. Do you have human immunodeficiency virus (HIV)? Consider occult infection or drug-related pancreatitis. Are you pregnant? Obtain urine pregnancy test in all women of child-bearing age-consider ectopic pregnancy. Colucciello SA, et al. Emerg Med Pract 1:2, 1999.

15. Pivotal Findings: History Are you taking antibiotics or steroids? These may mask infection. Did the pain start centrally and migrate to the right lower quadrant? High specificity for appendicitis. Do you have a history of vascular or heart disease, hypertension, or atrial fibrillation? Consider mesenteric ischemia and abdominal aneurysm. Colucciello SA, et al. Emerg Med Pract 1:2, 1999.

16. Pivotal Findings: History A few classic descriptions: diffuse, severe, colicky pain: bowel obstruction “ pain out of proportion to examination”: mesenteric ischemia radiation of pain from epigastrium straight through to the midback: pancreatitis, either primary or from a penetrating ulcer Always obtain a thorough gynecologic history including menses, mode of contraception (if any), vaginal discharge history of: pregnancies, deliveries, abortions, ectopics, cysts, fibroids, pelvic inflammatory disease, sexually transmitted diseases, laparoscopy

17. Physical Exam Vital signs: Tachypnea may be an indication of metabolic acidosis from gangrenous viscera or sepsis or DKA hypoxemia from pneumonia Tachycardia or hypotension may indicate hypovolemia or shock Fever does not accurately predict abdominal pathology often no fever in elderly patients with intraperitoneal infections Female patients should have a pelvic exam All patients with possible obstruction and with mid or lower abdominal pain should be examined for hernias Serial exams may reveal a diagnosis

18. Ancillary Testing Urinalysis and urine pregnancy test are perhaps the most cost-effective tests UPT should be sent on all women of reproductive age The urinalysis must be interpreted with respect to the clinical picture Pyuria often present without UTI Up to 30% of patients with appendicitis have abnormal urinalysis Elevated WBC is neither sensitive nor specific for anything Electrolytes are abnormal in <1% of patients

19. Ancillary Testing Plain radiography limited to suspected bowel obstruction, foreign body, and perforated viscus CT imaging modality of choice for nonobstetric abdominal pain. establishes a diagnosis in over 95% of cases unstable patients should not be moved to the radiology suite until stabilized Ultrasound: In life-threatening processes: detection of intrauterine pregnancy lowers the chances of ectopic pregnancy to < 1 in 20,000 but don’t forget about heterotopic pregnancies AAA free intraperitoneal hemorrhage or pus In non-life-threatening processes: detection of gallstones, dilated common bile duct hydronephrosis ascites ovarian torsion

20. Appendicitis The problem: Up to 20% of appendicitis is missed Normal appendix found in 15-40% of all operations for suspected appendicitis The acceptable number of negative appendectomies depends upon the age and sex of the patient: In young men: <10% In young women: approaches 20% (other pelvic processes make diagnosis more difficult) Two methods to achieve a low negative appendectomy rate: close in-hospital observation use of CT and ultrasound

21. Appendicitis “ The use of abdominal CT and ultrasound has had a dramatic impact on the rate of negative appendectomies.” True or False?

22. Appendicitis False. A large study suggests that the rate of negative appendectomies (15 to 20 percent) has not declined during the last 15 years despite the increasing use of CT and ultrasound 63,707 appendectomies from 1987-1998 despite the use of CT, US, and laparoscopy: 84.5% had appendicitis (25.8% with perforation) 15.5% had no evidence of appendicitis Flum DR, et al. JAMA 2001 Oct 10;286(14):1748-53

23. Appendicitis “ Among the history, physical exam, and laboratory tests, the clinical feature most predictive of appendicitis is right lower quadrant pain.” True or False?

24. Appendicitis: History and Exam True. Five clinical features have high predictive value for appendicitis the presence of any one should indicate an imaging procedure Gallagher EJ, in Emergency Medicine , Tintinalli JE, McGraw Hill, 2004; p 491 2 Positive psoas sign 2-3 Pain before vomiting 4 Rigidity 3 Pain migration from periumbilical area to RLQ 8 RLQ pain LR(+) CLINICAL FEATURE

25. Appendicitis: Ancillary Testing Laboratory tests are not particularly useful CBC 30% of patients have normal WBC count However, more than 95% of these have a left shift Urinalysis microscopic hematuria and pyuria found in up to 30% of pts (presumably because the inflamed appendix is in close proximity to the bladder and ureter)

26. Appendicitis: Ancillary Testing Ultrasound Technically challenging and operator dependent High enough LR (+) to diagnose appendicitis But LR (-) too high to rule out appendicitis CT The LR (+) for all varieties of CT (with/without oral, IV, rectal contrast) is so high that they invariably drive surgical intervention LR (-) is not as strong as LR (+) Hence, absence of appendicitis on CT does not exclude the diagnosis with as much certainty as a positive CT confirms it

27. Appendicitis: Ancillary Testing Gallagher EJ, in Emergency Medicine , Tintinalli JE, McGraw Hill, 2004; p 492 0.1 18 95% 91% Abdominopelvic helical CT (PO + IV contrast) 0.5 11 95% 55% Abdominopelvic ultrasound 0.9 1 58% 48% Plain Abdominal Radiograph LR(-) LR(+) Spec Sens Test

28. Appendicitis: Special Populations Children <5 y.o. Rate of misdiagnosis is high Poor communication Many childhood illnesses associated with anorexia, nausea, and vomiting Appendiceal wall thin  perforation Omentum immature  unable to wall off infection  peritonitis Maintain high index of suspicion and get surgical consultation early The elderly Misdiagnosis can exceed 50% 3x more likely to perforate than the general population (? Age-related weak appendiceal wall) Mortality for patients >70 y.o. with appendicitis ~ 30%

29. Case A 34 year old woman in her 34 th week of gestation presents with vague constant right-sided abdominal pain for about 12 hours. The pain seems to be located more in the RUQ than anywhere else. She feels some mild nausea, but otherwise has no complaint. On exam, her vital signs are normal, and her abdomen is gravid with some tenderness in the right lateral mid-abdomen, and right upper quadrant. What is your differential diagnosis?

30. Appendicitis: Special Populations Pregnant women Appendicitis the most common extra-uterine surgical emergency in pregnancy Diagnosis difficult Early symptoms (nausea/vomiting) are frequent in normal pregnancy Enlarging uterus changes the location of the appendix  can cause RUQ pain diagnosis often delayed  rate of perforation 2-3x higher than the general population Fetal mortality in 20% of cases of perforation Ultrasound the test of choice

31. Appendicitis: Disposition Stratify patients into 4 groups: Classic presentation Prompt surgical consultation  appendectomy Presentation suspicious but not diagnostic Options: Imaging studies (CT or US) Observation for 4-6 hrs with serial exams Surgical consultation for patients with evolving exam Appendicitis unlikely Observation in ED with serial exams If clinical course benign  discharge with diagnosis “nonspecific abdominal pain” (not “gastroenteritis”) Explain worrisome symptoms and instruct to return if any Arrange for reevaluation by primary care MD or ED in 12-24 hrs High-risk patients: Pediatric, elderly, pregnant Maintain low threshold for imaging and surgical consultation

32. Biliary Disease The most common diagnosis in patients >50 y.o Cholecystitis, biliary colic, and common duct obstruction often difficult to distinguish on clinical grounds alone The majority of patients with pathologically proven cholecystitis have no fever 40% of patients with cholecystitis have no leukocytosis Individual signs and symptoms are weak clinical indicators Only 1/3 of patients have RUQ pain The rest complain of diffuse upper abdominal pain A small group with RLQ pain Only 2/3 of patients have RUQ tenderness Murphy’s sign (inspiratory pause during RUQ palpation) is non-specific

33. Biliary Disease: Diagnostic Testing Ultrasound The most useful test Can be performed at the bedside by EP’s with a high degree of accuracy Visualization of the gallbladder without stones has a high negative predictive value for cholecystitis Visualization of stones, a thickened gallbladder wall, and pericholecystic fluid has a positive predictive value in excess of 90% [LR(+) = 29; LR(-) = 0.1] Nuclear scintigraphy with technetium-99m-labeled iminodiacetic acid (IDA) is the most sensitive and specific imaging test for cholecystitis

34. Small Bowel Obstruction The main issues: Diagnosis of the primary disorder Early detection of strangulation or ischemia Only 2 historical features have predictive value: Previous abdominal surgery Intermittent/colicky pain Only 2 physical findings have predictive value: Abdominal distention Abnormal bowel sounds 2/3 of patients complain of generalized or central abdominal pain ½ of patients have generalized abdominal tenderness

35. Small Bowel Obstruction Flat and upright plain abdominal films demonstrate small bowel obstruction in 50% to 60% of cases suggest obstruction in another 20% to 30% are hampered by the large number of indeterminate readings Gallagher EJ, in Emergency Medicine , Tintinalli JE, McGraw Hill, 2004; p 490

36. Small Bowel Obstruction

37. Small Bowel Obstruction

38. Small Bowel Obstruction CT far superior to plain films in the detection of high-grade SBO more limited in the detection of low-grade obstruction 0.5 3 CT + IV/po contrast SBO low-grade 0.1 22 CT + IV/po contrast SBO high-grade 0.7 1 Plain films SBO LR(-) LR(+) Test Target diagnosis

39. Small Bowel Obstruction CT, cont. not required in most cases for the diagnosis of bowel obstruction. main use is in better defining the site and cause of obstruction demonstrates intussusception, volvulus, and extraluminal lesions like abscesses and tumors useful in the setting of abdominal malignancy or inflammatory bowel disease demonstrates closed-loop obstruction and findings suggestive of strangulation

40. Large Bowel Obstruction Causes: Cancer, Diverticulitis, and Volvulus Volvulus usually in elderly, bedridden, or psychiatric patients taking anticholinergic meds Sigmoid much more common than cecal Abdominal pain, crampy and intermittent, distention, may hear “rushes” – high pitched bowel sounds

41. Perforation Rebound tenderness Severe abdominal pain] Tympanitic to percussion Bilious vomitus in proximal obstruction Feculent vomitus in distal obstruction Flat plate and upright xray to look for free air Labs, elevated WBC

42. Perforated Bowel

43. Volvulus NG tube to decompress the bowel Barium enema can be diagnostic and therapeutic Sigmoidoscopy and rectal tube often successful Surgical with closed loop obstruction, cecal volvulus, or necrotic bowel Intravenous fluids Antibiotics

44. Volvulus

45. Adynamic Ileus Abdominal distention No Flatus, obstipation Increased Belching Conservative Therapy: IVF, NG decompression, observation Discontinue meds that inhibit bowel motility

46. Case A 22 year old woman presents to the ED complaining of severe lower abdominal pain. The pain began the day before presentation, and was crampy and intermittent, but she was awakened today at 4 am with severe pain which is constant, and lightheadedness. On exam, her vital signs are: pulse 130 and thready, BP 80/60, RR 28, T 37, O 2 sat 94%. She has lower abdominal tenderness. What is your diagnosis?

47. Ectopic Pregnancy: Epidemiology 2% of all pregnancies in the USA The leading cause of pregnancy-related death during the first trimester The second leading cause (10%) of all maternal mortality Case-fatality rate per 100,000 ectopic pregnancies has dropped considerably because of improved diagnostics (pregnancy tests and US) and heightened awareness: 1970 35.5 1980 8.8 1989 3.8

48. Risk Factors for Ectopic Pregnancy Ankum WM, et al. Fertil Steril 1996;65:1093 1.6 Early age of intercourse (<18 years) 1.1 - 3.1 Vaginal douching 2.5 Smoking 0.9 - 3.8 Previous pelvic/abdominal surgery Low 2.1 Multiple sexual partners 2.5 - 21 Infertility 2.5 - 3.7 Previous genital infections Moderate 2.4 - 13 In utero DES exposure 3.5 - 25 Tubal pathology 21 Previous tubal surgery 8.3 Previous ectopic pregnancy High Odds ratio Risk factors Degree of risk

49. Ectopic Pregnancy Risk factors, history and physical exam have poor sensitivity and specificity <50% of women with ectopic pregnancy give a history of risk factors Therefore, all women of reproductive age presenting with abdominal pain or abnormal vaginal bleeding should receive a qualitative pregnancy test If the pregnancy test is positive  further testing to exclude ectopic (ultrasound and quantitative HCG)

50. Ectopic Pregnancy Bedside transvaginal sonography (TVS): One question: “Is this pregnancy in the uterus?” Clear visualization of IUP excludes ectopic pregnancy except for the rare heterotopic pregnancy : historically 0.3/10000 but now overall incidence 1.25/10000 (.3/10000 up to 2.5-6.25/10000 in PID, and 33/10000 in reproductive technology and 100/10000 in IVF patients If an IUP is not seen, it is correlated with the discriminatory zone (DZ) of the quantitative HCG DZ = the threshold level above which a normal IUP should be seen on US A typical DZ is 1500-2000 mIU/ml for TVS (corresponds to 5-6 weeks from LMP)

51. IUP OB consultation IUP No IUP If low risk for ruptured ectopic: Repeat hCG in 48 hrs Repeat TVS in 48 hrs or when hCG >1500 to determine ectopic or miscarriage Resuscitation: IV crystalloid + blood bedside TVS No IUP “ formal” TVS IUP Ectopic or no IUP “ formal” TVS bedside bedside (-)

52. Abdominal Aortic Aneurysm: Physical Exam <1/2 of ruptured AAA’s present with the triad of abdominal or back pain, hypotension, and pulsatile mass >3/4 are normotensive Absence of abdominal pain or tenderness does not rule out contained leak into the retroperitoneum Neither the presence nor absence of femoral pulses or abdominal bruits are helpful clinically LR’s ≈ 1 Palpation of AAA is the only feature of the exam with clinical utility LR(+) = 12 (for >3 cm) — 16 (for >4 cm) LR(-) = 0.5-0.7 (i.e. poor) Therefore, inability to palpate an AAA should not deter workup

53. Abdominal Aortic Aneurysm: Diagnostic Testing Ultrasound Advantage: bedside availability can exclude AAA from the differential diagnosis Disadvantage: can’t identify leakage CT: the standard test for leaking/ruptured AAA For unstable patients If bedside US demonstrates AAA in suggestive clinical circumstances  this is taken as evidence of rupture

54. AAA

55. Case An 85 year old man with HTN, Type II diabetes mellitus, CAD, history of MI x 2, CHF with an ejection fraction of 20%, paroxysmal atrial fibrillation (not on warfarin), stroke x 2, presents with severe constant diffuse abdominal pain which began 1 hour ago after dinner. He had a normal bowel movement today and had a good appetite at dinner. On exam, the patient is crying out in distress and writhing around on the stretcher. His vital signs are: pulse 110, BP 150/100, RR 24, T 37, O 2 sat 92%. His abdomen is not distended, there are no bowel sounds, and the abdomen is non-tender throughout. What is your diagnosis?

56. Mesenteric Ischemia Several types Mesenteric venous thrombosis (MVT) Usually hypercoagulable Mesenteric artery disease (>60% of cases; mortality >60%) Occlusive disease (usually SMA) Thrombotic – usually long months of ischemia Embolic – 40-50% - usually mural thrombus from MI or a fib Nonocclusive disease (NOMI or low-flow state) Young patients tend to have either Arrhythmia (usually Afib)  embolization Hypercoagulable state  MVT Most patients are old with lots of comorbidities

57. Mesenteric Ischemia Diagnosis is difficult Pain is typically poorly localized and visceral, without tenderness (“pain out of proportion to exam”) May be abrupt in onset (embolism) or indolent (MVT) Patients often become transiently better after a few hours of ischemia because of mucosal infarction  then develop peritoneal findings hours later after full thickness necrosis Nausea, vomiting, may also have bloody stools Distention, late finding Elderly patients often do not appear as ill as they are Timely diagnosis requires early angiography Must maintain a high clinical suspicion

58. Mesenteric Ischemia Elevated WBC counts Metabolic Acidosis, elevated lactate Arteriography for early diagnosis if stable Key to make diagnosis before infarction occurs IVF, Antibiotics, bowel decompression Surgery if infarction or dead bowel (70% mortality) Anticoagulation, infusion of vasodilating drugs

59. Mesenteric Ischemia