A Peculiar Case of Abdominal Pain

A Peculiar Case of Abdominal Pain James J. Foody, MD, FACP Vice Chairman of Medicine Northwestern University Feinberg School of Medicine June 17, 2005 History • CC: abdominal pain • Injury 5 days PTA-ketorolac & ibuprofen • Pain, vomiting 2 days PTA • Negatives: hematemesis, melena, diarrhea History • PMH: negative • FH: negative • SH: social alcohol, works as baggage handler; monogamous heterosexual; no illicit drugs • ROS: negative Physical Examination • BP 124/76; pulse 95; RR 18; T 37.2 • Height 177 cm; weight 69 kg; BMI 22 • Abdomen – diffuse tenderness w/ guarding – +/- diffuse rebound – bowel sounds normal – spleen not palpable #1 What is the most likely cause of abdominal pain in this setting? A. B. C. D. E. Irritable Bowel Syndrome Appendicitis Gallstone Disease Pancreatitis Peptic ulcer #1 What is the most likely cause of abdominal pain in this setting? B. Appendicitis Appendicitis • Most common in 2nd-3rd decade • Incidence 233/100,000/year in 10-19 year old • Male to female ratio 1.4:1 • Pain at McBurney’s point is late finding Rome II Criteria for IBS • • No structural or metabolic explanation At least 12 weeks of 2 of the following 1. Relieved by defecation 2. Onset with change of stool frequency 3. Onset with change of stool consistency • Supporting symptoms – Stool >3/day; <3/week; abnormal form; straining – Abdominal bloating Gallstone Prevalence • Older age • Female sex • Native American > Mexican American > Non-Hispanic white > Non-Hispanic black • Hemolytic anemia • Pregnancy • Estrogen • Obesity Pancreatitis • Prevalence of appendicitis 50x greater • Etiology – Gallstone • 35% attacks caused by gallstones • 3-7% people with gallstones develop pancreatitis • Small gallstones – – – – Alcohol Hypertriglyceridemia Hypercalcemia Drugs (e.g. didanosine, pentamadine, furosemide, etc.) Peptic Ulcer • Chronic time course – Duodenal ulcer relieved by eating – Gastric ulcer aggravated by eating • Chronic NSAID causes exacerbation Initial test results • • • • • • • • Hb 15.4 g/dL MCV 87 WBC 12,500; 86% neutrophils; 0 bands Sodium 143 Potassium 4.6 Chloride 103 Bicarbonate 29 Creatinine 3.2 BUN 29 Urinalysis • Trace protein • Trace blood • ++ ketones • SG 1.024 • Microscopic: no RBC; rare hyaline cast #2 What test(s) are most appropriate now? A. CT scan abdomen without contrast B. CT scan abdomen with contrast C. Exploratory laparoscopy D. Sonogram (ultrasound) of abdomen E. Serum b-hCG #2 What test(s) are most appropriate now? C. CT scan abdomen without contrast Rationale • CT contrast contraindicated in renal failure • Exploratory surgery more morbidity than further testing (5% complication rate) • Sonogram high positive predictive value, low negative predictive value for appendicitis • Serum b-hCG??? Abdominal CT w/o contrast NEGATIVE Clinical Algorithm for the Evaluation of Pain in the Right Lower Quadrant Paulson, E. K. et al. N Engl J Med 2003;348:236-242 #3 Is the elevated creatinine A. Part of the disease causing abdominal pain? B. Unrelated to abdominal pain? C. Likely a laboratory error? D. Due to a chronic pre-existing condition? #3 Is the elevated creatinine A. Part of the disease causing abdominal pain. Ockham’s Razor One should not increase, beyond what is necessary, the number of entities required to explain anything. William Ockham, OFM 1330 #3 Is the elevated creatinine A. Part of the disease causing abdominal pain? B. Unrelated to abdominal pain? C. Likely a laboratory error? D. Due to a chronic pre-existing condition? Hospital Course • • • • Admitted for observation & hydration Parenteral opioids in high doses for pain Surgical consultant declined to operate Serum amylase & lipase; urine amylase all normal • Sonogram hepatobiliary system normal • Emesis stopped; maximum temperature 37.7 • Eating resumes on day #4 Hospital Course-Diagnostics • • • • Transaminases all normal Serum c-ANCA & p-ANCA negative ANA negative MRA abdomen not consistent with vasculitis • Urine toxicology screen negative except opiates • Hemoglobin electrophoresis: A1 97.5%, A2 2.5% Differential Diagnosis • Appendicitis • Food poisoning • Pancreatitis • Cholecystitis • Peptic ulcer • Perforated viscus • Bowel obstruction • Drug intoxication • Hepatic hemangioma • Vasculitis • Celiac/mesenteric ischemia What next? Extended Differential Diagnosis • Henoch-Schönlein Purpura • Arsenic poisoning • Hereditary or acquired angioedema Henoch Schönlein Purpura Arsenic in Water Supply http://water.usgs.gov/nawqa/trace/pubs/fs-063-00/fig1.gif accessed 1/30/05 Hereditary Angioedema • Caused by a deficiency of C1-esterase inhibitor (C1 INH) • Initial episode typically in adolescence • In males, half of attacks are precipitated by trauma • Painless, non-pruritic skin and mucosal urticaria usually accompany other manifestations C1 INH http://webmed.unipv.it/immunology/complpaths.jpeg accessed 01/31/2005 Diagnostic tests • C1 esterase antigenic protein: normal • C1 esterase protein activity: normal • CH50: normal Differential Diagnosis • Adrenal crisis • Plumbism • Familial Mediterranean Fever • Acute intermittent porphyria #4 What is the best test for identifying adrenal crisis? A. B. C. D. E. Serum potassium Serum cortisol at 8 AM Serum cortisol at 5 PM 24 hour urinary free cortisol Retroperitoneal MR scan #4 What is the best test for identifying adrenal crisis? B. Serum cortisol at 8 AM 8 AM cortisol 7.4 μg/dL Sources of lead toxicity • Lead based paint (outlawed in USA 1955) – NHANES 13.6% prevalence of lead toxicity in urban black children • Leaded gasoline outlawed in USA 1976 • Lead solder on food cans outlawed 1991 – Still used in Latin America and Asia • Moonshine alcohol made in lead batteries – However, Chicago has plenty of liquor stores • Retained bullets #5 What is the best test for lead toxicity in this case? A. Serum lead B. Free erythrocyte protoporphyrin C. Radiographs of knees D. Urinary lead after EDTA infusion (chelation) #5 What is the best test for lead toxicity in this case? A. Serum lead Serum lead 0.4 μg/dL (normal <10) #6 Which statement best describes Familial Mediterranean Fever? A. I never heard of it. B. I think I might recognize the name, but I have no idea what it is. C. It is a recessive genetic disease due to mutations in the MEFV gene on the short arm of chromosome 16, causing recurrent episodes of polyserositis, leading to amyloidosis unless treated with colchicine. #6 Which statement best describes Familial Mediterranean Fever? Correct answers B & C http://www.utmb.edu/pmch/Porphyria/Porphyria accessed 01/27/05 www.photodermatologie.de/ Bilder/porphyria accessed 01/27/05 #7 What is the most sensitive and specific test for AIP? A. Urinary porphobilinogen B. I already forgot the previous slide #7 What is the most sensitive and specific test for AIP? A. Urinary porphobilinogen 43 mg in 24 hours (normal 0 to 4 mg/d)