Snapshot A 73-year-old woman presents with severe abdominal pain and a recent history of passing bloody stools. The pain began about 3 days ago and is more concentrated at the left side of the abdomen. Physical examination shows decreased-to-absent bowel sounds, abdominal distention, and diffuse tenderness to palpation over her abdomen. A barium-enema study is performed which shows "thumb-printing" of the colon. Introduction Clinical definition medical condition characterized by inadequate blood supply to the large intestine leading to inflammation and injury of the colon Epidemiology demographics more common in the elderly population most common form of bowel ischemia risk factors aortoiliac surgery/instrumentation myocardial infarction hemodialysis hypercoagulable states (e.g., hereditary thrombophilia) Pathogenesis ischemic colitis is the result of blood flow reduction to the colon and is particularly prominent at the “watershed” areas of the colon where collateral blood flow is limited the splenic flexure and rectosigmoid junction are particularly at risk for ischemia nonocclusive colonic ischemia accounts for the mass majority of cases (95%) typically transient hypoperfusion examples include shock, systemic hypotension or atherosclerosis of SMA occlusive colonic ischemia can be embolic (e.g., spontaneous or iatrogenic) or thrombotic secondary to atherosclerotic disease mesenteric vein thrombosis extremely rare and usually involves the small intestine Presentation Symptoms mild cramping abdominal pain commonly involving the left side less severe compared to mesenteric ischemia hematochezia usually follows within 24 hours after abdominal pain diarrhea vomiting Physical exam fever abdominal tenderness weight loss Imaging Abdominal radiograph usually normal but may be useful in excluding other causes of abdominal pain may also identify complications of mesenteric ischemia (e.g., necrosis) Computed tomography (CT) without oral contrast best initial test may see bowel wall thickening in a segmental pattern (thumbprinting), bowel dilation, mesenteric stranding, or intestinal pneumatosis Endoscopic evaluation can be done via colonoscopy for flexible sigmoidoscopy allows for biopsy of suspicious areas positive findings include edematous, friable mucosa, erythema, and interspersed pale areas Studies Laboratory studies leukocytosis elevated lactate metabolic acidosis Differential Mesenteric ischemia differentiating factors commonly presents with severe abdominal pain and does not accompany hematochezia Colonic malignancy differentiating factors will appear differently on endoscopy and abdominal CT Treatment Management approach treatment is dependent on its etiology, severity, and the clinical setting Mild colonic ischemia supportive care bowel rest and observation nasogastric tube if ileus is present monitor for persistent fever, leukocytosis, peritonitis, or other signs of clinical deterioration most patients will recover within days Moderate colonic ischemia antibiotics antithrombotic therapy indicated for patients with mesenteric venous thrombosis or thromboembolism Severe colonic ischemia signs of peritonitis, pneumatosis on imaging, or gangrene on colonoscopy exploratory laparotomy inidicated in patients with signs of bowel ischemia resected of necrotic bowel if applicable Complications Bowel necrosis Perforation Sepsis Death Stricture/obstruction
QUESTIONS 1 of 2 1 2 Previous Next Lab Values Blood Hematologic Cerebrospinal Sweat, Urine, and BMI Blood, Plasma, Serum Reference Range ALT 8-20 U/L Amylase, serum 25-125 U/L AST 8-20 U/L Bilirubin, serum (adult) Total // Direct 0.1-1.0 mg/dL // 0.0-0.3 mg/dL Calcium, serum (Ca2+) 8.4-10.2 mg/dL Cholesterol, serum Rec: < 200 mg/dL Cortisol, serum 0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h Creatine kinase, serum Male: 25-90 U/LFemale: 10-70 U/L Creatinine, serum 0.6-1.2 mg/dL Electrolytes, serum Sodium (Na+) 136-145 mEq/L Chloride (Cl-) 95-105 mEq/L Potassium (K+) 3.5-5.0 mEq/L Bicarbonate (HCO3-) 22-28 mEq/L Magnesium (Mg2+) 1.5-2.0 mEq/L Estriol, total, serum (in pregnancy) 24-28 wks // 32-36 wks 30-170 ng/mL // 60-280 ng/mL 28-32 wk // 36-40 wks 40-220 ng/mL // 80-350 ng/mL Ferritin, serum Male: 15-200 ng/mLFemale: 12-150 ng/mL Follicle-stimulating hormone, serum/plasma Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250 pH 7.35-7.45 PCO2 33-45 mmHg PO2 75-105 mmHg Glucose, serum Fasting: 70-110 mg/dL2-h postprandial:<120 mg/dL Growth hormone - arginine stimulation Fasting: <5 ng/mLProvocative stimuli: > 7ng/mL Immunoglobulins, serum IgA 76-390 mg/dL IgE 0-380 IU/mL IgG 650-1500 mg/dL IgM 40-345 mg/dL Iron 50-170 μg/dL Lactate dehydrogenase, serum 45-90 U/L Luteinizing hormone, serum/plasma Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL Osmolality, serum 275-295 mOsmol/kd H2O Parathyroid hormone, serume, N-terminal 230-630 pg/mL Phosphatase (alkaline), serum (p-NPP at 30° C) 20-70 U/L Phosphorus (inorganic), serum 3.0-4.5 mg/dL Prolactin, serum (hPRL) < 20 ng/mL Proteins, serum Total (recumbent) 6.0-7.8 g/dL Albumin 3.5-5.5 g/dL Globulin 2.3-3.5 g/dL Thyroid-stimulating hormone, serum or plasma .5-5.0 μU/mL Thyroidal iodine (123I) uptake 8%-30% of administered dose/24h Thyroxine (T4), serum 5-12 μg/dL Triglycerides, serum 35-160 mg/dL Triiodothyronine (T3), serum (RIA) 115-190 ng/dL Triiodothyronine (T3) resin uptake 25%-35% Urea nitrogen, serum 7-18 mg/dL Uric acid, serum 3.0-8.2 mg/dL Hematologic Reference Range Bleeding time 2-7 minutes Erythrocyte count Male: 4.3-5.9 million/mm3Female: 3.5-5.5 million mm3 Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/hFemale: 0-20 mm/h Hematocrit Male: 41%-53%Female: 36%-46% Hemoglobin A1c ≤ 6 % Hemoglobin, blood Male: 13.5-17.5 g/dLFemale: 12.0-16.0 g/dL Hemoglobin, plasma 1-4 mg/dL Leukocyte count and differential Leukocyte count 4,500-11,000/mm3 Segmented neutrophils 54%-62% Bands 3%-5% Eosinophils 1%-3% Basophils 0%-0.75% Lymphocytes 25%-33% Monocytes 3%-7% Mean corpuscular hemoglobin 25.4-34.6 pg/cell Mean corpuscular hemoglobin concentration 31%-36% Hb/cell Mean corpuscular volume 80-100 μm3 Partial thromboplastin time (activated) 25-40 seconds Platelet count 150,000-400,000/mm3 Prothrombin time 11-15 seconds Reticulocyte count 0.5%-1.5% of red cells Thrombin time < 2 seconds deviation from control Volume Plasma Male: 25-43 mL/kgFemale: 28-45 mL/kg Red cell Male: 20-36 mL/kgFemale: 19-31 mL/kg Cerebrospinal Fluid Reference Range Cell count 0-5/mm3 Chloride 118-132 mEq/L Gamma globulin 3%-12% total proteins Glucose 40-70 mg/dL Pressure 70-180 mm H2O Proteins, total < 40 mg/dL Sweat Reference Range Chloride 0-35 mmol/L Urine Calcium 100-300 mg/24 h Chloride Varies with intake Creatinine clearance Male: 97-137 mL/minFemale: 88-128 mL/min Estriol, total (in pregnancy) 30 wks 6-18 mg/24 h 35 wks 9-28 mg/24 h 40 wks 13-42 mg/24 h 17-Hydroxycorticosteroids Male: 3.0-10.0 mg/24 hFemale: 2.0-8.0 mg/24 h 17-Ketosteroids, total Male: 8-20 mg/24 hFemale: 6-15 mg/24 h Osmolality 50-1400 mOsmol/kg H2O Oxalate 8-40 μg/mL Potassium Varies with diet Proteins, total < 150 mg/24 h Sodium Varies with diet Uric acid Varies with diet Body Mass Index (BMI) Adult: 19-25 kg/m2 Calculator ( ) xy AC 7 8 9 ÷ 4 5 6 × 1 2 3 - 0 . = + You have 100% on this question. Just skip this one for now. Take This Question Anyway (M1.GI.91) A 71-year-old Caucasian male presents to your office with bloody diarrhea and epigastric pain that occurs 30 minutes after eating. He has lost 15 pounds in 1 month, which he attributes to fear that the pain will return following a meal. He has a history of hyperlipidemia and myocardial infarction. Physical exam and esophagogastroduodenoscopy are unremarkable. What is the most likely cause of this patient's pain? Review Topic | Tested Concept QID: 101148 Type & Select Correct Answer 1 Atherosclerosis 50% (58/115) 2 Peptic ulcer disease 26% (30/115) 3 Crohn's disease 3% (4/115) 4 Amyloid deposition 5% (6/115) 5 Diverticulosis 13% (15/115) M1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 You have 100% on this question. Just skip this one for now. Take This Question Anyway (M1.GI.107) A 75-year-old male is hospitalized for bloody diarrhea and abdominal pain after meals. Endoscopic work-up and CT scan lead the attending physician to diagnose ischemic colitis at the splenic flexure. Which of the following would most likely predispose this patient to ischemic colitis: Review Topic | Tested Concept QID: 101164 Type & Select Correct Answer 1 Increased splanchnic blood flow following a large meal 18% (38/207) 2 Essential hypertension 20% (42/207) 3 Obstruction of the abdominal aorta following surgery 51% (106/207) 4 Hyperreninemic hyperaldosteronism secondary to type II diabetes mellitus 4% (9/207) 5 Juxtaglomerular cell tumor 5% (10/207) M1 Question Complexity A Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3