Review Topic
2 2
  • A 69-year-old female presents to the emergency room for bright red blood per rectum for the past 2 hours. She noticed some blood in her stool shortly after experiencing some abdominal pain. The pain is reported as dull, achy, 5/10, and concentrated at the left lower quadrant. Her past medical history is significant for hypertension and a past myocardial infarction (MI).
  • 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 or systemic hypotension 
    • 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
  • Symptoms 
    • mild cramping abdominal pain commonly involving the left side  
      • less severe compared to mesenteric ischemia
    • hematochezia 
      • usually follows after abdominal pain
    • diarrhea
    • vomiting
  • Physical exam
    • fever
    • abdominal tenderness
    • weight loss
  • Diagnostic testing
    • diagnostic approach
      • diagnosis is often based on clinical presentation and confirmed via endoscopy
    • 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
  • 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
  • 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
  • Bowel necrosis
  • Perforation
  • Sepsis
  • Death
  • Stricture/obstruction

Please rate topic.

Average 3.1 of 7 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Questions (2)
Lab Values
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/L
Female: 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/mL
Female: 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/dL
2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation Fasting: <5 ng/mL
Provocative 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/mm3
Female: 3.5-5.5 million mm3
Erythrocyte sedimentation rate (Westergren) Male: 0-15 mm/h
Female: 0-20 mm/h
Hematocrit Male: 41%-53%
Female: 36%-46%
Hemoglobin A1c ≤ 6 %
Hemoglobin, blood Male: 13.5-17.5 g/dL
Female: 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
Plasma Male: 25-43 mL/kg
Female: 28-45 mL/kg
Red cell Male: 20-36 mL/kg
Female: 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
Calcium 100-300 mg/24 h
Chloride Varies with intake
Creatinine clearance Male: 97-137 mL/min
Female: 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 h
Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total Male: 8-20 mg/24 h
Female: 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

Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Question locked
Sorry, this question is for
PEAK Premium Subscribers only
Upgrade to PEAK
Topic COMMENTS (0)
Private Note