Snapshot A 44-year-old woman presents to the emergency room for watery diarrhea for 3 days. She was recently admitted to the hospital for a urinary tract infection and discharged to finish a course of ampicillin. She completed this course 2 weeks ago. She reports seeing occasional blood in her diarrhea, but that it has mostly been watery. She also reports having anorexia, malaise, and cramping abdominal pain. On physical exam, she is dehydrated and has tenderness to palpation in the abdomen. She is found with a marked leukocytosis and started on fluids as well as oral vancomycin. Introduction Classification Clostridium difficile anaerobic gram + rod produces 2 toxins that bind to intestinal mucosal cells forms heat-resistant spores Epidemiology incidence common risk factors recent antibiotics use clindamycin ampicillin cephalosporins fluoroquinolones proton-pump inhibitors recent hospitalization advanced age Pathogenesis causes a pseudomembranous colitis and diarrhea characterized by yellow-white plaques in intestinal mucosa toxin A is an enterotoxin that binds to the intestinal brush border toxin B is a cytotoxin and depolymerizes actin, disrupting the cytoskeleton Prognosis relapse occurs in ~20% of patients Presentation Symptoms crampy abdominal pain anorexia malaise diarrhea typically watery diarrhea occasionally may be bloody but without frank blood Physical exam fever dehydration abdominal tenderness to palpation rebound tenderness in severe cases Imaging Abdominal radiography indications if toxic megacolon is suspected for quick diagnosis and assess for early intervention findings dilated colon Sigmoidoscopy/colonoscopy indication if laboratory evaluation is unclear not always necessary findings pseudomembranes on intestinal mucosa Abdominal computed tomography (CT) indication suspicion for pseudomembranous colitis findings marked thickening of the colonic wall irregularity of bowel wall pericolonic stranding Studies Labs ↑ white blood cells ↓ hypoalbuminemia ↑ lactate diagnostic tests of the stool polymerase chain reaction for the organism detection of toxin + fecal leukocytes Making the diagnosis based on clinical presentation and stool studies Differential Ulcerative colitis distinguishing factors typically presents with bloody diarrhea can also present with dermatologic manifestations such as erythema nodosum Crohn disease distinguishing factors can be bloody or nonbloody can present with fistulas can also present with dermatologic manifestations such as erythema nodosum Treatment Management approach 10-day course of antibiotics discontinue inciting antibiotics or other drugs Medical oral vancomycin indications first line severe cases fidaxomicin indication recurrent cases oral metronidazole indications used as an alternative if vancomycin or fidaxomicin are not available used in addition to vancomycin if patients are refractory to monotherapy contraindicated in the elderly fecal microbiota transplant indication recurrent cases Complications Colonic perforation occurs in small percentage of patients Toxic megacolon occurs in small percentage of patients
QUESTIONS 1 of 5 1 2 3 4 5 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 . = + Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK You have 100% on this question. Just skip this one for now. Take This Question Anyway (M2.ID.26) A 33-year-old man presents to the emergency room for diarrhea. He states it is profuse and watery and has not been improving over the past week. He is generally healthy; however, he was recently hospitalized during spring break and treated for alcohol intoxication and an aspiration pneumonia. While on spring break, the patient also went camping and admits eating undercooked chicken and drinking from mountain streams. His temperature is 100.5°F (38.1°C), blood pressure is 111/74 mmHg, pulse is 110/min, respirations are 16/min, and oxygen saturation is 98% on room air. Physical exam is notable for a fatigued appearing man. His abdomen is non-tender. Which of the following is the best management of this patient? Review Topic | Tested Concept QID: 103516 Type & Select Correct Answer 1 Ciprofloxacin 3% (1/30) 2 Ciprofloxacin and metronidazole 10% (3/30) 3 Metronidazole 40% (12/30) 4 No treatment indicated 43% (13/30) 5 Vancomycin 0% (0/30) M2 D Tested Select Answer to see Preferred Response SUBMIT RESPONSE 5