Snapshot A 20-year-old college student presents to the emergency room after stepping on a piece of a rusted nail outside of his dorm. He reports that he has had all the appropriate childhood vaccinations but has had nothing since his last set of boosters at 10 years of age. His vital signs are within normal limits. Aside from erythema surrounding his left sole at the site of trauma, his physical exam is within normal limits. After cleaning the wound site, he is given the appropriate post-exposure prophylaxis. Introduction Classification Clostridium tetani anaerobic gram + rod produces tetanospasmin toxin transmission direct contact in contaminated soil Epidemiology demographics rare in the US more common in developing countries due to low rates of vaccination risk factors lack of vaccination trauma chronic wounds lack of immunity in mothers Pathogenesis forms spores that are resistant to heat and chemicals produces tetanospasmin, an exotoxin a protease that cleaves SNARE proteins (synaptobrevin 2), which blocks the release of inhibitory neurotransmitters (glycine and GABA) causes paralysis Associated conditions tetanus neonatal tetanus neonates who are born to unvaccinated mothers inability to suck or cry after day 2 of life colonization of the umbilical stump Prevention DTap vaccine vaccine against diphtheria, tetanus, and pertussis 5 doses before school-age, completed by 4-6 years of age Tdap vaccine booster vaccine at 11-12 years of age Td vaccine tetanus and diphtheria toxoid vaccine at 10-year intervals Prognosis spasms last for ~ 1 month mortality can be high if not treated Presentation Symptoms spastic paralysis muscle stiffness spasms fever Physical exam trismus lockjaw risus sardonicus raised eyebrows grin opisthotonos spinal muscle spasms causes backward arching of head and spine rigid abdominal muscles foul-smelling and erythematous umbilical stump in neonates Studies Serology or culture rarely used due to low sensitivity and specificity Making the diagnosis most cases are clinically diagnosed Differential Bacterial meningitis distinguishing factor nuchal rigidity without other signs of spastic paralysis Treatment Management approach treat all with antitoxin and booster if needed Conservative wound debridement indication all patients Medical tetanus antitoxin indication patients with contaminated or dirty wounds benzodiazepine indications muscle spasms booster vaccine indication patients with > 10 years from last dose patients with < 3 or uncertain number of tetanus vaccine doses Complications Respiratory compromise from spasm of respiratory muscles Aspiration pneumonia Contractures
QUESTIONS 1 of 7 1 2 3 4 5 6 7 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 (M1.MC.11) A 1-week-old infant that was birthed at home is rushed to the emergency room by his parents. His parents are recent immigrants who do not speak English. Through a translator, the child's parents say that during play with the infant, the infant's body became rigid and his mouth 'locked up'. The child likely suffered from a(n): Review Topic QID: 100432 1 Infection of a foot ulcer 0% (0/20) 2 Infection of the colon 0% (0/20) 3 Intrauterine infection 5% (1/20) 4 Infection of the umbilical stump 95% (19/20) 5 Dental infection 0% (0/20) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (M1.MC.74) A 6-year-old boy who recently immigrated to the United States is brought to the emergency department by his mother. His mother states that the boy had a deep cut several days ago, which she thoroughly washed and bandaged at home. He has now been having severe muscle spasms. When you examine the boy, you note the findings shown in Figure A. Which of the following best describes the pathological mechanism behind the boy's presentation? Review Topic QID: 106699 FIGURES: A 1 Inactivation of elongation factor 0% (0/22) 2 Increase in cyclic AMP 0% (0/22) 3 Destruction of protein leading to inhibition of neurotransmitter release 91% (20/22) 4 Destruction of cell membranes 5% (1/22) 5 Massive release of cytokines 0% (0/22) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 3 (M1.MC.1) A 71-year-old male is brought to the emergency room by his caretaker and presents with difficulty breathing, muscle rigidity in the face, neck, back and upper extremities, and profuse sweating. The intern notes a large wound on his head near the back of his right ear which his caretaker had bandaged up. The caretaker explains that the wound was the result of a fall while walking in his backyard. The intern performs a quick physical exam and observes increased reflexes. The patient was intubated to assist in his breathing and was given diazepam, metronidazole, and an immunoglobulin after the blood work came back. Which of the following neurotransmitters is affected in this patient? Review Topic QID: 106313 1 Glycine 63% (64/102) 2 Acetylcholine 26% (27/102) 3 Dopamine 4% (4/102) 4 Epinephrine 1% (1/102) 5 Serotonin 4% (4/102) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 1 (M1.MC.74) A one-week-old boy is brought to the emergency department by his mother, who recently immigrated to the United States and does not have health insurance. He was born at home, and has not received any medical care since birth. The mother states the boy has become irritable and has been feeding poorly. In the last day, she said he seems "stiff" and is having apparent muscle spasms. On your exam, you note the findings in figure A. Which of the following interventions might have prevented this disease? Review Topic QID: 106650 FIGURES: A 1 Conjugated polysaccharide vaccine given to infant at birth 11% (21/187) 2 Toxoid vaccine given to mother pre-natally 71% (132/187) 3 Vitamin injection given to newborn at birth 11% (21/187) 4 Improved maternal nutrition 4% (7/187) 5 Genetic counseling 2% (4/187) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 2 (M1.MC.1) A 9-year-old female child whose family recently emigrated from Afghanistan presents to the county hospital with difficulty swallowing and generalized muscle rigidity. Her parents note that although she is in severe pain she always appears to be smiling. After getting a detailed history from the parents, the residents comes to the conclusion that the child's clinical presentation is due to a lack of immunizations and a deep wound on her knee resulting from a fall six days ago. Which of the following is the mechanism of action of the toxin causing this child's symptoms? Review Topic QID: 106314 1 Inhibiting protein synthesis via ADP-ribosylation of elongation factor 2 0% (0/27) 2 Overactivating adenylate cyclase by ADP-ribosylation of the Gs alpha subunit 0% (0/27) 3 Overactivating adenylate cyclase by disabling the Gi subunit 0% (0/27) 4 Preventing release of GABA by cleaving of synaptobrevin 2 93% (25/27) 5 Preventing release of acetycholine by cleaving SNAP-25 4% (1/27) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 4 (M1.MC.22) A 45-year-old Caucasian male presents complaining of inability to open his mouth. Patient history reveals that he recently injured his foot from an exposed floor nail in his house. This patient's symptoms are likely the result of: Review Topic QID: 101481 1 Impaired motor neuron release of ACh 8% (1/12) 2 Impaired motor neuron release of GABA 83% (10/12) 3 Increased production of gas in his soft tissues 0% (0/12) 4 Cross-reactivity of bacterial antigens 0% (0/12) 5 Bacterial infiltration of the central nervous system 8% (1/12) M1 Select Answer to see Preferred Response PREFERRED RESPONSE 2