Eric Niederhoffer

SIU-SOM

Channeling a Clinician:

Design and Construction of Clinical Scenarios for

Teaching and Assessment

Outline

• USMLE style scenario template• Resources for clinical information• Single or multiple disciplines• Discuss example designs

USMLE Style Scenario Template• A n-year-old (Age) boy/girl/man/woman (Gender) comes/is

brought to the physician/emergency department (Site of Care) for evaluation of/with a problem (Presenting Complaint including Duration and Patient/Family History).

• Physical examination shows some combination of pertinent findings (Height/Weight/BMI/Percentile, Temperature/Heart Rate/Breathing Rate/Blood Pressure).

• Laboratory studies show some combination of test results (Reference Ranges provided for non-adult age groups/special tests).

• Which drug, toxic exposure, diet; predict physical findings, lab findings, sequelae; identify underlying cause/mechanism/diagnosis, cause of drug response, drug to administer (Questions)

Resources for Clinical Information

• Height/weight for children (growth charts)/adultshttp://www.babycenter.com/average-fetal-length-weight-chart

http://pediatrics.about.com/cs/growthcharts2/l/bl_ibw_rslts.htm

http://www.cdc.gov/growthcharts/charts.htm

https://www.nhlbi.nih.gov/health/resources/heart/latino-weight-html/need

• Heart/respiration rate, blood pressure for childrenhttp://www.emedicinehealth.com/pediatric_vital_signs/article_em.htm

• Physical exam/heart/lung soundshttp://www.meddean.luc.edu/lumen/meded/medicine/pulmonar/pd/contents.htm

http://www.med.umich.edu/lrc/psb_open/repo/primer_heartsound/primer_heartsound.html

Reference RangesSerum Arterial Blood Gases

Na+ 135-147 mEq/L pH 7.35-7.45K+ 3.5-5.0 mEq/L Pa.CO2 (PCO2) 33-44 mm HgCl- 95-105 mEq/L Pa.O2 (PO2) 75-105 mm HgHCO3

- 22-28 mEq/L HCO3- 22-28 mEq/L

Ca2+ 8.4-10.2 mg/dL O2 saturation 96-100%Urea nitrogen 7-18 mg/dL Anion gap (no K+) 8-16 mEq/LGlucose, fasting 70-110 mg/dL with K+ 12-20 mEq/LCreatinine 0.6-1.2 mg/dL Bicarbonate gap -6-+6 mEq/LPhosphorus 3-4.5 mg/dL BloodTotal CO2 24-30 mEq/L Hemoglobin, male 13-16 g/dLTotal protein 6-7.8 g/dL female 12-15 g/dLAlbumin 3.5-5.5 g/dL Hematocrit, male 42-50%Osmolality 275-295 mOsm/kg water female 40-48%Uric acid 3-7 mg/dL O2 binding capacity 1.34 mL O2/g Hb

Lipids UrineTotal cholesterol <200 mg/dL Creatinine clearance 90-140 mL/minLDL <130 mg/dL Osmolality 50-1400 mOsm/kg waterHDL >40 mg/dL Specific gravity 1.003-1.030Triglycerides <160 mg/dL Protein <150 mg/24 h

Potential DiseasesDisease

Anemia

Chronic obstructive pulmonary disease

Diabetes

Down syndrome

Gout

Lactase deficiency

Marfan syndrome

5,10-Methylenetetrahydrofolate reductase deficiency

Minimal change disease

Mixed acid-base disorders

Muscular dystrophy

Parkinson disease

Potential Concepts

Concept

Protein/enzyme structure/function in health/disease

DNA structure/function, transcription/translation in health/disease

Signal transduction mediated cellular responses

Protein/enzyme small molecule interactions in health/disease

Regulation of metabolic flux

Serum chemistries (anion/bicarbonate gap) as marker for organ function/disease

Example of Single Discipline Question

A 3430 g (7 lb 9 oz) infant delivered at 42 weeks gestation to a primigravida woman shows a positive result for newborn screening of hemoglobin disorders. A complete blood count shows:

Hemoglobin 17.0 g/dL

Hematocrit 49%

Mean corpuscular volume 72 fL

Hemoglobin electrophoresis shows 80% HbA, 5% HbA2 and 15% HbF. A defect in which of the

following globin genes is most likely in this patient?

A. Alpha

B. Beta

C. Gamma

D. Delta

E. Epsilon

F. Zeta

Example of Multiple Discipline Question

A 51-year-old woman with a history of diarrhea poorly controlled with medication comes to the physician for evaluation of food intolerance. She is 170 cm (5 ft 7 in) tall and weighs 69 kg (152 lb); BMI is 24 kg/m 2. Her temperature is 37.5°C (99.5°F), pulse is 72/min, respirations are 22/min and blood pressure is 120/80 mm Hg. A complete blood count, serum studies, and hemoglobin electrophoresis show:

Hemoglobin 12.4 g/dL Albumin 2.8 g/dL HbA 93%

Hematocrit 37% CO2 content 22 mmol/L HbA2 5%

Mean corpuscular volume 72 fL HbF 2%

Serum iron concentration is within the reference range. All other values are within the reference ranges. A peripheral blood smear shows microcytosis. Additional laboratory studies show increased concentrations of tissue transglutaminase–immunoglobulin A and tissue transglutaminase–immunoglobulin G. Which of the following changes in globin expression is most likely in this patient?

A. Decreased post-translational modification of zeta globin gene product

B. Decreased transcription of alpha globin gene

C. Decreased translation of beta globin gene

D. Increased post-translational modification of zeta globin gene product

E. Increased transcription of alpha globin gene

F. Increased translation of beta globin gene

Let’s Discuss What We Have Designed

• Is the presenting complaint/situation clearly defined?

• Dpes the physical examination data make sense?

• Do the laboratory testing results allow students to exclude differentials

and/or focus on the primary concern (how bad is the condition)?

• Can students understand the problem by using the information or is it

recall?

• How can the scenarios be improved or altered to fit the educational need

(ask for a clinician’s assistance)?