Case library

Case reasoning report · CDEMO02

Hyponatremia in the Outpatient Clinic

A short student debrief on the osmolality-then-volume framework for classifying hyponatremia.

StudentOutpatient ClinicTest stewardshipDiagnostic ability
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What the cohort showed

Main pattern:Cohorts navigated this case close to the expected reasoning path.

What it means:No dominant failure mode — use this case to reinforce strong reasoning rather than remediate.

Teach next:Highlight the exemplary path in a short debrief and move the cohort to a harder case.

Expected reasoning pathway

What the case was designed to test, in order

Key clues

  • Fatigue
  • Serum sodium
  • Sodium

Expected differential

  • Syndrome of inappropriate antidiuresis (SIADH)Working diagnosis
  • HypothyroidismReasonable alternative
  • Primary polydipsiaReasonable alternative

Expected tests

  • No hidden orderable tests.

Expected management

  • Serum and urine osmolality with urine sodium
  • Mild fluid restriction and recheck sodium

Completion funnel

Where learners dropped off

Case startedDifferential submittedPlan submittedCase completed
Assigned
14
—
Started
13
−1
Completed timeline
12
−1
Submitted DDx
11
−1
Submitted plan
9
−2
Completed case
8
−1

Signal selection — do learners know what matters?

Recall per pin intent; the distractor row is fixation risk

Pinned findingTagged pin
Pin intentOpportunitiesPinnedRateMedian time
Diagnostic clue141179%36s
Safety red flag000%—
Context factor14964%—
Management modifier000%—
Distractorlower is better000%—

Test strategy & stewardship

Ordering as questions — expected vs ordered, and reveal rate for earned tests

Test orderedOrders submittedHidden tests revealed
Order intentExpectedOrderedReveal rate
Diagnostic workupRight test, right time1419over—
Safety monitoringMonitoring gates00—
Pretreatment baselineReadiness before treatment00—

Diagnostic reasoning — did learners land it, near-miss, or wander?

Diagnosis rankedDifferential submittedResult viewed
  • Exact match58%×1
  • Broader (ancestor)8%×0.85
  • Sibling (same parent)14%×0.4
  • No match20%×0

Tiers and multipliers from DDx scoring policy v1.0.0. ×n is the credit a match in that tier earns relative to an exact hit.

Can't-miss omissions

    Anchoring

    78% updated after discriminator

    22% kept their top diagnosis unchanged after a discriminating result.

    Top wrong diagnoses

    • Hypothyroidism12% · sibling

    Management & safety

    Contraindicated actions, baseline readiness, and sequencing

    Intervention selectedDrug orderedPlan submitted

    Killer / contraindicated selections

      0%

      missed baseline labs before treatment

      8%

      sequenced management unsafely

      Knowledge & evidence

      Quiz performance by domain and reasoning objective

      Question submittedAnswer selected

      By domain

      Test interpretation
      71%n=14
      Clinical knowledge
      79%n=14

      By objective kind

      Knowledge check
      75%n=28

      Faculty debrief

      A 10-minute debrief plan, grounded in the case teaching

      1. 1

        Osmolality first, then volume status

      Recommended for: Hyponatremia in the Outpatient Clinic · drawn from the case teaching module.

      Per-cohort pillar scores

      How each assigned cohort performed on this case

      CohortDiagnostic abilityTest stewardshipManagement & safetyKnowledge & evidence

      Med-2 Clerkship

      		68606275

      Cells colored by status thresholds from DDx scoring policy v1.0.0 — success ≥ 70, warning ≥ 40.