Jan

19

2026

Module 4 — Boundary Drill (Practice & Reflection)

By William Aird

Leukocytosis in the hospitalized patient
A category-discipline drill to strengthen consult reasoning

1. How this module fits in Consult Practice

LensWhat it contributes here
OrientationDefines which facts describe terrain (context, trajectory, differential)
ThinkingDefines stance and weighting (signal-discrimination, measured vigilance)
ExecutionDefines what is communicated, watched, and revised

2. What this module is for

To practice:
Is this fact defining terrain, changing posture, or directing visible execution?

3. How to use this module

Use on rounds or during sign-out.

For each line:

  • assign it to Orientation, Thinking, or Execution
  • state what it changes in your posture
  • state what would cause you to revise that assignment

This makes cognitive discipline explicit and teachable.

4. Why this matters

Sorting protects against two common errors:

  • magnitude-only alarmism
  • premature reassurance (“it’s sepsis, so it’s fine”)

Most consult mistakes in leukocytosis are failures of category discipline, not failures of knowledge.

5. Core Content

Sorting cards

  1. WBC 30K, new today, was 12K yesterday.
  2. Patient is improving clinically on antibiotics.
  3. Differential shows 92% neutrophils with left shift.
  4. Smear shows blasts.
  5. This is a signal-discrimination problem, not a diagnosis.
  6. We should maintain measured vigilance and avoid premature closure.
  7. Repeat CBC and differential to follow trajectory.
  8. If blasts appear or the count accelerates, we will escalate the evaluation.
  9. Right now the leukocytosis is being treated as meaningful but provisional.
  10. Now that the count is falling and the patient remains stable, we can release earlier concern.

Answer key

CardDomain
1Orientation
2Orientation
3Orientation
4Orientation
5Thinking
6Thinking
7Execution
8Execution
9Execution
10Execution

6. Bottom line

This module reinforces category discipline:

  • Orientation defines the map
  • Thinking assigns weight
  • Execution makes judgment visible

Leukocytosis is a signal.
Sorting protects against magnitude-driven error and premature narrative closure.