Diabetic ketoacidosis (DKA)

Source: saved session 01a154bf-cfa0-743b-9ef2-78cd8a7b7cd3, October 19, 2026.

The original physiology write-up and follow-up control instructions are preserved verbatim below. Desktop paths and verification claims refer to that original session, not this import. Educational material only; not a clinical protocol. Medical statements and cited consensus thresholds have not been independently verified during import. The original limitations include assumed full respiratory compensation, potassium discussed only in the caption, and the fluid-deficit beaker interpretation. Clinical review is required before teaching or patient-care use.

I built the DKA figure: an interactive bench machine where each part stands for one piece of the physiology, driven by a small numerical model. Both pages open with no console errors. The line-end check showed no stray lines in either theme, at rest, in full DKA and partway through treatment. Hover and treatment both work in the browser, and I checked the desktop, phone and close-up views.

Files are in ~/Desktop/02_projects/anatomy-dka/:

dka.html and dka-light.html: the dark and light versions of the figure.
build.mjs: the model plus the drawing code. Rebuild with node build.mjs (add --light for the light page, or --table to print the numbers).
preview-dark.png and preview-light.png: snapshots at full DKA.

What each part stands for

Part	Meaning
Hopper with two valves on one bar	The liver: one valve releases glucose, the other ketoacids
Syringe holding the bar up	Insulin, keeping both valves shut
Springs pushing the bar down	Glucagon, cortisol and adrenaline, which push the valves open
Left column	Blood glucose. Above 180 mg/dL it spills over a lip into the beaker (urine), taking water with it
Right column, piston (the highlighted part)	Bicarbonate below the piston, ketone acids above it. Each acid uses up one bicarbonate, so the piston drops as the anion gap (the readout's AG) grows
Bellows on springs	The lungs, breathing out CO₂. They breathe deeper and faster as acid builds (Kussmaul breathing)
Dial	Blood pH, with a red band below 7.30
Red marks on the scales	DKA thresholds: glucose 200 mg/dL, bicarbonate 18

How it works

Hover: moving the pointer from left to right goes from normal insulin to none. Glucose rises first, and ketones climb once fat breakdown is no longer held back.
Click (or Space): runs 24 hours of treatment (fluids plus insulin at 0.1 U/kg/h) in about 15 seconds. Glucose reaches 200 mg/dL by about 5 h, when dextrose is added. Bicarbonate passes 18 at about 5 h, but β-hydroxybutyrate (the main ketone) takes about 15 h to fall below 0.6. That is the main teaching point: insulin keeps running until the ketones clear, not until the glucose does.
Readout: treatment hour (while treating) · glucose · β-hydroxybutyrate · bicarbonate · pH · anion gap.
When nobody is interacting: it loops on its own through normal, DKA developing, treatment and recovery.

Model and sources

Diagnosis and thresholds follow the 2024 ADA/EASD/JBDS/AACE/DTS consensus. DKA means glucose ≥ 200 mg/dL (or known diabetes), β-hydroxybutyrate ≥ 3.0 mmol/L, and pH < 7.3 and/or bicarbonate < 18. Resolution is β-hydroxybutyrate < 0.6 plus pH ≥ 7.3 or bicarbonate ≥ 18.
Breathing follows Winter's formula: expected PaCO₂ = 1.5 × bicarbonate + 8.
pH comes from the Henderson–Hasselbalch equation.
The rise in anion gap equals the fall in bicarbonate.
Water lost through the urine reaches up to about 7 L.

Limitations

Breathing is assumed to keep up fully. So with no insulin the model reaches pH 7.15, not below 7.0, even though bicarbonate (5) and β-hydroxybutyrate (14) are in the severe range. Real patients often fall short of full compensation and reach lower pH.
Potassium is in the caption only, not the drawing or readout. The caption covers the key point: check potassium is ≥ 3.5 before starting insulin.
One possible confusion: the beaker shows water still owed. It empties during treatment as fluids repay the deficit, not because urine flows back.

I've opened the light version (dka-light.html) in your browser. To open the dark version, run open ~/Desktop/02_projects/anatomy-dka/dka.html.

There are no on-screen buttons. Everything is controlled with the mouse or keyboard directly on the figure.

Mouse

Move across the figure: sets how much insulin is missing. The far left is normal insulin and the far right is none (full DKA). Pointer movement is ignored while treatment is running.
Click: starts the 24-hour treatment. Clicking again while it runs stops it.

Keyboard (press Tab to select the figure first; a thin outline appears)

Key	Action
→ or ↑	Less insulin (5% steps)
← or ↓	More insulin (5% steps)
Shift + arrow	25% steps
Home	Normal insulin
End	No insulin (full DKA)
Space or Enter	Start or stop treatment

Clicking also selects the figure for the keys, but it starts treatment at the same time. Tab selects it without that.

Touch: a tap starts treatment. Phones have no hover, so you can't set the insulin level by hand there; the automatic loop shows the full range.

When you stop interacting for 4 seconds, the automatic loop takes over again: normal, DKA developing, treatment, recovery.