EM Notes @ Jack CF Chong (張志華): 09/27/26

Sunday, September 27, 2026

Diabetic Ketoacidosis: Treat Ketones, Not Just Glucose

Diagnostic Framework

DKA requires all three of the following:
- Diabetes history or glucose at least 200 mg/dL.
- Ketosis.
- Metabolic acidosis.
Prefer blood beta-hydroxybutyrate when available.
- A value at least 3.0 mmol/L supports DKA.
- Neither glucose alone nor an anion gap alone establishes the diagnosis.

Use balanced crystalloids when available. Normal saline remains acceptable when balanced fluids are unavailable.
Reassess serially:
- Hemodynamics and urine output.
- Electrolytes.
- Glucose and acid-base status.

Potassium determines whether insulin can safely begin.
If potassium is below 3.5 mEq/L:
- Hold insulin.
- Replace potassium first.
If potassium is 3.5 to 5.0 mEq/L:
- Add 20 to 30 mEq potassium to each liter of intravenous fluid.
If potassium exceeds 5.0 mEq/L:
- Withhold initial replacement.
- Monitor closely.
Aim for potassium 4 to 5 mEq/L.

Once potassium is safe, use intravenous insulin.
Target a glucose decline of 50 to 70 mg/dL each hour.
When glucose falls below 200 mg/dL:
- Add dextrose.
- Continue insulin until ketosis and acidosis resolve.
Give basal insulin 2 to 4 hours before discontinuing the intravenous insulin infusion.

The endpoint is biochemical resolution, not euglycemia.
When beta-hydroxybutyrate is available, resolution requires:
- Plasma ketones below 0.6 mmol/L.
- Venous pH at least 7.30 or bicarbonate at least 18 mmol/L.
- Glucose ideally below 200 mg/dL.
Do not use anion-gap normalization as the primary endpoint. Saline-related hyperchloremic acidosis can persist after ketone clearance.

Key point: Treat ketone clearance and metabolic-acidosis resolution, not glucose alone.
This adult educational summary does not replace local DKA, ICU, perioperative, or endocrinology protocols.

Trephination is the controlled creation of a small opening in the nail plate to decompress a painful subungual hematoma.
A subungual hematoma is blood trapped beneath a fingernail after trauma.
Decompression can rapidly relieve pressure and throbbing pain.
The procedure is most useful when the hematoma is painful and the nail plate is intact and adherent to the nail bed.

Examine and document:
- Neurovascular status.
- Sensation and range of motion.
- Nail stability.
- Lacerations and contamination.
- Evidence of fracture.
Consider radiographs after a crush injury or with significant tenderness.
Seek hand-surgery assessment rather than simple trephination when there is:
- A displaced fracture.
- A disrupted or avulsed nail plate.
- Gross contamination.
- A suspected complex nail-bed laceration.

Obtain consent and clean the nail.
Anesthesia is often unnecessary because decompression is brief, but a digital block can be offered.
Create 1 or more small openings over the hematoma with electrocautery or a sterile needle.
Avoid excessive depth and contact with the nail bed.
Allow blood to drain. Gentle pressure may help.
Irrigate when needed and apply a nonadherent dressing.

Keep the digit clean and dry.
Change the dressing as instructed.
Use elevation, ice, and analgesia as needed.
Drainage may continue for 24 to 48 hours.
Routine antibiotics are generally not required for an uncomplicated injury. Management may change with an open fracture, contamination, immunocompromise, or bite injury.
Address tetanus status when indicated.
Advise urgent reassessment for increasing pain, redness, warmth, swelling, pus, fever, numbness, or impaired motion.
The nail may remain discolored or eventually shed. Regrowth takes months.

Simple trephination is a focused decompression procedure for a painful subungual hematoma with an intact, adherent nail plate.
Evaluate for associated fracture, nail disruption, contamination, and complex nail-bed injury before proceeding.
Local protocols and specialist advice should guide atypical injuries.