DKA versus HHS: two ways glucose becomes an emergency
| DIABETIC KETOACIDOSIS | HYPEROSMOLAR HYPERGLYCEMIC STATE | |
|---|---|---|
| Who | Usually younger, usually type 1 diabetes, often after an infection or a missed insulin dose | Usually an older adult with type 2 diabetes, often during an illness that limited access to fluids |
| Speed | Hours | Days, which is why the patient arrives far more dehydrated |
| Insulin | Almost none, so fat is broken down and ketoacids accumulate | Enough residual insulin to suppress ketone formation, not enough to control glucose |
| Acid | Metabolic acidosis with ketones in blood and urine | No significant ketosis and no acidosis |
| Breathing | Deep, rapid Kussmaul respirations, with a fruity acetone odor on the breath | Normal or merely rapid; there is no acidosis to blow off |
| Mental status | Alert to drowsy | Profound obtundation is characteristic, and it tracks with serum osmolality |
| Abdomen | Nausea, vomiting, and abdominal pain are common and can mimic a surgical abdomen | Uncommon |
The shared treatment sequence. Both conditions are corrected in the same order, and the order is the tested part. Isotonic fluid comes first, because the immediate threat in both is volume loss, and in hyperosmolar hyperglycemic state that deficit can be enormous. An insulin infusion follows. Potassium replacement is then guided by serial values → BOOK 07 · P6.
Watch outinsulin is withheld until a low serum potassium has been corrected. Total body potassium is already depleted in both conditions even when the serum value looks acceptable, and insulin drives potassium into cells. Giving insulin to a hypokalemic patient can precipitate a fatal arrhythmia. Dextrose is added to the intravenous fluid once glucose falls to the ordered threshold, to prevent hypoglycemia and to slow the osmotic shift that causes cerebral edema.
Margin noteglycemic thresholds and treatment targets are revised every year. Verify every number on this page against the current ADA Standards of Care in Diabetes before you rely on it, and never memorize a target without its edition year. Values themselves are → BOOK 07 · P6; insulin pharmacology is → BOOK 05; drip rates are → BOOK 06 · P8.
Memory hookKETONES ARE KUSSMAUL. If the breathing is deep and fast, you are in the acid problem.
Margin notefluids before insulin, always.
Takeawaydiabetic ketoacidosis is an acid problem that arrives in hours, hyperosmolar hyperglycemic state is a water problem that arrives in days, and both are treated fluid first.