Diabetic Ketoacidosis Calculator (Adult)

Diabetic ketoacidosis management rests on three parallel tracks -- fluid resuscitation, insulin therapy, and electrolyte monitoring -- and this calculator surfaces the key numbers for each from six inputs: weight, glucose, potassium, and three basic electrolytes. This tool implements ADULT DKA resuscitation only and requires a body weight of at least 40 kg; pediatric DKA uses different fluid-bolus and insulin-rate protocols (smaller boluses, slower insulin infusion) specifically because of cerebral-edema risk in children, and this calculator does not implement that separate protocol. Severity, fluid, and insulin-dosing figures follow the ADA's Hyperglycemic Crises position statement (Kitabchi et al., 2009). The anion gap, sodium minus the sum of chloride and bicarbonate, is the core diagnostic marker for the metabolic acidosis that defines DKA; sodium adds to the gap while chloride and bicarbonate subtract from it, all three with equal weight in the formula. Neither body weight nor glucose enters the anion gap calculation at all -- weight instead drives the fluid bolus and insulin infusion rate, and glucose instead drives the corrected sodium calculation, which adds 1.6 mEq/L to the measured sodium for every 100 mg/dL that glucose sits above 100, correcting for the dilutional pseudohyponatremia that hyperglycemia itself causes.

Effective osmolality (2 times sodium plus glucose divided by 18) deliberately excludes blood urea nitrogen, unlike total osmolality -- because urea crosses cell membranes freely and doesn't drive the fluid shifts that osmotic derangement causes, effective osmolality is the more clinically relevant figure for assessing altered mental status risk in DKA and hyperosmolar states. Severity classification here uses bicarbonate alone, consistent with ADA-style criteria: severe below 10, moderate 10-14.9, mild 15-17.9, not-DKA/resolving at 18 or above. Critically, this calculator enforces the ADA potassium safety gate on the insulin infusion rate: if potassium is below 3.3 mEq/L, the insulin rate is reported as zero and held, regardless of body weight, because starting insulin before potassium is corrected drives potassium further into cells and can precipitate a fatal arrhythmia. Weight only scales the insulin rate once potassium is at or above that threshold. This tool computes point-in-time numbers from entered labs -- it does not replace an institutional DKA protocol, ongoing reassessment, or physician judgment on fluid and insulin titration as labs and potassium change over the resuscitation.