DKA-To diagnose

Tintenelli 7th:

When DKA is suspected, initial steps should include a test-strip glucose determination, a urine test strip, an ECG, venous blood gas determination, and a normal saline (NS) IV infusion.

A blood glucose level >250 milligrams/dL, an anion gap >10, a bicarbonate level <15 mEq/L, and pH <7.3 with moderate ketonemia constitute the diagnosis.

Patients who present just after receiving insulin or who have impaired gluconeogenesis (alcohol abuse or liver failure) may have lower initial serum glucose levels. Elevated serum levels of HB and AcAc cause acidosis and ketonuria. The nitroprusside reagent normally used to detect urine and serum ketones only detects AcAc; acetone is only weakly reactive and HB not at all. NADH accumulation in mitochondria, as may occur with lactic acidosis or alcohol metabolism, favors the HB side of equilibrium noted earlier (AcAc + NADH ⇌ HB + NAD). The enzymatic test for HB is reliable but not widely available. Paradoxically, as the patient is being treated and clinically improves, measured ketone levels will increase as the body converts the more acidic HB to AcAc. Serum electrolytes should be examined carefully for multiple metabolic abnormalities. Elevated serum ketone levels lead to a wide anion gap metabolic acidosis. Hyperchloremic acidosis also occurs on the basis of ketoanion exchange for chloride in the urine and is especially common in patients who maintain good hydration status and glomerular filtration rate despite ketoacidosis. Metabolic alkalosis also can occur secondary to vomiting, osmotic diuresis, and concomitant diuretic use.

Some patients with DKA may present with normal-appearing [HCO3–] or even an elevated [HCO3–], if coexisting metabolic alkalosis is severe enough to mask the acidosis. In such situations, an elevated anion gap may be the only clue to the presence of an underlying metabolic acidosis otherwise masked by the concomitant volume contraction-related metabolic alkalosis.


According to James G Adam Emergency Medicine (co-author of Rosen) page 1744 :
1.No single standard lab diagnosis for DKA..however any diagnosis for DKA should include

a.Glucose >250mg/dl
b.Elevated beta hydroxybutyrate
c.At least two of the following
-ph < 7.3
-Serum bicarobonate <18 mmol/l (tintenelli 7th bicarbonate<15mmol/l)
-Anion gap> 15 mEq/L (tintenelli 7th anion gap >10)

2.It should be stress that the diagnosis of DKA is mainly based on clinical findi