(acanthosis nigricans) on the posterior neck is a sign of long-standing insulin resistance and should alert the clinician to the possibility of non–insulin-dependent diabetes Management/Diagnostic Testing Diagnostic laboratory findings include plasma glucose greater than 200 mg/dL (commonly 400 to 800 mg/dL) and elevated serum ketones (commonly above mmol/L), the presence of glucose and ketones in the urine, and acidosis (venous pH less than 7.3 and serum bicarbonate less than 15 mEq/L) Additionally, high or normal plasma potassium, and slightly elevated blood urea nitrogen are common Occasionally, DKA can occur with normoglycemia when persistent vomiting and decreased intake of carbohydrates are accompanied by continued administration of insulin or when patients have kept themselves particularly well hydrated with non–glucose-containing fluids The measured serum sodium is usually low or in the low to normal range In the setting of hyperglycemia, the measured sodium will be lowered; a commonly used estimate for correction is a decrease of mEq/L Na for every 100 mg/dL elevation in glucose above normal Leukocytosis with a left shift may be noted but does not necessarily signify an underlying infection Hyperglycemia in the absence of acidosis should cause the clinician to consider additional possibilities (see Hyperglycemia section) For the severely dehydrated child, initial treatment is directed toward expansion of intravascular volume and administration of insulin Subsequent treatment is directed at the normalization of the remaining abnormal biochemical parameters Medical intervention carries significant risks of hypokalemia and cerebral edema ( Tables 89.2 and 89.3 ) Fluid and Electrolyte Replacement Fluid replacement should be instituted promptly In the first to hours, if hypovolemia is apparent, 10 mL/kg isotonic (0.9%) crystalloid (either normal saline or lactated Ringer’s) should be infused intravenously to establish an adequate intravascular volume and improve tissue perfusion Normal saline is generally preferred for initial resuscitation given that DKA patients already have a degree of lactic acidosis, however, lactated Ringer’s has the benefit of a reduced chloride load A small head-to-head trial showed no significant differences between the two fluids Repeat bolus if the pulse rate and capillary refill rate not improve, but rarely is more than 20 mL/kg required in the first hour The goal of this initial rehydration therapy is not euvolemia but adequate perfusion of end organs, often best judged by monitoring mentation, capillary refill, and heart rate