Pediatric emergency medicine trisk 1864 1864
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(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 5 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 2 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 1 to 2 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 do 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.
