compensated for by a respiratory alkalosis (hyperventilation), with a resultant lowering of PCO − and plasma bicarbonate (HCO3 ) Intracellular potassium is depleted because of transcellular shifts of this ion brought about by the exchange of potassium with excess free hydrogen ions and extracellular dehydration Protein catabolism secondary to insulin deficiency causes a negative nitrogen balance and results in additional efflux of potassium from cells The potassium is then lost in the urine during the osmotic diuresis Volume depletion causes secondary hyperaldosteronism, which further promotes urinary potassium excretion Thus, total body depletion of potassium occurs, although the plasma potassium concentration may not reflect the loss at the time of presentation Clinical Considerations Clinical Recognition In cases of new-onset diabetes, the child usually has a history of polyuria and polydipsia for a few days or weeks before the acute decompensation Significant weight loss often occurs despite a vigorous appetite Vomiting is common once the child has ketoacidosis; these further losses plus the inability to compensate for polyuria contribute to the hypovolemia In children known to have diabetes, the prodrome may be less than 24 hours and precipitated by an intercurrent illness, inappropriate sick day management, or omission of insulin doses Triage On physical examination, particular attention should be paid to the degree of dehydration, including skin turgor and dryness of mucous membranes Urine output is not a reliable sign of hydration status In severe cases, the child may exhibit signs of compensated shock, including a thready pulse and cold extremities, and rarely, as uncompensated shock with hypotension The smell of ketones on the breath and the presence of hyperpneic (Kussmaul) respirations reflect the ketoacidosis The patient’s consciousness level, which may range from full alertness to deep coma, should be noted Initial Assessment/H&P Patients may complain of nausea, vomiting, and abdominal pain, and the parents may have noticed increasing listlessness Less than 1% of children are in coma at the time of hospital admission, although a higher percentage has an altered state of consciousness The history and physical examination usually suggest the diagnosis; however, particularly in the patient with new-onset diabetes, presenting clinical features can be misdiagnosed, especially in the infant or young child For example, abdominal pain may be misinterpreted as appendicitis; hyperpnea may be mistaken as a sign of pneumonia or asthma; and polyuria may be incorrectly diagnosed as a urinary tract infection Enuresis, polydipsia, and irritability are sometimes wrongly categorized as behavioral problems The child may have exquisite abdominal tenderness with guarding and rigidity, which can mimic an acute abdomen The ears, throat, chest, and urine should be examined because infection is often a precipitating factor Careful attention should be paid to the skin examination because there have been several case reports of fasciitis co-presenting with DKA The presence of hyperpigmentation