Diabetic Ketoacidosis and Hyperosmolar Coma

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar state (HHS) are acute complications of diabetes mellitus (DM). DKA is seen primarily in individuals withtype 1 DM and HHS in individuals withtype 2 DM. Both disorders are associated withabsolute or relative insulin deficiency, volume depletion, and altered mental status. The metabolic similarities and differences in DKA and HHS are summarized in Table 24-1.




Diabetic Ketoacidosis

Etiology DKA results from insulin deficiency witha relative or absolute increase in glucagon and may be caused by inadequate insulin administration, infection (pneumonia, UTI, gastroenteritis, sepsis), infarction (cerebral, coronary, mesenteric, peripheral), surgery, drugs (cocaine), or pregnancy.

Clinical Features The initial symptoms of DKA include anorexia, nausea, vomiting, polyuria, and thirst. Abdominal pain, altered mental function, or frank coma may ensue. Classic signs of DKA include Kussmaul respirations and an acetone odor on the pt’s breath. Volume depletion can lead to dry mucous membranes, tachycardia, and hypotension. Fever and abdominal tenderness may also be present. Laboratory evaluation reveals hyperglycemia, ketosis (Beta-hydroxybutyrate > acetoacetate), and metabolic acidosis (arterial pH 6.8–7.3) withan increased anion gap (Table 24-1). The fluid deficit is often 3–5 L.

Despite a total-body potassium deficit, the serum potassium at presentation may be normal or mildly high as a result of acidosis. Leukocytosis, hypertriglyceridemia, and hyperlipoproteinemia are common. Hyperamylasemia is usually of salivary origin but may suggest a diagnosis of pancreatitis. The measured serum sodium is reduced as a consequence of hyperglycemia (1.6-meq reduction for each100-mg/dL rise in the serum glucose).

Treatment
The management of DKA is outlined in Table 24-2.



Hyperglicemic Hyperosmolar State 

Etiology Relative insulin deficiency and inadequate fluid intake are the underlying causes of HHS. Hyperglycemia induces an osmotic diuresis that leads to profound intravascular volume depletion. HHS is often precipitated by a serious, concurrent illness suchas myocardial infarction or sepsis and compounded by conditions that impede access to water.

Clinical Features Presenting symptoms include polyuria, thirst, and altered mental state, ranging from lethargy to coma. Notably absent are symptoms of nausea, vomiting, and abdominal pain and the Kussmaul respirations characteristic of DKA. The prototypical pt is an elderly individual with a several week history of polyuria, weight loss, and diminished oral intake. The laboratory features are summarized in Table 24-1. In contrast to DKA, acidosis and ketonemia are usually not found; however, a small anion gap may be due to lactic acidosis, and moderate ketonuria may occur from starvation. Though the measured serum sodium may be normal or slightly low, the corrected serum sodium is usually increased (add 1.6 meq to measured sodium for each100- mg/dL rise in the serum glucose).

Treatment

The precipitating problem should be sought and treated. Sufficient IV fluids (1–3 L of 0.9% normal saline over the first 2–3 h) must be given to stabilize the hemodynamic status. The calculated free water deficit (usually 8–10 L) should be reversed over the next 1–2 days, using 0.45% saline initially then 5% dextrose in water. Potassium repletion is usually necessary. The plasma glucose may drop precipitously with hydration alone, though insulin therapy withan intravenous bolus of 5–10 units followed by a constant infusion rate (3–7 units/h) is usually required. Glucose should be added to intravenous fluid when the plasma glucose falls to 13.9 mmol/L (250 mg/dL). The insulin infusion should be continued until the patient has resumed eating and can be transitioned to a subcutaneous insulin regimen.

Salam

by Umaee
Source: Medical of Medicine
Image: ucdmc.edu

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