Acute complications

Diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is an acute, dangerous complication and is always a medical emergency. Lack of insulin causes the liver to turn fat into ketone bodies, a fuel mainly for the brain. Large concentration of ketone bodies in the blood decreases the blood's pH, leading to most of the symptoms of DKA. On presentation at hospital, the patient in DKA is typically dehydrated and breathing both fast and deeply. Abdominal pain is common and may be severe. The level of consciousness is typically normal until late in the process, when lethargy (dulled or reduced level of alertness or consciousness) may progress to coma. Ketoacidosis can become severe enough to cause hypotension, shock, and death. Prompt proper treatment usually results in full recovery, though death can result from inadequate treatment, delayed treatment or from a variety of complications. Ketoacidosis occurs in type 1 and type 2 but is much more common in type 1.

Emergency Department Care: Maintain extreme vigilance for any concomitant process such as infection, cerebrovascular accident (CVA), MI, sepsis, or deep venous thrombosis (DVT).

• Fluid resuscitation is a critical part of treating DKA. Intravenous (IV) solutions replace extravascular and intravascular fluids and electrolyte losses. They also dilute both the glucose level and the levels of circulating counterregulatory hormones. Insulin is needed to help switch from a catabolic to an anabolic state, with uptake of glucose in tissues and the reduction of gluconeogenesis as well as free fatty acid and ketone production.

• Administer 1 L of isotonic saline (or more if needed for significant hypovolemia) in the first hour. Further isotonic saline should be administered at a rate appropriate to maintain adequate blood pressure and pulse, urinary output, and mental status. If a patient is severely dehydrated and significant fluid resuscitation is needed, switching to a balanced electrolyte solution (such as Normosol-R, in which some of the chloride in isotonic saline is replaced with acetate) may help to avoid the development of a hyperchloremic acidosis.
• After initial stabilization with isotonic saline, switch to half-normal saline at 200-1000 mL/h (half-normal saline matches losses due to osmotic diuresis).

• Pediatric protocols to minimize the risk of cerebral edema by reducing the rate of fluid repletion vary. Initial fluid repletion in pediatric patients should be 10-20 mL/kg over the first 1-2 hours with a maximum of 50 mL/kg over the first 4 hours. This is felt to reduce chances of cerebral edema.

• Potassium replacement

• Add 20-40 mEq/L of KCl to each liter of fluid once K⁺ is under 5.5 mEq/L.

• Potassium can be given as follows: two thirds as KCl, one third as KPO₄.

• Bicarbonate typically is not replaced, although some physicians do so when pH <7. Administration of bicarbonate has been correlated with cerebral edema in children.

• Phosphate and magnesium replacements are not typically needed, since levels correct when patient resumes eating.

• Use data flow sheets to monitor timing of labs and therapy.

Nonketotic hyperosmolar coma

While not generally progressing to coma, this hyperosmolar nonketotic state (HNS) is another acute problem associated with diabetes mellitus. It has many symptoms in common with DKA, but an entirely different cause, and requires different treatment. In anyone with very high blood glucose levels (usually considered to be above 300 mg/dl (16 mmol/l)), water will be osmotically drawn out of cells into the blood. The kidneys will also be "dumping" glucose into the urine, resulting in concomitant loss of water, and causing an increase in blood osmolality. If fluid is not replaced (by mouth or intravenously), the osmotic effect of high glucose levels combined with the loss of water will eventually result in very high serum osmolality (i.e. dehydration). The body's cells will become progressively dehydrated as water is taken from them and excreted. Electrolyte imbalances are also common, and dangerous. This combination of changes, especially if prolonged, will result in symptoms of lethargy (dulled or reduced level of alertness or consciousness) and may progress to coma. As with DKA urgent medical treatment is necessary, especially volume replacement. This is the 'diabetic coma' which more commonly occurs in type 2 diabetics.

Treatment is similar to ketoacidosis.

Date: 2015-01-12; view: 978