Diabetic Ketoacidosis (DKA)
Develops when
there is an absolute deficiency of insulin and an increase in the insulin
counterregulatory hormones. Glucose production by the liver increases,
peripheral glucose use decreases, fat mobilization increases, and ketogenesis
(ketone formation) is stimulated. Increased glucagon levels activate the
gluconeogenic and ketogenic pathways in the liver. In the presence of insulin
deficiency, hepatic overproduction of beta- hydroxybutyrate and acetoacetic
acids (ketone bodies) causes increased ketone concentrations and an increased
release of free fatty acids. As a result of a loss bicarbonate (which occurs
when the ketone is formed), bicarbonate buffering does not occur, and a
metabolic acidosis occurs, called DKA.
DKA involves four metabolic problems:
·
Hyperosmolarity from
hyperglycemia and dehydration
·
Metabolic
acidosis from an accumulation of ketoacids
·
Extrracellular
volume depletion from osmotic dieresis
·
Electrolyte
imbalances (such as loss of potassium and sodium) from osmotic dieresis
Risk Factors:
·
Infection such as diarrhea, vomiting, and/or high fever (40%),
·
missed
or inadequate insulin (25%)
·
newly
diagnosed or previously unknown diabetes (15%).
·
trauma
·
Approximately
5% to 10% of cases have no identifiable cause
Signs and Symptoms
ü Dehydration (from hyperglycemia)
·
Thirst
·
Warm,
dry skin with poor turgor
·
Soft
eyeballs
·
Dry
mucous membranes
·
Weakness
·
Malaise
·
Rapid,
weak pulse
·
Hypotension
ü Metabolic Acidosis (from ketosis)
·
Nausea
and vomiting
·
Ketone
(fruity, alcohol – like)
·
Breath
odor
·
Lethargy
·
Coma
ü Other Manifestations
·
Abdominal
Pain (cause unknown)
·
Kussmaul’s respirations (increased rate and depth of respirations,
with a longer expiration; a compensatory response to prevent a further decrease
in pH)
Management:
a) When teaching the diabetic client about
foot care, the nurse should instruct the client to avoid walking barefooted.
b) Blood
Glucose Monitoring should be done to detect hypoglycemia and
hyperglycemia. It also helps the client
with diabetes reach a desired level of glycemic control.
c) During blood glucose monitoring, the
nurse must collect a blood sample from the side
of the finger (adult); Outer aspect of the heel (infant).
d) Blood sugar monitoring must be done
early monitoring before breakfast.
Diagnostic Tests to Monitor Diabetes Management
·
Fasting blood glucose
(FBG). This test is often ordered, especially
if the client is experiencing symptoms of hypoglycemia and hyperglycemia. In
most people, the normal range is 70 to 110 mg/ dL.
·
Glycosylated hemoglobin. This test determines the average blood glucose level over
approximately the previous 2 to 3 months. When glucose is elevated or control
of glucose is erratic, glucose attaches to the hemoglobin molecule and remains
attached for the life of the hemoglobin, which is about 120 days. The normal
level depends on the type of assay done, but values above 7% to 9% are
considered elevated.
·
Urine Glucose and ketone
levels. These are not as accurate in monitoring
changes in blood glucose as blood levels. The presence of glucose in the urine
indicates hyperglycemia. Most people have a renal threshold for glucose exceeds
180 mg/dL; that is, when the blood glucose exceeds 180 mg/ dL, glucose is not
reabsorbed by the kidneys and spills over into the urine. This number varies
highly, however.
·
Urine test for the presence of protein as albumin (albuminuria). If albuminuria
is present, a 24- hour urine test for creatinine clearance is used to detect
the early onset of nephropathy.
·
Serum cholesterol and
triglyceride levels. These are indicators of
atherosclerosis and an increased risk of cardiovascular impairments.
·
Serum electrolytes. Levels are measured in clients who have DKA or HHS to determine
imbalances.
Treatment of DKA
·
Alterations in level of
consciousness, acidosis, and vomiting are common necessitating intravenous
fluid placement. The initial fluid replacement may be accomplished by
administering 0.9% saline solution at a rate of 500 to 1,000 mL/h. After 2- 3
hours (or when blood pressure is returning to normal), the administration of 0.45%
saline at 200- 500 mL/h may continue for several more hours. When the blood
glucose levels reach 250 mg/dL, dextrose is added to prevent rapid decrease in
glucose; hypoglycemia could result in fatal cerebral edema.
·
Regular insulin is used in the
management of DKA and may be given by various routes, depending on the severity
of the condition. Mild ketosis may be treated with subcutaneous insulin,
whereas severe ketosis requires intravenous insulin infusion.
·
Potassium replacement is begun
early in the course of treatment, usually by adding potassium to the
rehydration fluids.