Diabetic Ketoacidosis

Irene N. Sills, MD

Albany Medical Center

Albany, NY

Diabetic Ketoacidosis

Presentation of new onset diabetes about 30% of the time

Is a life-threatening emergency

The metabolic abnormalities must be corrected in a careful, vigilant fashion

Diabetic Ketoacidosis

• Pathophysiology

• Diagnosis

• Treatment

• Complications of treatment

• When the acidosis is resolved

Diabetic Ketoacidosis

• Abnormal metabolic state

• Due to insulin deficiency

• In patient with type 1 diabetes

• Characterized by hyperglycemia and acidosis

Hyperglycemia Ketone production

Ketone utilization

Osmotic diuresis HYPERKETONEMIA

DEHYDRATION vomiting

Decreased GFR

Hydrogen ion production

exceeds utilization

ACIDOSIS

Endogenous Compensation for Acidosis

• Chemical buffering by extracellular (bicarbonate) and intracellular buffers (protein, organic and inorganic phosphates, hemoglobin)

• Control of CO2 levels by alveolar ventilation rate

• Control of blood bicarbonate concentration by changes in H+ excretion (excretion of titrable acidity and ammonium) and reabsorption of bicarbonate

Diabetic Ketoacidosis

• Failure to take insulin (total insulin deficiency)

• Relative insulin deficiency– infection

– trauma

– surgery

– stress

– dehydration **

• Hormones that lower glucose: INSULIN

• Hormones that raise glucose: catecholamines, cortisol, glucagon, growth hormone

Physical Exam

• Signs of dehydration

• Kussmaul type breathing

• Acetone odor

• Blood pressure and pulse

• Temperature

• Ileus and gastric atony

• State of consciousness

Laboratory 1

• Glucose 400-500 mg/dl, but may vary

• Arterial pH less than 7.3; bicarbonate less than 15mM/L

• Sodium usually normal, but may be low

• Potassium initially elevated

• Serum ketones positive

• Serum osmolality elevated

Laboratory 2

• Anion gap elevated: Na- (Cl + HCO3)

• Creatinine spuriously elevated

• Hemoglobin and hematocrit elevated

• WBC may be elevated

Therapy

• 1. Correction of the dehydration (PRIORITY)

• 2. Correction of the hyperglycemia

Dehydration

• Immediately decreases levels of “anti-insulin” hormones

• Insulin resistance exacerbates the insulin deficiency

• Rehydration will decrease stress hormones

• Rehydration will improve kidney perfusion

Dehydration• DKA is a hypertonic state and should be

corrected over 36-48 hours

• If clinically in shock, 10-20 cc/kg .9NS or plasma expander over 30-45 minutes

• Fluids should be no more hypotonic than .45 NS

• Maintenance fluid may be .9NS until serum glucose is less than 300 mg/dl when glucose containing solution is added

Dehydration

• Deficit replacement should be given EVENLY over 36-48 hours

• IV infusion rate usually calculates to one and a-half times maintenance

• On-going losses should be replaced• Potassium should be added when patient

voids• Bicarbonate is usually not needed

Insulin

• Regular (novolog) insulin U100

• 0.05 - .1U/kg/hr

• If glucose is <120-180 mg/dl and acidosis is persisting, it is better to increase the glucose in the infusion rather than decrease the insulin

Monitoring

• Serum glucose hourly

• Electrolytes, calcium, phosphorous every 2-4 hours

• Flowsheet with accurate I’s and O’s, vital signs, insulin doses, mental status checks, and laboratory results

Complications of therapy

• Hypokalemia

• Inadequate rehydration

• Hypoglycemia

• Cerebral edema and other CNS catastrophes

Hypokalemia

• Vomiting

• Renal losses exacerbated by hyperaldosteronism

• Insulin and pH correction moves potassium into the cells

• Danger if the initial potassium is less than 3.6 meq/L

Inadequate Rehydration

Hypoglycemia

Cerebral edema

• Paradoxical development of CSF and CNS acidosis

• Altered CNS oxygenation

• Unfavorable osmotic gradients

• A decline in the true sodium

Cerebral Edema

• Develops 4-12 hours after therapy begun

• Biochemically all is well

• If early mental status changes are not noticed, a child will develop neurologic changes leading to herniation and compromised cardiorespiratory status

Cerebral Edema

• NEJM: Cerebral edema that was not clinically expected developed in a small group of children

• CT scans while in DKA and after resolution

• Ventricular narrowing during therapy

• Perhaps, some degree of swelling in all children

Cerebral EdemaPrevention

• Slow rehydration with slow changes in osmolality

• Serum sodium should rise as serum glucose falls

• Hourly mental status checks

After Resolution

IV insulin until it is time for mealTwice daily short acting/intermediate acting insulin (or usual insulin dose)Approximately .75 units/kg2/3’s in am; 1/3 in pm2/3’s intermediate acting; 1/3 short actingLunch: .2 units/kg short acting

Team Management• Physician

• Certified diabetes educator

• Dietician

• Psychologist or social worker

Insulin• Rapid acting - Humalog or

Novolog

• Short acting - Regular

• Intermediate acting - NPH, Lente

• Long acting - Ultralente

• New, peakless - Glargine (Lantus)

Target Blood Glucose Levels

• Prebreakfast

• Prelunch and dinner

• Prebedtime snack

• Younger child

• 70 - 120 mg/dl

• 70 - 150 mg/dl

• 90 - 180 mg/dl

• 80 - 180 mg/dl

Principles of Meal Planning

• Meet nutritional requirements

• Well balanced meals and

• snacks

• Healthful fat consumption

• Avoid obesity

• Incorporate social and cultural factors

• Artificial sweeteners

Constituents of Meal Plan

• Carbohydrate

• Protein

• Fat

• 50-60% calories

• 15-20% calories

• 25-35% calories

Monitoring• Hemoglobin A1c

• Home glucose monitoring

• Glucowatch

• Subcutaneous sensor

Have Have a good day!

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