Diabetic Ketoacidosis

1. Diabetic Ketoacidosis Gary David Goulin, MD

2. Goals & Objectives Understand the action of insulin on the metabolism of carbohydrates, protein, and fat Understand the pathophysiology of IDDM and DKA Understand the management approach to the patient with DKA Appreciate the complications that can occur during treatment of DKA

3. Introduction Diabetes mellitus is a syndrome of disturbed energy homeostasis caused by a deficiency of insulin or of its action resulting in abnormal metabolism of carbohydrate, protein, and fat Diabetes mellitus is the most common endocrine-metabolic disorder of childhood and adolescence It is important to stress that IDDM is NOT just a disorder affecting glucose (carbohydrate) metabolism, but that ALL the body’s energy sources are affected.It is important to stress that IDDM is NOT just a disorder affecting glucose (carbohydrate) metabolism, but that ALL the body’s energy sources are affected.

4. Introduction Individuals affected by insulin-dependent diabetes confront serious burdens that include an absolute daily requirement for exogenous insulin, the need to monitor their own metabolic control, and the need to pay constant attention to dietary intake

5. Introduction Morbidity and mortality stem from metabolic derangements and from long-term complications that affect small and large vessels and result in retinopathy, nephropathy, neuropathy, ischemic heart disease, and arterial obstruction with gangrene of the extremities

6. Classification Type I Diabetes (insulin-dependent diabetes mellitus, IDDM) characterized by severe insulinopenia and dependence on exogenous insulin to prevent ketosis and to preserve life onset occurs predominantly in childhood probably has some genetic predisposition and is likely autoimmune-mediated

7. Classification Type II Diabetes (non-insulin-dependent diabetes mellitus, NIDDM) patients are not insulin dependent and rarely develop ketosis generally occurs after age 40, and there is a high incidence of associated obesity As the prevalence of childhood obesity increases, more adolescents are presenting with NIDDM insulin secretion is generally adequate; insulin resistance is present no associated genetic predisposition As the population becomes increasingly obese, more and more adolescents are presenting with Type II diabetes, a disease rarely seen by pediatricians.As the population becomes increasingly obese, more and more adolescents are presenting with Type II diabetes, a disease rarely seen by pediatricians.

8. Classification Secondary Diabetes occurs in response to other disease processes: exocrine pancreatic disease (cystic fibrosis) Cushing syndrome poison ingestion (rodenticides)

9. Type I Diabetes Mellitus: Epidemiology Prevalence of IDDM among school-age children in the US is 1.9 per 1000 The annual incidence in the US is about 12 - 15 new cases per 100,000 Male to female ratio is equal Among African-Americans, the occurrence of IDDM is about 20 - 30% of that seen in Caucasian-Americans

10. Type I Diabetes Mellitus: Epidemiology Peaks of presentation occur at 5 - 7 years of age and at adolescence Newly recognized cases appear with greater frequency in the autumn and winter Definite increased incidence of IDDM in children with congenital rubella syndrome

11. Type I Diabetes Mellitus: Etiology and Pathogenesis Basic cause of clinical findings is sharply diminished secretion of insulin The mechanisms that lead to failure of pancreatic ?-cell function are likely autoimmune destruction of pancreatic islets IDDM is more prevalent in persons with Addison’s disease, Hashimoto’s thyroiditis, and pernicious anemia

12. Type I Diabetes Mellitus: Etiology and Pathogenesis 80 - 90% of newly diagnosed patients with IDDM have anti-islet cell antibodies

13. Type I Diabetes Mellitus: Pathophysiology

14. Type I Diabetes Mellitus: Pathophysiology Progressive destruction of ?-cells leads to a progressive deficiency of insulin As IDDM evolves, it becomes a permanent low-insulin catabolic state which feeding does not reverse Secondary changes involving stress hormones accelerate the metabolic decompensation

15. Type I Diabetes Mellitus: Pathophysiology With progressive insulin deficiency, excessive glucose production and impairment of utilization result in hyperglycemia, with glucosuria developing when the renal threshold of ~ 180 mg/dL is exceeded The resultant osmotic diuresis produces polyuria, urinary losses of electrolytes, dehydration, and compensatory polydipsia

16. Type I Diabetes Mellitus: Pathophysiology Hyperosmolality as a result of progressive hyperglycemia contributes to cerebral obtundation in DKA Serum osmolality: {Serum Na+ + K+} x 2 + glucose + BUN

17. Type I Diabetes Mellitus: Pathophysiology DKA results in altered lipid metabolism increased concentrations of total lipids, cholesterol, triglycerides, and free fatty acids free fatty acids are shunted into ketone body formation due to lack of insulin; the rate of formation exceeds the capacity for their peripheral utilization and renal excretion leading to accumulation of ketoacids, and therefore metabolic acidosis

18. Type I Diabetes Mellitus: Pathophysiology With progressive dehydration, acidosis, hyperosmolality, and diminished cerebral oxygen utilization, consciousness becomes impaired, and the patient ultimately becomes comatose

19. Type I Diabetes Mellitus: Clinical Manifestations Classic presentation of diabetes in children is a history of polyuria, polydipsia, polyphagia, and weight loss, usually for up to one month Laboratory findings include glucosuria, ketonuria, hyperglycemia, ketonemia, and metabolic acidosis. Serum amylase may be elevated. Leukocytosis is common

20. Type I Diabetes Mellitus: Clinical Manifestations Keotacidosis is responsible for the initial presentation of IDDM in up to 25% of children early manifestations are mild and include vomiting, polyuria, and dehydration More severe cases include Kussmaul respirations, odor of acetone on the breath abdominal pain or rigidity may be present and mimic acute appendicitis or pancreatitis cerebral obtundation and coma ultimately ensue

21. Type I Diabetes Mellitus: Diagnosis Diagnosis of IDDM is dependent on the demonstration of hyperglycemia in association with glucosuria with or without ketonuria DKA must be differentiated from acidosis and coma due to other causes: hypoglycemia, uremia, gastroenteritis with metabolic acidosis, lactic acidosis, salicylate intoxication, encephalitis

22. Type I Diabetes Mellitus: Diagnosis DKA exists when there is hyperglycemia (> 300 mg/dL), ketonemia, acidosis, glucosuria, and ketonuria

23. Type I Diabetes Mellitus: Treatment Treatment is divided into 3 phases treatment of ketoacidosis transition period continuing phase and guidance

24. Type I Diabetes Mellitus: Treatment Goals of treatment of DKA intravascular volume expansion correction of deficits in fluids, electrolytes, and acid-base status initiation of insulin therapy to correct catabolism, acidosis

25. Type I Diabetes Mellitus: Treatment Intravascular volume expansion dehydration is most commonly in the order of 10% initial hydrating fluid should be isotonic saline this alone will often slightly lower the blood glucose rarely is more than 20 cc/kg fluid required to restore hemodynamics Treatment of electrolyte abnormalities serum K+ is often elevated, though total body K+ is depleted K+ is started early as resolution of acidosis and the administration of insulin will cause a decrease in serum K+ It should be emphasized that the dehydration in DKA is hypertonic dehydration, and therefore plasma volume is fairly well preserved. It is rare, even in severe DKA, that a patient will present shocky from hypovolemia and dehydration. Therefore, there is rarely a need for large volumes (> 40 cc/kg) of fluid in the acute settingIt should be emphasized that the dehydration in DKA is hypertonic dehydration, and therefore plasma volume is fairly well preserved. It is rare, even in severe DKA, that a patient will present shocky from hypovolemia and dehydration. Therefore, there is rarely a need for large volumes (> 40 cc/kg) of fluid in the acute setting

26. Type I Diabetes Mellitus: Treatment Phosphate is depleted as well. Phosphate may be added as KPO4 especially if serum chloride becomes elevated “Pseudohyponatremia” is often present Expect that the Na+ level will rise during treatment Corrected Na+ = Measured Na+ + 0.016(measured glucose - 100) If Na+ does not rise, true hyponatremia may be present (possibly increasing cerebral edema risk) and should be treated

27. Type I Diabetes Mellitus: Treatment BICARBONATE IS ALMOST NEVER ADMINISTERED bicarbonate administration leads to increased cerebral acidosis HCO3- combines with H+ and dissociated to CO2 and H2O. Whereas bicarbonate passes the blood-brain barrier slowly, CO2 diffuses freely, thereby exacerbating cerebral acidosis and cerebral depression

28. Type I Diabetes Mellitus: Treatment Indications for bicarbonate administration include severe acidosis leading to cardiorespiratory compromise Increasing evidence suggests that subclinical cerebral edema occurs in the majority of patients treated with fluids and insulin for DKA

29. Type I Diabetes Mellitus: Treatment Cerebral edema is the major life-threatening complication seen in the treatment of children with DKA clinically apparent cerebral edema occurs in ~1% of episodes of DKA mortality is 40 - 90% cerebral edema is responsible for 50 - 60% of diabetes deaths in children

30. Type I Diabetes Mellitus: Treatment Cerebral edema usually develops several hours after the institution of therapy manifestations include headache, alteration in level of consciousness, bradycardia, emesis, diminished responsiveness to painful stimuli, and unequal or fixed, dilated pupils

31. Type I Diabetes Mellitus: Treatment Excessive use of fluids, large doses of insulin, and especially the use of bicarbonate have been linked to the increased formation of cerebral edema fluids are generally limited to ~ 3 L/m2/24 hours Children who present with elevated BUN, PaCO2 < 15 torr, or who demonstrate a lack of an increase in serum Na+ during therapy have an increased probability of cerebral edema Therapy of cerebral edema may include treatment with mannitol, hypertonic saline and hyperventilation

32. Type I Diabetes Mellitus: Treatment Insulin Therapy continuous infusion of low-dose insulin IV (~ 0.1 U/kg/hr) is effective, simple, and physiologically sound goal is to slowly decrease serum glucose (< 100 mg/dL/hr frequent laboratory and blood gas analyses are obtained to ensure ongoing resolution of metabolic acidosis

33. Type I Diabetes Mellitus: Treatment “Maintenance” IV fluid at a rate of 2000 - 2400 cc/m2/day consists of 2/3 NS (0.66%) or NS 5% Dextrose is added to IVF when blood glucose is ~ 300 mg/dL 10% Dextrose is added when blood glucose is ~ 200 mg/dL

34. Type I Diabetes Mellitus: Treatment Insulin is used to treat acidosis, not hyperglycemia insulin should never be stopped if ongoing acidosis persists When the acidosis is corrected, the continuous insulin infusion may be discontinued and subcutaneous insulin initiated With this regimen, DKA usually is usually fully corrected in 36 to 48 hours It is important to emphasize that the acidosis, NOT hyperglycemia is the metabolic derangement in DKA. Therefore, the provision of adequate insulin is key. It is only when the acidosis begins resolving that we are sure that the amount of insulin provided is adequate. Once we know we are providing adequate insulin, we use added glucose to the IVF to adjust the blood sugar between 100 and 200 mg/dL. We don’t alter the rate of the insulin infusion to maintain desired blood glucose levels.It is important to emphasize that the acidosis, NOT hyperglycemia is the metabolic derangement in DKA. Therefore, the provision of adequate insulin is key. It is only when the acidosis begins resolving that we are sure that the amount of insulin provided is adequate. Once we know we are providing adequate insulin, we use added glucose to the IVF to adjust the blood sugar between 100 and 200 mg/dL. We don’t alter the rate of the insulin infusion to maintain desired blood glucose levels.

35. Type I Diabetes Mellitus: Treatment Hypoglycemic Reactions (Insulin Shock) symptoms and signs include pallor, sweating, apprehension, trembling, tachycardia, hunger, drowsiness, mental confusion, seizures and coma management includes administration (if conscious) of carbohydrate-containing snack or drink glucagon 0.5 mg is administered to an unconscious or vomiting child

36. Suggested Reading Glaser N, et al. Risk factors for cerebral edema in children with diabetic ketoacidosis. NEJM 355;4:264-269. Menon RK, Sperling MA. Diabetic Ketoacidosis. In: Fuhrman BP, Zimmerman JJ, ed. Pediatric Critical Care. Second Edition. St. Louis: Mosby-Year Book, Inc., 1998:844-52. Kohane DS, Tobin JR, Kohane IS. Endocrine, Mineral, and Metabolic Disease in Pediatric Intensive Care. In: Rogers, ed. Textbook of Pediatric Intensive Care. Third Edition. Baltimore: Williams & Wilkins, 1996:1261-72. Magee MF, Bhatt BA. Management of Decompensated Diabetes: Diabetic Ketoacidosis and Hyperglycemic Hyperosmolar Syndrome. In: Zaloga GP, Marik P, ed. Critical Care Clinics: Endocrine and Metabolic Dysfunction Syndromes in the Critically Ill. Volume 17:1. Philadelphia: W.B. Saunders Company, 2001: 75-106.

37. Case Scenario #1 A 10 y/o male (~30 kg) presents to the ED with a one-day history of emesis and lethargy. Vitals show T 37C, HR 110, RR 25 BP 99/65. Patient is lethargic, but oriented x 3. Exam reveals the odor of acetone on the breath, dry lips, but otherwise unremarkable Labs: pH 7.05 PaCO2 20, PaO2 100, BE -20, Na+ 133, K + 5.2, Cl 96 CO2 8. Urine shows 4+ glucose and large ketones

38. Case Scenario #1 How much fluid would you administer as a bolus? Would you administer bicarbonate? What is the “true” serum sodium? How much insulin would you administer? What IVF would you start? At what rate? 10 - 20 cc/kg bolus of NS would be adequate. Though the patient is dehydrated (dry lips), his hemodynamics are good, with acceptable vitals and good perfusion. There would be no reason to administer more than 20 cc/kg fluids. While this patient is clearly acidemic, he is NOT in impending cardiovascular collapse and therefore there is no justification for the administration of bicarbonate. In fact, administration of bicarbonate has been associated with the development of cerebral edema. The “true” serum sodium is 143 133 + 0.016[700-100] Insulin is generally started at 0.1 u/kg/hr. Therefore, in this 30 kg patient, an insulin infusion of 3 u/hr of regular insulin should be initiated. IVF of 2/3 NS or NS should be started at ~ 2400 cc/m2/day, which is approximately 1.5 x maintenance 10 - 20 cc/kg bolus of NS would be adequate. Though the patient is dehydrated (dry lips), his hemodynamics are good, with acceptable vitals and good perfusion. There would be no reason to administer more than 20 cc/kg fluids. While this patient is clearly acidemic, he is NOT in impending cardiovascular collapse and therefore there is no justification for the administration of bicarbonate. In fact, administration of bicarbonate has been associated with the development of cerebral edema. The “true” serum sodium is 143 133 + 0.016[700-100] Insulin is generally started at 0.1 u/kg/hr. Therefore, in this 30 kg patient, an insulin infusion of 3 u/hr of regular insulin should be initiated. IVF of 2/3 NS or NS should be started at ~ 2400 cc/m2/day, which is approximately 1.5 x maintenance

39. Case Scenario #2 A 4 y/o female in the PICU is undergoing treatment for new onset IDDM and DKA. She is on an insulin infusion at 0.1 u/kg/hr, and fluids are running at 2400 cc/m2/day. Over the last hour, she has been complaining about increasing headache. She is now found to be unresponsive with bilateral fixed and dilated pupils, HR is 50 with BP 150/100. What is your next step in management? This patient is exhibiting cerebral edema, the most feared and lethal complication of DKA. Management at this point consists of securing the airway by endotracheal intubation and hyperventilating the patient. Mannitol 0.5 - 1 g/kg and or hypertonic saline (~5cc/kg 3% NaCl) should be administered as well. It would not be appropriate to stop the insulin infusion, or to bolus the patient with glucose. It should be noted that even patients receiving proper management for DKA (like this patient) may nonetheless develop cerebral edema.This patient is exhibiting cerebral edema, the most feared and lethal complication of DKA. Management at this point consists of securing the airway by endotracheal intubation and hyperventilating the patient. Mannitol 0.5 - 1 g/kg and or hypertonic saline (~5cc/kg 3% NaCl) should be administered as well. It would not be appropriate to stop the insulin infusion, or to bolus the patient with glucose. It should be noted that even patients receiving proper management for DKA (like this patient) may nonetheless develop cerebral edema.