Anesthetic Management Of Pediatric Diabetes mellitus Prof. Dr. AzzaEzzat Professor of Anesthesiology Cairo University
Dealing with diabetic child is a challenge , not only to the anesthiologist but also to endocrinologist . Why? It is difficult to control their meals It is also difficult to put them on diet regimens Limited management options Frequent injection (fear of repeated insulin injection )
Our aim Is to do safe perioperative management Providing balanced glycemic control Avoiding hypoglycemia with its serious brain insult in this age group. Also preventing excessive hyperglycemia with it’s dangerous sequel.
both are secreted into the small intestine directly
Regulation of insulin secretion Insulin is secreted into the portal venous system in the basal state at rate of approximately 1 u/h . Food intake results in a prompt five to ten fold increase in the rate of insulin secretion Insulin is not secreted when the blood glucose level <50 mg /dl Max. stimulation of insulin release when blood glucose level >300 mg/dl
Role of insulin It facilitates transport of glucose across cell membranes and enhances phosphorylation of glucose within cells It promotes the use of CHO for energy conservation while depressing the use of fat and amino acids
Increases glucose and K entry into the cells
Excess glucose is stored in : -The liver as glycogen -Adipose tissue as fat -Skeletal muscle as protein and glycogen
Pathophysiology Insulin deficiency causes physiologic and metabolic changes in the body Glucose from dietary sources cannot be utilized by the cells Renal tubules have difficulty reabsorbing the glucose
Clinical Manifestations Elevated blood glucose leads to osmotic diuresis. (polyuria and thirst) Protein and fat breakdown lead to weight loss. Accumulation of ketones causes a drop in pH. (metabolic acidosis) and spilling of ketones in the urine
Polyphagia / attempt to compensate for lost calories
Diagnostic Tests Blood glucose levels greater than 200 mg/dl Urine sample reveals glucosuria and possible ketonuria Glucose tolerance test would reveal low insulin levels in the face of elevated glucose levels
Goals of Management Short term goals: Prevent the development of ketosis. Prevent electrolyte abnormalities and volume depletion secondary to osmotic diuresis. Prevent impairment of leukocyte function Prevent impairment of wound healing Long term goal: prevention of microcirculatory and neuropathic changes
Blood Glucose Levels Target levels Toddler and preschool: 100 to 180 mg/dl School-age: 90 to 180 mg/dl Adolescents (13 to 19 years): 90 to 130 mg/dl
Common types of DM in pediatrics Type 1 DM which is caused by pancreatic β cell destruction usually immune mediated. It results in absolute insulin deficiency. Incidence (11.7- 17.8/ 100000). Type 2 DM results from a combination from insulin resistance and relative deficiency of insulin.* *Diabetes Care 2004
Insulin regimens incorporate a combination of intermediate and long acting insulin with short or rapid insulin (2-3 injections/day) Insulin Pump (SC) Continuous administration of rapid acting insulin at a basal rate and supplemented with additional doses before meal or snacks.
Short acting (Soluble, Regular) insulin is used as an essential component of most daily replacement regimens.
- In combination with intermediate acting insulin - As premeal bolus injections 20-30 minutes before meals. - It is the only insulin suitable for IV therapy.
Rationale for insulin Glargine Insulin glargine was designed to provide a constant basal insulin concentration to control basal metabolism with one injection daily Insulin Glargine is indicated for the treatment of adult and pediatric patients (over the age of 6 years) with type I diabetes.
Summary of types of insulin Rapid acting = ultra short (neonates & infants) with meal (lactation) Short acting = regular insulin (all ages) Intermediate at basal rate (children & infants) Long acting (pre puberty i.e. 10 years) Galargine (not less than 6 years if used pre puberty)
Oral Antihyperglycemics Metformine is the only drug approved in pediatric population. Action: - It decreases hepatic glucose production. - It increases insulin sensitivity in peripheral tissues.
Preoperative Assessment Blood Glucose Metabolic Control Electrolyte balance Glycosylated Hb ↓ 5 years 7% to 9% 5-13 years 6% to 8.5% ↑ 13 years 6% to 8%
On the day of surgery Short procedure Withhold morning dose Glucose-free solution When postoperative oral intake is established 40 – 60 % of usual daily dose is administered
On the day of surgeryLong ProcedureIf Blood Glucose 100 – 200 mg/dl Hold rapid or short acting insulin. Administration 50% the intermediate or long acting insulin. Omit breakfast Patient scheduled first case (Avoid starvation). Rhodes et al 2005
Insulin Infusion - Add soluble insulin 50 units to 50 ml NS 0.9%. - Start infusion at: 0.025 ml/kg/h if blood glucose is < 6-7 mmol/l 0.05 ml/kg/h if blood glucose is 8-12 mmol/l 0.075 ml/kg/h if blood glucose is 5-10 mmol/l 0.1 U/kg/h if blood glucose is > 15 mmol/l - Aim to maintain BG between 5-10 mmol/l . - BG must be measured at least hourly when the patient is on IV inf. - Do not stop the insulin infusion if BG < 5-6 mmol/l (90 mg/dl) as this will cause rebound hyperglycemia. Reduce the rate of infusion. - The insulin infusion may be stopped temporarily if BG < 4mmol/l (55 mg/dl) but only for 10-15 min. Bett et al 2009
On the day of surgeryLong ProcedureIf Blood Glucose > 250 mg/dl On the morning of surgery: No rapid or short-acting insulin is given unless blood glucose is > 250 mg/dl >250 mg/dl give a dose of rapid-acting insulin using “correction factor” Correction factor: The decrease in blood glucose level expected after administering 1 unit of rapid acting insulin
How to calculate corrective dose? Using the rule of 1500 for regular insulin Example: The total daily dose of a child is 30 U So the correction factor = 1500/30 = 50 i.e. each unit of insulin will decrease his blood glucose level by 50 mg/dl If this child’s blood glucose level = 300 mg/dl and his target glucose level = 150 mg/dl his corrective dose = 300 – 150/50 = 3 U OR 0.1 u/kg SC of rapid acting insulin
Hyperglycemia Osmotic diuresis loss of free water and electrolytes Hypovolemia tissue hypoperfusion and lactic acidosis The ketoacids (acetoacetate, beta-hydroxybutyrate, acetone) are products of proteolysis and lipolysisKETOACIDOSIS Potassium is the most important electrolyte in patients with severe diabetic ketoacidosis ( Hyperkalemia or Hypokalemia)
Once the child has been resuscitated, potassium should be commenced immediately with rehydration fluid unless anuria is suspected
Potassium is mainly an intracellular ion, and there is always massive depletion of total body potassium although initial plasma levels may be low, normal or even high
Levels in the blood will fall once insulin is commenced
If serum potassium level is greater than 5.5 mmol per litre, do not add additional potassium to intravenous fluids
The final goal is to obtain a serum glucose concentration within the reference range (serum glucose level, 100-150 mg/dL), to obtain neutral blood pH (pH =7.4; serum bicarbonate = 15-18 mEq/dL), and to eliminate serum ketones.
Identification and treatment of the precipitant event, antibiotic for infection
Hourly monitoring of serum markers of diabetic ketoacidosis
Assess for other associated endocrine or congenital disease.
Fasting diabetic child should be scheduled first case.