Treatment of Neonatal Hypoglycemia

DR MANDAR HAVAL

DCH.DNB.

FELLOW IN NEONATOLOGY (NNF)

• NEONATAL HYPOGLYCEMIA IS A METABOLIC DISORDER AND OPERATIONAL THRESHOLD VALUE OF BLOOD GLUCOSE <40MG/DL (PLASMA GLUCOSE < 45MG/DL) SHOULD BE USED TO GUIDE MANAGEMENT

What should be the operational threshold for management of neonatal

hypoglycemia

Why should hypoglycemia in new born should manage aggressively

• Glucose is a predominant fuel of a neonatal brain

• Low blood glucose in new born period in isolation as well as associated with other morbidities predispose to long term neurological output

Which neonate should be screen for hypoglycemia

• All at risk neonate and sick infant should be screen

• Eg1. preterm infants /Small for gestation / Large for

gestation 2. Infant of diabetic mother3. Post exchange blood transfusion 4. On intravenous fluid and parenteral nutrition5. Mother on Beta blocker, OHA, intrapartam

dextrose infusion

Schedule of blood glucose monitoring

Category of infants Time schedule

1 At risk neonates (SN 1-8 in Table 1) 2, 6, 12, 24, 48, and 72 hrs

2 Sick infants (Infants with sepsis, asphyxia,

shock during active phase of illness.

Once the underlying condition is under control,

frequency of screening can be reduced or omitted) Every 6-8 hrs

(individualize as needed)

3 Stable VLBW infants on parenteral nutrition Initial 72 h: every 6 to 8 hrs

After 72 hr: once a day

Infants exhibiting signs compatible with hypoglycemia at any time also need to be

investigated.

How should blood glucose be tested in neonate

• Glucose reagent strip are use to screen for hypoglycemia.

• If values are low , a blood sample should be sent to a lab for confirmation by glucose oxidase or glucose electrode method

• Treatment should be commenced on the basis of screening test and should not be delayed till lab results

Neonate with asymptomatic hypoglycemia management

Healthy asymptomatic hypoglycemic neonate

Measured breast milk or formula feed* by spoon or gavage

Check blood glucose after 30 – 60 min later

If BSL>45 , 2-3 hr feed is ensure with 4-6hr monitoring for blood glucose upto 48hr

IV Glucose infusion should be started in babies with asymptomatic

hypoglycemia

• BSL< 25mg/dl

• BSL< 40mg/dl despite of one attempt of feeding breast milk

• Enteral feeding is contraindicated

• Baby became symptomatic

How to mix various solution for creating a desired concentration of

glucose in IV infusate

• 100ml of fluid of desired dextrose concentration by using 5% and 25% dextrose is as follows

• 5X – 25 = Y (X- required percentage of dextrose , Y – amount of 25%D to be made up with 5% D to make a total of 100ml)

Eg. To prepare 100ml 0f 25% D

• Formula – 5X – 25 =Y ( X – 12.5)

5 * 12.5 – 25 = 37.5 (Y)

• Thus 37.5ml of 25%D is to be added in 62.5ml (100-37.5) of 5%D to get 100ml of 12.5% D

Calculation of GIR

1. GIR = %D being infused X rate of infusion

Body Wt X 6

2. GIR = Rate of IV fluids (ml/kg/day) X % of

dextrose infused

144

• 3. GIR = Rate of IV fluid (ml/kg/day) X % of dextrose infused X 0.007

Note -

• 10%D – 100mg/ml

• 5% D – 50mg/ml

• 7.5% D – 75mg/ml

• 12.5% D – 125mg/ml

Simple method to calculate GIR

• Desired fluid intake (ml/kg/day) eg-80ml/kg/day

• Convert it into ml/kg/min by dividing the figure by 1440 ( 24hr – 1440min)

i.e 80/1440 = 0.055

• If 10% D is used then multiply the above fig by 100 (as 10% D has 100mg)

i.e 0.055 X 100= 5.5mg/kg/min

How to increase GIR by 1mg/kg/min

• Add 2ml/kg of 25% D to the volume of the fluid infused over 8 hr .

• Explanation –

i) 25% D has 250mg/ml of D(2ml = 500mg)

ii) 8hr period has 8 X 60min = 480 min

iii) so 2ml/kg of 25%D over 8 hr will increase the GIR by 500/480 = 1mg/kg/min(roughly)

Daily

fluid volume

(mL/kg/d) Glucose infusion rate (GIR)

6 mg/kg/min 8 mg/kg/min 10 mg/kg/min

D10 D25 D10 D25 D10 D25

• 60 42 18 24 36 5 55

• 75 68 7 49 26 30 45

• 90 90 - 74 16 55 35

• 105 85* - 99 6 80 25

• 120 100* - 120 - 97 18

Achieving appropriate glucose infusion rate at different daily fluid intakes

How to covert mg/dl to mmol/L

• To convert mmol/L to mg/dl multiply by 18

1mmol = 1 X (18) mg/dl

• Similarly divide by 18 if converting into mg/dl from mmol/L

How to calculate GIR in an infant on oral feed along with simultaneously

intravenous infusion of glucose

• GIR =

IV rate (ml/hr) X Dextrose conc (g/dl) X 0.0167/wt(kg)

Feed rate(ml/hr) X Dextrose conc*(gm/dl) X 0.0167/wt(kg)

•Amount of dextrose in milk: breast milk 7.1gm/dl, Term formula 7.1gm/dlpreterm formula 8.5gm/dl

How should be refractory and prolong hypoglycemia be evaluated

• GIR requiring more than 12mg/kg/min for more than 24 hr

OR

• Blood glucose level remain unstable beyond 5 to 7 days respectively

Investigation to be done

• Sr insulin, cortisol (adrenal insufficiency), TSH

• Ammonia, Lactate urine for ketone and reducing substance for Metabolic disorder (galactosemia, glycogen storage disease, organic acidemia and mitochondrial disorder)

• Rarely 17 OHP, GALT assay, TMS, Growth harmone , glucagon level

Note

• Persistent hyperinsulinemia (PHHI) is diagnosed if there is hyper insulinemia plasma insulin > 2uU/ml, in presence of documented lab hypoglycemia

Note..

• Drugs like hydrocortisone, diazoxide, octreotide , nifedipin, or glucagon may be prescribed only in consultation with pediatric endocrinologist

• Hydrocortisone 5 mg/kg/day IV or PO in two divided doses for 24 to 48 hrs

• Diazoxide can be given orally 10-25 mg/kg/day in three divided doses . Diazoxide acts by keeping the KATP channels of the Beta-cells of the pancreas open, thereby reducing the secretion of insulin. It is therefore useful in states of unregulated insulin secretion like in insulinomas.

• Glucagon 100 ug/kg subcutaneous or intramuscular (max 300 ug) – maximum of three doses. Glucagon acts by mobilizing hepatic glycogen stores, enhancing gluconeogenesis and promoting ketogenesis. These effects are not consistently seen in small-for-gestational age infants. Side effects of glucagon include vomiting, diarrhea and hypokalemia and at high doses it may stimulate insulin release.

• Octreotide (synthetic somatostatin in dose of 2-10 μg/kg/day subcutaneously two to three times a day.

Best practice for prevention of neonatal hypoglycemia

• Support and prompt early exclusive breast feeding

( sucrose fortified milk 5gm of sucrose in 100ml milk is shown to raise blood glucose level to prevent hypoglycemia*)

• Prevent hypothermia

• Do not feed 5%,10% or 25% D as a substituefor breast feeding (risk of rebound hypoglycemia is more)

* However risk of contamination cannot be ruled out