Indian Pediatrics 2001; 38: 928-929  

Sion Hospital Formulae for Management of Hypoglycemia

The management of persistent hypo-glycemia is a demanding task requiring continuous monitoring and quick change in both the rate and concentration of the glucose infusion. We, at the Lokmanya Tilak Muni-cipal general Hospital (Sion Hospital), Mumbai, have devised a set of simple, easy to use formulae (as below) to tackle this problem.

Step 1: Calculation of Glucose Infusion Rate (GIR) with 10% D

Glucose Infusion Rate (mg/kg/min) = Fluid Rate (ml/kg/day) ´ 0.07 (e.g., if the baby is getting 100 ml/kg/day of 10% D, GIR = 100 ´ 0.07 – 7.0 mg/kg/min).

Step 2: To increase the GIR by 1 mg/kg/min

Add 2 ml/kg of 25% D to each 8 hour drip (e.g., add 2 ml/kg of 25% D to each 8 h drip in the example above to increase the GIR from 7.0 mg/kg/min to 8.0 mg/kg/min).

Step 3: While Using Step 2, to Ensure That Drip Concentration Does Not Exceed 12.5% D (Maximum Permissible Through a Peripheral Vein).

Do not increase the GIR (in numerical value) by more than numerical value of the fluid rate in ml/kg/day divided by ten (e.g., if the GIR is 7.0 mg/kg/min with a fluid rate of 100 ml/kg/day, do not increase to more than 10 mg/kg/ min, i.e. the numerical value of the fluid rate divided by 10 using step 2).

Note:

• If a further increase in GIR is required, increase the total fluid per day (ml/kg/day).

• The total fluid increases by 6 ml/day for every 1 mg/kg/min increase in GIR.

• These formulae are valid only if the preparations of 10% and 25% D used are made with the anhydrous form and not the monohydrate form (as this contains only 85% D in each molecule). However, to date, all preparations of glucose in India are made with the anhydrous form.

Besides being easy, accurate and quick to calculate at the bedside, the GIR can be increased slowly in increments of 1 mg/kg/min to the required amount thus avoiding inadventent hyperglycemia and rebound hypoglycemia. Also, mixing of solutions to prepare different concentrations of Dextrose solutions is avoided and an easy check is kept so as not to exceed the maximum concentration permitted through a peripheral vein.

Sheila S. Mathai,
Jayshree A. Mondkar
Professor and Head,
Department of Neonatology,
Lokmanya Tilak Municipal Medical 
College and General Hospital,
Sion, Mumbai 400 022, India.

Denouement

Step 1

100 ml of 10% D contains 10 g or 10000 mg of glucose.

If this has to be given over 24 h (144 minutes) then the infusion rate is 10000/144 or 6.95 mg/min (for convenience this is taken as 7 mg/min)

Hence, 1 ml/day of 10% D will give 7/100 or 0.07 mg/min of dextrose.

Hence, the fluid rate in ml/kg/day ´ 0.7 will give the GIR in mg/kg/min.

Step 2

25% D contains 25000 mg of dextrose in 100 ml or 500 mg in 2 ml.

There are 480 minutes in 8 hours. Hence, 2 ml of 25% D given over 8 hours will give approximately 1 mg/min of dextrose.

Hence, 2 ml/kg of 25%D given over 8 hours will give 1 mg/min of dextrose.

Step 3

Take the example of a 1 kg baby receiving 100 ml/kg/day of 10% Dextrose.

The GIR is 100 ´ 0.07 or 7 mg/min.

He gets 10000 mg of Dextrose in 24 hours.

To increase his GIR to 8 mg/kg/min (by adding 2 ml/kg of 25% D to each 8-hour drip) he will be getting (500 ´ 3) or 1500 mg of Dextrose more in 24 hours. This will give a total of 11500 mg or 11.5g in 24 hours. His total fluid will increase by 6 ml in 24 hours and will now be 106 ml/24 hours.

Hence, the concentration of Dextrose he gets will become (11.5/106) ´ 100 or 10.85%.

The Dextrose concentration will increase by approximately. 0.85% for the first 1 mg/kg/min increase in GIR but by a marginally lesser amount for each further aliquot of increase as the denominatior (i.e., the total fluid/day) increases and hence the concentra-tion of Dextrose will increase to 12.23% (and not 12.5%) for a 3 mg/kg/min increase in GIR. The amount to which Step 2 can be used increases with the initial fluid rate as the denominator increases. This step is best checked by doing multiple calculations using different initial fluid rates.