Insulin - Neutral for the newborn intensive care
To treat hyperglycaemia in VLBW infants with persistent glucose intolerance and hyperkalaemia in critically ill VLBW infants.
Dose and administration
Continuous IV infusion: 0.01 - 0.1 U/kg/hr (starting dose usually 0.05 U/kg/hr). Titrate infusion rate according to blood glucose response.
Infusion should not be included in the daily prescribed fluid total. Insulin should be given in addition to daily fluid intake.
Insulin (units of 1 Unit/ml dilution) to be added to 50ml = 50 x weight (kg) x dose (units/kg/hour) IV rate (ml/hr)
Intermittent dose: 0.1 - 0.2 U/kg 6-12 hourly SC/IM.
Indications
Hyperglycaemia in VLBW infants with persistent glucose intolerance.
Hyperkalaemia in critically ill VLBW infants.
Contraindications and precautions
May rapidly induce hypoglycaemia.
Hypersensitivity to insulin (extremely rare).
Insulin resistance may develop causing a larger dose requirement.
Clinical pharmacology
Insulin enhances uptake of glucose in insulin sensitive tissues, enhances glycogen and fat synthesis, enhances muscle uptake of amino acids and cellular uptake of potassium. It inhibits lipolysis and gluconeogenesis. Plasma half-life is short (approximately 9 minutes in adults), with degradation in liver and kidneys. Absorption from IM or SC doses is variable.
Possible adverse effects
Hypoglycaemia
If the blood glucose concentration is:
< 4.0 mM consider stopping insulin or at least halve the insulin dose
< 2.6 mM stop insulin, consider dextrose bolus
Check blood glucose concentration again in 1 hour
Hypokalaemia
Special considerations
If given by infusion, should be via a line that will not need to be flushed (to avoid boluses) and ideally the same line as is used for glucose or intravenous nutrition infusion. This ensures cessation of insulin at the same time as glucose infusion if the drip tissues, and thus reduces the risk of hypoglycaemia.
Incompatible with aminophylline, chlorothiazide, dobutamine, lignocaine, phenobarbitone, phenytoin, sodium bicarbonate.
Effect decreased by drug-induced hyperglycaemia e.g. corticosteroids, thiazide diuretics, adrenaline, glucagon, thyroid preparations, phenytoin.
Adsorbs onto plastic i.e. syringes, extension tubing, filters, and 3-way taps therefore the line is primed and left to stand before using. For this reason, if blood glucose fails to show a decline after the first check, check again in 2-4 hours before increasing the insulin infusion rate.
Is considered safe by National Women's Hospital Paediatricians to mix insulin and heparin in the same syringe for administration via a central venous line.
Management of Insulin administration
Description
Clear colourless solution 100 ΙU/ml in 1.5 ml cartridges.
Discard if discoloured or shows precipitate.
Prescription
Continuous Infusions:
Charted on fluid chart giving:
rate in ml/hr
dose in units/kg/hr
Also charted on drug chart under continuous infusions:
Instructions for 1st and 2nd dilution: Base fluid, type and volume
Insulin to be added
Units/kg/ml
SC/IM Injection:
Charted on the prescription chart:
dose in units
dosing interval
rate of administration
Administration of Insulin
Continuous IV Infusion:
Note: Insulin infusion is not to be filtered.
First dilution (1 unit/ml):
Dilute 50 units (0.5 ml) of insulin into 49.5 ml 5% glucose to make a solution of 1 unit/ml. Mix well.
Using a 5 ml syringe draw up required amount of insulin (1 unit/ml) as charted.
Discard the remainder of the 50ml syringe of insulin (1 unit/ml).
Second dilution:
With another 50 ml syringe draw up 5% glucose at an amount to make the solution to a total of 50 ml.
Add the insulin dose (1 unit/ml from the 5 ml syringe). Mix well.
Prime the BC 566 (no filter is required).
Leave syringe and extension for 1 hour to saturate the plastic binding sites.
Flush a further 20 ml of the prepared solution into a gallipot.
Connect to a continuous infusion pump and then to infant.
Change solution and tubing every 24 hours.
SC/IM Injection:
No dilution required.
Observation and documentation
Monitor blood glucose frequently (initially 1-2 hourly until stable).
Check urine for glucose at least 4-hourly.
Monitor for signs of hypoglycaemia and hypokalaemia.
Notify doctor / NS-ANP immediately if dextrose or intravenous nutrition infusion is interrupted e.g. tissued drip. Insulin infusion may need to be discontinued until dextrose infusion is restored.
When insulin is in the IVN or dextrose infusion, a separate cannula will be required for IV medications.
Storage
Store in refrigerator (2-8°C) in carton.
Protect from light.
Discard opened cartridge after use.