New Zealand Emergency Bolus and Infusion Calculators

New Zealand has a single national PICU retrieving all critically ill children. The emergency drug calculator is used to calculate emergency drug doses and volumes based on weight and age.

New Zealand has a single national PICU, retrieving all critically ill children. It was quite common, prior to the development of this tool (about 4 years ago), for the following to occur:
  • Patients to be receiving inappropriately low or high infusion rates of medications such as inotropes.
  • Resuscitation drugs to be drawn up very slowly due to unfamiliarity with dosing/volume involved.
  • Obese children to be overdosed.
  • Errors made when following complex algorithms, such as n-acetyl cysteine for paracetamol overdose.


To reduce all the errors described above, and to provide a degree of standardisation across New Zealand such that infusions did not need to be re-made up by the retrieving team (particularly important with expensive medications such as prostin). To provide tools to decrease not just medication errors, but also the stress experienced by staff dealing with an arrest or peri-arrest situation, who do so infrequently.

The development team included Rob Ticehurst, a senior medication safety pharmacist, Elaine McCall, a senior nurse working in hospital quality and safety, Mike Shepherd, emergency physician, Carl Horsley, an adult intensivist with paediatric experience.


The emergency drug calculator calculates emergency drug doses and volumes based on weight and age (the age component is used in a number of calculations, and also determines which infusions are displayed – prostin is irrelevant over 3 months and life threatening asthma infusions irrelevant under 1 year). Infusions are calculated to be drawn up according to starship protocols, which vary on age and weight.

For older children, this involves a ‘per vial’ dilution method to save opening expensive medications for a tiny portion of the vial. The emergency bolus chart also provides ETT size and length at nares and teeth. The anthropometry calculator gives estimates of lean body mass, and sites references for those calculations. The chart is customisable for each centre using it (an administrators guide can be downloaded in .pdf form from the website).

The drug calculator is available online here.

The anthropometry calculator is available online here.


It is used in about 5 hospitals throughout New Zealand on a daily basis, and some in the South Pacific. Emergency dosing charts are printed on admission for all inpatients, and kept at the foot or the head of the bed. It receives over 20 000 hits a month, predominantly from the 5 hospitals using it.

All feedback has been positive, and our simulation team (who outreach around the country) state that team performance in scenarios involving critically unwell children, almost universally improves when the chart is used. The charts became integral in our complex multidisciplinary crisis resource management courses/simulations.

Suggestions for Further Implementation

To include mobile device support. More tools for dosing obese children according to the specific drug to be given (a professor of paediatric pharmacokinetics & expert on dose changes for obesity works in our department!) hosted on content delivery network.

Challenges and Learning

I would have developed in a slightly different framework, and coded a little more for readibility than performance. Precision/rounding has been somewhat of a bone of contention (in PICU we were very keen to avoid doses like 1.342 ml) and the main input was Prof Brian Anderson – a colleague here in Starship PICU who is a professor of pharmacokinetics and editor of Paediatric Anaesthesia.

The calculator is endorsed by the management of Starship Hospital.

It has been in use now for 4 years with no errors reported.


Project Lead: Dr Brent McSharry, Paediatric Intensive Care Physician

Organisation: Starship Hospital, New Zealand

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