Overview
Start with the Order and the Patient
A correct calculation can still produce harm if it is applied to the wrong patient, wrong concentration, wrong route, or an inappropriate order.
A correct calculation can still produce harm if it is applied to the wrong patient, wrong concentration, wrong route, or an inappropriate order. Read the complete order before reaching for a calculator: medication, dose, route, frequency or infusion duration, indication where relevant, and any maximum dose or titration instruction. Confirm the patient’s identity, allergies, current weight when weight-based dosing is ordered, relevant laboratory results, and clinical status. The nurse must know why the medication is being given, its expected effect, important precautions, adverse effects, compatibility requirements, and monitoring needs. Drug-specific dilution, maximum rates, organ-function restrictions, and emergency actions come from the current product monograph, pharmacy direction, prescriber order, and local protocol—not from a general calculation rule. Pause when the order is incomplete, internally inconsistent, illegible, or clinically implausible. A dose that is mathematically possible may still be unsafe for that patient. Clarify the order before preparing or administering the medication. Medication authority and infusion workflows are set by provincial or territorial regulation and employer policy. Before administering or adjusting an IV medication, the nurse must be authorized and competent for...