What is an Intravenous Bolus?

An intravenous bolus is a rapid delivery of medication via an intravenous route. The time required to deliver a drug bolus can range from a few seconds to as much as 30 minutes, depending on the volume of medication being administered and other safety precautions. When a doctor writes a prescription for an intravenous bolus, the amount of the drug is specified along with the period of administration.

There are a number of reasons why a doctor might want to introduce a medication into a patient's system very quickly. One goal may be to rapidly achieve a peak level of the medication in the system, as seen in emergency situations. It may also be desirable to achieve quick results or because there is no other way to deliver the medication.

Some medications cannot be given in the form of an intravenous bolus. These drugs can be dangerous if they are introduced too rapidly or if their levels rise too high. Other medications must be introduced in dilute form and are unsuitable for boluses because of the high volume created by mixing the medication with saline solution or another diluent. For some patients, boluses can be dangerous, usually because their bodies are not able to process medication or fluids efficiently and the bolus could endanger their organs. People with edema, certain heart problems, or low urine output are examples of individuals who may not be suitable candidates for an intravenous bolus.

The medication can be delivered through an intravenous catheter or an intravenous injection. In both cases, the diameter of the needle is considered when calculating how long the bolus will take, as the medication can only move through the needle so quickly. The placement of the needle is checked before delivering the bolus to confirm that it is inserted properly.

Dosage calculators can be used to determine an appropriate dosage and length of time recommended for an intravenous bolus. Hospital safety procedures may require that certain medications have warning labels alerting people to the fact that they should not be administered in the form of boluses. Nurses and other providers are also alert to anything unusual in a prescription, such as a strange amount that might suggest that the caregiver transposed numbers or put a decimal point in the wrong place. Because boluses involve delivering high volumes of medication rapidly, it is especially critical to watch out for mistakes that could harm a patient, as they may not be identified until it is too late.