What type of administration method is described as a bolus or infusion through an existing IV line?

The administration method described as a bolus or infusion through an existing IV line is referred to as an IV push. This technique involves delivering medication directly into the bloodstream through an existing intravenous (IV) line, where a medication is rapidly administered in a single dose (bolus) or over a short period of time via a syringe, allowing immediate therapeutic effects.

In clinical practice, an IV push is commonly used for medications that need to act quickly, such as pain relief or emergency treatments, due to its direct entry into the circulatory system. This method offers advantages such as rapid onset of action and precise control over the dosage administered.

While intermittent infusion is also a method of medication delivery through an IV line, it generally involves a scheduled infusion of fluids or medications over a longer period rather than a rapid bolus. Direct injection typically implies giving medication without the use of an IV line, such as in intramuscular or subcutaneous routes. Subcutaneous injection refers to the administration of medication into the subcutaneous tissue, which is completely different from intravenous methods. Therefore, it's clear that IV push is the appropriate term for this method of administration when utilizing an existing IV line for either a bolus or infusion.