Using an intravenous line that has already been placed into the patient's vein to provide fluids, drugs, or nutrients is known as IV infusion with a cannula already in place. The procedure is speedier and less intrusive because the cannula—a tiny, flexible tube—is already installed and the needle doesn't need to be reinserted. 

The distinction between IV infusion and IV infusion using a pre-existing cannula: 

IV Infusion: Before giving the infusion, a cannula must be inserted. 

IV infusion (Cannula in Place): By using a cannula that has already been implanted, minimizes discomfort and preparation time. 

Efficiency: For patients who need frequent or ongoing IV therapy, the latter is best.