Drops Per Minute

IV Drops per Minute Explained

In calculating the drops per minute for an intravenous administration of fluids, it is important to note the three variables involved:

• The volume to be administered (usually expressed in mL);
• Administration time (usually in minutes or hours);
• Drop factor i.e. determined by macrodrip tubing (expressed in gtts/mL).

The formula used is:

IV Drip rate (Drops per minute) = (Volume to be given in mL x Drop factor in gtts/min) / Time in minutes

The rate at which a fluid is administered intravenously (the drops per minute) is in practice regulated by a burette (consisting of a needle or plastic dropper).

Most common drip sets include:

• 10 gtts/ml regular drip set;
• 15 gtts/ml regular drip set;
• 20 gtts/ml regular drip set;
• 60 gtts/mL minidrip set.

IV administration of fluids has multiple applications, such as administering medicine, correcting electrolyte imbalances or dehydration, or administering blood transfusions.

The PEACE method may be used to ensure that none of the crucial steps of IV administration is omitted:

• P stands for plan – considering dosage of medication or fluids;
• E stands for estimate – before calculation it may be useful to also use an estimation method;
• A stands for approach – answering questions such as what, how, when and where;
• C stands for calculate – for example flow and drop rate;
• E stands for evaluate – ensuring that the calculation is checked and reviewed by a colleague and outlier results are thoroughly scrutinised.

References

Duell, D. J., Martin, B. C., & Smith, S. F. Clinical nursing skills: Basic to advanced skills (6th edition). 2004. Upper Saddle River, NJ: Pearson Education.

Gage CB, Toney-Butler TJ. Dose Calculation. [Updated 2020 May 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan.

Boyle MJ, Eastwood K. Drug calculation ability of qualified paramedics: A pilot study. World J Emerg Med. 2018; 9(1):41-45.