IV Placement for Administrating Anesthesia
Though anesthesia can be delivered in non-invasive forms (i.e. orally, or through inhalation), intravenous (IV) administration allows for continuous dispensation and easy dose adjustments in real time. Moreover, when compared to volatile agents, IV anesthesia involves no risk of operating room “leaks.” As a result, the use of IV cannulas to administer anesthesia is extremely common, leading to the choice of optimal placement.
The aim of IV placement is to directly administer a drug into the bloodstream, which allows anesthesia to quickly diffuse to target areas with little to no obstacle to absorption.1 Voluntary contraction of nearby muscles, ensuring that the patient is properly hydrated and warm, and/or placement of a tourniquet can be used to engorge the selected vein, therefore improving ease of insertion. Prior to insertion, the target vein should feel spongy and non-pulsatile upon palpation, to ensure that it is at low risk of thrombosis and not an artery, respectively.1 Depending on the exact placement and the time/effort required to insert the IV cannula for anesthesia, patients may experience varying levels of mild to moderate pain. Special care should be taken to minimize discomfort when possible, as it is common for patients to have anxiety regarding IV insertion.
Peripheral line placement refers to the placement of a line in a peripheral vein – a vein in the arms or legs. The procedure is minimally invasive, low risk, and one of the most common procedures practiced in acute care. In fact, it is estimated that over one billion peripheral lines are placed a year worldwide.2 Though a routine procedure, peripheral line placement is not without its technicalities. For example, while there are many possible sites where one could potentially start a peripheral line, placement in the non-dominant arm confers a number of benefits, including increased comfort, reduced risk of dislodgement, and lower incidence of thrombosis or thrombophlebitis.3 Within the upper extremity, there are a number of ideal targets, including the metacarpal veins on the back of the hand. However, if the upper extremity is not a viable option, another potential target is the dorsal venous plexus of the foot.1
In some patients, the insertion of an IV may be less straightforward. Neonates and infants in particular have much smaller veins, making it difficult to insert a peripheral line. Upon failure to insert in the upper and lower extremities, healthcare providers might attempt to place the IV in the scalp. The frontal, occipital, superficial temporal, or posterior auricular veins in the scalp might prove more accessible.2 Other patients for whom IV placement for anesthesia or other medications may be more challenging are children, obese individuals, pregnant women, patients with heavily vasoconstricted veins (due to shock or cold temperature, for example), and those whose veins are already compromised by previous trauma/repeated injections.4
Patients who are unable to receive a peripheral line or require long-term intravenous insertion may receive a central line instead. Central lines can be inserted into the jugular vein in the neck or the femoral vein in the groin. Though placement of a central IV line involves higher risk of serious complications such as thrombosis or severe infection,5 it ultimately results in long-term ease of access for the administration of anesthesia and other drugs. Therefore, risks and benefits should be thoroughly evaluated for each unique patient when choosing between a central line or peripheral line.
References
1 Peripheral line placement – Statpearls – NCBI bookshelf. (2021). Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK539795/
2 Carr, P. J., Higgins, N. S., Cooke, M. L., Rippey, J., & Rickard, C. M. (2017). Tools, Clinical Prediction Rules, and Algorithms for the Insertion of Peripheral Intravenous Catheters in Adult Hospitalized Patients: A Systematic Scoping Review of Literature. Journal of hospital medicine, 12(10), 851–858. https://doi.org/10.12788/jhm.2836
3 Mbamalu, D., & Banerjee, A. (1999). Methods of obtaining peripheral venous access in difficult situations. Postgraduate medical journal, 75(886), 459–462. https://doi.org/10.1136/pgmj.75.886.459
4 Lamperti, M., & Pittiruti, M. (2013). II. Difficult peripheral veins: turn on the lights. British journal of anaesthesia, 110(6), 888–891. https://doi.org/10.1093/bja/aet078
5 U.S. National Library of Medicine. (2022). Central Line Management. National Center for Biotechnology Information. Retrieved from https://www.ncbi.nlm.nih.gov/books