Irritants and vesicants: ensuring safe IV therapy

Certain infusates used in patient treatments can cause discomfort or injury, either to the veins directly, or to surrounding tissues if the infusate escapes the intended vascular route.¹ According to the Infusion Therapy Standards of Practice, 9^th Edition, an irritant is “an agent capable of producing discomfort (e.g., burning, stinging) or pain as a result of irritation in the internal lumen of the vein with or without immediate external signs of vein inflammation;”¹ while a vesicant is “an agent capable of causing tissue damage when it escapes from the intended vascular pathway into surrounding tissue.”¹  Vesicant chemotherapy extravasation, for example, has the potential to cause tissue necrosis if it is left untreated.²

Drugs that are potentially associated with endothelial damage are sometimes referred to as peripherally incompatible drugs,³ in contrast to peripherally compatible infusates, which do not commonly cause vein irritation or tissue damage.³ Peripherally incompatible drugs can include antibiotics, antiviral drugs, vasoactive amines, vesicant antiblastic drugs and high osmolarity parenteral nutrition.³ Anti-cancer drugs in particular can cause adverse reactions, including phlebitis, pain, or necrotising vasculitis.⁵ Anthracyclines, taxanes, and vinca alkaloids are examples of vesicant drugs which can necrose local tissue when extravasation occurs.⁵ Platinum agents, topoisomerase inhibitors, alkylating agents, and some antimetabolites are examples of irritants which can cause inflammation.⁵

Is drug dilution with saline an effective way to reduce the risks? According to the European Recommendations for Proper Indication and Use of Peripheral Venous Access (ERPIUP) Consensus: “Dilution…might have a role in reducing the risk of vein damage, but only for solutions with high osmolarity: dilution cannot significantly modify the pH of a solution.”³ The Infusion Therapy Standards of Practice, 9^th Edition, states: “Avoid unnecessary dilution. Only dilute IV medications when recommended by the manufac­turer or in accordance with organisational policies, procedures, or practice guidelines.”¹ With dilution, there are other factors to consider to help minimise the risks including, but not limited to, flow rate of infused medication and vein selection.¹

More on this topic: IV fluid osmolarity: what to know for IV catheter selection

Future complications

Beyond the immediate risks of vein irritation, pain, discomfort and potential tissue damage during an infusion, irritants and vesicants can damage vascular endothelial cells.⁵ Studies have shown that endothelial cell injury can contribute to vascular disorders and is associated with the pathophysiology of a number of diseases.⁵

Selecting the right vascular access device (VAD): factoring in the risks related to irritants and vesicants

Clinicians are becoming increasingly aware of the indications in choosing a peripheral or central vascular access device (CVAD), including the chemical characteristics of infusates and possible damage to the endothelium.³ The choice between a peripheral or central device depends on a multitude of factors. These are just some points to consider:

CVADs to prevent endothelial injury. CVADs are suitable for all types of infusates without incurring the risk of endothelial damage.³ According the ERPIUP Consensus, these infusates should be delivered by a CVAD: vesicant drug solutions with low (<5) or high (>9) pH or very high osmolarity (>600 mOsm/L), as should any other infusate that could potentially irritate the vein wall.³

Risks of low flow systems. Infusing irritant or vesicant solutions via a low flow peripheral vein may result in injury such as damage to the endothelial layer of the intima, which could result in thrombus formation, or inflammation of the tunica media of the vein, which may lead to oedema or even rupture of vein wall integrity.³

Very slow flow rate. The time duration of the infusion must be considered. If a high-osmolarity solution (800–850 mOsm/L) is infused over 24 hours, it may be tolerated by the endothelium.³ Or if a vesicant is infused via peripheral vascular access device (PVAD) for less than an hour, it can minimise the risk of endothelial injury.³

Risks associated with PVAD dislocation. Irritants and vesicants may lead to catheter dislocation, which can result in tissue damage or even tissue death.³

More on this topic: PVAM care bundles: how we can measure their economic benefit

Irritants and vesicants: Preventing risks and avoiding injury

Vessel health preservation is the ultimate goal. The ERPIUP Consensus recommends that clinicians have a master list of peripherally incompatible drugs when choosing between a PVAD or CVAD for patients.³ A comprehensive, updated list can aid in identifying medications and solutions which may be associated with patient harm.³

Another useful tool is the BD Vascular Access Device Assessment Decision Tree. This one-page guide provides a decision-tree format to help identify the appropriate VAD, based on treatment, length of therapy, venous assessment and other criteria.

References