In this episode, I’ll discuss if phentolamine the only thing you can use for vasopressor extravasation.
Extravasation is a complication of IV therapy that refers to the infiltration of tissues with a medication that is an irritant or vesicant.
Infiltration can be done purposefully with therapeutic intent, such as when lidocaine is used to provide local anesthesia.
Extravasation with an irritant causes discomfort but usually does not cause tissue damage.
Extravasation with a vesicant can cause tissue necrosis, damage and even the loss of a limb or extremity.
The main difference is that vesicants are inherently toxic when they leak into tissue whereas irritants are not.
When vasopressors extravasate, the resulting vasoconstriction can cause tissue ischemia and necrosis.
Phentolamine is the antidote of choice for the extravasation of vasoactive medications that work on alpha receptors: phenylephrine, norepinephrine, epinephrine, dopamine, and dobutamine.
In the past decade, phentolamine has had several periods of limited or no supply, and clinicians should be prepared to use alternative agents to treat vasopressor extravasation should phentolamine become unavailable again.
The two main alternatives to phentolamine for vasopressor extravasation are terbutaline and nitroglycerin.
While phentolamine works by directly opposing the alpha receptor-mediated vasoconstriction effects of vasopressors, terbutaline and nitroglycerin work indirectly by causing local vasodilation.
There is less data on the use of terbutaline and nitroglycerin but some published information does exist, especially in response to previous phentolamine shortages.
Terbutaline is typically diluted to 1 mg in 10 mL of normal saline and infiltrated around the area of extravasation in a manner identical to phentolamine.
The data for using topical nitroglycerin to treat extravasation comes primarily from reports of its use in children. Up to 1 inch of 2% nitroglycerin is applied topically to the site of ischemia. As the children in case studies required redosing every 8 hours, it is presumed that this redosing interval can be applied to adults as well if needed.
Members of my Hospital Pharmacy Academy have access to practical training on dealing with extravasation due to vasopressors and other medications from a pharmacist’s point of view, along with hundreds of other resources to help in your practice. To get immediate access, go to pharmacyjoe.com/academy.
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