Episode 719: Peripheral Vasopressor Feasibility

In this episode, I’ll discuss the feasibility of peripheral vasopressors.

Vasopressors are traditionally administered via central line only due to concerns about extravasation and tissue damage when they are given via a peripheral line.

However central lines can be time consuming to place and have a risk of complication and infection. In addition, some patients may need vasopressors at a low dose or for a short time period and have no other indication for central line placement. This leads many clinicians to consider the peripheral administration of vasopressors for a subset of hypotensive critically ill patients.

Some publications in the past few years have suggested that under the right circumstances, peripheral administration of vasopressors in select patients does not have a high risk of extravasation injury.

One institution has recently published their experience using peripheral vasopressors at conservative doses in select ICU patients in the form of a retrospective chart review study.

The dosing guidelines set by the hospital for peripheral vasopressor use in ICU patients were as follows:

• Norepinephrine at a dose of 16 mcg/min or less
• Phenylephrine at a dose of 200 mcg/min or less
• Vasopressin at a dose of 0.04 units/min or less
• Epinephrine at a dose of 0.1 mcg/kg/min or less

Patients could not be on more than one vasopressor, and there were several restrictions placed on the peripheral line that could be used including:

• Peripheral IV site must be in an upper extremity proximal to the wrist
• No antecubital sites could be used
• The line must be dedicated to the vasopressor only and another peripheral line must be placed prior to starting the vasopressor
• The peripheral site must be on the opposite extremity as the blood pressure cuff
• The duration of peripheral vasopressors must be 72 hours or less

The concentrations of vasopressors used were as follows:

• Norepinephrine at a concentration of 32 mcg/mL
• Phenylephrine at a concentration of 160 mcg/mL
• Vasopressin at a concentration of 0.4 units/mL
• Epinephrine at a concentration of 16 mcg/mL

A total of 79 patients were analyzed.  For all vasopressors except epinephrine, the average infusion dose was below the hospital’s dosing guidelines.  Only 3 epinephrine infusions were in the cohort, and 2 of them averaged above the guideline limit of 0.1 mcg/kg/min.

The 79 patients actually had 129 orders for peripheral vasopressors and much of the analysis in the study is done per-order not per-patient.  Excursions above the guideline dose limits occurred during 23 of the 129 orders, and 7 orders were run for longer than the 72 hours set in the guideline.

No patient in the study cohort required treatment for extravasation, and the bedside team taking care of each patient never documented an extravasation event.

The study reviewers did however note 3 possible cases of extravasation when looking back at the care team’s notes.

1. A patient receiving norepinephrine at 6 mcg/min at hour 28 was documented to have “phlebitis/erythema at access site”
2. A patient with phenylephrine at 160 mcg/min at hour 76 was documented to have “infiltration/skin blanched/edema <1 inch”
3. A patient with epinephrine at hour 62 was also documented to have “infiltration/skin blanched/edema <1 inch”

Just over half of the patients (57%) did not go on to require a central line be placed in the ICU stay.  If these patients otherwise would have received a central line placement, this represents a substantial reduction in central line placement with the use of peripheral vasopressors.  However the authors do note that during the study period, central line placement in all patients seemed to be less frequent than usual, so the benefit of reduced central line placement may not be as great as this study suggests.

The hospital concluded that peripheral vasopressors used according to their conservative dosing protocol was safe to continue on a larger scale.

This study represents a real world implementation of peripheral vasopressors and while the sample size is small, it seems to confirm 3 previously published systematic reviews (1, 2, 3) that suggest there are circumstances where peripheral vasopressor use is safe.

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