Are central lines really needed for vasopressor infusions?

image: Wikipedia

There’s only one sure way to prevent complications from a central line: don’t place one.

Like many invasive interventions, some of central venous catheters’ indications have been called into question in recent years. Monitoring of central venous pressure and central venous oxygen saturation via central IV access — once considered essential to good care of severe sepsis — have been shown to be unnecessary for most patients. Having secure access was once seen as a reason for central lines, but peripheral IV access can be obtained on most patients in shock, with ultrasound or by experienced nurses.

Central lines are still widely believed to be necessary for safe infusion of vasopressors to patients in shock, to avoid tissue ischemic injury from local extravasation (and vasopressor interruption) if a peripheral IV infiltrates subcutaneous tissue. Two recent studies suggest that risk is likely lower than was thought, and vasopressors might be safely administered through peripheral IVs in the large majority of patients -- but only if your ICU team is handy with ultrasound.

North Shore-Long Island Jewish Medical Center successfully treated over 730 patients with vasopressors through peripheral IVs, and published their results in the Journal of Hospital Medicine. More than 2/3 were given norepinephrine, considered to be a relatively dangerous vasoconstrictor in peripheral tissues, at up to 0.70 mcg/kg/min. They report no tissue injuries among the patients, even though extravasation of vasopressor into subcutaneous tissue occurred in 19 patients (2%, which were recognized and treated).

Don't try this at home, yet -- patients receiving vasopressor through peripheral IVs were carefully managed and monitored through a protocol designed by physicians, pharmacy, and nursing leadership.

Among other requirements, veins had to be measured by ultrasound and confirmed > 4 mm diameter. 18-20 gauge IVs had to be placed in the opposite arm from the blood pressure cuff, not in the hand, wrist, or antecubital fossa (where most peripheral IVs are placed). IV sites were maintained less than 72 hours and checked every 2 hours for signs of extravasation or absent blood return (these checks necessitated frequent brief interruptions in vasopressor infusions). For extravasation, local phentolamine injection and nitroglycerin paste to skin were applied.

Only 13% of patients "failed" the peripheral IV protocol and required central line placement (e.g., for vasopressor use > 72 hours).

Previously considered essential to high-quality care for almost all critically ill patients, central lines may in fact be unnecessary for most patients.

A previous systematic review (mostly of case reports) concluded that when vasopressor is administered in the antecubital fossa (the arm opposite the elbow) for <4 hours, tissue injury is exceptionally rare. Although a risk was seen with longer infusions, few if any of these reports originated from centers employing a multidisciplinary protocol to manage peripheral vasopressor administration.

In a 2013 randomized trial comparing central vs. peripheral vasopressor administration (without an institutional protocol for peripheral vasopressors), 19 (14%) of the patients with peripheral IVs had extravasation of vasopressors, but none had any tissue injury, and only required observation and conservative management.

This practice change is unlikely to spread rapidly. Institution of the protocol used would require significant training (ultrasound for all peripheral IV placements in the ICU), culture change, and ongoing vigilance. That said, the q2-hour extremity checks would not likely impose a significant burden on ICU nurses. Patients would probably prefer to not have the additional procedure and piece of plastic in their necks, chests or groins, if it could be avoided.

Clinical Takeaway: If these authors' findings are replicated in a multicenter trial, we may one day conclude the risk of tissue injury from careful peripheral administration of vasopressor is lower than the combined (also low) risks of pneumothorax, arterial puncture, and bacteremia associated with central venous catheterization. Few centers without an ultrasound expert in a leadership role (Paul Mayo is the last author on this paper) will climb the significant hurdles of training and culture shift toward the routine use of ultrasound for peripheral IV placement in the ICU. Nevertheless, paired with the results of recent trials confirming lack of clinical benefit from monitoring of central venous oxygenation or central venous pressure in the vast majority of patients with severe sepsis, this study suggests central lines are probably needed by far fewer patients than currently receive them.

Read more:

Cardenas-Garcia J et al. Safety of peripheral intravenous administration of vasoactive medication. J Hosp Med. 2015 May 26. doi: 10.1002/jhm.2394. [pubmed]

EMCrit review and podcast on peripheral vasopressor administration and extravasation treatment

What to do for extravasation of peripherally administered vasopressor (from University of Kansas, posted by EmCrit)