Standardizing Central Line KVO Rates in the Adult Inpatient Population

By Vivian Huang, RN, BSN, OCN, BMTCN

Purpose

The goal of this evidence-based project was to identify best practices for minimum central line infusion rates, determine optimal rate to keep veins open (KVO), and standardize these institutionally. Secondly, this project aimed to determine whether adhering to best practices would have an effect on central line complication rates at the observed institution, a quaternary medical center.

Background

There is widespread use of KVO rates in nursing practice, but preferred rates and institutional policies vary. The purpose of a minimum infusion (KVO) rate is to prevent central line occlusions and any associated delays in care. Current institutional policy mandates a minimum infusion rate of 30 mL/hour for central lines on acute care units, but only 10 mL/hour in intensive care. This lack of standardization can cause confusion among staff and inconsistent patient care. At the adult acute care KVO rate of 30 mL/hour, patients with two central lumens passively receive 1440 mL of fluid per day.  Decreasing KVO rates may decrease the incidence and severity of fluid overload, the need for antidiuretic administration, and falls rates. The Infusion Nurses Society, in the absence of any conclusive evidence to support one rate over another, has set a practice recommendation for a KVO rate at 10 mL/hour for electronic volumetric pumps.

Methods

A small test of change was conducted on a 53-bed oncology unit, where nearly every patient has a central line, to implement change from a KVO rate of 30 mL/hour to 10 mL/hour. After support from key stakeholders was garnered, a policy amendment was crafted for piloting the KVO change and disseminated via huddle announcements, emails, and flyers. On the morning of the start date, each patient’s KVO rates were changed to the new rate without event. 

Results

As thrombus formation can seed infection, central line infection rates were tracked along with occlusions. Incidences of central line occlusions and infections were compiled via pharmacy and infection control reports, as well as chart audits. Data was compiled for the month prior to the rate change, then for three months post-implementation. Complication rates for each month were standardized by the number of central line days. No clinically significant effect on the rates of central line occlusions or infections was observed in the period after implementation. While this was a small sample size, the unit saw approximately 1400 central line days per month.

Discussion

This project revealed that the best available evidence recommends a KVO rate of 10 mL/hour, and standardizing to this rate in adult acute care would have little-to-no effect on central line occlusions and infections. The major limitations were the sample size, confounding factors on complication rates, and the inability to investigate effects on patient fluid balance in the scope of this project.

Conclusions

There is a surprising dearth of research regarding KVO rates, a fundamental aspect of vascular access in nursing practice. This project aimed to address this discrepancy, add to the body of literature, and guide standardization to the practice recommendation set out by the Infusion Nursing Society. KVO standardization will be set into nursing policy at its home institution, and possibly its sister medical centers.