Preventing CRBSIs related to IV connectors

Connector designs and care routines

All I.V. connectors available have four design elements in common—external housing, a septum, a fluid pathway, and a mechanism that permits entry into the fluid pathway on connection and allows it to close to its original position with disconnection. Dead space refers to areas within the fluid pathway that can’t be cleared with flushing.

Three categories of I.V. connectors

I.V. connectors fall into three categories based on reflux:

  • Split-septum (SS) and negative-displacement (ND) connectors are associated with blood moving back into the catheter (reflux) on disconnection. This repeated reflux is thought to coat the intraluminal fluid pathway with blood fibrin, to which bacteria adhere.
  • Positive-displacement (PD) connectors are associated with reflux on connection. They cause a final outward push with disconnection; for this to occur, reflux equal to the outward push occurs on connection.
  • Zero-fluid displacement (ZFD) connectors cause zero reflux on connection or disconnection and eliminate fluid displacement associated with use.
Septum design

The septum of an I.V. connector is exposed to and contaminated by the environment. An I.V. catheter may be accessed several times daily to withdraw blood or deliver medications. Each connection provides an opportunity for bacteria to enter the fluid pathway via the septum. Therefore, the septum must be disinfected before each access.

Every blood withdrawal or drug administration requires three separate connections (or four, if heparin is instilled):
  1. Before any procedure, check for blood return to verify placement.
  2. Flush the catheter.
  3. After blood withdrawal or drug administration, flush again to clean the catheter and connector.
Some connector designs make complete disinfection difficult even when performed meticulously. In an effort to improve disinfection, some clinicians have increased swabbing times and use chlorhexidine instead of alcohol. But some connectors are hard to disinfect even with thorough and prolonged scrubbing. An in vitro study of five popular connectors that was designed to replicate the clinical practice outlined above found that microorganisms migrated into the fluid pathway after routine disinfection. The connectors with the most colony-forming units (CFUs) to the least CFUs included one SS type (Q-Syte), two ND types (TKO Clave, MicroCLAVE), one PD type (MaxPlus-Clear), and one ZFD (RyMed-500) connector. (See by clicking the PDF icon above.)

The best septum design is smooth with a tight seal to the connector housing to prevent bacterial entry. A smooth septum eases disinfection. In vitro studies show that ZFD connectors, which have a smooth septum and tight seal, can be disinfected completely with three twists of an alcohol swab. A connector that’s easy to swab reduces the risk of infection due to bacterial migration and supports nursing practice. Although nursing practice is attempting to overcome I.V. connector design issues with long and complicated swabbing procedures, it’s often blamed when infections occur.

What the research shows

Her research supports the use of ZFD connectors to enhance intraluminal protection and improve patient outcomes. At Methodist Extended Care Hospital in Memphis, Tennessee, an acute long-term care facility, three different connectors were studied over 3.5 years—Q-Syte (SS), SmartSite (ND), and InVision-Plus (ZFD). Use of the SS yielded the highest CR-BSI rate—six per 1,000 catheter days. The ND performed better at 3.3 per CR-BSIs per 1,000 days. Only the ZFD connector produced an acceptable rate by today’s standards—0.5 per 1,000, including the most desired "zero" rate for the final 10 months of the study period. All patients in this facility had complex comorbidities and therapeutic regimens and came to the facility with the catheter in place. Even with this challenging population, combining technology with practice offers a better approach than depending strictly on nursing practice.

Although FDA’s requirement of postmarketing surveillance study centers on PDs, a closer look at the record shows that SS and ND connectors are linked to elevated CR-BSI incidence. Only in the last decade has the intraluminal pathway has been studied and identified as a problem. Protecting the pathway requires specific I.V. connector features developed to minimize bacterial migration and internal surface adhesion in addition to eliminating needles. Only the ZFD connector design, created to protect the intraluminal fluid pathway by offering fail-safe backup to nursing care and maintenance efforts, achieves this higher standard.

Nonetheless, while the ZFD connector is the safest choice, it’s unrealistic to expect healthcare facilities to switch to it right away. In fact, many facilities are contractually bound to purchasing groups that don’t stock them. Until regulators act more comprehensively against risky connector products, facilities should take these crucial steps:
  • Teach all clinicians involved with vascular access to identify all catheter connector types they’re using.
  • If possible, stock only one connector type to minimize confusion about the proper clamping procedure.
  • Develop swabbing protocols based on the connector type in use, instead of imposing an artificial swabbing time.
  • Educate all clinicians about the importance of swabbing and flushing catheter connectors.
Pressure is mounting for healthcare facilities to eliminate CR-BSIs. The Center for Medicare & Medicaid Services no longer reimburses hospitals for treating these infections because it deems them preventable. It also requires all Medicare-eligible hospitals to report certain hospital-acquired infections, including CR-BSIs, to get full payment in its pay-for-reporting program. Obviously, patients pay the heaviest price for CR-BSIs, but the price is rising for healthcare facilities, too.

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