Thrombus is the formation of a blood clot within a blood vessel. It is caused by any injury that breaks the integrity of the endothelial cells of the venous wall, and usually occurs at the point at which the catheter touches the intima of the vein. Platelets adhere to the injured wall, and a thrombus is formed.
To understand this just imagine drinking water from a straw. Flow in this case is the amount of liquid that comes out of the cup into your mouth in a given period of time, and the pressure difference is provided by your lungs sucking in air. If the radius of the straw is twice as big you will get not twice as much, but 16 times as much liquid! On the other hand, if you are trying to suck syrup out of the straw, whose viscosity is much higher than water, the flow will be substantially diminished. In the same sense, the longer the straw you use, the less flow you will have.
Catheter Related Thrombus Management
(enhanced by VisualBee)
Karen Williford RN, CRNI<br />Beebe Medical Center<br />Tunnell Cancer Center<br />Lewes, Delaware<br />Catheter Related Thrombus Management<br />
Objectives<br />•Discuss the pathophysiology of catheter related thrombosis<br />•Discuss thrombosis prevention strategies related to vascular access device assessment and insertion<br />•Discuss current research findings as they relate to vascular access device thrombosis<br />
Upper Extremity Deep Vein Thrombosis (UEDVT)<br />Increasing prevalence with potential for considerable morbidity<br />Increased use of CVC/PICC<br />Chemotherapy<br />Bone Marrow Transplant<br />Parenteral Nutrition<br />Dialysis<br />
Risk Factors<br />Administration of incompatible solutions and medications<br />Administration of solutions or medications with high pH or tonicity<br />Ineffective filtration<br />Thrombogenic catheter materials<br />Malpositioned catheter<br />
Endothelial Injury<br />Larger stiffer catheters pose a higher risk of endothelial injury on insertion<br />Infusion of irritants or vesicants<br />Sub Optimal Catheter Tip Locations carry larger risk of endothelial injury<br />
Tretola Study 2010<br />Stopped at 50 of 167 planned patients<br />Scheduled interim US showed an DVT rate of 20% (10 of 50)<br />Venous Thrombosis (symptomatic or asymptomatic) 58%<br />0% CRBSI<br />Colonization 10%<br />Malfunction & Dislodgement in 1 patient<br />
Duke University 2011<br />Purpose: Evaluate the effectiveness of practice changes to reduce PICC thrombus risk<br />Retrospective analysis of adult patients<br />1307 charts reviewed January 2008, October 2008, and August 2010. Clinical Practice change to include US & tip in SVC<br />
Duke University 2011<br />PICC related DVT rates decreased from<br />4.8% to 2.9% (January 2008-October 2008)<br />October 2008-August 2010 practice change to<br />measure & document native vein diameters prior to PICC insertion -2X outer cath diameter<br />PICC related DVT decreased from 2.9% to 1.4%<br />
INS National Standards<br />Medications with a pH <5 or >9<br />OR<br />Osmolarity greater than 600mOsm/L<br />can cause vein irritation,<br />phlebitis, infiltration or extravasation.<br />
Hypertonic<br />Hypertonic solution has an osmolality of<br />350 mOSM/liter and above.<br />The osmolality of PPN is about 750<br />mOSM/liter and above.<br />Hypertonic solutions cause phlebitis<br />peripherally in less than 24 hours<br />
Examples<br />D25W (1330mOSM/liter).<br />D40W (2020mOSM/liter).<br />D50W (2525mOSM/liter).<br />Literature states hypertonic drugs withan osmolality over 600mOSM/liter resultin phlebitis in 24 hours with shortperipheral catheters.<br />Consider central venous administration<br />
Take this Home!!<br />History and Physical/Physician Collaboration<br />Limit Catheter Manipulation*Catheter Exchange can increase thrombosis and infection risk<br />Prevent catheter related infections<br />Get the tip in the right place!<br />