- Email: [email protected]
Reflux in Venous Access Devices: A Manageable Problem
A MdndCJedble
Problem
Donna Jo Mayo, MA, RM enous access devices (VADs) are used widely in both adult and pediatric medicine for the delivery of a variety of intravenous agents and to obtain blood samples for laboratory analyses.
V
However convenient these devices may
be, they have complications associated with their use that health care providers must be aware of in order to provide the best possible management of the
malfunction.' One may ask, "How does the blood get into the catheter if there has been an adequate flushing of
manufacturer's
guidelines?"
In
an
anempt to answer this question, let us
subclavian vein and superior vena cava
categorized as:
thrombosis), and withdrawal occlusion have been described in detail, along with associated treatment regimens. I ,23,"
• Complete occlusion: Total inability to withdraw blood and infuse fluids via the catheter. • Partial occlusion: Difficulty in withdrawing and infusing fluids via the
lumen occlusion, can be caused by the reflux of blood back into the catheter's tip during a flushing procedure. Recent advances in technology have been
obstruction (usually a thrombus) in the vein that completely or partially stops blood flow; it mayor may not affect the catheter's functionality.
standards set by professional organizations and/or when one follows the
sheath formation, catheter-related infection, central venous thrombosis (both
One of these complications, cannula
• Intravenous obstruaion: An
the cannula, as well as adherence to
focus upon the phenomenon of blood reflux and the technological strategies that have been developed to minimize the problem. Catheter-relared occlusions can be
devices. Such complications as fibrin
tion outside the lumen of the catheter, typically causing withdrawal occlus"ion.
mised with a clot that can result in
• Mechanical obstruction: An obstruction not related to precipitate or
blood that partially or completely occludes the catheter. Examples of mechanical obstruction are catheter "pinch off," tight sutures at the exit site, and kinked or twisted tubing.
Blood Reflux Prevention of intraluminal obstruc-
tion by thrombus is extremely important,
catheter.
• Withdrawal occlusion: Inability to withdraw blood via the catheter but
developed to reduce the incidence of
it retains a capacity to infuse solu-
this problem; however, these technological strategies have been mentioned only briefly in scattered reports. If blood refluxes into the catheter's lumen, the catheter may be compro-
tions without difficulty. • Intraluminal obstruction: Obstruction within the catheter lumen that causes complete or partial occlusion.
• Extraluminal obstruction: Obstruc-
W
not
only
because
catheter
function is lost but also because of the potential for bacterial growth. Reflux of blood into the catheter, despite following appropriate flushing and mainte-
nance procedures, is of concern to infusion therapists. During a catheter flush procedure, blood can reflux into a catheter in two ways:
nter
2001
,JVAD
39
1. From the withdrawal of the syringe. When the syringe is withdrawn from the injection cap, negative pressure is generated that pulls a small amount of blood into the catheter tip. Despite the use of heparin, this small amount of blood can cause obstruction over time and can occlude the catheter's lumen over time.
one way to minimize the problem of blood reflux. This is done by withdrawing the syringe's tip from the injection cap during the flush of the last 1 mL of the flush solution or by clamping while maintaining pressure on the syringe.' Despite patient and staff education programs, wrinen procedures and doc-
2. From the syringe itself (prior to
umentation, catheter care and mainte-
disconnection). When a venous access
nance continues to be problematic. Treatment regimens that include low infusion rates, frequent blood sampling, frequent administration of blood products, and smaller catheter lumens add to the problem.
device is flushed, the syringe is emptied and the rubber plunger in the syringe compresses against the end of the syringe. Once pressure is released from the plunger, the rubber inside the r- syringe relaxes, creating negative pres0' sure that will cause blood to be sucked into the tip of the catheter (Data on file at BD Medical Systems, Franklin Lakes, NJ).
Recent Technology Developments to Prevent Reflux Through their research and develop-
are available on the market and their use has been shown to improve patient outcomes in the clinical litera-
ture (Table I).
Conclusion There are two alternatives to consider when taking measures to eliminate blood reflux into a catheter during the flushing procedure. One is to employ a consistent positive pressure
technique and the other is to consider the use of a supplemental device designed to avoid reflux during the process of disconnecting a syringe from the IV catheter. These techniquedependent approaches require continued training and monitoring of staff and patients to ensure compliance and
effectiveness. On the other hand, the use of new devices to prevent carheter
blood reflux offers clinicians an option catheters have developed certain independent of technique alone. The devices to prevent the problem of obvious benefits to this approach are blood reflux. These products currently compliance and reduction in training/monitoring expenses. ment activities, manufacturers of N
Prevention byTechnique Adopting a positive pressure technique when flushing and IV catheter is
It is imperative that infusion thera-
BD Posiflow ™
BD Medical Systems, Franklin Lakes NJ
luer access valve
Provides positive
displacement of fluid during the disconnection
Data on file, BD Medical Systems.
from the luer. CLC2000 luer access valve
ICU Medical, San Clemente, CA
Provides positive
displacement of fluid
Lenhart 2000 (6)
during the disconnection
B-Braun, Bethleham, PA
access valve
Provides positive
displacement of fluid
Berger 2000 (7)
during the disconnection
from the luer. BD Posiflush ™ Syringes
BD Medical Systems, Franklin Lakes NJ
Reduces rebound pressure from
syringe plunger.
and maintenance of venous access devices. New devices, as well as new
flushing techniques, should be evaluated and research/evaluation results
should be disseminated to the health
from the luer.
UltraSite luer
pists and other health care providers become knowledgeable about the eqUipment used to support the care
Data on file, BD Medical Systems
care community. •
DonnaJo Mayo is a Research Nurse Specialisl in Ihe Department 01 Laboralory Medicine, Nematology Section, at Ihe Warren eranl Magnussen Clinical Cenler, National Institutes 01 Health in Belhesda Maryland.
REFERENCES 1. Home MK, Mayo DJ. Low-
4.
chemotherapy extravasation: a case
40
"'VAC
W
n t e r
6.
Clinical Journal of Oncology Nursing 1997; I(J); 5-10.
2. Mayo Dj. Fibrin sheath formation and report. Supportive Care in Cancer 1998; 6, 51-56. 3. Mayo DJ, Pearson DC. Superior vena
ing 1998; 21esS); 5143-5160.
cava thrombosis associated with a venous access device: a case report.
5.
Mayo DJ. Catheter-related thrombosis.
Lenhart C. Prevention vs. treatment of VAD occlusions.
7.
journal of Vascular
Access DevIces 2000; 5(4);34-35. Berger L. The effects of positive pres-
journal of Intravenous Nursing 2001; 24G5} 513-522.
journal of Vascular Access Devices
Hadaway Le. Major thrombotic and
2000; 5(4); 31-'\3.
nonthrombotic complications: Loss of
patency. journal of Intravenous Nurs-
20 0 I
sure devices on catheter occlusions.
Problem
Donna Jo Mayo, MA, RM enous access devices (VADs) are used widely in both adult and pediatric medicine for the delivery of a variety of intravenous agents and to obtain blood samples for laboratory analyses.
V
However convenient these devices may
be, they have complications associated with their use that health care providers must be aware of in order to provide the best possible management of the
malfunction.' One may ask, "How does the blood get into the catheter if there has been an adequate flushing of
manufacturer's
guidelines?"
In
an
anempt to answer this question, let us
subclavian vein and superior vena cava
categorized as:
thrombosis), and withdrawal occlusion have been described in detail, along with associated treatment regimens. I ,23,"
• Complete occlusion: Total inability to withdraw blood and infuse fluids via the catheter. • Partial occlusion: Difficulty in withdrawing and infusing fluids via the
lumen occlusion, can be caused by the reflux of blood back into the catheter's tip during a flushing procedure. Recent advances in technology have been
obstruction (usually a thrombus) in the vein that completely or partially stops blood flow; it mayor may not affect the catheter's functionality.
standards set by professional organizations and/or when one follows the
sheath formation, catheter-related infection, central venous thrombosis (both
One of these complications, cannula
• Intravenous obstruaion: An
the cannula, as well as adherence to
focus upon the phenomenon of blood reflux and the technological strategies that have been developed to minimize the problem. Catheter-relared occlusions can be
devices. Such complications as fibrin
tion outside the lumen of the catheter, typically causing withdrawal occlus"ion.
mised with a clot that can result in
• Mechanical obstruction: An obstruction not related to precipitate or
blood that partially or completely occludes the catheter. Examples of mechanical obstruction are catheter "pinch off," tight sutures at the exit site, and kinked or twisted tubing.
Blood Reflux Prevention of intraluminal obstruc-
tion by thrombus is extremely important,
catheter.
• Withdrawal occlusion: Inability to withdraw blood via the catheter but
developed to reduce the incidence of
it retains a capacity to infuse solu-
this problem; however, these technological strategies have been mentioned only briefly in scattered reports. If blood refluxes into the catheter's lumen, the catheter may be compro-
tions without difficulty. • Intraluminal obstruction: Obstruction within the catheter lumen that causes complete or partial occlusion.
• Extraluminal obstruction: Obstruc-
W
not
only
because
catheter
function is lost but also because of the potential for bacterial growth. Reflux of blood into the catheter, despite following appropriate flushing and mainte-
nance procedures, is of concern to infusion therapists. During a catheter flush procedure, blood can reflux into a catheter in two ways:
nter
2001
,JVAD
39
1. From the withdrawal of the syringe. When the syringe is withdrawn from the injection cap, negative pressure is generated that pulls a small amount of blood into the catheter tip. Despite the use of heparin, this small amount of blood can cause obstruction over time and can occlude the catheter's lumen over time.
one way to minimize the problem of blood reflux. This is done by withdrawing the syringe's tip from the injection cap during the flush of the last 1 mL of the flush solution or by clamping while maintaining pressure on the syringe.' Despite patient and staff education programs, wrinen procedures and doc-
2. From the syringe itself (prior to
umentation, catheter care and mainte-
disconnection). When a venous access
nance continues to be problematic. Treatment regimens that include low infusion rates, frequent blood sampling, frequent administration of blood products, and smaller catheter lumens add to the problem.
device is flushed, the syringe is emptied and the rubber plunger in the syringe compresses against the end of the syringe. Once pressure is released from the plunger, the rubber inside the r- syringe relaxes, creating negative pres0' sure that will cause blood to be sucked into the tip of the catheter (Data on file at BD Medical Systems, Franklin Lakes, NJ).
Recent Technology Developments to Prevent Reflux Through their research and develop-
are available on the market and their use has been shown to improve patient outcomes in the clinical litera-
ture (Table I).
Conclusion There are two alternatives to consider when taking measures to eliminate blood reflux into a catheter during the flushing procedure. One is to employ a consistent positive pressure
technique and the other is to consider the use of a supplemental device designed to avoid reflux during the process of disconnecting a syringe from the IV catheter. These techniquedependent approaches require continued training and monitoring of staff and patients to ensure compliance and
effectiveness. On the other hand, the use of new devices to prevent carheter
blood reflux offers clinicians an option catheters have developed certain independent of technique alone. The devices to prevent the problem of obvious benefits to this approach are blood reflux. These products currently compliance and reduction in training/monitoring expenses. ment activities, manufacturers of N
Prevention byTechnique Adopting a positive pressure technique when flushing and IV catheter is
It is imperative that infusion thera-
BD Posiflow ™
BD Medical Systems, Franklin Lakes NJ
luer access valve
Provides positive
displacement of fluid during the disconnection
Data on file, BD Medical Systems.
from the luer. CLC2000 luer access valve
ICU Medical, San Clemente, CA
Provides positive
displacement of fluid
Lenhart 2000 (6)
during the disconnection
B-Braun, Bethleham, PA
access valve
Provides positive
displacement of fluid
Berger 2000 (7)
during the disconnection
from the luer. BD Posiflush ™ Syringes
BD Medical Systems, Franklin Lakes NJ
Reduces rebound pressure from
syringe plunger.
and maintenance of venous access devices. New devices, as well as new
flushing techniques, should be evaluated and research/evaluation results
should be disseminated to the health
from the luer.
UltraSite luer
pists and other health care providers become knowledgeable about the eqUipment used to support the care
Data on file, BD Medical Systems
care community. •
DonnaJo Mayo is a Research Nurse Specialisl in Ihe Department 01 Laboralory Medicine, Nematology Section, at Ihe Warren eranl Magnussen Clinical Cenler, National Institutes 01 Health in Belhesda Maryland.
REFERENCES 1. Home MK, Mayo DJ. Low-
4.
chemotherapy extravasation: a case
40
"'VAC
W
n t e r
6.
Clinical Journal of Oncology Nursing 1997; I(J); 5-10.
2. Mayo Dj. Fibrin sheath formation and report. Supportive Care in Cancer 1998; 6, 51-56. 3. Mayo DJ, Pearson DC. Superior vena
ing 1998; 21esS); 5143-5160.
cava thrombosis associated with a venous access device: a case report.
5.
Mayo DJ. Catheter-related thrombosis.
Lenhart C. Prevention vs. treatment of VAD occlusions.
7.
journal of Vascular
Access DevIces 2000; 5(4);34-35. Berger L. The effects of positive pres-
journal of Intravenous Nursing 2001; 24G5} 513-522.
journal of Vascular Access Devices
Hadaway Le. Major thrombotic and
2000; 5(4); 31-'\3.
nonthrombotic complications: Loss of
patency. journal of Intravenous Nurs-
20 0 I
sure devices on catheter occlusions.