Biomed Imaging Interv J 2006; 2(4):e55
© 2006 Biomedical Imaging and
Accidental blood exposure: risk and prevention in interventional radiology
A Vijayananthan*,1, MBBS, MRad,
LH Tan2, MMed,
A Owen3, BSc, MRCP, FRCR,
R Edwards3, MBChB, MRCP, FRCR,
I Robertson3, MBChB, MRCP, FRCR,
JG Moss3, MBChB, FRCS, FRCR,
1 Department of Biomedical Imaging (Radiology),
Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
2 Department of Medicine, Faculty of Medicine, University of Malaya,
Kuala Lumpur, Malaysia
3 Department of Radiology, Gartnavel General Hospital, Glasgow, United
There is a growing concern about the transmission of
bloodborne pathogens during medical procedures among health care workers and
patients. Over the last three decades, radiological services have undergone
many changes with the introduction of new modalities. One of these new
disciplines is interventional radiology (IR) which deals with procedures such
as arteriography, image-guided biopsies, intravascular catheter insertions,
angioplasty and stent placements. Despite these developments, the potential for
accidental blood exposure and exposure to other infectious material continues
to exist. Therefore, it is important for all radiologists who perform invasive
procedures to observe specific recommendations for infection control. In this
review, we look at the different policies for protection and universal
standards on infection control. � 2006 Biomedical Imaging and Intervention
Journal. All rights reserved.
Keywords: Interventional radiology, bloodborne pathogens, prevention
Blood borne pathogens are a definite threat to health care
workers due to potential occupational exposure. Concern about Hepatitis B
(HBV), Hepatitis C (HCV) and the Human Immunodeficiency Virus (HIV) are rising
in societies globally. This is especially true for interventional radiologists
who perform diagnostic and therapeutic procedures involving needles and
catheters. Many practitioners have expressed the need for official statements
regarding the issue of infection control and prevention unique to
interventional radiology. The Society of Cardiovascular and Interventional
Radiology (SCVIR) Subcommittee on HIV and Bloodborne Pathogens was formed to
review current knowledge on the risk of transmission during interventional
procedures, to summarize regulations and formulate prevention policies . The
Guidelines for Prevention of Intravascular Catheter-Related Infections was
developed by the Center for Disease Control and Prevention in 1996 and updated
in 2002. These were developed for practitioners who insert catheters and health
care workers responsible for the surveillance and control of infection in the
hospital [2,3]. Studies have also been carried out involving the risk of
infection to interventional radiologists. The message from these studies is
that the risk of infection to interventional radiologists is real and the
standards of infection control are suboptimal.
Risk of pathogen transmission
There is a wide disparity in the figures regarding the
prevalence of infection in developed and developing nations. A number of
factors influence the risk of pathogen transmission. The nature of potentially
infectious material, the likelihood of sharps or other exposures occurring
during the procedure, the prevalence of infection in the population, the
seroconversion rates after exposure and the type of procedure undertaken, are
some of the important criteria that need to be considered .
An estimated two billion people have been infected by HBV
worldwide and there are approximately 50 million new cases diagnosed annually. Seventy
five percent of such cases are found in Asia . The evidence of HBV exposure
in the general population in the United States is approximately 3-14% with an
estimated 0.1-0.7% of the general population being HBV carriers . Asian
statistics showed a prevalence of hepatitis B markers in the general population
in the Philippines and Malaysia to be 5-16% and 3-5% respectively .
Approximately three percent of the world population is
chronically infected with HCV . In France, the prevalence of HCV in the
general population is estimated to be about 1.05-1.2% while in the United
States it is almost 2% and Malaysia carries a figure of 0.6-1.0%.
[4,6]. In the Philippines the prevalence of HCV in the general population is
estimated to be about 5.2%. Approximately 15-20% of patients with HCV will
develop cirrhosis . Unlike HBV, there is no vaccine for the prevention of
HCV and HCV-related end stage liver disease is the most common indication for
liver transplant in adults in the Unites States .
Globally, an estimated 40 million people are currently
living with HIV, and about 20 million people have already succumbed to it, with
the worst of the epidemic centred in Africa . As of 2005, there has been an
estimated five million new cases of HIV and the virus shows no sign of abating.
The prevalence of HIV in the general
population in the United States is estimated to be less than one percent.
Studies at an urban trauma center found that 0.2-14.2% of inpatients at the
acute care wards, and six percent of unselected patients observed in the
emergency department of the same center were HIV positive .
HIV and HBV are found in most body fluids like blood, breast
milk, cerebrospinal fluid, semen, vaginal secretions, pleural, pericardial,
peritoneal or amniotic fluid and saliva. Faeces do not contain these viruses
unless contaminated with blood. Urine is also not considered to be infective
unless the patient has sustained trauma or undergone instrumentation to cause
bleeding [1,9]. HIV survives on environmental surfaces at room temperature for
a very brief period, but HBV can survive for about seven days. Three phases of
chronic HBV infection are recognized. In Phase 1, the patients are HbeAg positive
with high serum levels of virus and minimal hepatitis. In Phase 2, there is
intermittent or continuous hepatitis and in Phase three (inactive phase), the
viral concentrations are at its lowest and there is minimal liver involvement.
The risk of needle stick or other sharps injuries during an
interventional radiology procedure is quite low when compared to the risk in
surgical procedures. In a prospective study of 501 procedures, Hansen et al.
found an injury rate of only 0.6% . In a national survey done in the United
States, the median number of injuries per year was found to be considerably
low at 0.3 for practicing interventional radiologists .
Percutaneous exposure poses a greater risk as compared to
mucocutaneous exposure. In IR procedures, cutaneous exposure is more common due
to the frequency of glove perforations and splash-type exposures. Occult glove
perforations were found in 23% of gloves worn for more than two hours and
cutaneous blood exposure occurred in 3% [1,9].
Studies in the United Kingdom by Davidson et al. and McWilliams et
al. stated that splashing and spraying of blood occurred in 6.7-8.7% of
angiographic procedures [11,12]. The risk of accidental blood exposure was also
found to be greater for procedures requiring more than two catheter exchanges,
for thrombolysis and angioplasty as well as for procedures lasting more than 30
For a given exposure, seroconversion depends on several
factors, including the type of exposure (percutaneous, cutaneous or mucous
membrane), severity, type of body fluid involved and the patients� immune
status . The type of instrument is also important in sharps injuries as
large bore needles have a greater volume of infected material. Seroconversion
of blood borne pathogens has been reported after percutaneous exposure and
contact with mucous membranes and non-intact skin, but not after contact with
intact skin .
According to past data, the risk of HIV transmission to
health care workers after percutaneous injury is 0.3-0.4% and after exposure to
mucous membranes is 0.09% . The risk for HBV is reported to be 12% but can
be a high as 30% in health care workers with a positive HBeAg. The risk for HCV
was estimated to be about 3% .
A multicenter trial was conducted in France by the Study
Group on Hygiene Practices in Interventional Radiology on the potential of HBC
exposure in the IR population. Seventy seven radiologists from 11 IR wards
participated, and 44% reported one incident of mucous membrane exposure and 52%
reported at least one percutaneous injury . This study concluded that
compliance with standard precautions, especially with the use of protective
clothes and safety material was poor. It also concluded that the risk of HCV
transmission from contact with contaminated blood after percutaneous injury
ranged from 0.013-0.030 %. This figure was derived simply by multiplying three
numbers: an interventional radiologist�s estimated risk of accidental blood
exposure, prevalence of HCV in patient population presenting for IR procedures,
and the risk of seroconversion after a percutaneous injury.
Baffoy-Fayard et al.  used a seroconversion rate
of 1.8-3.0% based on previously published reports and the calculated a low end
risk after percutaneous injury of 1/1,330 whereas the high end risk was found
to be 1/800. In the 2003 issue of the Journal of Interventional Radiology (JVIR),
a commentary on this particular study was written by MV Marx. She calculated
the risk of percutaneous injury to an interventional radiologist using a
different set of figures, assuming a worst case scenario. Her numerical
conclusions derived a risk of 1/100, which puts a whole new light on the
situation. It indicates a 1% chance of contracting hepatitis C due to
occupational exposure in an IR practice . These figures are not to be taken
lightly, and are only meant to enlighten us about the real threat of blood
borne exposure in interventional radiology.
Regulations on infection control
In 1992, the Bloodborne Pathogens Standard was developed by
the Occupational Safety and Health Administration (OSHA) and enacted into law
in the United States. The Needlestick and Prevention Act (P.L. 106-430)
formulated in 2000 is a revision of the OSHA standard and clarifies the need
for employers to select safer needle devices and to involve employees
(clinicians directly involved in patient care) in identifying and choosing
these devices . The updated standard also requires employers to maintain a
log of injuries from contaminated sharps. The Guidelines for Prevention of
Intravascular Catheter-Related Infections were developed by the Center for
Disease Control and Prevention in 1996 and updated in 2002. These guidelines
have served as a backbone in the formation of many infectious diseases
guidelines globally . Epic, was established in 1998 in the United Kingdom,
and its focus was to provide evidence-based guidelines for infection prevention
and control in the National Health Service (NHS).
There have been various organizations across the world with
evidence-based guidelines on infectious diseases and control, and some of them
are listed in Table 1 .
Table 1 Organisations with evidence-based
guidelines on infection control
We will now look at some of the general guidelines and
summarize the important elements to be observed by radiology personnel performing
interventional procedures (Table 2).
Table 2 Summary of guidelines to be
observed in interventional radiology suite
Currently only Hepatitis B is preventable through
vaccination and not blood-borne pathogens like HIV and HCV. All health care
workers should have Hepatitis B vaccination as a prerequisite to employment.
For those not vaccinated, the Hepatitis B vaccination should be provided free
by the employer .
2. Planning and Training
An infection control plan must be developed by employers of
the establishment, in which an IR practice is held. This plan must contain
schedules for vaccination, training of personnel, post-exposure treatment and
also must detail the measures taken by the employer to minimize exposure to
health care personnel.
It is recommended that training in infection control, should
be provided within 10 days of an employee being hired and annually thereafter.
This training should be documented and records of this should be maintained .
Procedure Safety and Precautions
1. Proper handling and disposal of sharps
Avoid recapping of needles or resheathing of scalpel blades.
If this is unavoidable, a one-handed technique is used, where the cap is
scooped up by the sharp edge of the instrument or a two-handed technique, where
the cap is held by a forceps or any other instrument but not by the operator�s
Any sharp instrument that is reused should be placed
sharp-end down on a sterile pad, plastic container or any other holding device,
and placed in a corner of the tray where it will not be readily knocked over.
In IR procedures, reassembly of multi-part sharp needles and devices is common
and this should be done in the same manner as recapping needles i.e., with the assistance
of an instrument and with caution [1,9,14].
Communication of team members is vital during a procedure,
especially if there is passing of sharps from one person to another. Generally,
this is to be avoided and the �no touch� method should be used, in which the
sharp instrument is set down on a stable surface by one team member and then picked
up by the second team member after the first has withdrawn his or her hand .
Communication with the patient is also important to avoid
sudden surprise movements which may lead to injury with sharp objects or
instruments. The patient should be informed about the procedure at all times.
Designated containers should be available for all sharps
after use. These containers should have a wide opening and should be placed at
strategic points in the interventional suite. All team members should be aware
of the location of sharps disposal containers. These containers should be
emptied when � or 2/3 full to prevent injury to the next person using the
container and to house keeping staff .
Suturing should be performed with needle holders only and
never by grasping the needle in one�s fingers. Trying to locate a needle tip by
palpation should never be done. Cut the suture and dispose of needle once it is
no longer needed. If an injury occurs, the sharp instrument should be discarded
2. Safety devices and protective garments
Universal precautions should be strictly adhered to in IR
procedures. Proper hand washing techniques with a germicidal agent before
putting on protective gloves, and after removal of gloves should be practiced.
Glove use during procedures is generally accepted and due to the increasing
frequency of occult glove perforations, changing of gloves after 90 min is
advised. Gloves should also be changed in the event of a contamination or if
perforation is suspected [1,9].
A very common violation is the failure to remove gloves
before touching a door knob, telephone or other equipment. This will lead to
exposure of the next person who touches that object with an ungloved hand, and
should therefore be avoided.
Due to the fact that permeability of fabric is increased
after prolonged contact with blood, changing of gowns during lengthy and bloody
procedures is advised. Protective face shields and eyewear should be worn
whenever there is potential for splashing or spraying of blood or other
infectious fluid .
3. Equipment protection and precaution
Image intensifiers and controls which are connected to the
table should be covered with sterile covers to maintain a sterile environment.
Similarly, the foot pedals should be covered with a non-sterile cover to
preserve disinfection .
Parts of the angiographic machine contaminated with blood
and other body fluids should be cleaned with a bactericidal agent before the
next procedure to prevent cross-contamination. The angiographic suite should be
mopped with a germicidal agent after each procedure.
While flushing syringes with saline during a procedure, some
blood still remains in the syringe. Ideally, flushing should be done into a
closed one-way flow system to prevent spilling or splashing. Glass syringes
should never be used unless plastic syringes are not suitable. Luer-lock
fittings are preferred over slip fittings for syringes, connecting tubes and
drainage systems to prevent the possibility of spillage. If possible, bloodless
arterial and venous access puncture systems should be used at the discretion of
the operator .
Antibiotic prophylaxis is defined as the use of antibiotics
prior to or during a procedure to minimize the risk of infection. There are many
disputes regarding the use of prophylactic antibiotics; however, there are some
procedures where antibiotics are routinely used universally. According to Ryan et
al. , the benefits of antibiotic prophylaxis in IR practice has never
been scientifically proven, as no randomized trials have been carried out.
However, antibiotic prophylaxis has been the standard practice in some IR
procedures and the use of broad spectrum antibiotics has led to an increasing
problem of antibiotic resistance [14, 15]. Stopping the use of antibiotic
prophylaxis may combat this problem but is very difficult since prophylactic
antibiotic treatment has been a standard part of interventional procedures and
many clinicians are worried about legal issues if their patients develop a
In choosing a prophylactic antibiotic, the source and
pathogen should be considered and the antibiotic should target specific
organisms. This will avoid the excessive use of broad spectrum antibiotics. The
timing of prophylaxis is also important and it is suggested that prophylactic
antibiotics should be given just before or less than two hours before the start
of a procedure. An antibiotic administered more than three hours before a
procedure increases the incidence of infection five-fold . There are some
clinical conditions in which antibiotic cover is mandatory and they include
patients with bacterial endocarditis and also biliary and urinary tract
interventions in patients with sepsis.
In Table 3, we have listed a summary of IR procedures where
antibiotic prophylaxis is routinely used.
Table 3 Interventional
procedures in which antibiotics are routinely used
Post exposure recommendations
If splashing of contaminated fluid on skin occurs, the
exposed skin should be washed immediately with soap and water. If contamination
occurs to the mucous membrane, it should be flushed with water and saline.
In the event of a sharps injury with exposure to blood borne
pathogens, it should be reported to the relevant authorities as soon as
possible and counselling should be given with regards to post exposure
prophylaxis (PEP) against HBV and HIV. No effective PEP is available for HCV [9,14].
If the HIV/HBV status of the source is not known, then
consent for blood testing should be obtained and the test carried out
immediately. If the source is HIV positive, the exposed individual should
undergo blood testing at three and six months after exposure if the initial
test was negative. During this period of six months, safe sexual practices
should be observed and pregnancy and blood donation should be avoided.
According to a CDC report, the risk of infection to HIV was
reduced by 79% by the use of ziduvudine (AZT) after percutaneous exposure.
Current recommendations call for combination therapy with zidovudine,
lamivudine (3TC) and indinavir . However, if the source patients have been
on antiretroviral therapy, these recommendations need to be adjusted in view of
potential HIV drug resistance.
If the source is HBV positive, PEP consists of the Hepatitis
B vaccine in combination with Hepatitis B immune globulin (HBIG). The vaccine
should be started within seven days of exposure and HBIG should be administered
within 24 hours. This is done if the exposed person has not been vaccinated
before or his anti-HBV antibody level is <10mIU/ml after vaccination. If the
exposed person has been vaccinated and his anti-HBV antibody level is
>10mIU/ml, no treatment is necessary.
Further testing should be done in 4-6 months [1,9].
Counselling is important to alleviate anxiety and fear and to provide advice
regarding safe sexual practices and pregnancy.
The risk of blood borne exposure in IR practice is real and
from the literature available, it is obvious that there is insufficient knowledge
about it. There have not been many studies done regarding the transmission of
infection in the interventional radiology suite and more data is required. The
worldwide guidelines for infection control are important and are useful in
planning rules and regulations in a particular establishment. In general,
radiology departments are units that have been unnoticed in terms of hospital
infection, but with the advent of interventional procedures, more attention
should be given to address the issue of infection control in the interventional
suite. There is no doubt that the future will bring more information, data and
research on this issue.
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|Received 21 June 2006; received in revised form 16 October 2006; accepted 23 November 2006
Correspondence: Department of Biomedical Imaging
(Radiology), Faculty of Medicine, University of Malaya,
50603 Kuala Lumpur, Malaysia. Tel.: +603-79502069; Fax.:
+603-79581973; E-mail: firstname.lastname@example.org
Please cite as: Vijayananthan A, Tan LH,
Owen A, Bhat R, Edwards R, Robertson I, Moss JG, Nicholls
Accidental blood exposure: risk and prevention in interventional radiology, Biomed Imaging Interv J 2006; 2(4):e55
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