1. 54 March 2006MANAGING INFECTION CONTROL
Abstract
Insertion of intravenous cannulae is probably the most
commonly performed invasive medical procedure. Failed
attempts cause stress to patients and embarrassment to the
provider and make subsequent attempts increasingly difficult.
Making several attempts increases costs and the risk of
introducing infection into the patient. Discarded used needles
also pose a risk of needlestick injury to staff, increasing their
chances of contracting HIV and other bloodborne infections.
For the past 10 years Dr. Kadiyali Srivatsa has been
developing a solution—U-Cannula™. Using the device makes
it easy to insert a cannula at the first attempt. It also has an
important additional benefit of eliminating cannula breakage
and needlestick injuries, as the needle tip is safely encased
within the needle guard after use.
Introduction
S. aureus is a common pathogen in humans, found in
the nose or on the skin of about a third of normal, healthy
people (i.e., carriers). However, it can cause infections, with
clinical manifestations ranging from pustules to sepsis and
death. In the past the infections were usually simple to clear up
using antibiotics; however, since the 1960s S. aureus has
progressively acquired resistance to previously effective
antimicrobial agents,1 including methicillin.
MRSA (methicillin-resistant Staphylococcus aureus)
infections are becoming increasingly common in healthcare
settings.1 In certain circumstances—for instance, if a person
has breaks in their skin or they are particularly vulnerable to
infection due to their medical condition or treaent—MRSA
may enter the body, where it can cause infections of varying
degrees of severity.
Patients on surgical wards and in intensive care units are
particularly vulnerable to infection with MRSA (NISRA and
CDSC, Statistics on MRSA. October 2004). In 1999, 4,744
patients in U.S. intensive care units were recorded as having
contracted S. aureus infections. Of these patients, 53.5 percent
(2,538) had MRSA.2
Operating Room & Infection Control
U-Cannula™
Alternative method of cannulation could reduce needlestick
injuries and the spread of hospital-acquired infections
by Martina Benzing, MRCPCH (UK), PhD, and Kadiyali M. Srivatsa, MD

2. 56 March 2006MANAGING INFECTION CONTROL
Operating Room & Infection Control
Certain cannulae (e.g., peripheral arterial cannulae)
are accessed several times a day to check arterial blood
gas or obtain samples for laboratory analysis. This
increases the potential for contamination and subsequent
clinical infection.
In modern medical practice, up to 80 percent of
hospitalized patients receive intravenous therapy at some
point during their stay. Since Dr. Crile4 used it to manage
shock in 1915, cannulation has become the most
commonly performed invasive medical procedure. This
has been associated with increased incidence of needle-
stick injuries and spread of infections.5 There is a growing
awareness in the medical community that the cannulation
technique needs to be reviewed.
Problems
Cannula insertion is particularly difficult in certain
cases, including in intravenous drug users, patients having
repeated courses of chemotherapy, infants and children,
and dark-skinned or obese patients.
It is often complicated in patients who are afraid, as
fear activates the sympathetic nervous system, provoking
peripheral vasoconstriction.6 Once an initial attempt at
cannulation has failed, nearly all patients experience
a degree of sympathetic activation that makes subsequent
attempts increasingly difficult.
Failed attempts are also
embarrassing for the provider,
causing a degree of nervousness
that also hampers further
attempts. It is therefore important
that a cannula is inserted
quickly the first time.6
Many doctors claim a
high success rate for inserting
cannulae, but may still require
several attempts to get it right
in certain cases. Cannulation
can prove problematic and
time consuming, which causes
difficulties in urgent situations.7
In emergencies optimal atten-
tion to aseptic technique is not
always feasible and multiple
punctures are more likely to
result in infection, including
septic thrombophlebitis, endo-
carditis and other metastatic
infections (e.g., lung and
brain abscesses, osteomyelitis
and endophthalmitis).
Less information is available on MRSA in long-term
care facilities, but it is estimated that up to 33 percent of
residents in some homes may be carriers. The incidence of
community-acquired MRSA infections appears to be rising,3
although little is known about their epidemiology. Most reported
cases are uncomplicated skin infections, although some are
more severe, including pneumonia and bloodstream infections.
Risk factors for infection with MRSA in healthcare
settings include prolonged hospital stay, time spent in an inten-
sive care or burns unit, exposure to multiple antibiotics or
prolonged broad-spectrum antimicrobial therapy, proximity to
patients colonized or infected with MRSA, use of invasive
devices, surgical procedures, underlying illnesses and MRSA
nasal carriage.
The incidence of Staphylococcus aureus infections
acquired in hospitals has risen in tandem with increased use
of cannulation since the Braunule (cannula) was introduced
in 1962.
Cannulation
Peripheral venous cannulae are the devices most
frequently used for vascular access. Although the proportion of
cannulations leading to infections is low, the frequency of the
procedure means that resultant infections do lead to consider-
able annual morbidity.
U-cannula. Retracting the knob allows
the cannula to move smoothly forward
in the vein. The tip of the needle is then
protected by the needle guard.

3. 58 March 2006MANAGING INFECTION CONTROL
Ultrasound guidance has been shown not to decrease the
number of attempts at cannulation or the time taken to do it
successfully. Neither does it lead to improved patient satisfaction.8
Currently doctors and nurses often try to recannulate by
reintroducing the needle tip through the hub. In fact some
cannula manufacturers recommend reusing cannulae up to
three times to save costs. However, reusing or reintroducing
cannula needles increases the risk of introducing infection,
cannula tip fracture and embolisation.
If a cannula is used for an extended period of time, a
patient may be colonized with hospital-acquired organisms.
The cannula may be manipulated several times a day to take
samples or administer fluids, drugs or blood products, and each
contact increases the risk of infection.
Discarded cannulae pose a risk of needlestick injury to
medical staff, encouraging the spread of infections, including
HIV. Growing concern about this issue has led to a desire to
reassess cannulation techniques. Various cannula manufacturers
now offer devices designed to reduce needlestick injuries.
However, none have claimed to reduce the number of
attempts required to cannulate. Unsuccessful attempts not
only cause distress to the patient and make cannulation more
difficult, but each unnecessary puncture wound provides an
access route for MRSA or other drug-resistant organisms into
the bloodstream.
Current Cannulation Trends
Cannulation is a valuable skill and has many advantages
for practitioner and patient. Most doctors assume the currently
used technique is safe and therefore continue to use it,
tolerating the frustration of failure and the sadness of causing
distressing to patients.9
Some doctors learn to accept failure while others blame
the vein, but few think to assess their own technique or that of
others. Most related studies have looked into issues such as
cannula-associated infections, pain relief or needlestick
injuries,10 rather than insertion techniques or the number of
attempts needed to cannulate a vein. Dougherty (1998)
suggests that only two cannulation attempts should be
permitted before deferring to a more experienced practitioner.11
Operating Room & Infection Control

4. 60 March 2006MANAGING INFECTION CONTROL
There is currently a trend in the United Kingdom and the
United States to train nurses and paramedics to cannulate to
reduce time for doctors. However, nurses and paramedics may
lack the skill or experience to cannulate in complex cases.9
There is also some concern that allowing other staff to carry out
cannulation could, over time, deskill doctors, possibly resulting
in inadequate care in difficult cases.
Dr. Kadiyali Srivatsa believes he has found the solution,
in the form of a unique device that simplifies this life-
saving technique.
The U-Cannula
In 1997, Dr. Srivatsa conducted his own observational
study to assess cannulation technique, looking at failure rates
and the time taken to cannulate successfully.
The average number of attempts required by doctors to
successfully cannulate a vein was 2.84 (0 to 6 attempts). Junior
doctors were reluctant to cannulate obese people, children or
patients suffering from edema or shock. He also found, perhaps
surprisingly, that senior doctors were not noticeably better at
inserting cannulae, although they were better at acknowledging
their own failure.
Based on this initial work, Dr. Srivatsa invented the
spring-loaded cannulae. He organized clinical trials in which he
assessed doctors using the device to cannulate 50 infants (92
percent weighing less than 4Kg). Cannulation was successful at
the first attempt in 94 percent of these cases.12
Various cannula manufacturers have so far evaluated
the concept; however, none have yet chosen to manufacture
the product for fear of deskilling practitioners. They are
perhaps also concerned at the prospect of endangering the
lucrative market for cannula needles, so many of which
are currently wasted through breakage and unsuccessful
cannulation attempts.
With the cannulae currently in common use the sharp end
of the needle is exposed, which can result in accidental injury
to medical staff and patients. In addition to making it easy to
insert a cannula at the first attempt, U-Cannula has the impor-
tant additional benefit of eliminating needlestick injuries, as the
needle is safely encased within the introducer. It also avoids
cannula fracture, reducing wasted time and resources.
How Does the U-Cannula Work?
U-Cannula has been specially designed to help medical
staff cannulate with ease, reducing the number of attempts
needed to get it right.
The U-Cannula has a knob, connected internally to a plunger.
Once the cannula has been placed in the right position in the
vein, retracting the knob moves the needle guard, allowing the
cannula to move forward in a controlled manner into the lumen
of the blood vessel. This eliminates the accidental jerky
forward thrust of the needle tip, reducing the risk of double
puncture. After use, the guard protects the needle tip, preventing
accidental needlestick injuries to the practitioner. For the safety
of the patients, forward movement of the knob is blocked to
reduce cannula fracture and embolisation.
The U-Cannula can be used in a variety of ways, requiring
varying levels of skill. This will make cannulation easier while
avoiding deskilling practitioners.
Dr. Srivatsa is currently working to bring the product to
market. He is determined to make it affordable to developing
countries, where it could make an enormous impact, cutting the
transmission of HIV, hepatitis and other serious infections to
healthcare workers through needlestick injuries.
To find out more, visit www.u-cannula.com.
References
1. Lowy FD. Staphylococcus aureus infections. N Engl J Med 1998,
339: 520-32.
2. CDC. Semiannual report: aggregated data from the National
Nosocomial Infections Surveillance System. September 2001.
3. Strausbaugh LJ, Jacobson C, Sewell DL, Potter S and Ward TT.
Methicillin-resistant Staphylococcus aureus in extended-care facili-
ties: experiences in a Veterans’ Affairs nursing home and a review of
the literature. Infect Control Hosp Epidemiol 1991, 12: 36-45.
4. George Washington Crile: Medical Innovation in the Progressive Era.
Westport, Connecticut, and London: Greenwood Press, 1980.
5. Mermel LA. Prevention of intravascular catheter-related infections.
Ann Intern Med 2000, 132: 391-402.
6. Johnstone M. The effect of lorazepam on the vasoconstriction of fear.
Anaesthesia 1976, 31: 868-872.
7. Cleary M. Peripheral intravenous cannulation. Aust Fam Physician
1991, 20: 1285-1288.
8. McDermott D, George B, Kramer N and Stein J. Ultrasound
Guidance for Difficult Peripheral Intravenous Access: A Randomized
Trial. Academic Emergency Medicine Volume 12, Number 5 suppl 1,
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9. Jackson A. Reflecting on the nursing contribution to vascular access.
British Journal of Nursing 2003, 12, 11, 657-665.
10. Wise H and McCormick R. Reinforcing hygiene practices of anaes-
thestists. Anaesthesia 1999, 54: 1220-1221.
11. Dougherty L. Intravenous cannulation in A Guide to Intravenous
Therapy. Continuing Education Reader, RCN Publishing, Middlesex;
1998, 11-16.
12. Srivatsa KM. Cannulation of vessels using a spring-loaded device,
Anesth Analg 1992, 75: 867b-868b.
Dr. Martina Benzing is a Specialist Registrar, Paediatrics
and Neonates in St. Peters Hospital, Chertsey, United
Kingdom. Her special interests are in Paediatric and Neonatal
intensive care. Since she became a mother, she finds it
traumatic to see doctors perform various practical procedures
in Paediatrics.
Dr. Kadiyali M. Srivatsa worked as staff Paediatrician in
paediatric neonatal and intensive care from 1984 to 1999.
His vision is to reduce disposable product waste, reducing
environmental pollution, and spreading acquired hospital
infections. Dr. Srivatsa is currently a practicing family
physician in the United Kingdom and CEO of Medifix Limited.
He invented the cannula introducer and U-Cannula.
Operating Room & Infection Control
Copyright©2006/Workhorse Publishing L.L.C./All Rights Reseved. Reprint with permission from Workhorse Publishing L.L.C.