U-Cannula Article in Medical Journal

8/14/2019 U-Cannula Article in Medical Journal

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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 solutionU-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. aure u s 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. aure u s h a s

progressively acquired resistance to previously eff e c t i v e

antimicrobial agents,1 including methicillin.

M R S A (methicillin-resistant Staphylococcus aure u s)

infections are becoming increasingly common in healthcare

settings.1 In certain circumstancesfor instance, if a person

has breaks in their skin or they are particularly vulnerable to

infection due to their medical condition or treaentMRSA

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


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Certain cannulae (e.g., peripheral arterial cannulae)

are accessed several times a day to check arterial blood

gas or obtain samples for laboratory analysis. T h i s

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. T h i s

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.

P r o b l e m s

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 diff i c u l t .

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

i nfections (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 aure u s i n f e c t i o n s

acquired in hospitals has risen in tandem with increased use

of cannulation since the Braunule (cannula) was introduced

in 1962.

C a n n u l a t i o nPeripheral 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.


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Ultrasound guidance has been shown not to decrease the

number of attempts at cannulation or the time taken to do it

s u c c e s s f u l l y. 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 org a n i s m s .

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

H I V. 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.

H o w e v e r, 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

d i fficult, but each unnecessary puncture wound provides an

access route for MRSA or other drug-resistant organisms into

the bloodstream.

Current Cannulation TrendsCannulation 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



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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 atinserting 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

s t a ff 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.

References1. Lowy FD. Staphylococcus aureus infections. N Engl J Med 1998,

339: 520-32.

2. CDC. Semiannual report: aggregated data from the NationalNosocomial Infections Surveillance System. September 2001.

3. Strausbaugh LJ, Jacobson C, Sewell DL, Potter S and Ward T T.

Methicillin-resistant Staphylococcus aureus in extended-care facili-ties: experiences in a VeteransAffairs nursing home and a review ofthe 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 Physician1991, 20: 1285-1288.

8. McDermott D, George B, Kramer N and Stein J. UltrasoundGuidance for Difficult Peripheral Intravenous Access: A RandomizedTrial. Academic Emergency Medicine Volume 12, Number 5 suppl 1,48.

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 IntravenousTherapy. 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, Chert s e y, 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, re d u c i n g

e n v i ronmental pollu tion, and spreading acquired hospi tal

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.


Copyright2006/Workhorse Publishing L.L.C./All Rights Reseved. Reprint with permission from Workhorse Publishing L.L.C.

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U-Cannula Article in Medical Journal