Peripheral Venous Cannula Introducing Technique And Mrsa Infection

Peripheral venous cannula introducing technique, number of attempts required and association with spreading MRSA Dr Kadiyali M Srivatsa INTRODUCTION Initially reported among injecting drug users in Detroit in 1981 and then associated with the deaths of 4 children in Minnesota and North Dakota in 1997. Community-associated methicillin-resistant Staphylococcus aureus (MRSA) has become the most frequent cause of skin and soft tissue infections presenting to emergency departments in the United States (1). Some paper quotes 74% of organisms present in the skin to be Staph aureus. The most commonly used device in the forearm and hands are the short peripheral venous cannula. Due to its relatively short duration of use, it is said be rarely associated with blood stream infection (Gantz et al 1984; Maki and Ringer 1991; Ena et al 1992). Phlebitis is the most important complication associated with peripheral venous cannulas, and is largely a physiochemical or mechanical, rather than an infectious, phenomenon. Risk factors for the development of phlebitis include type of infuscate, cannula material, size, and host factors.

When phlebitis does occur, the risk of local cannula-related infection may also increase (Gantz et al 1984; Larson and Hargiss 1984; Hoffman et al 1988). The pathogenesis of cannula-related infections is complex but most appear to result from skin organisms at the cannula insertion site migrating into the cannula track, eventually colonising the cannula tip (Snydman et al 1982; Cooper and Hopkins 1985). Contamination of the cannula hub may also be an important contributor to the colonisation of cannula lumens (Linares et al 1985; Radd et al 1993; Salzman et al 1993). Hand washing and aseptic technique are the major preventive strategies for cannula-related infections.

Insertion of a peripheral venous cannula is a common, although painful, procedure performed by every doctor. Intravenous cannula – as well as the word ‘Venfon@ - is hated by all, especially patients and house officers (2). Though it is an operation performed many times each day, and one that every doctor will perform countless times in the span of his career, it can nevertheless be a daunting experience. The procedure requires very fine hand control and considerable practice. As junior doctors accept 60% success rate to insert cannula in the first attempt and about 90% as experienced seniors.

It is widely accepted that among hospitalised patients, central venous catheters pose a greater risk for than do peripheral vascular catheters (3) although largely preventable, vascular catheter related bloodstream infections are frequent and potentially serious infections among hospitalised patients (4). Bacteraemia due to vascular catheters prolongs hospital stay and increases both healthcare costs and morbidity and mortality rates, particularly when caused by invasive pathogens such as Staphylococcus aureus (5, 6). However, the enormous number of peripheral venous cannula currently used in clinical practice may result in an increasing number of cannula-related complications such as phlebitis, thrombosis, bacteraemia (7) and invasive MRSA infections Among patients with peripheral venous cannula blood stream infection, catheters inserted in the emergency department had a significantly shorter duration in situ compared with those inserted on hospital wards. Patients with peripheral venous cannula blood stream infection caused by S. aureus had a higher rate of complicated bacteraemia (8). Bloodstream infections remain underestimated and potentially serious complications of peripheral vascular cannula. Targeted interventions should be introduced to minimise this complication by identifying the number of attempts & duration required. We could not find any literature to define adequate skin preparation required to make the are sterile before puncturing the skin. This method has been used by three generations of doctors. However it has not yet been properly evaluated. Most of us assume that the technique is safe and therefore continue to puncture veins, despite having experienced the frustration of failure and sadness of inflicting pain to the child (2). Some doctors learn to accept failure, others blame the vein but not many have assessed their own technique. Most studies look into various types of cannula, associated infections and pain relief. Discussions regarding cannulation are restricted to blood flow through the cannulae, risk factors and prevention of contamination, but not much has been written regarding the actual technique of inserting peripheral lines. We could not find any study which compares success rates, time taken, reason for failure and the number of attempts required to successfully cannulate a vein and adequate skin preparation required prior to insertion to prevent infection. This strict aseptic technique is often ignored when the doctors and nurses fail to introduce cannula in the first attempt. This factor is likely to result in introducing spreading antibiotic resistant organisms. Mastering this technique takes years, yet we fail at times of great urgency, but struggle repeatedly and we may succeed due to perseverance.

Observational Study An observational study of cannulation a vein was conducted in the Paediatric unit of a district general hospital in UK . The aim of this study was to identify the number of attempts, the duration required and to compare the success rate of cannulating a vein by senior and Junior Resident doctors. Cannulating veins of seventy-three babies (1.6+/-2.6 months) were observed. The number of attempts required to successfully cannulate a vein was 2.48 +/1.58 and the time taken was 21+/-0.14 minutes. One hundred and seventy seven (n=177) cannulae were used to successfully cannulate seventy three (n=73) children but (104) 58.7% discarded due to failed cannulation . Doctors used three (1 - 9) cannulae to successfully cannulate one vein. Success rate of cannulating a vein in the first attempt by senior doctor was 9/22 (49.3%) and the Junior Resident doctor success was 5/40 (12.5%). Doctors successfully cannulated a vein without a double puncture in 10/73 (13.7%) and failed to cannulate a vein after locating (puncturing) a vein in 27/73 (34.2%). Senior doctors repositioned cannulae 16/22 (72.7%) after double puncturing a vein. Junior Resident doctors successfully cannulate a vein in the 2nd attempt in 17.5 % (14/40), the registrars in 36.35% (4/11) and the seniors in 14/22 (63.63%) of attempts.

DOCTOR

One

Two

Three

Four

Five

> Five

Total

Junior Resident

32.5% (13)

20% (8)

35% (14)

5% (2)

5% (2)

5% (2)

54.79% (4)

Registrar

9.09% (1)

54.5% (6)

9.09% (1)

9.09% (1)

9.09% (1)

9.09% (1)

15.07% (11)

Senior Doctors

45.5% (10)

22.7% (5)

4.55% (1)

18.2% (4)

0% (0)

4.55% (1)

30.14% (22)

32.9% (24)

26%(19)

21.9% (16)

9.59% (7)

4.11% (3)

5.48 % (4)

13.5% (24)

21.4% (38)

27.1% (48)

15.8% (28 )

8.4% (15)

13.5% (24)

41.2% (73)

18.2% (19)

30.7% (32)

20.1% (21)

11.5% (12)

19.2% (20)

58.7% (104)

Cannulae used Cannula Discarded

(n=73)

The technique of cannulation involves identifying a good vein to cannulate, inserting the needle through the skin and then slowly moving the tip of the needle forward. Noticing flash back of blood in the collecting chamber indicate puncturing of the vein. After the vessel has been punctured the cannula is slowly advanced over the needle to place the cannula in the lumen of the vein. The procedure of puncturing a vein (indicated by flash back) but failing to properly place the cannula in the lumen was noted as "double puncture". If the flash back of blood was not

noticed this was recorded as "not double punctured" (failed to locate a vein). We also noted observers comment and the reason given by the doctor after he failed to cannulate. The duration of this observation was for two months. During this period we could observe and collect information from seventy-three babies (n=73). 43 (58.9%) babies were less than a month and 30 (41.1%) babies were less than a year. The average age of babies in our study was 51.28 days. The average weight of these babies was 3.43 +/- 2.17 Kilograms (range 0.63 Kg – 10.1 Kg

AGE of Children

Junior Doctor

Registrar

Consultant

TOTAL

< 1 Month

37.5% (15)

54.55% (6)

40.9% (9)

41.1% (30)

1 - 12 Months

62.5% (25)

45.45% (5)

59.1% (13)

58.9% (43)

TOTAL

54.8% (40)

15.07% (40)

30.1% (22)

100% (73)

Number of Attempts 30 25 20 15 10 5 0 ONE

TWO

Junior Doctors

THREE

FOUR

Registrar

FIVE

SIX

Senior Doctors

The number of babies Junior Resident doctors attempted cannulating a vein was 40 (54.79%), Senior Resident doctors in 11 (15.07%) and the Consultants doctors in 22 (30.14%). Only 24 (32.9%) children were cannulated in the first attempt, 19 (26.0%) in the second and 30 (41%) required three or more attempts

Attempts

One

Two

Three

Four

Five

> Five

Total

Junior Resident (Failed)

20% (8)

15% (6)

27.5% (11)

5% (2)

2.5% (1)

2.5% (1)

72.5% (29)

Junior Resident (Success)

12.5% (5)

5% (2)

7.5% (3)

0% (0)

2.5% (1)

0% (0)

27.5% (11)

Registrs (Failed)

9.09% (1)

18.2% (2)

0% (0)

9.09% (1)

0% (0)

9.09% (1)

45.45% (5)

Registrar (Success)

0% (0)

36.4% (4)

9.09% (1)

0% (0)

9.09% (1)

0% (0)

54.55% (6)

Senior Doctor (Failed)

4.55% (1)

0% (0)

0% (0)

4.55% (1)

0% (0)

0% (0)

9.091% (2)

Senior Doc (Success)

40.9% (9)

22.7% (5)

4.55% (1)

13.6% (3)

0% (0)

9.09% (2)

90.91% (20)

32.9% (24)

26% (19)

21.9% (16)

9.59% (7)

4.11% (3)

5.48% (4)

100% (73)

One hundred and seventy seven (n=177) cannulas were used by doctors to successfully cannulate these seventy three (n=73) children. The number of cannulae discarded due to failure was one hundred and four (n=104). The number of babies cannulated in the first attempt by Junior Resident doctors was 5 (12.5%) babies and Consultants doctors in 9/22 (40.9%). At the end of third attempt the number of infants successfully cannulated by Junior Resident was10/40 (25%), Senior Resident: 5/11 (45.45%) and Consultants: 15/22 (68.18%). Doctors failed to locate a vein in 11/73 (15.1%), but failed to cannulate a vein after locating (and double puncturing) in 25/73 (34.25%). Group doctors punctured and failed to cannulate in 20/40 (50%), but the Consultants doctors punctured and successfully manipulated the cannula into the lumen of vein in 16/22 (72.7%). Successfully cannulating vein without any difficulty was almost equal when seniors (18%) were compared to Junior Resident doctors (15%). Success and failure rate of these three group of doctors were statistically significant (X2 = 22.91, p < 0.00001)

DOCTORS

PUNCTURE (Found vein)

NOT PUNCTURE (Not found vein)

TOTAL

Junior Doctor

60% (24)

40% (16)

55.7% (40)

Registrar

91% (10)

9.09% (1)

15% (11)

Senior Doctors

77% (17)

22.7% (5)

30.1% (22)

69.86 % (51)

30.1% (22)

100% (73)

Junior Resident doctors to successfully cannulated 9/40 (22.5%) infants in 20 minutes, Senior Resident doctors 4/11 (36.36%) and Consultants doctors 15/22 (68.18%). At the end of thirty minutes the number of attempts increased but the proportional success rate declined. Total number of attempts in twenty minutes was 52 (71.2%) and at thirty minutes 65 (89.0%). At the end of thirty minutes the rate of success was minimal (43.0% to 47.6%). The average time spent on the procedure by the House officers (Junior Resident) was 0.32 min, the Registrar (Senior Resident) 0.34 min and the Senior Registrar (Consultants) 0.29 min. The observers felt multiple punctures (11.5%), shock (5.2%) and oedema (4.2%) contributed to failure. 71.5% of the children did not have any factor contributing to failure. Cannulation of veins can be the most stressful but simple surgical procedure to perform and difficult procedures to evaluate. The junior doctors find it difficult to accept failure and tend to avoid the situation. Most doctors do identify and puncture the vein, but still find it difficult to move the cannula forward into the lumen of the vein. Junior doctors were reluctant to attempt cannulating when they noticed the child is obese, oedematous or stopped cannulating at an early stage, as they were happy to hand over the responsibility to the waiting senior doctor. They were not informed about the study as we felt this might increase their anxiety and result in higher failure rate. The senior doctors during this study cannulated babies who are considerably difficult to cannulate. We noticed doctors who fail to cannulate have a tendency to quickly move the cannula forward, once they notice the flash back of blood into the collecting chamber. The vein proximal to the tip of the needle would have collapsed as the blood is draining into the collecting chamber. It is advisable to pause for a few seconds or allow some time for the collecting chamber to fill with blood before moving the cannula forwards into the lumen of the vein. The average number of attempts required by the doctors to successfully cannulate is 2.48 (0-6 attempts). It is advisable to initially allow doctors to have three unsuccessful attempts prior to another doctor taking over the procedure.

Conclusion We advice doctors to abandon the procedure after two attempts, as the failure rate increases. This is due to lack of concentration by the doctor and difficulty to stabilise distressed infants. The senior doctors master this technique of manipulating the cannula after double puncture contributing to higher success rate. The percentage chance of success without double puncturing a vein is almost similar in three groups.

Failure to

cannulate is not due to difficulty in identifying the vein, but due to difficulty in propelling the cannula forward. The comments made by the doctors in our study were based on their own observations. The result from our study should help doctors to improve the success rate making them more confidants at cannulating veins. We feel this method of evaluating the technique should be conducted in every tertiary centre to help doctors identify their deficiency and improve their performance. This would reduce trauma to the infants and cost of paediatric intensive care. To reduce peripheral venous cannula spreading Invasive MRSA infection, adequate skin preparation and time for adequate bactericidal action to occur must be followed (9). We must also use sterile gloves because organisms colonising on latex gloves placed in ward is not known. Band and Maki (1980) provide evidence to recommended changing cannula every 72 hours. This evidence may not be relevant now because existence of MRSA was not known before 1980. Failed cannulation and multiple puncture will result in trauma to vein and may be predisposing phlebitis which results in spreading MRSA infection, bacterial associated septicaemia and death due to toxic shock syndrome. Most studies published are in post operative patients and association with phlabitis. Studies identifying association with number of attempts taken, inadequate skin preparation and duration taken to introduce cannula have not been published for us to comment. We sincerely hope this publication will help others to identify causes which will reduce spreading invasive MRSA infection in the community and also warn doctors and nurses to take adequate care when introducing cannula. This proceedure which was not thought to be threatening life has become a major contributor of mortality giving raise to ethical and legal debate.

Reference (1) Klevens RM, et al; Invasive MRSA in USA; JAMA, (15) October 17, 2007; Vol 298; 17641771.

(2) Wedisinghe L; GMC-Today; 11; Jan 2007. (3) Vomberg RP, Behnke M, Geffers C, et al. Device-associated infection rates for nonintensive care unit patients. Infect Control Hosp Epidemiol 2006;27:357e361.

(4) Harbarth S, Sax H, Gastmeier P. The preventable proportion of nosocomial infections: an overview of published reports. J Hosp Infect 2003;54:258e266

(5) Dimick JB, Pelz RK, Consunji R, Swoboda SM, Hendrix CW, Lipset PA. Increased resource use associated with catheter- related bloodstream infection in the surgical intensive care unit. Arch Surg 2001;136:229e234

(6) Wenzel RP, Edmond MB. The impact of hospital-acquired bloodstream infections. Emerg Infect Dis 2001;7: 174e177)

(7) Tagalakis V, Kahn SR, Libman M, Blostein M. The epidemiology of peripheral vein infusion thrombophlebitis: a critical review. Am J Med 2002;113:146e151. / Vandenbos F, Basar A, Tempesta S, et al. Relevance and complications of intravenous infusion at the emergency unit at Nice university hospital. J Infect 2003;46:173e176

(8) Pujol M et al ; Clinical epidemiology and outcomes of peripheral venous catheter-related bloodstream infections at a university-affiliated hospital; Journal of Hospital Infection (2007) 67, 22-29

(9) Care and maintence to reduce vascular access complication; http://www.rnao.org/bestpractices/PDF/BPG_Reduce_Vascular_Access_Complications.p df