aprof fisher- wound infections – preventable or inevitable

Wound Infections…….. Preventable or Inevitable?

A/Prof. Dale FisherNational University HospitalSLH 6th Wound Conference

May 25 2012

Outline

• History

• Pathogenesis

• Surgical site infection prevention strategies

• Burns

• Traumatic wounds

Infection Inevitable: Compound fractures, almost 100% mortality….amputation,

miasma, no hand hygiene

“Yah, but there is a slight drawback. Most patients here do NOT

survive surgery. to get infected.”

Robert Liston, 1794 - 1847

“The fastest knife in the West End”

Because blood loss was a major obstacle and modern anesthesia was unknown, the primary skill to recommend a good surgeon was speed rather than finesse.

First anaesthetic in 1840s

Ignaz Semmelweiss

Hungarian obstetrician

• Showed in 1847 that hand washing with chlorinated lime solution markedly reduced maternal mortality (strep)

• Died in a mental institution in 1865

Louis Pasteur, 1822 - 1895

Joseph Lister, 1827 - 1912

Lister carried out experiments to sterilise surgical instruments, wounds and dressings

with carbolic acid (phenol). Surgeons had to wear clean gloves and wash their hands in

carbolic acid solutions before operating. This was resisted by the medical community at the time!

Carbolic Acid

Lister‟s cloud of carbolic spray drenched the whole area, surgeon and all.

Their skin became bleached and numb, nails cracked, and “lungs sore”

Lister described it as „a necessary evil incurred to attain a greater good.‟

Alternatives were found and mortality from amputation fell from 40% to 3% in

60 years.

Initially as a

surgical

antiseptic; not

popular until

sold as a cure

for halitosis in

the 1920s

Robert Koch

• 1843-1910

• 28th birthday present

• Anthrax, TB, cholera

• Cultured, purified and caused disease

Alexander Fleming, 1881 - 1955

next major drop in mortality post trauma or surgery started in 1929 with “mould juice”

Mass production after Pearl Harbour in 1941

Outline

• History

• Pathogenesis

• Surgical site infection prevention strategies

• Burns

• Traumatic wounds

The Significance of Wound Infections

• Second most common adverse event in hospitalised patients

• SSI accounts for 40% of hospital associated infections for surgical patients

• In Singapore, rates for clean operations = 1.6%, contaminated operations = 4%.

• Extends duration of admission

• 60% more likely to require ICU

• $3000 excess costs per case (US data)

Liau KH. Surg Infect. 2010 Apr;11(2):151-9. Outcome of a strategy to reduce surgical site infection in a tertiary-care hospital.

Uçkay. Preventing surgical site infections. Expert Review of Anti-infective Therapy, June 2010, Vol. 8, No. 6, 657-670

Risk Factors

• Coincident remote site infection

• Diabetes

• Smoking

• Steroids

• Poor nutritional status

• Other immune suppression

• Prolonged hospital stay

• Colonisation with Staph. aureus

Uçkay. Preventing surgical site infections. Expert Review of Anti-infective Therapy, June 2010, Vol. 8, No. 6, 657-670

Pathogen Sources

• Endogenous

– Patient flora

• skin

• mucous membranes

– GI tract

– Seeding from a distant focus of infection

Pathogen Sources

• Exogenous

– Health care staff

• Inadequate hand hygiene

• Breaks in aseptic technique

• Soiled attire

– Physical environment and ventilation

– Equipment and materials associated with the operative field/wound

Bacillus epidemic curve

0

10

20

30

40

50

60

70

Heavy contamination of linen

Towels most densely contaminated- 7403 (±1054.3) spores per cm2 fabric Other linen less affected

Patient gowns:585 (±356.4)spores/cm2

Flat cotton sheets: 80 (± 36.4) spores/cm2

Organisms

Staphylococcus aureus 30.0%Coagulase-negative staphylococci 13.7%Enterococcus spp. 11.2%Escherichia coli 9.6%Pseudomonas aeruginosa 5.6%Enterobacter spp 4.2%Klebsiella pneumoniae 3.0%Candida spp. 2.0%Klebsiella oxytoca 0.7%Acinetobacter baumannii 0.6%

Take a good swab!

- Does not have to be established

infection to delay wound healing (therefore still infection prevention)

- Swab technique: - Debride, rinse with sterile saline/gauze

- rotate a swab in deep bed over a 1cm2 area and with sufficient pressure to extract fluid.

- sensitivity of 90% and a specificity of 57% 2

- Want pus cells not epithelial cells

1. Gardner SE, Frantz RA, Saltzman CL, et al. Diagnostic validity of three swab techniques for identifying chronic wound infection. Wound Rep Regen 2006;14:548–557.

2. Consensus Guidelines. Int Wound J 2008; 5 (Suppl 3): 1-11

Biofilm

• Bacteria create a protected colony of communicating organisms by secreting a polysaccharide extra-cellular matrix

• More resistant to killing by immune system or antibiotics

• Wounds that contain foreign materials are most likely to have biofilm firmly attached

Outline

• History

• Pathogenesis

• Surgical site infection prevention strategies

• Burns

• Traumatic wounds

NHS Care bundle to prevent surgical site infection

http://hcai.dh.gov.uk/files/2011/03/2011-03-14-HII-Prevent-Surgical-Site-infection-FINAL.pdf

NHS Bundle

NHS Bundle

Latest innovations & the future!

Evaluation ItemsStrongly

disagreeDisagree Agree Strongly agree

1.The training was clear and easy to follow

(N=339) 3 (0.9%) 2 (0.6%) 212 (62.5%) 122 (36%)

2.I understood the "5 moments of hand hygiene"

better after the training (N=339) 4 (1.2%) 0 149 (43.9%) 186 (54.9%)

3.I was able to carry out the hand hygiene audit

after the training (N=339) 3 (0.9%) 1 ( 0.3%) 215 (63.4%) 120 (35.4%)

4.The auditing experience has given me

opportunities to observe how infections could be

transmitted in the hospital (N=339)5 (1.5%) 1 ( 0.3%) 215 (63.4%) 118 (34.8%)

5.The audit experience has enhanced my hand

hygiene practice (N=339)4 (1.2%) 4 ( 1.2%) 188 (55.5%) 143 (42.2%)

6.I would like to be an advocate of hand hygiene

(N=339)5 (1.5%) 15 ( 4.4%) 257 (75.8%) 62 (18.3%)

7.I would recommend that more nursing students

be involved in hand hygiene audits (N=339)3 (0.9%) 7 ( 2.1%) 196 (57.8%) 133 (39.2%)

Training Nursing Students as hand hygiene auditors

NUH Hand Hygiene Products Consumption

January 2005 to March 2012

6555

3055

27022916

3480 3480

28202660

3570 3670 3585 3666 35723762

3883 3824

3577

38223978 3959

3733

3977 3973 3970

4792

4160

3959

4642

4095

3053

3,428

3657

3381

1766

2732

30432914

26742790

30523139

2824 2916

3311

2975

3277

3705

32343349 3274 3231

35073645

3505

4013

4568

4883 4896

723

1190 1225 1228

870

1081

1329 14161305 1223

1520

1940

1754

20122140

2470

3308

4598

43394247 4284

4847

5673

6326

5880

7142

8055

9231 9157

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

Q1 '05

Q2

Q3

Q4

Q1 '06

Q2

Q3

Q4

Q1 '07

Q2

Q3

Q4

Q1 '08

Q2

Q3

Q4

Q1 '09

Q2

Q3

Q4

Q1 '10

Q2

Q3

Q4

Q1 '11

Q2

Q3

Q4

Q1 '12

Quarters

HH

Pro

du

cts

(B

ott

les)

Hand Foam Soap 500mls per pack* Chlorhexidine 4% Antiseptic skin cleanser (overall) 500mls per bottle^

Alcohol Handrub (overall) 500mls per bottle#

Overall Hospital Wide Hand Hygiene Compliance for Inpatient Area

38%

45%

49%

54% 55%

60%

64% 63%65%

69% 69%67%

70% 69%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Baseline(Jun,

Aug & Oct

08)

Q1 2009 Q 2 2009 Q3 2009 Q4 2009 Q1 2010 Q2 2010 Q3 2010 Q4 2010 Q1 2011 Q2 2011 Q3 2011 Q4 2011 Q1 2012

% C

om

pli

an

ce

1404/2197 1602/2536 1541/22191656/2534417/1088 490/1098 653/1346 906/1669 1094/2001 1187/1965

1452/2110 1622/2418 1664/2362 1542/2247

Hand Hygiene Compliance Rate For Different Healthcare Workers

Hand Hygiene Compliance

Q1 2010 - Q1 2012

50%

69% 68% 68%

42%

34%

52%

40%

56%

73% 73%

70%

47%

83%

63%

48%49%

74%72%

74%

50%

27%

64%

45%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Doctors Nurses Patient Care Assistants Therapists Radiographers Medical Students Nursing Students Others

Healthcare Professionals

% C

om

pli

an

ce

2010 2011 Q1 2012

680

13473913

5668

598

876139

204

303

586

176

437

781

1406

4100

5584

545

743

139

200

32

95

8

19

14

30

186

225

306

485

208

436

148

3001077

1446

123

170

50

682

43

11

89

138

50

110

Hand Hygiene Compliance Rate-

Breakdown by hand hygiene moments

61%

74%

86%

79%

53%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

1 2 3 4 5

Hand Hygiene Moment

Co

mp

lian

ce R

ate

(%

)

Project Safe Hands

• Trial in Ward 63

• Pilot started in March

More on the interventions for surgical wound infection

prevention………..

Staph. aureus decolonisation

• Nasal colonisation a risk factor for SSI 1

• Decolonisation reduces risk of SSI 2

– 808 S.aureus (all MSSA) colonised patients undergoing surgical procedures randomised to nasal mupirocin + chlorhex body wash vs placebo

– RR 0.42 for all SSI

– RR 0.21 for deep site infection

– Study used PCR for screening

– Study did not look at MRSAKluytmans JA. Nasal carriage of Staphylococcus aureus as a major risk factor for wound infections after cardiac surgery. J Infect

Dis 1995; 171:216.

Bode LG. Preventing surgical-site infections in nasal carriers of Staphylococcus aureus. N Engl J Med 2010; 362:9

Hair removal………

clip & probably best on the day of op!

• Cochrane review:

– Shaving n=575, RR=1.75 (0.93 – 3.28)

– Clipping n=130, RR=1.00 (0.06 - 15.65)

– Cream n=267, RR=1.02 (0.45 - 2.31)

– Timing• no difference for shaving

• Clipping on the day probably better than day before for 30 day SSI: n=457, RR=2.30 (0.98-5.41)

Skin antisepsis

• Reduce burden of bacteria

• Bacteria remain in pores/follicles

• 2% Chlorhexidine-alcohol superior to povidone-iodine skin prep. RR 0.59 (0.41 –0.85)1

– JEJM RCT published after cochrane review

• Bathing with chlorhexidine prior to surgery not beneficial: RR 0.91 (0.8-1.04)2

1. Darouiche RO, Wall MJ Jr, Itani KM, et al. Chlorhexidine-Alcohol versus Povidone-Iodine for Surgical-Site Antisepsis. N Engl J Med 2010; 362:18.

2. Webster J, Osborne S. Preoperative bathing or showering with skin antiseptics to prevent surgical site infection. Cochrane Database Syst Rev 2006; :CD004985.

Prophylactic Antibiotics

• Recommended for high risk surgery

– Contaminated surgery (colorectal)

– Foreign material implanted

– Where development of wound infection could be disastrous

Enzler. Antimicrobial prophylaxis in adults. Mayo Clin Proc. 2011 Jul;86(7):686-701.

Efficacy of antibiotic prophylaxis

Prophylactic Antibiotics

• Antibiotics should ideally be

– Bactericidal

– Non toxic

– Cheap

– Active against common pathogens

• Frequently cephazolin used

• Vancomycin if true allergy or high MRSA rate

Timing of antibiotics

• prospective observational study

• 4 Groups:

– early 2–24 hours pre-incision

– preoperative 0–2 hours pre-incision

– perioperative up to 3 hours post-incision

– postoperative 3–24 hours post-incision

Classen DC. The timing of prophylactic administration of antibiotics and the risk of surgical-wound infection.

New England Journal of Medicine 1992;326:281–6.

Timing of antibiotics

• Lowest rates if given 0-2 hours pre-op• If given post op, higher rates of infection with

each successive hour post op

• Therapeutic antibiotics should be present in the tissue throughout the period the wound is opened, top up doses may be needed

• Antibiotic duration: <24h • except cardiac surgery 48h

Perioperative normothermia

• Hypothermia causes vasoconstriction reducing tissue perfusion

• Warming the patient reduces the rate of SSI in colorectal surgery (16% vs 6%)1

• In cardiac surgery there were no differences in outcome between hypothermic and normothermic groups 2

1. Kurz A. Perioperative normothermia to reduce the incidence of surgical-wound infection and shorten hospitalization. Study of

Wound Infection and Temperature Group. N Engl J Med 1996; 334:1209.

2. The Warm Heart Investigators.Randomised trial of normothermic versus hypothermic coronary bypass surgery. Lancet 1994;

343:559.

Surgical attire

• No data looking at surgical attire and SSI risk

• Experimental data show that live microorganisms are shed from hair, exposed skin, and mucous membranes of operating room personnel

• Surgical masks, gowns and scrubs also essential to protect staff from potentially infectious materials from patient

CDC recommendations

Surgical technique

• Suture material: Monofilament sutures appear to have less SSI risk

• Place drains through a separate incision, distant from the operative incision

• Closed suction drains better than open drains

• Avoidance of hypothermia – vasoconstriction reduces perfusion of O2 and neutrophils

Supplemental Oxygen Therapy

• Theoretical benefit of improved tissue oxygenation and wound healing and better immune function

• Meta-analysis of 5 RCTs (3000 patients) comparing perioperative Fi 80% O2 with standard care

– Infection rate 9% vs 12% (RR 0.74, 0.60 – 0.92)

• A subsequent RCT of 1400 patients concluded no difference

1. Qadan M. Perioperative supplemental oxygen therapy and surgical site infection: a meta-analysis of randomized controlled

trials. Arch Surg 2009; 144:359.

2. Meyhoff CS. Effect of high perioperative oxygen fraction on surgical site infection and pulmonary complications after

abdominal surgery: the PROXI randomized clinical trial. JAMA 2009; 302:1543.

Glucose control

• Diabetes associated with increased SSI2

– (OR 2.7)

• Pre1 and post2 operative hyperglycaemia associated with increased SSI

– (OR 10.2 and 2.0 respectively)

• Continuous infusion insulin better than intermittent s/c insulin3

– Risk of deep infection 0.8% vs 2.0% respectively

1.Trick WE. Modifiable risk factors associated with deep sternal site infection after coronary artery bypass grafting. J Thorac

Cardiovasc Surg 2000; 119:108.

2. Latham R. The association of diabetes and glucose control with surgical-site infections among cardiothoracic surgery

patients. Infect Control Hosp Epidemiol 2001; 22:607.

3. Furnary AP. Continuous intravenous insulin infusion reduces the incidence of deep sternal wound infection in diabetic

patients after cardiac surgical procedures. Ann Thorac Surg 1999; 67:352.

Topical silver sulphadiazine (SSD)

• Cochrane review 2010 – multiple studies

• None of the trials indicated a beneficial effect for SSD when compared with other silver-containing or non-silver dressings

• evidence that SSD may delay wound healing, may be more expensive

• may be more painful when applied to burns

Storm-Versloot MN. Topical silver for preventing wound infection. Cochrane Database Syst Rev. 2010 Mar 17;(3):CD006478.

Outline

• History

• Pathogenesis

• Surgical site infection prevention strategies

• Burns

• Traumatic wounds

Burns

• Burns; immunosuppressive effect (Anti inflammatory response)

– decreased production of monocytes and macrophages; IL 12

– increased IL 4 & IL 10, glucocorticoids, PGE2

• 75% of burns deaths are from infection

Church. Burn Wound Infections. Clin microbio rev. http://cmr.asm.org/content/19/2/403

Burns

• A burn is initially sterile, then over next 24-48h becomes colonised with bacteria– Endogenous: patients own skin flora– Exogenous bacteria transmitted from the environment or from

healthcare workers

• Initially colonised with gram positive• Then antibiotic susceptible gram negatives• After antibiotic treatment they are replaced by

yeasts, moulds and antibiotic resistant organisms• Colonisation with pseudomonas before 30 days incurs 7x

higher mortality compared to colonisation after 30 days

Rowley-Conwy (2010) Infection prevention and treatment in patients with major burn injuries. Nursing Standard. 25, 7, 51-60.

Rafla. Burns. 2011 Feb;37(1):5-15. Infection control in the burn unit.

Infection Control in Burns

• Burn can be colonised by contact, droplet or airborne spread

• Mode of transmission

– Common treatment rooms

– Contaminated equipment (eg. BP cuffs)

– Hydrotherapy

– Hand hygiene failure by staff and visitors

Rafla K, Infection control in the burn unit. Burns. 2011 Feb;37(1):5-15. Epub 2010 Jun 18.

Prevention of Burn Infection

• Daily wound assessment• Aseptic technique when handling wound• Minimise wound exposure time• Debriding dressing for necrotic wounds• Surgical debridement of invasive infection• Avoid IV catheters through burned tissue if

possible• Private rooms to prevent cross contamination• Avoid plants in unit (pseudomonas and fungi)• Antibiotic prophylaxis only in perioperative

period

Bali; October 12, 2002

Silla RC Infection in acute burn wounds following the Bali bombings: a comparative prospective audit.

Burns. 2006 Mar;32(2):139-44

The incidence of primary BWI in the Bali-tourist group (68.2%) compared

with the standard WA group (18.2%) was significant (p=0.001).

Outline

• History

• Pathogenesis

• Surgical site infection prevention strategies

• Burns

• Traumatic wounds

Wound Debridement

• Bacteria thrive in necrotic tissue that is poorly penetrated by immune cells or antibiotics.

• Surgical debridement for heavily necrotic wounds

• VACC dressing

– Negative pressure removes wound pus and promotes granulation tissue

• Maggots (popular in Europe)

– Secretions dissolve dead tissue

– More rapid debridement than conventional dressings

Venturi. Mechanisms and clinical applications of the vacuum-assisted closure (VAC) device; a review. Am J Clin

Dermatol 2005; 6:185–194

Opletalová. Maggot therapy for wound debridement: a randomized multicenter trial. Arch Dermatol. 2012 Apr;148(4):432-8.

Mammalian Bites

• Tetanus shot

• Rabies post exposure prophylaxis

• Antibiotics?

– Effective post human bite OR 0.02 (0.00 - 0.33)

– Insufficient evidence for animal bites

– Dog bite OR 0.74 (0.30 - 1.85)

– Cat bite n=11, infection rate 67% control group vs 0% antibiotic group

Cochrane 2008 - Antibiotic prophylaxis for mammalian bites (Review)

Outline

• History

• Pathogenesis

• Surgical site infection prevention strategies

• Burns

• Traumatic wounds

The future of infection prevention

• RNA III inhibiting peptide to disrupt quorum signaling between bacteria in biofilms

– promising in animal studies

• Doing what we know better

Giacometti A. RNA III inhibiting peptide inhibits in vivo biofilm formation by drug-resistant Staphylococcus

aureus. Antimicrob Agents Chemother 2003; 47:1979–1983.

Conclusions

• Concept of a continuum between sterile, critical colonisation and infection

• While infection will always be a risk, interventions over the last 200 years have reduced rates from 50% to single digits

• Strict adherence to infection control protocols & bundles together with new innovations can reduce this further

Thank You!