AProf Fisher- Wound Infections – Preventable or Inevitable
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Transcript of 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!