Preventing Infection in the Operating Room. What do we know? Where do we go from here? Ventilation

Transcription

1 Preventing Infection in the Operating Room. What do we know? Where do we go from here? Ventilation Hilary Humphreys Royal College of Surgeons in Ireland (RCSI) & Beaumont Hospital, Dublin, Ireland Meet-the-Expert Session, ECCMID 2015, 26 th April 2015

2 Declaration The views expressed are in a personal & professional capacity; they do not necessarily reflect those of the RCSI or Beaumont Hospital, Dublin, Ireland I have had research collaborations with Steris Corporation, Inov8 Science, Pfizer & Cepheid in recent years. I have also recently received lecture & other fees from Novartis, AstraZenca & Astellas.

3 J Hosp Infect 2012;80: The Surgeon 2015; 13: 52-58

4 Objectives 1. To review the basis for operating room (OR) ventilation 2. To discuss the impact of ventilation 3. To reflect on the evidence for ultraclean ventilation (UCV) in preventing infection in prosthetic joint surgery 4. To consider issues about ventilation requirements for minor surgery

5 Background

6 Middlesex Hospital, London, 1927 (Wellcome) Boston, USA, 1846 (Wellcome)

7 Ventilation Standards Four classes of Operating Room o Ultra clean ventilation, UCV or orthopaedic o Conventional (plenum) ventilation o Ventilated/air conditioning o Treatment room natural ventilation There is no technical difference between an unventilated OR & a treatment room

8 Ceiling Central Supply

9 Standard OR Ventilation During walking, 10 4 skin scales shed per minute; 10% with microbes Air supply should be free of dust & particles; air intake distant from weather, sources of dust ~ 20 air changes/h Pressure gradients from sterile areas

10 UCV & Prosthetic Orthopaedic Surgery

11 UCV OR (HIRL, Birmingham, UK)

12 8,055 6,781 hips 1,274 knees Br Med J 1982; 285: Mean follow up, years Substantial reduction in bacteria in plenum versus UCV 0.6% sepsis in UCV versus 1.5 in plenum (<0.001) Uncontrolled for prophylactic antibiotics; given in 2/3 Suggestion that UCV & antibiotic prophylaxis had independent & cumulative effect

13 Impact of VCV & Prophylaxis Prophylaxis prevents 255 infections of 10,000 operations, most effective measures (3.4% to 0.85%) UCV prevents another 255/10,000 (to 0.42%) Body Exhaust Suits prevent another 23/10,000 (to 0.19%) Br Med J 1983; 286:

14 Systematic Review of SSI & UCV 140 hip & 68 studies of knee prosthetic surgery; 5 suitable for inclusion 75,000 knee & 120,000 hip procedures in four different countries UCV, RR for SSI of 1.36 for knee & 1.71 for hip J Hosp Infect 2012; 81: 73-78

15 UCV, Space Suits & Deep Infection J Bone Joint Surg; 2011; 93-B: New Zealand Joint Registry, Revision rates for deep infection after hip & knee replacements Findings independent of age, disease & operating time Hip replacements

16 Am J infect Control 2013; 41: 803-9

17 Low & High Outliers for SSI Rates Visits & structured interviews but inspectors blind to hospital status Low outliers were smaller, more efficient with less staff turnaround & had a policy of minimising operating theatre traffic (p<0.052) J Am Coll Surg 2008; 207:

18 Traffic Flow & Air Counts Am J infect Control 2012; 40: Swedish university hospital & 30 procedures Upward displacement air system 52/91 samples had colony forming units (cfu) >10/m 3 Duration of surgery & traffic flow (door openings = 529) correlated with air counts Necessary Optional Unnecessary Consultations 40 Team members 76 Planning 30 Instruments 137 Lunch/coffee 108 Social 45 No reason 93 Total 177 Total 184 Total 168

19 Forced-Air Warming & UCV J Bone Joint Surg Br 2011: 93-B: Forced air warming generates heat that leads to air currents Conductive fabric warming releases much less heat

20 What is the effect of different sized canopy? Am J Infect Control 2011; 39: 25-9

21 Minor & Minimally Invasive Surgery

22 A Minor Procedure Q. What is minor surgery? A. Does it depend on, - location, e.g. hand versus brain - depth of incision, e.g. excision of rodent ulcer versus mastectomy - time required, e.g. 10 minutes versus 90 minutes - who does it, plastic surgeon versus dermatologist - risk to patient, hernia repair in a 19 year old male as day case versus 86 year old male with diabetes mellitus, on steroids, etc.

23 Minimal access intervention (MAI) Therapeutic or diagnostic procedures, under local (LA) or general anaesthetic, small operative site, e.g. laparoscopic colectomy & may proceed to open surgery Minor surgical procedure (MSP) Carried out under LA, superficial & small operative site, e.g. incision of ingrown toe nail

24 Ventilation MAI 15 air changes/hour for removal of gases & microbiologically adequate; avoids deposition of airborne particles especially if sterile prosthesis EN 779 F7 filter Pressure differential of 5Pa between operating facility & surrounding area Indicator panel, o C & 20-60% humidity MSP Natural ventilation

25 Questions

26 Why are SSI rates higher with UCV theatres? If developing a new prosthetic joint surgery service, would you want a UCV installed? Can most minor surgery be done outside the operating room? Are practices more important than the inanimate environment?

27 Thank you