Improving the cleaning of surgical instruments the importance of pretreatment. qualification testing. Professor Andrew Smith

Transcription

1 Improving the cleaning of surgical instruments the importance of pretreatment and performance qualification testing Professor Andrew Smith

2 Disclosures Funding to attend WFHSS from Study funded by Scottish Infection Research Network

3 Improving the cleaning of surgical instruments.. Plan 1. Defining clean 2. vcjd update in UK 3. Role of wetting agents 4. Improvement from what baseline? 5. Laboratory studies 6. Clinical trial of wetting agents 7. Conclusions

4 "Those who cannot learn from history are doomed to repeat it." George Santayana "We learn from history that we learn nothing from history." George Bernard Shaw

5 1. Defining clean 3.9 Cleaning: removal of contamination from an item to the extent necessary for its further processing and its intended subsequent use (BS EN ISO :2006) Cleaning shall be deemed to have been achieved if the acceptance criteria for the test method in 6.10 and the relevant subsequent parts of ISO have been met. The test method for type testing and operational testing (6.10.2) shall employ one of the nationally published tests soils and methods as described in ISO/TS

6 1. Defining clean The test method for PERFORMANCE QUALIFICATION of cleaning efficacy is described in and shall include the use of one of the methods for the detection and assessment of residual proteinaceous contamination given in Annex C Performance qualification: process of obtaining and documenting evidence that the equipment, as installed and operated in accordance with operational procedures, CONSISTENTLY performs in accordance with predetermined criteria and thereby yields product meeting its specification

7 1. Defining clean Annex C protein residue tests are not equal are not equally sensitive. C.1 Ninhydrin & Biuret method (C.3) similar sensitivities but are regarded as a limit test and a semi-quantitative test respectively.

8 1. Defining clean Both ninhydrin and OPA methods react with α- and ε-amino groups The OPA method (C.2) of proteins. More sensitive Requires use of laboratory facilities.

9 1. Defining clean C.2.4 Acceptance criteria When tested in accordance with C.2.3, the extinction value shall be < 0,020. Corresponds to 200ug protein/instrument Why worry about protein?

10 2. vcjd update in UK BSE & vcjd history Background to measures to improve cleaning

11 vcjd epidemiology vcjd MM MV VV Normal 39% 50% 11% scjd vcjd 100 * 0 * = x2 asymptomatic cases Total vcjd deaths Aug 2017 = 178

12 vcjd

13 Appendix I study: Taken out (3/12,674 +ve) Appendix II study: Taken out (16/32,441 +ve)

14 Appendix III study: Taken out pre-1980 (2/14,692 +ve) Appendix III study: Taken out pts born after 1996 (5/14,824 +ve)

15 vcjd scjd Appendix I study: approx 1:4,000 Appendix II study: approx 1:2,000 Appendix III study: approx 1:4,200 Take home message: Continue precautionary approach

16 2. vcjd update in UK Advisory Committee on Dangerous Pathogens (ACDP)..that there should be 5 μg of protein in situ on the side of any instrument tested. Timescale: Neurosurgery by 1 st July 2017 Other instruments (acute sector) by 1 st July 2018

17 3. Role of wetting agents nd Ed: Instruments must be cleaned as soon as possible after use, to avoid rusting or pitting, and to remove soil before it can dry and harden in the serrations and crevices.

18 3. Role of wetting agents Lipscomb et al. Effect of drying time, ambient temperature and pre-soaks... J Hosp Inf 2007; 65: Secker et al. Adsorption of prion and tissue proteins.. following dry and wet storage conditions. J Hosp Inf 2011; 78: Secker et al Efficacy of humidity retention bags..improved cleaning of tissue proteins...to surgical stainless steel surfaces. Biofouling 2015; 31:

19 4. Improvement from what baseline? Measurement based on compliance with technical requirements Equipment, Facilities, Staff, Management.

20 Residual protein on range of instruments One hospital mg Max residual protein = 45mg on one instrument! Murdoch et al JHI

21 2006 Sterile service Departments

22 5. Laboratory studies Oral Presentation at WFHSS 2017 by Dr Sandra Winter

23 6. Clinical trial of wetting agents Study funded by the Scottish Infection Research Network Reducing the risk of vcjd by improving the cleaning of neurosurgical instruments Post Doc Scientists: Tim Tomkinson, Meg Pajak & Sandra Winter Co-investigators include; David Lappin & Andrea Sherriff Ian McIvor (Cowlairs SSD, NHS GG&C), Pamela Philp (Senior Charge Nurse, QEUH, NHS GG&C), Nigel Suttner (Consultant Neurosurgeon, QEUH, NHS GG&C), Alan Stewart (Cowlairs SSD, NHS GG&C). Sulisti Holmes Health Facilities Scotland, NHS National Services)

24 6. Clinical trial of wetting agents Project aims a. Which neurosurgical instruments are the most difficult to clean prior to steam sterilization? b. Which pre-cleaning treatment methods are most efficacious and cost-effective at improving the cleaning of neurosurgical instruments under operational conditions? c. Can a quantitative residual protein assay quality control programme be used to quality assure the cleaning of neurosurgical instruments?

25 6. Clinical trial of wetting agents The sites QEUH Neurosurgical theatres Cowlairs, Sterile Service Department 324,553 trays per annum

26 6. Clinical trial of wetting agents The neurosurgical instrument sets Craniotomy set

27 6. Clinical trial of wetting agents Instruments assayed from Craniotomy set Bard-Parker handle Sharp elevator Blunt elevator Toothed forceps Bayonet forceps Swedish/McDonalds Dissector Adsons Dural forceps McKissock Dural scissors

28 The washer, wash cycle and detergent AWD: Getinge CM310 Detergent: Metal Clean 5% (1-2% NaOH solution) ph 13.1

29 6. Clinical trial of wetting agents Protein assay ISO method C ml of 1% SDS 30 mins This study = 10ml of 1% SDS 30 mins To ensure more efficient coverage of instrument Disadvantage: LOD 30ug/Instrument

30 6. Clinical trial of wetting agents Arm 1: Sets returned from theatre in plastic bag Arm 2: Commercial wetting agent foam applied & sets contained in plastic bag Arm 3: Wound pad soaked in sterile water & sets contained in plastic bag N= 10 sets for each arm Each set tested 8 instruments

31 6. Clinical trial of wetting agents Note: Limit of detection 30ug/instrument Com Wet Sterile H20 No wet Protein ug/ instrument BP handle Sharp el Blunt el toothed forc baynot forc dissector Adsons McKissok Commercial wetting agent or sterile water equivalent efficacy Both (p<0.0001) significantly better than no water agent

32 Difficult to clean? & Quality Control? G- Box (Pro-reveal) methodology

33 ug protein Instrument side 70,0 65,0 Results ProReveal assay for protein levels from all instruments. N= 187 instruments 60,0 55,0 50,0 45,0 40,0 35,0 30,0 25,0 20,0 15,0 10,0 5,0 0,0 Instrument number

34 Proteins per instrument (µg) G-box cleaned instruments Whole instrument Instrument

35 Cleaned Instruments 22- Instrument name G-Box value 24s (ug/instrument) (n=1) 22 Periosteal elevators

36 Difficult to clean? No obvious pattern 70,0 65,0 60,0 55,0 50,0 45,0 40,0 35,0 30,0 25,0 20,0 15,0 10,0 5,0 0,0 Quality Control? Loading pattern of instruments

37 Craniotomy tray ready for loading into automated washer disinfector

38 Loading pattern of test instruments into washer basket as part of PQ test, addition of Edinburgh test soil and AFTER wash process Loading pattern of test instruments into washer basket as part of PQ test, addition of Edinburgh test soil and BEFORE wash process

39 7. Conclusions 1. Wetting systems after use improve cleaning efficacy 2. A proprietary plastic bag, absorbent pad & sterile water are equivalent to commercial wetting systems. Assume N= 324,553 trays per annum Costs if implemented a commercial wetting agent =233,308 Euro Costs if implemented a pad & sterile water = 176,081 Euro (25%) Costs if implemented a liner & tap water = 26,412 Euro (89%)

40 7. Conclusions 3. Systematic PQ testing is essential in establishing operating parameters. 4. The loading pattern established at PQ MUST be repeated for each load

41 "Those who cannot learn from history are doomed to repeat it." George Santayana "We learn from history that we learn nothing from history." George Bernard Shaw