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HLD and Sterilization: Current Issues and New Technologies. William A. Rutala, PhD, MPH
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HLD and Sterilization:Current Issues and New Technologies William A. Rutala, PhD, MPH Director, Hospital Epidemiology, Occupational Health and Safety at UNC Health Care; Research Professor of Medicine and Director, Statewide Program for Infection Control and Epidemiology at University of North Carolina School of Medicine at Chapel Hill, USA Disclosure: 3M
HLD and Sterilization:Current Issues and New Technologies • Sterilization • Cleaning, washer disinfector, emerging technologies, biological indicators, outpatient surgeries/procedures • High-Level Disinfection • Endoscope-related infections, new HLD, channeled scopes, laryngoscopes, reuse of single-use items • D/S and Emerging Pathogens • MERS-CoV, HPV, C. difficile, Prions, Enterovirus 68, Ebola
CDC Guideline for Disinfection and SterilizationRutala, Weber, HICPAC. November 2008. www.cdc.gov
Disinfection and Sterilization in Healthcare FacilitiesWA Rutala, DJ Weber, and HICPAC, www.cdc.gov • Overview • Last Centers for Disease Control and Prevention guideline in 1985 • 158 pages (>82 pages preamble, 34 pages recommendations, glossary of terms, tables/figures, >1000 references) • Evidence-based guideline • Cleared by HICPAC February 2003; delayed by FDA • Published in November 2008
HLD and Sterilization:Current Issues and New Technologies • Sterilization • Cleaning, washer disinfector, emerging technologies, biological indicators, outpatient surgeries/procedures • High-Level Disinfection • Endoscope-related infections, new HLD, channeled scopes, laryngoscopes, reuse of single-use items • D/S and Emerging Pathogens • MERS-CoV, HPV, C. difficile, Prions, Enterovirus 68, Ebola
Disinfection and SterilizationWA Rutala, DJ Weber, and HICPAC, www.cdc.gov EH Spaulding believed that how an object will be disinfected depended on the object’s intended use. CRITICAL - objects which enter normally sterile tissue or the vascular system or through which blood flows should be sterile. SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection [HLD]) that kills all microorganisms but high numbers of bacterial spores. NONCRITICAL -objects that touch only intact skin require low-level disinfection (or non-germicidal detergent).
Efficacy of Disinfection/SterilizationInfluencing FactorsWA Rutala, DJ Weber, and HICPAC, www.cdc.gov Cleaning of the object Organic and inorganic load present Type and level of microbial contamination Concentration of and exposure time to disinfectant/sterilant Nature of the object Temperature and relative humidity
Cleaning • Items must be cleaned using water with detergents or enzymatic cleaners before processing. • Cleaning reduces the bioburden and removes foreign material (organic residue and inorganic salts) that interferes with the sterilization process. • Cleaning and decontamination should be done as soon as possible after the items have been used as soiled materials become dried onto the instruments.
Cleaning • Mechanical cleaning machines-automated equipment may increase productivity, improve cleaning effectiveness, and decrease worker exposure • Utensil washer-sanitizer • Ultrasonic cleaner • Washer sterilizer • Dishwasher • Washer disinfector • Manual
Bioburden on Surgical DevicesNon-lumen Surgical Instruments Carry a Low Microbial Load (<100 CFU, 85%) • Bioburden on instruments used in surgery (Nystrom, J Hosp Infect 1981) • 62% contaminated with <101 • 82% contaminated with <102 • 91% contaminated with <103 • Bioburden on surgical instruments (Rutala, Am J Infect Control 1997) • 72% contained <101 • 86% contained <102 • Bioburden on surgical instruments (50) submitted to CP (Rutala, AJIC 2014) • 58% contained <10 • 20% contained < 102 • 16% contained <5x102 • 6% contained <103
Washer/DisinfectorRutala WA et al. Infect Control Hosp Epidemiol 2014;35:883-885 • Five Chambers • Pre-wash: water/enzymatic is circulated over the load for 1 min • Wash: detergent wash solution (150oF) is sprayed over load for 4 min • Ultrasonic cleaning: basket is lowered into ultrasonic cleaning tank with detergent for 4 min • Thermal and lubricant rinse: hot water (180oF) is sprayed over load for 1 min; instrument milk lubricant is added to the water and is sprayed over the load • Drying: blower starts for 4 min and temperature in drying chamber 180F
Washer/DisinfectorRemoval/Inactivation of Inoculum (Exposed) on InstrumentsRutala et al. Infect Control Hosp Epidemiol 2014. 35:883-885.
Washer/disinfectors are very effective (>7 log10 reduction) in removing/inactivating microorganisms from instruments
Cleaning Indicators for Washer Disinfector • Monitor the automated washer and instrument cleaning chemistry functionality; AAMI recommends weekly (preferably daily) • Washer indicators have been used in Europe and Canada and some US hospitals • Indicator includes proteins, lipids, and polysaccharides to mimic common challenging test soils • Washer indicators are chemical indicators imprinted with a dried test soil formula and a dye
How Clean Is Clean? • AAMI and FDA trying to gain consensus • Reached consensus on maximum levels of top three common markers after a device is cleaned • Less than 6.4 µg/cm2 for protein • Less than 12 µg/cm2 for total organic compound • Less than 2.2 µg/cm2 for hemoglobin • Research needs to be performed to determine how healthcare facilities should verify cleanliness (real-time tests and meaningful analytical endpoints) • Manufacturers’ ensure the HCF can clean the device (time, resources, device design)
Sterilization of “Critical Objects” Steam sterilization-1970s Ethylene oxide-1970s Hydrogen peroxide gas plasma-1993 Vaporized hydrogen peroxide-2011
Ozone and Hydrogen Peroxide • Sterizone VP4, 510(k) FDA clearance,TSO3 Canada • Sterilizer has a 4.4ft3 chamber • Advantages/Disadvantages-not yet known
Nitrogen Dioxide(Noxilizer, MD 2004; seeking industrial claim; 2016 HC) • NO2 has unique properties including a low boiling point (21oC) and a high vapor pressure, which facilitate effective dispersion of NO2 gas at low concentration • Log-linear inactivation at 3.5mg/L NO2 gas concentration and 75% RH using G. stearothermophilus spores • Toxicity-OSHA PEL for NO2 is 5ppm • Compatible with most polymers used in medical devices
New LTST Technology • Supercritical CO2 • Peracetic acid vapor • Gaseous chlorine dioxide
Biological Indicators • Select BIs that contain spores of Bacillus atrophaeus • Rationale: BIs are the onlysterilization process monitoringdevice that provides a direct measure of the lethality of the process Bacillus atrophaeus
Rapid Readout BIs for Steam Now Require a 1-3h Readout Compared to 24-48hRutala, Jones, Weber ICHE 1996. 17:423
Super Rapid Readout Biological IndicatorsCommercially available • 1491 BI (blue cap) • Monitors 270°F and 275°F gravity –displacement steam sterilization cycles • 30 minute result (from 1hour) • 1492V BI (brown cap) • Monitors 270°F and 275°F dynamic-air-removal (pre-vacuum) steam sterilization cycles • 1 hour result (from 3 hours)
Routine Load Release/Routine Sterilizer Efficacy Monitoring Ethylene Oxide Sterilizers BI Process Challenge Device • BI placed in PCD representative of packs being sterilized • AAMI routine test pack or commercially available, FDA cleared BI PCD • Placement: Full load in center • Frequency: in each load • Attest™ 1298 Test Pack contains Attest 1294™ Rapid Readout BI for EO with 4 hour final result ANSI/AAMI ST41:2008( R)2012, Section 10
US Outpatient Surgery/Procedures Pass Inpatient Surgery/Procedure
Outpatient vs Inpatient Surgery/Procedure2010, US DHHS Top 10 Outpatient Surg/Proc-53M Top 10 Inpatient Surg/Proc-46M Coronary artery exam-1M C-section 1.3M Cardiac cath-1.1M Endoscopy of small intestine-1M Diagnostic ultrasound-~900K CAT scans-740K Realign broken bone-672K Balloon angioplasty of coronary-661K Coronary artery stent-661K • Lens and cataract procedures-7M • Endoscopy of large intestine-5.7M • Endoscopy of small intestine-3.4M • Therapeutic injections-1.4M • Coronary artery exam-1M • Knee arthroscopy-~1M • Hernia repair-~1M • Tonsillectomy/adenoidectomy-750K • Cystoscopy-750K
HLD and Sterilization:Current Issues and New Technologies • Sterilization • Cleaning, washer disinfector, emerging technologies, biological indicators, outpatient surgeries/procedures • High-Level Disinfection • Endoscope-related infections, new HLD, channeled scopes, laryngoscopes, reuse of single-use items • D/S and Emerging Pathogens • MERS-CoV, HPV, C. difficile, Prions, Enterovirus 68, Ebola
DISINFECTION AND STERILIZATION • EH Spaulding believed that how an object will be disinfected depended on the object’s intended use • CRITICAL - objects which enter normally sterile tissue or the vascular system or through which blood flows should be sterile • SEMICRITICAL - objects that touch mucous membranes or skin that is not intact require a disinfection process (high-level disinfection[HLD]) that kills all microorganisms except for high numbers of bacterial spores • NONCRITICAL - objects that touch only intact skin require low-level disinfection
High-Level Disinfection of “Semicritical Objects” Exposure Time > 8m-45m (US), 20oC Germicide Concentration_____ Glutaraldehyde > 2.0% Ortho-phthalaldehyde0.55% Hydrogen peroxide* 7.5% Hydrogen peroxide and peracetic acid* 1.0%/0.08% Hydrogen peroxide and peracetic acid* 7.5%/0.23% Hypochlorite (free chlorine)* 650-675 ppm Accelerated hydrogen peroxide 2.0% Peracetic acid 0.2% Glut and isopropanol 3.4%/26% Glut and phenol/phenate** 1.21%/1.93%___ *May cause cosmetic and functional damage; **efficacy not verified
ResertTM HLD • High Level Disinfectant - Chemosterilant • 2% hydrogen peroxide, in formulation • pH stabilizers • Chelating agents • Corrosion inhibitors • Efficacy (claims need verification) • Sporicidal, virucidal, bactericidal, tuberculocidal, fungicidal • HLD: 8 mins at 20oC • Odorless, non-staining, ready-to-use • No special shipping or venting requirements • Manual or automated applications • 12-month shelf life, 21 days reuse • Material compatibility/organic material resistance (Fe, Cu)? *The Accelerated Hydrogen Peroxide technology and logo are the property of Virox Technologies, Inc. Modified from G MacDonald. AJIC 2006;34:571
Reprocessing Semicritical Items • New Developments in Reprocessing • Endoscopes • Cystoscopes, ureteroscopes, hysteroscopes • Prostate probes • Laryngoscopes
Reprocessing Semicritical Items • New Developments in Reprocessing • Endoscopes • Cystoscopes, ureteroscopes, hysteroscopes • Prostate probes • Laryngoscopes
“Superbug” Outbreaks • Cedars-Sinai Medical Center, UCLA Ronald Reagan Medical Center, University of Pittsburgh Medical Center, Virginia Mason Medical Center, tertiary care facility in NE Illinois • ABC, CBS, NBC, CNN, New York Times, LA Times • Congress asked the FDA why “didn’t move more quickly and aggressively to ensure patient safety” • Professional organizations (ASGE, AGA) and FDA investigating
GI ENDOSCOPES • Widely used diagnostic and therapeutic procedure (~20 million GI procedures annually in the US) • GI endoscope contamination during use (107-10 in/105 out) • Semicritical items require high-level disinfection minimally • Inappropriate cleaning and disinfection has lead to cross-transmission • In the inanimate environment, although the incidence remains very low, endoscopes represent a significant risk of disease transmission. In fact, more outbreaks of infection associated with endoscopes than any reusable medical device in healthcare.
Transmission of Infection by EndoscopyKovaleva et al. Clin Microbiol Rev 2013. 26:231-254 Based on outbreak data, if eliminated deficiencies associated with cleaning, disinfection, AER , contaminated water and drying would eliminate about 85% of the outbreaks.
Nosocomial Infections via GI Endoscopes • Infections traced to deficient practices • Inadequate cleaning (clean all channels) • Inappropriate/ineffective disinfection (time exposure, perfuse channels, test concentration, ineffective disinfectant, inappropriate disinfectant) • Failure to follow recommended disinfection practices (tapwater rinse) • Flaws and complexity in design of endoscopes or AERs
Recent Outbreaks When Manufacturer’s Instructions and Professional Guidelines Followed • Epstein et al. JAMA 2014;312:1447-1455 (NE IL) • Wendorf et al. ICHE 2015 (Seattle) • At least four other CRE outbreaks related to ERCP • UCLA Ronald Reagan Medical Center • Cedar Sinai Medical Center • Univ of Pittsburgh Medical Center • Wisconsin medical facility
ENDOSCOPE REPROCESSING: CHALLENGESNDM-Producing E. coli Associated ERCPMMWR 2014;62:1051; Epstein et al. JAMA 2014;312:1447-1455 NDM-producing E.coli recovered from elevator channel (elevator channel orients catheters, guide wires and accessories into the endoscope visual field; crevices difficult to access with cleaning brush and may impede effective reprocessing or killing CRE)
Reason for Endoscope-Related OutbreaksRutala WA, Weber WA. Infect Control Hosp Epidemiol 2015, In press • Margin of safety with endoscope reprocessing minimal or non-existent for two reasons: • Microbial load • GI endoscopes contain 107-10 • Cleaning results in 2-6 log10 reduction • High-level disinfection results in 4-6 log10 reduction • Results in a total 6-12 log10 reduction of microbes • Level of contamination after processing: 4 log10 (maximum contamination, minimal cleaning/HLD) • Complexity of endoscope
Reason for Endoscope-Related OutbreaksRutala WA, Weber WA. Infect Control Hosp Epidemiol 2015, In press • Margin of safety with endoscope reprocessing minimal or non-existent • Microbial load • GI endoscopes contain 107-10 • Cleaning results in 2-6 log10 reduction • High-level disinfection results in 4-6 log10 reduction • Results in a total 6-12 log10 reduction of microbes • Level of contamination after processing: 4log10 (maximum contamination, minimal cleaning/HLD) • Complexity of endoscope • Biofilms-unclear if contribute to failure of endoscope reprocessing
BIOFILMS(Multi-layered bacteria plus exopolysaccharides that cement cell to surface; develop in wet environments; if reprocessing performed promptly after use and endoscope dry the opportunity for biofilm formation is minimal)
Reason for Endoscope-Related OutbreaksRutala WA, Weber WA. Infect Control Hosp Epidemiol 2015, In press • Margin of safety with endoscope reprocessing minimal or non-existent for two reasons: • Microbial load • GI endoscopes contain 107-10 • Cleaning results in 2-6 log10 reduction • High-level disinfection results in 4-6 log10 reduction • Results in a total 6-12 log10 reduction of microbes • Level of contamination after processing: 4log10 (maximum contamination, minimal cleaning/HLD • Complexity of endoscope
ENDOSCOPE REPROCESSING: CHALLENGES Surgical instruments-<102 bacteria Complex [elevator channel]-109 bacteria