Evaluating the effect of Novarerus NV800 air purifier units during orthopaedic surgery to reduce bioburden in the air.

BACKGROUND: A locally installed air purifier unit (Novaerus Protect 800) has been shown to reduce the air bioburden in an intensive care unit and the incidence of healthcare-associated infections. AIM: To explore whether this type of air purifying unit could reduce bacterial concentrations in the air of an operating room (OR) during orthopaedic surgery, thereby reducing the risk of surgical site infections. METHODS: In this prospective experimental study, undertaken in 2018, three air purifying units were installed in an OR in a Swedish hospital in 2018. The air was actively sampled during 11 operations by a slit-to-slit agar impactor with the air purifying units either switched on or switched off. Air movements were visualized with the aid of smoke in mock-up studies. FINDINGS: No significant difference in bacterial concentrations in air was found between the two conditions (air purifying units switched off or on) (P=0.54). Air movements around and above the surgical wound were disordered and resembled those of dilution mixing air. CONCLUSION: The three air purifying units installed in the OR did not reduce the airborne bacterial levels in the critical zone during orthopaedic surgery.

Source strength as a measurement to define the ability of clean air suits to reduce airborne contamination in operating rooms.

BACKGROUND: Surgical site infections after total hip and knee replacement are linked to the quality of the operating room (OR) air. Applying tight occlusive clothing, effective ventilation and correct working methods are key concepts to obtain low bacterial concentrations in the OR air. The dry penetration test referred to in European standard EN 13795-2:2019 is a screening method for materials used in surgical clothing. Source strength, defined as the dispersal of bacteria-carrying particles from persons during activity, is a functional test of clothing systems and has been calculated in a dispersal chamber and in ORs. Results from both tests can be used when comparing surgical clothing systems. AIM: This study relates results of dry penetration tests to source strength values for five surgical clothing systems available on the Swedish market. METHODS: Experimental data are reported on the function of these products, expressed as source strength calculated from results in a dispersal chamber and in ORs during orthopaedic operations. FINDINGS: All materials tested with dry penetration ≤50 colony-forming units (cfu) had source strength values <3 cfu/s for one person in the dispersal chamber, whereas the material of one product when laundered >50 times had source strength in the dispersal chamber of up to 8 cfu/s. CONCLUSION: The dry penetration test could predict the performance of clean air suits of the same design, but more studies are needed to obtain a more valid correlation. Requirements of source strength should be included in standards.

Ventilation design conditions associated with airborne bacteria levels within the wound area during surgical procedures: a systematic review.

BACKGROUND: Without confirmation of the ventilation design conditions (typology and airflow rate), the common practice of identifying unidirectional airflow (UDAF) systems as equivalent to ultra-clean air ventilation systems may be misleading, but also any claims about the ineffectiveness of UDAF systems should be doubted. The aim of this review was to assess and compare ventilation system design conditions for which ultra-clean air (mean <10 cfu/m3) within 50 cm from the wound has been reported. Six medical databases were systematically searched to identify and select studies reporting intraoperative airborne levels expressed as cfu/m3 close to the wound site, and ventilation system design conditions. Available data on confounding factors such as the number of persons present in the operating room, number of door openings, and clothing material were also included. Predictors for achieving mean airborne bacteria levels within <10 cfu/m3 were identified using a penalized multivariate logistic regression model. Twelve studies met the eligibility criteria and were included for analysis. UDAF systems considered had significantly higher air volume flows compared with turbulent ventilation (TV) systems considered. Ultra-clean environments were reported in all UDAF-ventilated (N = 7) rooms compared with four of 11 operating rooms equipped with TV. On multivariate analysis, the total number of air exchange rates (P=0.019; odds ratio (OR) 95% confidence interval (CI): 0.66-0.96) and type of clothing material (P=0.031; OR 95% CI: 0.01-0.71) were significantly associated with achieving mean levels of airborne bacteria <10 cfu/m3. High-volume UDAF systems complying with DIN 1946-4:2008 standards for the airflow rate and ceiling diffuser size unconditionally achieve ultra-clean air close to the wound site. In conclusion, the studied articles demonstrate that high-volume UDAF systems perform as ultra-clean air systems and are superior to TV systems in reducing airborne bacteria levels close to the wound site.

Healthcare workers' perceptions and acceptance of an electronic reminder system for hand hygiene.

BACKGROUND: Healthcare-associated infections (HCAIs) have a large negative impact on morbidity, mortality, and quality of life. Approximately 9% of all patients hospitalized in Sweden suffer from HCAI. Hand hygiene plays a key role and is considered the single most important measure to reduce HCAI. The hospital organization works actively to reduce HCAI. Implementing electronic systems to remind and/or notify healthcare workers raises awareness of and adherence to hand hygiene. However, there is a paucity of studies addressing individuals' perceptions of having such a system and how the organization works. AIM: To investigate healthcare workers' perceptions of infection prevention in the healthcare organization and perceptions and acceptance of an electronic reminder system that encourages good hand hygiene. METHODS: Qualitative descriptive design with data collected in eight focus group interviews including assistant nurses, nurses, and physicians (N = 38). Content analysis was applied and data were related to the Theory of Planned Behaviour. FINDINGS: Healthcare workers perceive lack of feedback from the hospital organization and are positive towards an electronic reminder system to increase adherence to hand hygiene. The electronic reminder system should not register data at an individual level since it could be used as an instrument for control by the management that could be stressful for staff. CONCLUSION: In general, there is positive acceptance of the electronic reminder system, and the respondents perceived it as having the ability to change behaviour. However, the concept has to be further developed to protect the individual's integrity and needs to be used with feedback on a group level.

Ultraclean air systems and the claim that laminar airflow systems fail to prevent deep infections after total joint arthroplasty.

The World Health Organization published guidelines in 2016 for preventing surgical site infections. The guidelines contained a conditional recommendation that laminar airflow (LAF) ventilation systems should not be used to reduce the risk of infection after total joint arthroplasty (TJA). This recommendation was largely based on a systematic review and meta-analysis of information from hospital infection surveillance registries. The recommendation contradicts information published in earlier major studies carried out by Charnley and the UK Medical Research Council (MRC). The first aim of this article is to revisit and explain the MRC study, and reply to criticisms of it. The second aim is to suggest reasons why some recent studies have failed to demonstrate that ultraclean air (UCA) systems reduce deep joint infection after TJA. It demonstrates that if a UCA system establishes average airborne concentrations of microbe-carrying particles (MCPs) <10/m3, and preferably <1/m3, then deep joint infection after TJA will be lower than in conventionally ventilated operating theatres.

Legionellosis acquired through a dental unit: a case study.

In 2012, an elderly immunocompromised man died from legionellosis at a hospital in Uppsala, Sweden. The patient had visited a dental ward at the hospital during the incubation period. Legionella spp. at a concentration of 2000 colony-forming units/L were isolated from the cupfiller outlet providing water for oral rinsing. Isolates from the patient and the dental unit were Legionella pneumophila serogroup 1, subgroup Knoxville and ST9. Pulsed-field gel electrophoresis and whole-genome sequencing strongly suggested that the isolates were of common origin. This report presents one of few documented cases of legionellosis acquired through a dental unit.

Hygienic interventions to decrease deep sternal wound infections following coronary artery bypass grafting.

BACKGROUND: The department of Cardiothoracic Surgery at Uppsala University Hospital has 25 beds in one to four patient rooms and an operating suite consisting of five operating rooms with ultraclean air. Around 700 open heart (250 isolated coronary artery bypass grafting, CABG) operations are performed annually. In 2009, the numbers of deep sternal wound infections (DSWIs) increased to unacceptable rates despite existing hygienic guidelines. AIM: To show how root cause analysis (RCA) followed by quality improvement interventions reduced the rate of DSWI after CABG surgery. METHODS: Only isolated CABG patients requiring surgical revision due to DSWI were included. Swabs and tissue biopsies were taken during surgical revision and analysed with standard methods. DSWIs were registered prospectively according to US Centers for Disease Control and Prevention definitions. RCA for infection was performed between September 2009 and April 2010. Interventions based on results of the RCA and on nationally recommended practices were concluded in April 2010, and thought to have taken full effect by July 1st, 2010. Air was actively sampled at ≤0.5m from the sternal incision. FINDINGS: DSWI incidence rates per CABG operations decreased from 5.1% pre intervention to 0.9% post intervention. Wound cultures pre intervention grew Staphylococcus aureus 27.1% and coagulase negative staphylococcus (CoNS) 47.1%, post intervention S. aureus 23.1% and CoNS 30.8%. Air counts did not exceed 5cfu/m(3). CONCLUSION: When the aetiology of an error is multifactorial, RCA engaging both the medical professions and the infection control team is a potential tool to map causes leading to adverse events such as healthcare-associated infections. A systematic quality improvement intervention based on the RCA may reduce the number of deep sternal wound infections after CABG surgery.

The adenosine triphosphate method as a quality control tool to assess 'cleanliness' of frequently touched hospital surfaces.

BACKGROUND: The adenosine triphosphate (ATP) method is widely accepted as a quality control method to complement visual assessment, in the specifications of requirements, when purchasing cleaning contractors in Swedish hospitals. AIM: To examine whether the amount of biological load, as measured by ATP on frequently touched near-patient surfaces, had been reduced after an intervention; to evaluate the correlation between visual assessment and ATP levels on the same surfaces; to identify aspects of the performance of the ATP method as a tool in evaluating hospital cleanliness. METHODS: A prospective intervention study in three phases was carried out in a medical ward and an intensive care unit (ICU) at a regional hospital in mid-Sweden between 2012 and 2013. Existing cleaning procedures were defined and baseline tests were sampled by visual inspection and ATP measurements of ten frequently touched surfaces in patients' rooms before and after intervention. The intervention consisted of educating nursing staff about the importance of hospital cleaning and direct feedback of ATP levels before and after cleaning. FINDINGS: The mixed model showed a significant decrease in ATP levels after the intervention (P < 0.001). Relative light unit values were lower in the ICU. Cleanliness as judged by visual assessments improved. In the logistic regression analysis, there was a significant association between visual assessments and ATP levels. CONCLUSION: Direct feedback of ATP levels, together with education and introduction of written cleaning protocols, were effective tools to improve cleanliness. Visual assessment correlated with the level of ATP but the correlation was not absolute. The ATP method could serve as an educational tool for staff, but is not enough to assess hospital cleanliness in general as only a limited part of a large area is covered.

Hospital outbreak control requires joint efforts from hospital management, microbiology and infection control.

An outbreak of multidrug-resistant Klebsiella pneumoniae producing the extended-spectrum beta-lactamase CTX-M15 affected 247 mainly elderly patients in more than 30 wards in a 1000-bedded swedish teaching hospital between May 2005 and August 2007. A manual search of the hospital administrative records for possible contacts between cases in wards and outpatient settings revealed a complex chain of transmission. Faecal screening identified twice as many cases as cultures from clinical samples. Transmission occurred by direct and indirect patient-to-patient contact, facilitated by patient overcrowding. Interventions included formation of a steering group with economic power, increased bed numbers, better compliance with alcohol hand disinfection and hospital dress code, better hand hygiene for patients and improved cleaning. The cost of the interventions was estimated to be euro3 million. Special infection control policies were not necessary, but resources were needed to make existing policies possible to follow, and for educational efforts to improve compliance.