A mobile device reducing airborne particulate can improve air quality.

Surgical site infections are the second major cause of hospital acquired infections, accounting for a large part of overall annual medical costs. Airborne particulate is known to be a potential carrier of pathogenic bacteria. We assessed a mobile air particle filter unit for improvement of air quality in an operating room (OR). A new mobile air decontamination and recirculation unit, equipped with a crystalline ultraviolet C (Illuvia® 500 UV) reactor and a HEPA filter, was tested in an OR. Airborne particulate was monitored in four consecutive phases: I) device OFF and OR at rest; II) device OFF and OR in operation; III) device ON and OR in operation; IV) device OFF and OR in operation. We used a particle counter to measure airborne particles of different sizes: ≥0.3, ≥0.5, ≥1, ≥3, ≥5, >10 µm. Activation of the device (phases III) produced a significant reduction (p < 0.05) in airborne particulate of all sizes. Switching the device OFF (phase IV) led to a statistically significant increase (p < 0.05) in the number of particles of most sizes: ≥0.3, ≥0.5, ≥1, ≥3 µm. The device significantly reduced airborne particulate in the OR, improving air quality and possibly lowering the probability of surgical site infections.

Association between air changes and airborne microbial contamination in operating rooms.

BACKGROUND: Control of airborne microbial contamination is important in operating rooms (ORs). To keep airborne contamination low, guidelines should highlight the importance of air turnover. The aims of the study were: (1) to verify the association between air turnover and airborne contamination in ORs; and (2) to identify a statistical relationship between air turnover and airborne microbial contamination. METHODS: A cross sectional study was carried out from November 2014 to July 2017 in the teaching Hospital of Siena. Nineteen ORs (14 with turbulent and 5 with laminar flow ventilation) were surveyed a total of 59 times under operating conditions. Air samples were collected with an air sampler. Petri dishes, incubated at 36 °C for 48 h, were used to quantify colony forming units in the samples (CFU). The data was transformed to evaluate several statistically significant nonlinear associations between air turnover, quantified as air changes per hour (ACH) and CFU per cubic meter of air (p < 0.05). RESULTS: A log-linear regression model provided the best fit between ACH and CFU for laminar (p = 0.013; R2 = 0.3911) and turbulent flow systems (p = 0.002; R2 = 0.3443). The corresponding model was: ln(CFU) = (a - b*ACH), where the regression parameters were estimated at a = 4.02 and b = 0.037 for laminar flow and a = 5.24 and b = 0.067 for turbulent flow. CONCLUSIONS: Italian guidelines indicate microbial load limits of 20 and 180 CFU/m3 for operating rooms with laminar and turbulent flow ventilation, respectively. The model allowed us to evaluate the minimum number of ACHs to keep CFU within these limits. Ad hoc measurements in other environments can be used to calibrate the relationship between ACH and CFU.

A novel approach to stethoscope hygiene: A coat-pocket innovation.

BACKGROUND: The stethoscope is the most widely used instrument in healthcare. Studies have found similar rates of contamination on the stethoscope diaphragm and on physician fingertips after a single examination. Our aim was to test the effectiveness of an innovative portable device for disinfecting stethoscope membranes. METHODS: From November 2016 to May 2017, a cross-sectional study was conducted in four wards of a private clinic: General Ward (GW), Internal Medicine Ward (IMW), Post-Operative Observation Ward (POW) and Permanent Vegetative State Ward (PVSW). Five wearable medical devices, designed to disinfect stethoscope membranes automatically by means of UV-C radiation, were provided to operators. Spot checks were made for microbial counts of stethoscope membranes, classified as treated or otherwise on the basis of whether they were found coupled or otherwise with the devices. The percentage reduction in colony forming units (CFU) was calculated between the two groups. RESULTS: The number of tests of stethoscopes treated with the device was 116 out of 272. Untreated samples had a mean contamination of 132.2 CFU versus 6.9 CFU of treated samples: a 94.8% reduction (95% CI 91.3%-97.7). Highly significant statistical differences in CFU were found between untreated and treated membranes (p < 0.001). In particular, microbial contamination showed a reduction of 88.7% (CI 77.5%-96.05%) in PVSW, 95.9% (CI 88.2%-98.5%) in GW, 84.5% (CI 76.4%-90.5%) in IMW and 95.8% (CI 90.3%-98.1%) in POW. CONCLUSION: The devices proved effective and efficient in reducing the microbial load of stethoscope membranes. Wearing the device on the coat may act as a reminder of the need for hygiene.