Ultraclean Air Research Articles

Operating Room Air May Harbor Pathogens: The Role of an Ultraviolet Air Filtration Unit

BackgroundOne important factor for the prevention of surgical site infections is ultraclean air in the operating room (OR). Still, the direct sterilization potential of most technologies, especially in a dynamic clinical setting, is not well understood. We aimed to determine and compare the microbial presence from the inlet and outlet flow of a filtration unit with crystalline ultraviolet-C (C-UVC) light. MethodsA prospective study was conducted at a single institution, where primary total joint arthroplasty and spine surgeries were performed. The OR was fitted with a positive ventilation system. In addition, a filtration unit with a C-UVC sterilizing light was placed in the OR. The inlet and outlet air flows were swabbed simultaneously and compared. Swabs were processed for culture and next-generation sequencing. ResultsThe mean length of the surgical procedures sampled was 68 ± 13 minutes. Overall, 19 out of 200 (9.5%) swabs isolated microorganisms. Inlet air swabs were positive at a higher rate (16 versus 3%; P < .01) compared to the outlet air swabs. A wide variety of Gram-positive, Gram-negative, and anaerobic bacteria were isolated, but fungi were only recovered from inlet air swabs. The detection of microorganisms was also higher when more door openings were performed (32.5 ± 7.1 versus 27.9 ± 5.6; P < .01). ConclusionsAir swabs mainly isolated microorganisms from the inlet flow to the filtration unit with a C-UVC light. The sterilizing unit counteracted factors affecting the air quality in the OR, namely door openings, surgical personnel, and tissue combustion.

Analysis of the airflow features and ventilation efficiency of an Ultra-Clean-Air operating theatre by qDNS simulations and experimental validation

Ultra-Clean-Air (UCA) operating theatres aim to minimise surgical instrument contamination and wound infection through high flow rates of ultra-clean air, reducing the presence of Microbe Carrying Particles (MCPs). This study investigates the airflow patterns and ventilation characteristics of a UCA operating theatre (OT) under standard ventilation system operating conditions, considering both empty and partially occupied scenarios. Utilising a precise computational model, quasi-Direct Numerical Simulations (qDNS) were conducted to delineate flow velocity profiles, energy spectra, distributions of turbulent kinetic energy, energy dissipation rate, local Kolmogorov scales, and pressure-based coherent structures. These results were also complemented by a tracer gas decay analysis following ASHRAE standard guidelines. Simulations showed that contrary to the intended laminar regime, the OT’s geometry inherently fosters a predominantly turbulent airflow, sustained until evacuation through the exhaust vents, and facilitating recirculation zones irrespective of occupancy level. Notably, the occupied scenario demonstrated superior ventilation efficiency, a phenomenon attributed to enhanced kinetic energy induced by the additional obstructions. The findings underscore the critical role of UCA-OT design in mitigating MCP dissemination, highlighting the potential to augment the design to optimise airflow across a broader theatre spectrum, thereby diminishing recirculation zones and consequently reducing the propensity for Surgical Site Infections (SSIs). The study advocates for design refinements to harness the turbulent dynamics beneficially, steering towards a safer surgical environment.

Capital and operational expenditures of different operating room air-handling installations with conventional or ultra-clean air supply systems

When making a decision on the operating room air handling installation and type of air supply system, it is relevant to know the expenditures of the different air handling installations and air supply systems. The aim of this study was to determine the capital and operational expenditures of air handling installations equipped with an ultra-clean or with a conventional system. To compare the technical requirements of Dutch air handling installations with European standards and guidelines, and evaluate the costs of surgical site infections in comparison with the capital expenditures. This study fills a gap in knowledge, detailed technical information and costs of air handling installations and air supply systems from multiple completed projects of 24 hospitals were collected, analyzed and compared. Per OR capital expenditures increase by €62,491 to €139,018 when an air handling installation with an ultra-clean system is compared to a conventional system, which is 3%–7% of the total construction costs of a completely new OR department. The yearly increase in operational expenditures per OR with an ultra-clean system compared to a conventional system was €673 to €1,896. The capital and operational expenditures of air handling installations with an ultra-clean system are higher than those with a conventional system. The technical specifications of the ORs studied in the Netherlands correspond to European standards and guidelines. When the impact on patient suffering and costs associated with surgical site infections are weighed against the investment required for an air handling installation with an ultra-clean system, it is worth considering.

WHEN SHOULD A DEEP INFECTION IN TOTAL HIP ARTHROPLASTY BE CLASSIFIED AS THEATRE-ACQUIRED? NEW INSIGHTS FROM OLD DATA

The documentation of deep infection rates in joint replacement is fraught with multiple difficulties. Deep infections acquired in theatre may present late, but some later presenting deep infections are clearly haematogenous, and not related to surgical management. The effect of Ultra Clean Air on infection rates was published by Charnley in 1972 (CORR,87:167–187). The data is valuable because large numbers of THRs were performed in standard and Ultra Clean theatres, and detailed microbiology of the air was also recorded. No IV antibiotics were used, so only the effect of air quality was studied.We extracted the data on theatre type and numbers from Table 3, and numbers and intervals from surgery of deep infections from Table 7. Theatre types with 300 air changes per hour and 3.5 CFU/M3 were classified as Ultra Clean. A logistic regression model was used to examine the effect of theatre type and time elapsed after procedure on the probability of becoming infected.The model suggests that, controlling for time period, Ultra Clean Air is associated with a significantly lower probability of infection, with an OR of 0.30, p = 2.74 × 10−6. The effect is larger earlier post-surgery, but it does persist. The results are best reviewed as a graphic, which shows that Ultra Clean Air clearly affects the deep infection rate for up to four years post-surgery.Ultra Clean Air reduces infection rates for up to four years post-surgery, so it is safe to assume that infections presenting after this are haematogenous. Ultra Clean Air does not eliminate early deep infection, so some early infections are not related to air quality. It is not practical to undertake widespread detailed retrospective analyses of cases. When monitoring infection rates there needs to be a balance between failing to record infections related to surgical technique and waiting many years to record low numbers of very late presenting problems. We suggest that registries should regard infections documented within three years of surgery as treatment complications.For any figures or tables, please contact the authors directly.

Effect of forced-air warming blankets on indoor air quality in unidirectional flow operating theatres

Perioperative hypothermia increases the likelihood that a patient will get a surgical site infection, which is one of the biggest public health problems. Controversy exists regarding the effect of forced-air warming systems on the disruption of unidirectional discharge of ultra-clean air in operating theaters. However, researchers agree that thermal blankets are indeed useful to prevent hypothermia. This work aims to analyze the effect of a forced-air warming blanket on the indoor air quality in the surgical field of a high-performance operating theater as a function of the supply velocity employing Computational Fluid Dynamics. An operating theater, its facilities, medical staff, and patient covered with a drape were modeled. Ten cases with driving speeds between 0.20 and 0.40 m/s at 0.05 m/s intervals, with thermal blankets ON and OFF, were simulated. Both air renewal and particle dispersion results in the breathing zone were analyzed. The results show that the use of thermal blankets to avoid patient hypothermia is acceptable at discharge velocities of 0.30 m/s because both the decontamination kinetics and air renewal are improved by 45.6% and 37.6%, respectively. Unfavorable results were obtained for the rest of the case studies with different supply velocities.

Observational study of sterile field bioburden levels during orthopedic arthroplasty surgery in operating rooms complying with current United States ventilation specifications

Airborne contamination from microbe carrying particles (MCPs) is a risk factor for devastating early onset periprosthetic joint infection(PJIs). There are no published guidelines to quantify this risk factor for PJI events. This observational cohort project addresses this gap and utilizes a simple passive system to produce quantitative data from 80 total joint replacement cases performed in operating rooms built to current USA standards. A petri dish-based system inspired by industrial cleanroom technology was deployed. Surgical helmet systems (SHSs) and strict protocols were used in all cases. 450 MCPs/m2 was used as a cutoff for bioburden. This benchmark corresponds to the ultraclean air standard of 10 MCPs/m3. 75/80 cases (94%) achieved desired benchmark levels of bioburden at the wound zone compared to only 52/80 (65%) of back table zones. No surgical site infections (SSI) or PJI events (0/80; 95% CI, 0.00-3.68%) at minimum 18-month (average 25.8 months) follow-up were detected. The current USA ventilation design uses low velocity airflow and appears to achieve ultraclean air conditions at the surgical site but requires SHSs and strict protocols. Higher contamination levels seen in back tables are consistent with this design. This settle plate system may be useful for early onset PJI event investigations and thus lower the incidence of these complications.

Changes in orthopaedic operating theatre practice, monitored using settle plates.

The importance of ultraclean air in reducing deep infection was studied by Charnley who showed that the rate decreased as the airborne bacterial load was reduced. The effectiveness was shown in a large Medical Research Council (MRC) trial, but registry data have not shown a consistent benefit. Because we treat patients with rheumatoid arthritis, we decided to look at our theatre air quality. In phase 1 we monitored air quality using settle plates, exposed for one hour after the incision, on the instrument trolleys in a joint replacement theatre. In phase 1 the scrub person did not wear a body exhaust system. In phase 2 all three staff used a body exhaust system, and we played close attention to the orientation and position of the surgical lights and trolleys. In phase 1 we grew 0.24 colonies/plate/hour in the ultraclean zone, which is comparable to the Charnley trial findings. In the second phase we grew 0.03 colonies/plate/hour (p<0.001). When plates were placed on the trolleys in controlled positions there was a tendency for the colonies to appear on the corners of the trolleys at the edge of the clean zone (NS). The study showed that in phase 1 colony counts comparable to the original Charnley studies were achieved. Colony counts of 0.03 colonies/plate/hour can be achieved in contemporary practice, with all team members using body exhausts.

Can clothing systems and human activity in operating rooms with mixed flow ventilation systems help achieve the ultraclean air requirement (≤10 CFU/m3) during orthopaedic surgeries?

The level of airborne microbial contamination in operating rooms (ORs) is an important indicator of indoor air quality and ensures a clean surgical environment. The main objective of this study was to clarify the possibility of achieving the requirement for an ultraclean operating room (≤ 10 CFU/m3) with mixed flow ventilation based on clothing and human activity. Experimental measurements during mock surgeries were conducted in an actual OR with mixed flow ventilation in the Emergency, Heart and Lung Centre at St. Olavs Hospital in Trondheim. The bacterial concentration close to the surgical site was measured during five mock-up surgeries. All five mock-up surgeries followed real surgical procedures which could represent similar conditions in the OR. The experiment results verified that the average CFU/m3 of three of the five mock-up surgeries was 8.5, which was below or equal to the ultraclean requirement, while the other two mock-up surgeries did not meet the ultraclean requirement. Surgical activity together with the type of clothing worn by surgical staff in ORs seem to be the most significant reason for the high CFU level during surgery. It is possible to achieve the ultraclean air requirement (≤ 10 CFU/m3) during a surgical process with proper clothing and low surgical activity in ORs. This study clarifies the effect of clothing and human activity on the CFU level in the surgical micro-environment in ORs, and contributes to developing new products for the surgical team.

Laminar airflow decreases microbial air contamination compared with turbulent ventilated operating theatres during live total joint arthroplasty: a nationwide survey

Preventing surgical site infections and prosthetic joint infections is crucial for patient safety after total joint arthroplasty. Microbial air contamination has been suggested as a risk factor. Therefore, the ventilation system that will reduce air contamination most effectively in operating theatres (OTs) has been discussed. To determine whether laminar airflow (LAF) ventilation is superior to turbulent airflow (TAF) ventilation by looking at the colony forming units (cfu) count during live total hip and knee arthroplasties. Furthermore, to explore whether the number of OT personnel, door and cabinet lock openings and technical parameters of the ventilation systems have an impact on the number of cfu. Active air sampling and passive sedimented bacterial load were performed in 17 OTs, equipped with either LAF or TAF ventilation, during 51 live surgeries while observations were noted. LAF OTs reduced cfu counts compared with TAF OTs during live surgery (P<0.001). All LAF OTs provided ultraclean air whereas TAF had nine procedures exceeding the threshold of 10 cfu/m3. Door and cabinet lock openings and number of personnel did not influence the cfu count, while it decreased with increasing volume and total air change per hour (P<0.05). All LAF OTs had cfu counts within recommendations and provided lower cfu counts compared with TAF OTs. The number of OT personnel and total openings did not have an influence on cfu counts. Increased volume of the OT and total air change per hour showed a decrease in active cfu counts.

Use of an ultra-clean air flow for surgical field asepsis when performing intravitreous injections in an ambulatory surgical environment

BackgroundIntravitreal injection of medications is one of the most common procedures performed in ophthalmology. Intravitreal anti-VEGF agents are currently the chosen treatment for ocular fundus diseases, including age-related macular degeneration and diabetic retinopathy. As an invasive procedure it involves risks. The most serious complication from intravitreal injection of anti-VEGF agents is endophthalmitis (EO). Although rare, EO can result in devastating loss of vision. This article evaluates whether the use of an ultra-clean air flow (UA) can be another useful tool in the prevention of EOs. Accordingly, the maintenance of asepsis of the surgical field of intravitreal injections was verified with and without the use of UA.MethodsThe study was conducted in operating room of an ambulatory surgery center on four different surgical days when just intravitreal injections were scheduled. Two experiments using two Blood Agar and two Chocolate Agar plates (first 2 days; 4 plates by day) were carried out by positioning an UA directed to the surgical table and two other experiments (last 2 days; 4 plates per day) were carried out using similar plates without the use of the UA. All Blood Agar and four Chocolate Agar plates were positioned on the surgical table, close to the surgical filed. At the end of the day, after the conclusion of the intravitreous injections, the plates were sent for a biomolecular study that was carried out after 1 day of incubation at 37 °C.ResultsThe sixteen plates, eight Blood Agar and eight Chocolate Agar, were analyzed qualitatively for the growth or not of microorganism’s colonies and identification of their species. The biomolecular study demonstrated the growth of bacteria of the genus Micrococcus sp. with the use of the UA and without the the UA bacterias of the genera Bacillus sp, Staphylococcus haemolyticus, Staphylococcus aureus and Staphylococcus cohnii ssp urealyticus were found.ConclusionThe use of UA close to the operating table prevented the growth of pathogenic bacteria and should be considered as an alternative tool to avoid the contamination of materials and drugs used for intravitreal injections.

Úloha ultra čistého vzduchu v prevencii infekcií operačných rán

Úloha ultra čistého vzduchu v prevencii infekcií operačných rán

Influence of air velocity on indoor environment quality in unidirectional flow operating theatres: A study based on Computational Fluid Dynamics

It is necessary to characterise air-conditioning airflow in omanuscriprder to optimize hospital Indoor Environment Quality in high-performance operating theatres, and also reduce the risk of nosocomial infection due to pathogen contamination. The aim of this article is to study the prevalence of optimal healthy conditions from controlled air flow quality in hospital facilities, and to minimize energy consumption. To this purpose, the indoor air movement was modelled by Computational Fluid Dynamics technology. The optimal results showed that it is necessary to drive ultra-clean air ranging between 0.25 m/s and 0.40 m/s, values which are adequate to perform efficient sweeping and cleaning of the air near the patient, maintaining unidirectional air flow permanently as the air passes through the surgical field. These speeds must be taken into account as calculation parameters in new hospital facility projects, and as control parameters for the existing operating theatres.

The effectiveness of ultra-clean air operating theatres in the prevention of deep infection in joint arthroplasty surgery.

Deep infection was identified as a serious complication in the earliest days of total hip arthroplasty. It was identified that airborne contamination in conventional operating theatres was the major contributing factor. As progress was made in improving the engineering of operating theatres, airborne contamination was reduced. Detailed studies were carried out relating airborne contamination to deep infection rates. In a trial conducted by the United Kingdom Medical Research Council (MRC), it was found that the use of ultra-clean air (UCA) operating theatres was associated with a significant reduction in deep infection rates. Deep infection rates were further reduced by the use of a body exhaust system. The MRC trial also included a detailed microbiology study, which confirmed the relationship between airborne contamination and deep infection rates. Recent observational evidence from joint registries has shown that in contemporary practice, infection rates remain a problem, and may be getting worse. Registry observations have also called into question the value of "laminar flow" operating theatres. Observational evidence from joint registries provides very limited evidence on the efficacy of UCA operating theatres. Although there have been some changes in surgical practice in recent years, the conclusions of the MRC trial remain valid, and the use of UCA is essential in preventing deep infection. There is evidence that if UCA operating theatres are not used correctly, they may have poor microbiological performance. Current UCA operating theatres have limitations, and further research is required to update them and improve their microbiological performance in contemporary practice. Cite this article: Bone Joint J 2018;100-B:1264-9.

A Clinical Test to Measure Airborne Microbial Contamination on the Sterile Field During Total Joint Replacement: Method, Reference Values, and Pilot Study.

Background:Airborne microbe-carrying particles in the operating-room environment during total joint replacement are a risk factor for periprosthetic joint infection. The present study focuses on a simple environmental test, based on practices used in aseptic cleanrooms, to quantify the deposition of microbe-carrying particles onto the sterile field.Methods:Settle plates are exposed Petri dishes. A settle plate test system and sampling plan were developed from current practices used in aseptic manufacturing. A pilot study evaluated this system in an orthopaedic operating room during 22 total knee and hip arthroplasties. The microbial deposition total (MDT), expressed in colonies/m2, is proposed as an outcome variable to report airborne sterile-field contamination as measured with settle plates. Two reference MDT levels were developed: (1) an upper limit of 450, corresponding with the ultraclean air definition of 10 colonies/m3, and (2) a target level of 100, corresponding with 1 colony/m3. These levels also correspond with widely used limits in aseptic cleanrooms and controlled environments.Results:High MDT standard deviations were noted. Ninety-one percent (95% confidence interval, 71.0% to 98.7%) of wound zone MDT levels were within the upper limit. Twenty-seven percent (95% confidence interval, 12.9% to 48.4%) of wound zone levels were within the target level.Conclusions:Settle plates are a feasible technique to test environmental levels of microbe-carrying particles on sterile fields during total joint replacement for scientific and environmental quality studies.Clinical Relevance:This settle plate operating-room environmental test can be used in future research to validate the presence of actual ultraclean-air conditions during periprosthetic joint infection outcome studies. Surgeons also can use this test to measure intraoperative airborne microbe-carrying-particle sterile-field contamination and compare it with ultraclean-air reference levels for environmental quality-control programs.

P038] Reduction of patient radiation dose, excellent image quality and good air cleanliness in a hybrid cardiac catheterization laboratory: A paradox?

Purpose Nowadays borders between cardiac surgery and interventional cardiology are fading and more hybrid procedures are being performed. A hybrid cardiac catheterization lab (hCCL) is needed combining optimal image quality, reduction of patient radiation dose and ultra clean air. The practical standard for a high-tech OR has been the laminar flow (LAF) principle. In a hCCL, a complete C-arm is attached to the ceiling together with multiple other ceiling mounts. LAF works as designed only when there is no or very low disturbance of the air streamlines, which is not the case in most procedures. Moreover the air cleanliness is only guaranteed in the area beneath the plenum. In practice instrumentation tables are placed outside the plenum. The purpose of this work was to compare the air cleanliness of LAF with a novel technique of smart controlled- dilution flow (SCDF) for a state-of-the art hCCL. Methods The complete deployment for a TAVI (Transcatheter Aortic Valve Implantation) procedure including personnel, devices and a state-of-the-art new monoplane imaging system was modelled in the new room. This complex procedure was analysed by Computational fluid dynamics (CFD) simulations. A set of steady state 3D analyses with particle tracking were executed, the focus being on cleanliness in three critical zones (wound area and two instrumentation tables). Results The C-arm is blocking the LAF causing air to stagnate and even create turbulences underneath the obstacle. Contaminations are not pushed away, so there is no cleaning effect of the LAF. Moreover critical areas outside the central area are not protected. In the critical zones LAF is not capable of producing ultra clean ( Conclusions All challenges of patient safety must be examined when designing and building a new hCCL. One should rethink the applicability of LAF in a hCCL with large obstacles and need for clean conditions in different areas of the room. CFD calculation is necessary. SCDF technology gives good air quality even in complex hCCL with multiple critical zones.

Effect of mobile laminar airflow units on airborne bacterial contamination during neurosurgical procedures

Surgical site infections (SSIs) after neurosurgery are potentially life-threatening and entail great costs. SSIs may occur from airborne bacteria in the operating room, and ultraclean air is desired during infection-prone cleaning procedures. Door openings and the number of persons present in the operating room affect the air quality. Mobile laminar airflow (MLAF) units, with horizontal laminar airflow, have previously been shown to reduce airborne bacterial contamination. To assess the effect of MLAF units on airborne bacterial contamination during neurosurgical procedures. In a quasi-experimental design, bacteria-carrying particles (colony-forming units: cfu) during neurosurgical procedures were measured with active air-sampling in operating rooms with conventional turbulent ventilation, and with additional MLAF units. The MLAF units were shifted between operating rooms monthly. Colony-forming unit count and bacterial species detection were conducted after incubation. Data was collected for a period of 18 months. A total of 233 samples were collected during 45 neurosurgical procedures. The use of MLAF units significantly reduced the numbers of cfu in the surgical site area (P<0.001) and above the instrument table (P<0.001). Logistic regression showed that the only significant predictor affecting cfu count was the use of MLAF units (odds ratio: 41.6; 95% confidence interval: 11.3-152.8; P<0.001). The most frequently detected bacteria were coagulase-negative staphylococci. MLAF successfully reduces cfu during neurosurgery to ultraclean air levels. MLAF units are valuable when the main operating room ventilation system is unable to produce ultraclean air in infection-prone clean neurosurgery.

Impact of surgical lights on the velocity distribution and airborne contamination level in an operating room with laminar airflow system

The presence of surgical lights disturbs the flow of ultraclean air in operating rooms (ORs) with vertical laminar airflow systems (LAF) by creating a wake downstream of the lights. The wake may be characterised by velocities low enough to directly influence the level of airborne microbe-carrying particles (MCP) close to the surgical site in an OR, eventually leading to surgical site infections (SSIs). The influence of surgical lights on airflow distribution during non-operating conditions and on airborne contamination level close to the operating table during mock surgeries was analysed in ORs with vertical LAF systems. The velocity and turbulence intensity (TI) distributions were recorded through a cross-sectional grid of points under surgical lights during non-operating conditions. In order to detect microbiological contamination during operating conditions, four mock surgeries were performed mimicking real surgeries on a porcine tissue. Three of the surgeries were performed under different types of surgical lights and one surgery did not include surgical lights at all. The mean velocity under all three surgical lights was significantly lower (≤0.07 m/s) compared with the mean velocity measured when the LAF was not obstructed by lights (0.24 m/s). At several points in the grid under all three lights, velocities as low as ≤0.02 m/s were measured. Air sampling during mock surgeries recorded at least 1 CFU/m3 for 43% of the samples (n = 16; mean = 1.25; range 0–4) using surgical lights, while not a single bacteria count was recorded without the use of lights (n = 7).

Comprehensive review and study of the buoyant air flow within positive-pressure hospital operating rooms

ABSTRACTA comprehensive investigation is provided on the flow of air within a positive-pressure operating room during a simulated surgery. The simulated surgery made use of an over-body patient-warming blanket whose purpose is to maintain patient temperatures. One issue to be studied was whether a forced-air patient-warming unit with the blanket caused airflow disturbances at the surgical site that would otherwise not occur without the blanket. In the study, measurements from an operating room, including dimensions, flowrates, temperatures, and the positions of potential flow blockages were taken. Airflow simulated using the large-eddy simulation method showed that at no time, and under no conditions did the device cause potentially unclean air to intrude into the sterile surgical field during the operation of the warming device. In addition, a series of flow-visualization experiments made with neutrally buoyant tracers showed the surgical site was washed by ultraclean air from the ventilation system of the operating room regardless of whether the patient-warming device was being used. A comparison of the numerical simulations and experiments showed a near perfect match in temperature measurements and flow patterns. The mutually reinforcing simulations and experiments lend added credibility to the results.

Transmission of Mycobacterium chimaera from Heater-Cooler Units during Cardiac Surgery despite an Ultraclean Air Ventilation System.

Heater-cooler units (HCUs) were recently identified as a source of Mycobacterium chimaera causing surgical site infections. We investigated transmission of this bacterium from HCUs to the surgical field by using a thermic anemometer and particle counter, videotape of an operating room equipped with an ultraclean laminar airflow ventilation system, and bacterial culture sedimentation plates in a nonventilated room. Smoke from the HCU reached the surgical field in 23 s by merging with ultraclean air. The HCU produced on average 5.2, 139, and 14.8 particles/min in the surgical field at positions Off, On/oriented toward, and On/oriented away, respectively. Culture plates were positive for M. chimaera <5 m from the HCU in the test room. These experiments confirm airborne transmission of M. chimaera aerosols from a contaminated HCU to an open surgical field despite ultraclean air ventilation. Efforts to mitigate infectious risks during surgery should consider contamination from water sources and airflow-generating devices.

Reducing bacterial contamination in an Orthopedic Theatre ventilated by natural ventilation, in a Developing Country.

All surgical procedures have the potential for infection and some of the main sources are contamination from airborne particles, theatre personnel and the theatre environment. There is strong evidence that the use of ultra-clean air flow systems in orthopedic operating theatres reduces the incidence of deep sepsis after surgery. In the developing world however, this is often an unrealistic solution. The aim of this study was to establish baseline levels of contamination in a working orthopedic theatre, at the Queen Elizabeth Central Hospital, Blantyre, Malawi. To feedback results to the theatre team, promote infection prevention discussion and work with the team to implement workable and realistic goals to improve the intra-operative environment. Samples were collected from theatre equipment available at the time of surgery, from theatre water and theatre air using passive air sampling techniques. Samples were immediately transferred to the Central Microbiology Laboratory for culture on basic culture media. Bacterial contamination of theatre equipment, intra-operative theatre air and water was detected. Results were discussed with the theatre and infection prevention team who were receptive to feedback with regards to infection prevention strategies and keen to develop simple measures which could be put in place to change practice. In this setting, we suggest that implementing workable and realistic goals such as, establishing baseline rates of bacterial contamination and introduction of strict protocols for asepsis and theatre etiquette, may reduce bacterial contamination rates and subsequent intra-operative infection in the absence of expensive engineering solutions.