scholarly journals Surgical Smoke and Airborne Microbial Contamination in Operating Theatres: Influence of Ventilation and Surgical Phases

Author(s):  
Francesco Romano ◽  
Samanta Milani ◽  
Jan Gustén ◽  
Cesare Maria Joppolo

Air cleanliness is a crucial factor in operating theatres (OTs), where the health of patients and staff must be preserved by controlling air contamination. Particular attention must be paid to ultrafine particles (UFPs) size range, generated for instance by electrosurgical instruments (ESTs). OT contamination is also affected by ventilation systems, medical staff and their gowning system, staff routines, instruments, etc. This comparative study is based on experimental measurements of airborne microbial contamination and UFPs carried out during real ongoing surgeries in two OTs equipped with upward displacement ventilation (UWD) and hybrid ventilation, with unidirectional airflow on the operating table and peripheral mixing (UDAF+Mixing) ventilation systems. Airborne contamination concentration at the exit grilles has been analyzed as function of four different surgical phases normally performed during an operation. Results highlight that airborne contamination is influenced by the activities carried out during the surgical phases. EST usage affects the contamination level more than staff size during operation observed. Colony forming unit (CFU) values in the protected area close to the patient’s wound are influenced more by the type of ventilation system than by surgical phases. CFU values decrease by 18 to 50 times from the UWD system to the hybrid one. The large airflow volumes supply together with high air velocities in OTs equipped with UDAF+Mixing systems guarantee a better and a safer airborne contamination control for patients and medical team in comparison with UWD systems.

Author(s):  
Francesco Romano ◽  
Samanta Milani ◽  
Roberto Ricci ◽  
Cesare Maria Joppolo

In Operating Theatres (OT), the ventilation system plays an important role in controlling airborne contamination and reducing the risks of Surgical Site Infections (SSIs). The air cleanliness is really crucial in this field and different measurements are used in order to characterize the situation in terms of both airborne microbiological pollutants and particle size and concentration. Although the ventilation systems and airborne contamination are strictly linked, different air diffusion schemes (in particular, the Partial Unidirectional Airflow, P-UDAF, and the Mixing Airflow, MAF) and various design parameters are used, and there is still no consensus on real performance and optimum solutions. This study presents measurements procedures and results obtained during Inspection and Periodic Performance Testing (1228 observations) in a large sample of Italian OTs (175 OTs in 31 Italian hospitals) in their operative life (period from 2010 to 2018). The inspections were made after a cleaning procedure, both in “at-rest” conditions and “in operation” state. Inert and microbial contamination data (in air and on surfaces) are analyzed and commented according to four relevant air diffusion schemes and design classes. Related data on Recovery Time (RT) and personnel presence were picked up and are commented. The results confirm that the ventilation systems are able to maintain the targeted performance levels in the OT operative life. However, they attest that significant differences in real OT contamination control capabilities do exist and could be ascribed to various design choices and to different operation and maintenance practices. The study shows and confirms that the air diffusion scheme and the design airflow rate are critical factors. Beside large variations in measurements, the performance values, in terms of control of airborne particle and microbial contamination (in air and on surfaces), for P-UDAF systems are better than those that were assessed for the MAF air diffusion solution. The average performances do increase with increasing airflows, and the results offer a better insight on this relationship leading to some possible optimization.


1997 ◽  
Vol 60 (1) ◽  
pp. 38-42 ◽  
Author(s):  
T. MARJATTA RAHKIO ◽  
HANNU J. KORKEALA

Microbiological contamination of air and carcasses .was studied in four slaughterhouses by using impactor samples taken at the back-splitting and weighing areas and by sampling carcasses with the swabbing method. Air flow was determined by an air-flow detector, and the movement of workers was observed. The air contamination level in the back-splitting areas (2.25 log CFU/100 liters of air) was generally higher than that in the weighing areas (2.03 log CFU/100 liters of air). Associations between the microbiological contamination of air and carcasses with the movements of workers were found. Layout of the slaughtering line was shown to be important in decreasing airborne contamination. Separation of the clean and unclean parts of the line as well as separation of the weighing area from the other clean parts of the line decreased the contamination level. It appears that airborne bacteria have an important role in carcass contamination.


2019 ◽  
Vol 9 (3) ◽  
pp. 272-279
Author(s):  
A. P. Palii ◽  
O. A. Naumenko ◽  
O. I. Shkromada ◽  
L. A. Tarasenko ◽  
K. A. Rodionova ◽  
...  

One of the main reasons of the destabilization of the ecological environment around poultry farms is the widespread use of resource-consuming and environmentally irrational production processes and technological preparation, processing and disposal of poultry waste. Nowadays, cage batteries with a belt removal system are becoming more widespread in the poultry farming. However, the use of such equipment does not guarantee compliance with applicable veterinary and sanitary requirements for the content of harmful gases in the air of the poultry houses and its microbial contamination. This, in turn, has a negative impact on the state of the environment. In addition, the equipment designed for countries with a milder climate than in Ukraine does not support the designed regimes of its individual systems. Therefore, the study of the effect of the accumulation of the litter on the belts of the cage batteries on its humidity, chemical composition and microclimate in the poultry house, from the environmental point of view, remains an urgent problem. On the basis of complex studies, the kinetics of the drying of the litter on the belt conveyors of the cage batteries for keeping laying hens with built-in air ducts and without air ducts in different seasons, as well as the effect of the duration of the accumulation of the litter on the microclimate in the poultry house, microbial contamination and chemical composition of the litter have been studied. The study of the microclimate in the poultry house, depending on the time of accumulation of the litter on the conveyor belts, showed that with the increase in the time of accumulation of excrements in the air, the content of ammonia increased, and after 5 days of accumulation in the cold season its level began to exceed the maximum contamination level (MCL)-15 mg per m3 of the air. The amount of ammonia on the 7th day of the litter accumulation in all poultry houses was 1.8-2.8 times greater (P 0.001) compared to the first day. The amount of carbon dioxide in the air increased by 1.14-2.00 times, but it never exceeded the MCL - 0.25%. When studying the both types of cage batteries, 1.2-2.6 times the maximum contamination level of the air (220 thous. microbic units per m3) was established in the poultry houses. In the case of cage batteries without built-in ducts from the 1st to the 7th day of accumulation, microbial air contamination increased by 1.9 times in the cold season, and by 1.7 times - in the warm season; and on the 7th day it was 579 and 462 thous. microbic units per m3, respectively. When using the cage batteries with built-in ducts, microbial air contamination increased slightly: by 1.7 times in the cold season and 1.4 times in the warm season and on the 7th day it was 535 and 580 thous. units per m3, respectively.


2020 ◽  
Author(s):  
GABRIEL BIRGAND ◽  
Nathan PEIFFER-SMADJA ◽  
Sandra Fournier ◽  
Solen Kerneis ◽  
Francois Xavier Lescure ◽  
...  

Introduction A controversy remains worldwide regarding the transmission routes of SARS-CoV-2 in hospital settings. We reviewed the current evidence on the air contamination with SARS-CoV-2 in hospital settings, and the factors associated to the contamination including the viral load and the particles size. Methods The MEDLINE, Embase, Web of Science databases were systematically interrogated for original English-language articles detailing COVID-19 air contamination in hospital settings between 1 December 2019 and 21 July 2020. This study was conducted in accordance with the PRISMA-ScR guidelines. The positivity rate of SARS-CoV-2 viral RNA and culture were described and compared according to the setting, clinical context, air ventilation system, and distance from patient. The SARS-CoV-2 RNA concentrations in copies per m3 of air were pooled and their distribution were described by hospital areas. Particle sizes and SARS-CoV-2 RNA concentrations in copies or TCID50 per m3 were analysed after categorization of sizes in <1 micrometers, 1-4 micrometers, and >4 micrometers. Results Among 2,034 records identified, 17 articles were included in the review. Overall, 27.5% (68/247) of air sampled from close patients environment were positive for SARS-CoV-2 RNA, without difference according to the setting (ICU: 27/97, 27.8%; non-ICU: 41/150, 27.3%; p=0.93), the distance from patients (<1 meter: 1/64, 1.5%; 1-5 meters: 4/67, 6%; p=0.4). In other areas, the positivity rate was 23.8% (5/21) in toilets, 9.5% (20/221) in clinical areas, 12.4% (15/121) in staff areas, and 34.1% (14/41) in public areas. A total of 78 viral cultures were performed in three studies, and 3 (4%) were positive, all from close patients environment. The median SARS-CoV-2 RNA concentrations varied from 1.103 copies per m3 (IQR: 0.4.103-9.103) in clinical areas to 9.7.103 (5.1.103-14.3.103) in the air of toilets or bathrooms. The protective equipment removal and patients rooms had high concentrations/titre of SARS-CoV-2 with aerosol size distributions that showed peaks in the <1 micrometers region, and staff offices in the >4 micrometers region. Conclusion In hospital, the air near and away from COVID-19 patients is frequently contaminated with SARS-CoV-2 RNA, with however, rare proofs of their viability. High viral loads found in toilet/bathrooms, staff and public hallways suggests to carefully consider these areas.


Author(s):  
Tshokey Tshokey ◽  
Pranitha Somaratne ◽  
Suneth Agampodi

Air contamination in the operating room (OR) is an important contributor for surgical site infections. Air quality should be assessed during microbiological commissioning of new ORs and as required thereafter. Despite many modern methods of sampling air, developing countries mostly depended on conventional methods. This was studied in two ORs of the National Hospital of Sri Lanka (NHSL) with different ventilation system; a conventional ventilation (CV) and a laminar air flow (LAF). Both ORs were sampled simultaneously by two different methods, the settle plate and sampler when empty and during use for a defined time period. Laboratory work was done in the Medical Research Institute. The two methods of sampling showed moderate but highly significant correlation. The OR with CV was significantly more contaminated than LAF when empty as well as during use by both methods. Overall, the difference in contamination was more significant when sampled by the sampler. Differences in contamination in empty and in-use ORs were significant in both ORs, but significance is less in LAF rooms. The consistent and significant correlation between settle plate and sampler showed that the settle plate is an acceptable method. The LAF theatre showed less contamination while empty and during use as expected. Air contamination differences were more significant when sampled with sampler indicating that it is a more sensitive method. Both CV and LAF ORs of the NHSL did not meet the contamination standards for empty theatres but met the standards for in-use indicating that the theatre etiquette was acceptable.


1960 ◽  
Vol 58 (4) ◽  
pp. 449-464 ◽  
Author(s):  
O. M. Lidwell ◽  
R. E. O. Williams

Measurements to assess the performance of the ventilating system have been carried out in a series of twenty six operating theatres using nitrous oxide as a gaseous tracer to simulate the movement of airborne bacterial contamination. In order to prevent local clouds of contamination derived from the activities of the operating-team persisting in the neighbourhood of the operating-site it is desirable that there should be appreciable air movement in the centre of the room. Downward displacement, ‘piston type’, ventilation systems may be an exception to this but the indications for their use are not clear. Other points discussed include the necessity for the limitation of the volume of mechanical exhaust if adequate positive pressure is to be maintained in the theatre and the need to control heat dissipation from sterilizers, autoclaves and other sources.


2021 ◽  
Vol 775 ◽  
pp. 145690
Author(s):  
Marie-Ève Benoit ◽  
Michèle Prévost ◽  
Antonella Succar ◽  
Dominique Charron ◽  
Eric Déziel ◽  
...  

2011 ◽  
Vol 40 (6) ◽  
pp. 1372-1380
Author(s):  
Valéria Maria Nascimento Abreu ◽  
Doralice Pedroso de Paiva ◽  
Paulo Giovanni de Abreu ◽  
Arlei Coldebella

It was evaluated the quality of rice husks or soybean straw as litter substrate and the effect of litter reuse for four consecutive flocks of broiler chickens on populations of darkling beetle and intestinal parasite and as organic fertilizer. The experiment was carried out in four 12 m × 10 m poultry houses, internally divided in 4 boxes/poultry house with 200 birds/pen for four consecutive flocks, each flock with a duration of 42 days and with a 15-day downtime between flocks. The evaluated treatments were two ventilation systems (stationary or oscillating fans) and two litter materials (soybean straw or rice husks). Darkling beetle population was followed by collecting the insects in traps, three traps per box, and endoparasite litter contamination was determined by eggs/oocyst counts per gram of litter. Levels of dry matter, total nitrogen, total phosphorus, potassium, copper, zinc, manganese, iron, organic carbon and pH were evaluated by physical/chemical analyses of samples of the litters in each flock. Overall, litters of broilers used by three flocks meet the minimal legal requirements to be marketed as simple organic fertilizer, regardless to the material used as substrate. Soybean straw presented higher darkling beetle counts in stationary ventilation system as well as in oscillating ventilation system. The probability of rice husks litter present contamination by Eimeria spp oocysts is 18.78 times higher in rice husks than in soybean straw litter when both are submitted to oscillating ventilation, and 1.32 higher when stationary ventilation is used. Litter temperature does not influence significantly levels of contamination by oocysts.


2018 ◽  
Vol 33 (6) ◽  
pp. 602-606
Author(s):  
Roohollah Farhadloo ◽  
Jalil Goodarzi Far ◽  
Mohammad Reza Azadeh ◽  
Saeed Shams ◽  
Mohammad Parvaresh-Masoud

AbstractBackgroundThe contamination of the environment, ambulance equipment, and staff hands consequently are major factors which create nosocomial infections in emergency patients. The contamination of equipment and devices plays an important role in nosocomial infections.ObjectivesThe aim of this study was to determine the effectiveness of a disinfectant on the rate of microbial contamination of ambulances in Qom Emergency Medical Services (EMS), Qom, Iran.MethodsThis is a quasi-experimental study with a before-after design in order to determine microbial contaminations at the rear and front cabin of ambulances, as well as medical equipment being utilized in Qom EMS. Saya sept-HP-2% solution was used for disinfection. Bacteriological standard methods were used to identify the contaminations.ResultsThe contamination rates before and after use of disinfection solution were 52% and eight percent, respectively. Coagulase-negative staphylococci were the most commonly isolated bacterial agent from the equipment (53%). In all equipment, the contamination level has shown a significant reduction after applying disinfectant.Conclusions:In spite of the fact that the rate of infection from ambulance equipment is high, the results showed that the use of the suitable disinfectant had an effective role in the reduction of bacteria.FarhadlooR, Goodarzi FarJ, AzadehMR, ShamsS, Parvaresh-MasoudM.Evaluation of bacterial contamination on prehospital ambulances before and after disinfection. Prehosp Disaster Med. 2018;33(6):602–606.


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