Airborne particle dispersion around the feet of surgical staff while walking in and out of a bio-clean operating theatre

Does time of intraoperative exposure to the aerobiome increase microbial growth on inflatable penile prostheses?

Inflatable penile prosthesis (IPP) implantation is a surgical approach for the management of erectile dysfunction (ED). A feared complication is IPP infection, and increased operative time is a risk factor for infection. Exposure of an IPP implant to ambient air in the operating room (OR aerobiome) is thought to contribute to risk of infection from increased operative time, but this is not well-supported. The objective of this study was to evaluate if exposure to the OR aerobiome increased microbial colonization of IPPs. This was an ex vivo study using an uncoated IPP, observing standard surgical sterility and OR conditions. A sterile swab was collected every 30 min for 3 h from each IPP component. Positive controls consisted of swabs exposed to unprepped scrotal skin during in-office vasectomies. All swabs underwent quantitative polymerase chain reaction (qPCR) and next generation sequencing (NGS). Bioinformatic processing was carried out and taxonomic assignment was performed. No microbial growth was detected on any component of the IPPs at any time point, while positive control swabs all detected various skin flora, including bacterial and fungal growth. These findings suggest that exposure to the OR aerobiome does not increase the risk of IPP microbial colonization, at least within a 3-hour period. Further in vivo studies are needed.

Time-Dependent Bacterial Contamination of a Surgical Suction Tip

Background: No in vitro surgical study has evaluated the time-dependent contamination of surgical suction tips compared with controls. Our purpose was to determine the difference in suction tip bacterial contamination rates between suction-positive and suction-negative tips. Materials and Methods: A matched-pair analysis of the contamination of surgical suction tips over a six-hour period was performed in two clean operating rooms. One suction tip was connected to standard wall suction (suction-positive group), with a matched control tip not connected to wall suction (suction-negative group). At time zero and then at hourly intervals for six hours, the distal 3 cm of suction tips were removed, placed in nutrient broth for 48 hours, then plate cultured. One hundred tips were collected for each time interval. Results: Eighty-two of 700 (11.7%) suction tips had bacterial contamination. Sixty-three (18.0%) of 350 suction-positive tips were contaminated, with 19 (5.4%) of the 350 suction-negative tips contaminated (χ2 = 26.7, p < 0.001). Suction tip contamination was time-dependent with the first significant difference between groups occurring after two hours of continuous suction (χ2 = 4.0, p = 0.04). Contamination rate in the suction-positive group increased significantly after one hour compared with time-zero controls (χ2 = 7.1, p = 0.008). There was no significant difference in frequency of positive cultures over time in the suction-negative group compared with time-zero controls. Conclusions: This is the first controlled laboratory study suggesting a time-dependent increase in positive suction tip cultures. From our data, operating room staff should have an awareness that suction tips represent a potential source of bacterial concentration. We recommend that when not in use, suction tip valves be closed if this feature is available, that hosing be manipulated to cease suction when not needed, that suckers be disconnected from tubing, or that suckers be exchanged at frequent intervals. Doing so may reduce bacterial contamination on the suction tip.

Enhancing Surgical Safety: Microbiological Air Control in Operating Theatres at University Medical Centre Maribor

BACKGROUND

the aim of the study was to assess microbiological air quality in operating theatres by determining the level of microbiological contamination of the air and critical surfaces using the passive air sampling method and compliance of the operating theatre staff with infection control measures.

MATERIALS AND METHODS

The prospective study was conducted in the surgical block of the University Medical Centre Maribor. For two months continuously, ten operating theatres were assessed for microbial contamination of air and surfaces during quiet and active times of the day. A passive air sampling method with Petri dishes on an agar specially adapted for this purpose (plate count agar) was used. In addition, ten surgical procedures were observed to assess staff compliance with recommended practises.

RESULTS

Air samples met microbiological standards in all operating theatres. In both sampling sessions of the day (quiet and active periods), microbial contamination of the air was always within the limit of 10 CFU/m3. The average number of bacterial colonies was zero to two during quiet phases and one to four during active phases. Approximately 60% of the isolates from the operating theatres belonged mainly to the genus Staphylococcus: S. epidermidis (36% of the isolates), S. hominis (17.5%) and S. haemolyticus (5.5%). The rest were identified as Streptococcus anginosus (23%) and Bacillus sp. (18%). Pathogenic bacteria and moulds were not present. In regard to staff compliance with good surgical practise, the former varied by behaviour and function, with non-compliance in pre-operative skin preparation and operating theatre congestion being notable. The cleanliness of the environment was satisfactory.

CONCLUSIONS

Microbiological air control is extremely important for the safety and success of both surgical and postoperative practises. In spite of good results obtained in the study, further improvements in surgical staff compliance with good surgical practise are essential to reduce surgical site infections.

Effect of far-infrared radiation on inhibition of colonies on packaging during storage of sterilised surgical instruments

The sterilisation of surgical instruments is a major factor in infection control in the operating room (OR). All items used in the OR must be sterile for patient safety. Therefore, the present study evaluated the effect of far-infrared radiation (FIR) on the inhibition of colonies on packaging surface during the long-term storage of sterilised surgical instruments. From September 2021 to July 2022, 68.2% of 85 packages without FIR treatment showed microbial growth after incubation at 35 °C for 30 days and at room temperature for 5 days. A total of 34 bacterial species were identified, with the number of colonies increasing over time. In total, 130 colony-forming units were observed. The main microorganisms detected were Staphylococcus spp. (35%) and Bacillus spp. (21%) , Kocuria marina and Lactobacillus spp. (14%), and mould (5%). No colonies were found in 72 packages treated with FIR in the OR. Even after sterilisation, microbial growth can occur due to movement of the packages by staff, sweeping of floors, lack of high-efficiency particulate air filtration, high humidity, and inadequate hand hygiene. Thus, safe and simple far-infrared devices that allow continuous disinfection for storage spaces, as well as temperature and humidity control, help to reduce microorganisms in the OR.

The safety of a novel single-drape cover for sterile back tables in the operating room compared to the standard two-drape method: an experimental study

BACKGROUND

Covering the prepared sterile back tables (PSBTs) during periods of nonuse and during active surgeries may decrease contamination of sterile surgical instruments that have direct contact to surgical wound. The Association of periOperative Registered Nurses (AORN) declared that an easy method for covering and removing the drape will ultimately be most effective (e.g. standard two-drape method). Hence, this study was designed to test the hypothesis that using a novel single-drape cover had more efficiency and safety in decreasing airborne bacteria-carrying particles (ABCPs) settling on the PSBTs during static and dynamic periods than the standard two-drape method.

METHODS

This experimental study was conducted with using 918 agar plates to detect contamination of the PSBTs with ABCPs on two conditions (static and dynamic) at an academic medical center in Kashan, Iran, from September 25, 2021, to January 20, 2022. The contamination of PSBTs was evaluated by 6 agar settle plates (n = 918 in total) on each PSBT in static and dynamic operating room (OR) conditions. At each time-point, this set-up was repeated on two occasions else during data collection, establishing 81 PSBTs in total. Tested groups included the PSBTs covered with the standard two-drape method, the novel single-drape cover, or no cover. The plates were collected after 15, 30, 45, 60, 120, 180, 240 min and 24 h. The primary outcome measured was comparison of mean bioburden of ABCPs settling on covered PSBTs on two conditions by using agar settle plates. The secondary outcomes measured were to determine the role of covering in decreasing contamination of PSBTs and the estimation of time-dependent surgical instrument contamination in the uncovered PSBTs on two conditions by using agar settle plates.

RESULTS

Covering the PSBTs during static and dynamic OR conditions lead to a significantly decreased bioburden of ABCPs on them (P < 0.05). No differences were seen between the standard two-drape method and the novel single-drape cover (P > 0.05).

CONCLUSIONS

We found that there is no preference for using the novel single-drape cover than the standard two-drape method. Our results showed a significant decrease in bioburden of ABCPs on the PSBTs when those were covered during static and dynamic OR conditions, indicating the efficiency for covering the PSBTs during periods of nonuse and during active surgery.

Effect of Ozone Gas on Removal of Airborne Particles

Objective  Airborne particles are one of the most important factors in the spread of infectious pathogens and must be monitored in healthcare facilities. Viable particles are living microorganisms, whereas non-viable particles do not contain microorganisms but act as transport for viable particles. The effectiveness of ozone in reducing these particles in a non-controlled room and a controlled cleanroom using high-efficiency particles air (HEPA) filter was analyzed in this study.

Materials and Methods  Viable particles and non-viable particles sized 0.5 and 5 μm were quantified before and after ozonation in two different health environments: non-controlled (group 1) and controlled area, which was associated with a HEPA filtering system (group 2). Active air sampling using a MAS 100 was used to count the number of viable particles, while the number of non-viable particles/m ³ was obtained following the manufacturer's recommendations of the Lasair III 310C system.

Results  Our results of the viable particles counting were not quantifiable and analyzed using statistical tests. Both groups showed a slight tendency to reduce the number of viable particles after ozonation of the environmental air. A statistically significant reduction of non-viable 5 μm particles after ozonation was observed in both groups (G1: p  = 0,009; G2: p  = 0,002). Reduction in the non-viable 0.5 μm particles after ozonation was observed only in group 2, associated with the HEPA filter. In group 1, after ozonation, a significant increase in 0.5 μm particles was observed, probably due to the breaking of 5 μm particles by ozone gas. Our results suggest that ozone gas can break 5 μm particles and, when associated with a HEPA filter, increases its effectiveness in removing 0.5 μm particles.

Conclusion  Considering that 5 μm particles are important in the air transport of microorganisms, their reduction in the environment can be a relevant parameter in controlling the dissemination of infections.

Important interventions in the operating room to prevent bacterial contamination and surgical site infections

BACKGROUND

The aim of this study was to explore interventions that Swedish operating room (OR) nurses considered important for the prevention of bacterial contamination and surgical site infections (SSIs).

METHODS

A web-based cross-sectional survey with an open-ended question was answered by OR nurses and analyzed using summative content analysis and descriptive statistics.

RESULTS

The OR nurses (n = 890) worked within 11 surgical specialties and most of them worked at university hospitals (37%) or county hospitals (53%). The nurses described twelve important interventions to prevent bacterial contamination and SSI: skin disinfection (25.9%), the OR environment (18.2%), aseptic technique (16.4%), OR clothes (13.4%), draping (9.8%), preparation (6.1%), dressing (3.6%), basic hygiene (3.4%), normothermia (2.1%), communication (0.7%), knowledge (0.3%), and work strategies (0.2%).

DISCUSSION

Skin disinfection was considered the most important intervention in order to prevent bacterial contamination and SSI. The responses indicated that many OR nurses believed the patients' skin to be sterile after the skin disinfection process. This is not a certainty, but skin disinfection does significantly decrease the amount of bacterial growth.

CONCLUSIONS

This study shows that many OR nurses' interventions are in line with recommendations. Although, knowledge regarding the effect of skin disinfection needs further research, and continued education.

Visualization of Airborne Particles as a Risk for Microbial Contamination in Orthopedic Surgery

Background: The operating theater is recognized to involve a high frequency of occupational blood and body fluid contacts. Objectives: This study aimed to visualize the production of blood and body fluid airborne particles by surgical procedures and to investigate risks of microbial contamination of the conjunctival membranes of surgical staff during orthopedic operations. Methods: Two physicians simulated total knee arthroplasty (TKA) and total hip arthroplasty (THA) in a bio-clean theater using model bones. The generation and behaviors of airborne particles were filmed using a fine particle visualization system, and numbers of airborne particles per 2.83 L of air were counted at the height of the operating and instrument tables. Each action was repeated five times, and particle counts were evaluated statistically. Results: Numerous airborne particles were dispersed to higher and wider areas while "cutting bones in TKA" and "striking and driving the cup component on the pelvic bone in THA" compared to other surgical procedures. The highest particle counts were detected while "cutting bones in TKA" under unidirectional laminar air flow. Discussion: These results provide a clearer image of the dispersion and distribution of airborne particles and identified higher-risk surgical procedures for microbial contamination of the conjunctival membranes. Surgical staff including surgeons, nurses, anesthesiologists, and visitors, should pay attention to and take measures against occupational infection particularly in high-risk surgical situations.

Time-dependent bacterial air contamination of sterile fields in a controlled operating room environment: an experimental intervention study

BACKGROUND

Surgical site infections are a global patient safety concern. Due to lack of evidence on contamination, pre-set surgical goods are sometimes disposed of or re-sterilized, thus increasing costs, resource use, and environmental effects.

AIM

To investigate time-dependent bacterial air contamination of covered and uncovered sterile goods in the operating room.

METHODS

Blood agar plates (N = 1584) were used to detect bacterial air contamination of sterile fields on 48 occasions. Each time, three aerobe and three anaerobe plates were used as baseline to model the preparation time, and 60 (30 aerobe, 30 anaerobe) were used to model the time pending before operation; half of these were covered with sterile drapes and half remained uncovered. Plates were collected after 4, 8, 12, 16, and 24 h.

FINDINGS

Mean time before contamination was 2.8 h (95% confidence interval: 2.1-3.4) in the uncovered group and 3.8 h (3.2-4.4) in the covered group (P = 0.005). The uncovered group had 98 colony-forming units (cfu) versus 20 in the covered group (P = 0.0001). Sixteen different micro-organisms were isolated, the most common being Cutibacterium acnes followed by Micrococcus luteus. Of 32 Staphylococcus cfu, 14 were antibiotic resistant, including one multidrug-resistant Staphylococcus epidermidis.

CONCLUSION

Protecting sterile fields from bacterial air contamination with sterile covers enhances the durability of sterile goods up to 24 h. Prolonged durability of sterile goods might benefit patient safety, since surgical sterile material could be prepared in advance for acute surgery, thereby enhancing quality of care and reducing both climate impact and costs.