General Assembly, Prevention, Operating Room - Personnel: Proceedings of International Consensus on Orthopedic Infections

Do Ultraviolet Air Disinfection Units Reduce Contamination by Particulates in Total Knee Replacement Procedures?

BACKGROUND

Prosthetic joint infections have become the leading cause of joint replacement failure. The primary sources of contamination are skin flora and bacteria from airborne particles. Portable ultraviolet air disinfection units are used in the Operating Room (OR) to prevent contamination from airborne particles; however, their effectiveness is not proven. The purpose of this study was to compare the rate of contamination of sites with and without Ultraviolet (UV) air disinfection units during active surgeries.

METHODS

Sedimentation rates of viable particles were measured during 40 primary TKA procedures. Half of the procedures were performed with ultraviolet air disinfection units. Air-borne particles were collected on nitrocellulose membranes at 5 locations within the OR. After incubation, all microbial colonies were counted and the sedimentation rates were reported in CFUs/m²/hr. 10 additional trials were performed in an empty OR with no staff present.

RESULTS

The average contamination rate of all sites was 22 ± 1.1 CFUs/m²/hr in the empty OR vs. 21.3 ± 4.6 CFUs/m²/hr with UV units and 20.3 ± 4.9 CFUs/m²/hr without (P = .03, P = .03, P = .964). Viable contaminates were found in the sterile field in 25% of UV cases vs 45% non-UV. These differences were not statistically significant. There were differences found however, according to the number of staff in the room (6 vs 7 staff: P = .036, 6 vs 8 staff: P = .004).

CONCLUSION

There was no statistical difference in contamination rate with the usage or non-usage of UV units. These 40 cases shows that the largest variables affecting the contamination rate were the number of staff present and size of the OR.

An in vitro model of microbial contamination in the operating room

Infection associated with tissue-contacting biomedical devices is a compelling clinical problem initiated by the microbial colonization of the device surface. Among the possible sources of contaminating bacteria is the operating room (OR) itself, where viable bacteria in the atmosphere can sediment onto a device surface intraoperatively. We have developed an aerosolizing system that can reproducibly spray small quantities of aerosolized bacteria onto a surface to mimic OR contamination. This paper describes the design of the system and characterizes key aspects associated with its operation. The area density of sprayed bacteria is on the order of 10² /cm² . Using titanium (Ti) alloy coupons as test substrates contaminated by staphylococci, we quantify the fraction of bacteria that are well adhered to the substrate, those that can be removed by sonication, and those that are not recovered after spraying. Despite the relatively low levels of surface contamination, we furthermore show that such a model is able to demonstrate a statistically significant reduction in colonization of Ti coupons modified by antimicrobial quaternary ammonium compounds relative to unmodified controls.

The Effect of Operating Room Size on Orthopaedic Surgical Site Infection Rates

OBJECTIVE

With many preventable causes of surgical site infections (SSIs) identified, the effect of operating room (OR) size on SSI rates has not been assessed. This study investigated the effect of OR size on incidence of SSIs for orthopaedic procedures.

BACKGROUND

SSIs remain a common complication within the perioperative realm. Responsible for increasing length of hospitalization and costs, SSIs result in a decreased quality of life for patients.

METHODS

A retrospective review of 11,163 patients who underwent orthopaedic surgery-including total knee and hip arthroplasties, laminectomies, and spinal fusions-between January 2018 and January 2020 were reviewed. Total net square footage (NSF) of all ORs was recorded, and incidence of SSIs was calculated. Cases were categorized based on the size of the OR (small: 250 to 399 NSF; medium: 400 to 549 NSF; and large: 550 to 699 NSF). Chi-square analysis compared infection rates between the different OR sizes, and a binary logistic regression model identified other predictors of infection.

RESULTS

Overall, 137 patients (1.2%) developed an SSI. Of these infections, 16 (11.7%) occurred in small ORs, 83 (60.6%) in medium ORs, and 38 (27.7%) in large ORs. The incidence of SSIs was 0.7% in small ORs, 1.3% in medium ORs, and 1.8% in large ORs. Factors found to significantly impact SSI's included medium-sized ORs, younger patients, procedure type (fusions and emergencies/traumas), longer procedures, and higher American Society of Anesthesiologists scores (>3).

CONCLUSION

Our study shows that OR size in addition to various other perioperative parameters plays a role in the rate of SSIs for orthopaedic procedures.

LEVEL OF EVIDENCE

Retrospective Cohort Study; Level III Evidence.

Prevention of Prosthetic Joint Infection: From Traditional Approaches towards Quality Improvement and Data Mining

A projected increased use of total joint arthroplasties will naturally result in a related increase in the number of prosthetic joint infections (PJIs). Suppression of the local peri-implant immune response counters efforts to eradicate bacteria, allowing the formation of biofilms and compromising preventive measures taken in the operating room. For these reasons, the prevention of PJI should focus concurrently on the following targets: (i) identifying at-risk patients; (ii) reducing “bacterial load” perioperatively; (iii) creating an antibacterial/antibiofilm environment at the site of surgery; and (iv) stimulating the local immune response. Despite considerable recent progress made in experimental and clinical research, a large discrepancy persists between proposed and clinically implemented preventative strategies. The ultimate anti-infective strategy lies in an optimal combination of all preventative approaches into a single “clinical pack”, applied rigorously in all settings involving prosthetic joint implantation. In addition, “anti-infective” implants might be a choice in patients who have an increased risk for PJI. However, further progress in the prevention of PJI is not imaginable without a close commitment to using quality improvement tools in combination with continual data mining, reflecting the efficacy of the preventative strategy in a particular clinical setting.

Intraoperative and Postoperative Infection Prevention

Implementation of strategies for prevention of surgical site infection and periprosthetic joint infection is gaining further attention. We provide an overview of the pertinent evidence-based guidelines for infection prevention from the World Health Organization, the Centers for Disease Control and Prevention, and the second International Consensus Meeting on Musculoskeletal Infection. Future work is needed to ascertain clinical efficacy, optimal combinations, and the cost-effectiveness of certain measures.

Hospital infection control and behaviour of operating room staff

OBJECTIVES

Surgical site infections (SSIs) are a frequent complication of surgical procedures and one of the most common forms of hospital acquired infection (HAI). National/international guidelines and recommendations have been issued for prevention. The objective of this study was to observe the behaviour of healthcare workers engaged in surgical procedures and hence assess compliance with SSI guidelines.

METHODS

An observational descriptive study was conducted at a University hospital in southern Italy. A specifically designed form was used to record the actions of the surgical team during randomly selected surgical operations. Observations comprised the use of surgical attire, the frequency of doors opening and the number of staff in the operating room.

RESULTS

A total of 308 operating room personnel was observed during 402 surgical procedures: 127 surgeons (41%), 39 anaesthesiologists (13%), 62 nurses (20%) and 80 students in training (26%). 96% of the surgical team wore scrubs, 93% of health workers wore a mask and of these 78% wore it correctly in order to completely cover the nose, mouth and beard (when present), 99% wore a cap (only in 48% was the hair completely covered), 50% of the operators wore gloves, 95% wore shoes dedicated to the operating theater and 23% also wore shoe covers, 56% wore gowns, and 22% had eye protection. Furthermore, the average number of health personnel in the operating theater was 8, the doors remained closed in 261 (65%) surgical operations.

CONCLUSION

As the results indicated a low adherence to international guidelines among the personnel, it is suggested that training courses should be provided to increase staff awareness on prevention and management of HAI.

Sterile Parts of Operating Gown during Lower Limb Joint Replacement Surgery

BACKGROUND

The prevention of surgical site infection is one of the most concerning issues in operating rooms. Surgical gowns are worn as one of the intraoperative strategies for infection prevention. The present study investigated whether the gowns remained sterile during the surgical procedure. Furthermore, this study examined which parts of the surgical gown were more prone to contamination.

METHODS

The sterility of the gowns was investigated during eight total joint arthroplasties all of which were performed by four surgeons. The samples were taken from the arms and frontal part of the sterile gowns pre- and postoperatively. In the anterior surface of the gown, the sampling was initiated at a strip with 50 cm height from the ground followed by the strips with 15 cm distances from caudal to cephalad. Furthermore, the frontal part of the gown was divided into three parts in relation to the operating room table. Finally, the contamination rate was evaluated in each part. A semiquantitative method was used for the analysis of bacterial culture.

RESULTS

Before the operation, there were four samples tested positive for bacterial culture (1.06%). All of these samples were taken from the most proximal strip near the neckline. After the surgery, the rate of contamination in the strips on the frontal part of the gown was reported as 3.1% to 53%. Based on the operating table, the contamination rate was 35.9%, 8.9%, and 47.3% in the distal, middle, and proximal parts of the gown, respectively. The contamination rate at the elbow crease was 23%, and at 5 and 10 cm above the creases were 24% and 36%, respectively.

CONCLUSION

The high rate of gown contamination during the operation is concerning. However, part of the gown that was in contact with the operating room table remained clean most of the time. More safe strategies should be used for infection prevention in operating rooms.