Does laminar airflow make a difference to the infection rates for lower limb arthroplasty: a study using the National Joint Registry and local surgical site infection data for two hospitals with and without laminar airflow

International comparison of variation in performance between hospitals for THA and TKA: Is it even possible? A systematic review including 33 studies and 8 arthroplasty register reports

In order to improve care for total hip and knee arthroplasties (THA/TKA), hospitals may want to compare their performance with hospitals in other countries. Pooling data across countries also enable early detection of infrequently occurring safety issues. We therefore aimed to assess the between-hospital variation and definitions used for revision, readmission, and complications across countries.

PubMed, Embase, Web of Science, Cochrane library, Emcare, and Academic Search Premier were searched from January 2009 to August 2020 for studies reporting on: (i) primary THA/TKA; (ii) revision, readmission, or complications; and (iii) between-hospital variation. Most recent registry reports of Network of Orthopedic Registries of Europe members were also reviewed. Two reviewers independently screened records, extracted data, and assessed the risk of bias using the Integrated quality Criteria for the Review Of Multiple Study designs tool for studies and relevant domains for registries. We assessed agreement for the following domains: (i) outcome definition; (ii) follow-up and starting point; (iii) case-mix adjustment; and (iv) type of patients and hospitals included.

Between-hospital variation was reported in 33 (1 high-quality, 13 moderate-quality, and 19 low-quality) studies and 8 registry reports. The range of variation for revision was 0–33% for THA and 0–27% for TKA varying between assessment within hospital admission until 10 years of follow-up; for readmission, 0–40% and 0–32% for THA and TKA, respectively; and for complications, 0–75% and 0–50% for THA and TKA, respectively. Indicator definitions and methodological variables varied considerably across domains.

The large heterogeneity in definitions and methods used likely explains the considerable variation in between-hospital variation reported for revision, readmission, and complications , making it impossible to benchmark hospitals across countries or pool data for earlier detection of safety issues. It is necessary to collaborate internationally and strive for more uniformity in indicator definitions and methods in order to achieve reliable international benchmarking in the future.

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

BACKGROUND

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.

AIM

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.

METHODS

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.

FINDINGS

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).

CONCLUSION

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.

The possible effect of different types of ventilation on reducing operation theatre infections: a meta-analysis

INTRODUCTION

The relation between type of ventilation used in the operating theatre and surgical site infection has drawn considerable attention. It has been reported that there is a possible relationship between the type of ventilation used in the operation theatre and surgical site infection. This meta-analysis was performed to evaluate this relationship.

METHODS

Through a systematic literature search up to May 2020, 14 studies describing 590,121 operations, 328,183 were performed under laminar airflow ventilation and 2,611,938 were performed under conventional ventilation. Studies were identified that reported relationships between type of ventilation with its different categories and surgical site infection (10 studies were related to surgical site infection in total hip replacement, 7 in total knee arthroplasties and 3 in different abdominal and open vascular surgery). Odds ratios with 95% confidence intervals were calculated comparing surgical site infection prevalence and type of theatre ventilation using the dichotomous method with a random or fixed-effect model.

FINDINGS

No significant difference was found between surgery performed under laminar airflow ventilation and conventional ventilation in total hip replacement (OR 1.23; 95% CI 0.97-1.56, p = 0.09), total knee arthroplasties (OR 1.14; 95% CI 0.62-2.09, p = 0.67) or different abdominal and open vascular surgery (OR 0.75; 95% CI 0.43-1.33, p = 0.33). The impact of the type of theatre ventilation may have no influence on surgical site infection as a tool for decreasing its occurrence.

CONCLUSIONS

Based on this meta-analysis, operating under laminar airflow or conventional ventilation may have no independent relationship with the risk of surgical site infection. This relationship forces us not to recommend the use of laminar airflow ventilation since it has a much higher cost compared with conventional ventilation.

The effect of type of ventilation used in the operating room and surgical site infection: A meta-analysis

BACKGROUND

The relation between type of ventilation used in the operating room and surgical site infection has drawn considerable attention with its conflicting results. A possible relationship between the type of ventilation used in the operating room and surgical site infection has been reported. This meta-analysis was performed to evaluate this relationship.

METHODS

A systematic literature search up to May 2020 identified 14 studies with 590,121 operations, 328,183 operations of which were performed under laminar airflow ventilation and 261,938 of which were performed operations under conventional ventilation. These articles reported relationships between type of operating-room ventilation with its different categories and surgical site infection: 10 studies were related to surgical site infection in the total hip replacement; 7 studies in total knee arthroplasties; and 3 studies in different abdominal and open vascular surgery. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated comparing surgical site infection prevalence and type of operating room ventilation using the dichotomous method with a random-effects or fixed-effects model.

RESULTS

No significant difference was found between operation performed under laminar airflow ventilation and conventional ventilation in total hip replacement (OR, 1.23; 95% CI, 0.97-1.56, P = .09), in total knee arthroplasties (OR, 1.14; 95% CI, 0.62-2.09; P = .67), and in different abdominal and open vascular surgery (OR, 0.75; 95% CI, 0.43-1.33; P = .33). The impact of the type of operating room ventilation may have no influence on surgical site infection as a tool for decreasing its occurrence.

CONCLUSIONS

Based on this meta-analysis, operating under laminar airflow or conventional ventilation may have no independent relationship with the risk of surgical site infection. This relationship forces us not to recommend the use of laminar airflow ventilation because it has a much higher cost compared to conventional ventilation.

Prevention of infection in primary THA and TKA

Rates of peri-prosthetic joint infection (PJI) in primary total hip and total knee arthroplasty range between 0.3% and 1.9%, and up to 10% in revision cases. Significant morbidity is associated with this devastating complication, the economic burden on our healthcare system is considerable, and the personal cost to the affected patient is immeasurable.

The risk of surgical site infection (SSI) and PJI is related to surgical factors and patient factors such as age, body mass index (BMI), co-morbidities, and lifestyle. Reducing the risk of SSI in primary hip and knee arthroplasty requires a multi-faceted strategy including pre-operative patient bacterial decolonization, screening and avoidance of anaemia, peri-operative patient warming, skin antisepsis, povidone-iodine wound lavage, and anti-bacterial coated sutures.

This article also considers newer concepts such as the influence of bearing surfaces on infection risk, as well as current controversies such as the potential effects of blood transfusion, laminar flow, and protective hoods and suits, on infection risk.

Cite this article: EFORT Open Rev 2020;5:604-613. DOI: 10.1302/2058-5241.5.200004

Are high-efficiency particulate air (HEPA) filters and laminar air flow necessary in operating rooms to control acute post-operative endophthalmitis?

Purpose

To compare the five-year incidence of acute post-operative endophthalmitis following cataract surgery, between centers with and without laminar air flow and high-efficiency particulate air (HEPA) filters in operating rooms.

Methods

Retrospective analysis of medical records of patients operated in a single network of a tertiary and four secondary hospitals across north India. Cases of endophthalmitis were identified from the records between January 2013 and June 2018. Protocols and consumables were standardized across all hospitals. The only infrastructural difference being the presence of laminar air flow and high energy particulate air filters in operating rooms of the tertiary center. The type of surgery, along with the demographic and socio-economic details, were captured and analyzed, using z-test for proportions and logistic regression.

Results

Out of 88,297 cataract surgeries conducted, 36 cases of endophthalmitis were reported. The incidence of endophthalmitis across the network was estimated to be 0.041%, (95% CI: 0.027 to 0.054). There was no statistically significant difference between the incidence of POE at the tertiary (0.042%) and secondary centers (0.039%). Certain risk factors for high endophthalmitis incidence were identified, namely patients undergoing small incision cataract surgery and belonging to lower socio-economic status. However, for both factors the difference was not statistically significant.

Conclusion

The five-year incidence of acute post-operative endophthalmitis in our network was found comparable to the best reported in literature. Incidence at secondary centers, without laminar air flow and high energy particulate air filters was found comparable to that in the tertiary center having these facilities.

Reducing Implant Infection in Orthopaedics (RIIiO): Results of a pilot study comparing the influence of forced air and resistive fabric warming technologies on postoperative infections following orthopaedic implant surgery

BACKGROUND

Active warming during surgery prevents perioperative hypothermia but the effectiveness and postoperative infection rates may differ between warming technologies.

AIM

To establish the recruitment and data management strategies needed for a full trial comparing postoperative infection rates associated with forced air warming (FAW) versus resistive fabric warming (RFW) in patients aged >65 years undergoing hemiarthroplasty following fractured neck of femur.

METHODS

Participants were randomized 1:1 in permuted blocks to FAW or RFW. Hypothermia was defined as a temperature of <36°C at the end of surgery. Primary outcomes were the number of participants recruited and the number with definitive deep surgical site infections.

FINDINGS

A total of 515 participants were randomized at six sites over a period of 18 months. Follow-up was completed for 70.1%. Thirty-seven participants were hypothermic (7.5% in the FAW group; 9.7% in the RFW group). The mean temperatures before anaesthesia and at the end of surgery were similar. For the primary clinical outcome, there were four deep surgical site infections in the FAW group and three in the RFW group. All participants who developed a postoperative infection had antibiotic prophylaxis, a cemented prosthesis, and were operated under laminar airflow; none was hypothermic. There were no serious adverse events related to warming.

CONCLUSION

Surgical site infections were identified in both groups. Progression from the pilot to the full trial is possible but will need to take account of the high attrition rate.

Laminar Air Flow Handling Systems in the Operating Room

BACKGROUND

Surgical site infection is associated with a substantial healthcare burden and remains one of the most challenging complications to treat. Airborne particles carrying contaminating micro-organisms are responsible for the majority of these infections.

METHODS

Various operating theater ventilatory systems have been developed to prevent direct airborne bacterial inoculation of the surgical wound. Laminar air flow uses positive pressure air currents through filtration units to direct air streams away from the operative field in order to create an ultraclean zone around the operative site.

DISCUSSION

Early studies reported lower infection rates with laminar air flow and therefore it became the accepted standard for implant-related surgery. However, more recent evidence has questioned its clinical importance. The purpose of this article is to review contemporary laminar air flow handling systems and the current evidence behind their use.

Assessment of theatre shoe contamination in an orthopaedic theatre

Prosthetic joint infection (PJI) is a devastating complication of arthroplasty. Numerous protocols reduce potential risk for PJI peri-operatively, but none exist for the management of theatre shoes. Our aim was to assess for bacteria known to cause prosthetic infection on theatre shoes. Forty theatre shoes were analysed; there were coagulase-negative staphylococci on 65% (N = 25), meticillin-susceptible Staphylococcus aureus on 40% (N = 16), and meticillin-resistant S. aureus on 25% (N = 10). Amount of blood spatter correlated poorly with microbial contamination. Shoes harbouring Gram-positive bacteria, including antibiotic-resistant strains, provide a potential route of transmission to the theatre environment.

Prevention of Periprosthetic Joint Infection: Examining the Recent Guidelines

BACKGROUND

The global rise in infectious disease has led the Center for Disease Control and Prevention and the World Health Organization to release new guidelines for the prevention of surgical site infection.

METHODS

In this article, we summarize current recommendations based on level of evidence, review unresolved and unaddressed issues, and supplement them with new literature.

RESULTS

Although the guidelines discuss major issues in reducing surgical site infection, many questions remain unanswered.

CONCLUSION

These guidelines will hopefully help in setting a standard of care based on best evidence available and focus investigators on areas where evidence is lacking.