Infection rate in total hip arthroplasty as a function of air cleanliness and antibiotic prophylaxis. 10-year experience with 2,384 cementless Lord madreporic prostheses

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.

Operating room ventilation-Validation of reported data on 108 067 primary total hip arthroplasties in the Norwegian Arthroplasty Register

RATIONALE, AIMS, AND OBJECTIVES

The true effect of laminar airflow (LAF) systems on postoperative infection is disputed, partly due to uncertainty regarding the validity of ventilation data in register studies. The aim of this study was to validate the information on operating room (OR) ventilation reported by the orthopaedic surgeons to the Norwegian Arthroplasty Register (NAR) after primary total hip arthroplasty (THA).

METHOD

Forty of the 62 public orthopaedic units performing primary THA in Norway during the period 1987-2015 were included. The hospitals' current and previous ventilation systems were evaluated in cooperation with the hospitals head engineer. We identified the type of ventilation system reported to the NAR and compared the information with the factual ventilation in the specific ORs at the time of primary THA.

RESULTS

A total of 108 067 primary THAs were eligible for assessment. None of the hospitals performed THA in true "greenhouse" (GH) ventilation. Fifty-seven percent of the primary THAs were performed in ORs with LAF and 43% in ORs with conventional, turbulent ventilation (CV). Comparing the reported data with the validated data, LAF was reported with a sensitivity of 86%, specificity of 89%, and positive predictive value (PPV) of 92%, with an accuracy of 88%. CV was reported with a sensitivity of 89%, specificity of 87%, and PPV of 84%, with an accuracy of 88%. The total, mean misreporting rate was 12%.

CONCLUSIONS

Surgeons were not fully aware of what kind of ventilation system they operated in. This study indicates that conclusions based on ventilation data reported on THA in the NAR should not be interpreted without considering the inaccuracy of the data.

Effect of laminar airflow ventilation on surgical site infections: a systematic review and meta-analysis

BACKGROUND

The role of the operating room's ventilation system in the prevention of surgical site infections (SSIs) is widely discussed, and existing guidelines do not reflect current evidence. In this context, laminar airflow ventilation was compared with conventional ventilation to assess their effectiveness in reducing the risk of SSIs.

METHODS

We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and WHO regional medical databases from Jan 1, 1990, to Jan 31, 2014. We updated the search for MEDLINE for the period between Feb 1, 2014, and May 25, 2016. We included studies most relevant to our predefined question: is the use of laminar airflow in the operating room associated with the reduction of overall or deep SSI as outcomes in patients of any age undergoing surgical operations? We excluded studies not relevant to the study question, studies not in the selected languages, studies published before Jan 1, 1990, or after May 25, 2016, meeting or conference abstracts, and studies of which the full text was not available. Data were extracted by two independent investigators, with disagreements resolved through further discussion. Authors were contacted if the full-text article was not available, or if important data or information on the paper's content was absent. Studies were assessed for publication bias. Grading of recommendations assessment, development, and evaluation was used to assess the quality of the identified evidence. Meta-analyses were done with RevMan (version 5.3).

FINDINGS

We identified 1947 records of which 12 observational studies were comparing laminar airflow ventilation with conventional turbulent ventilation in orthopaedic, abdominal, and vascular surgery. The meta-analysis of eight cohort studies showed no difference in risk for deep SSIs following total hip arthroplasty (330 146 procedures, odds ratio [OR] 1·29, 95% CI 0·98-1·71; p=0·07, I²=83%). For total knee arthroplasty, the meta-analysis of six cohort studies showed no difference in risk for deep SSIs (134 368 procedures, OR 1·08, 95% CI 0·77-1·52; p=0·65, I²=71%). For abdominal and open vascular surgery, the meta-analysis of three cohort studies found no difference in risk for overall SSIs (63 472 procedures, OR 0·75, 95% CI 0·43-1·33; p=0·33, I²=95%).

INTERPRETATION

The available evidence shows no benefit for laminar airflow compared with conventional turbulent ventilation of the operating room in reducing the risk of SSIs in total hip and knee arthroplasties, and abdominal surgery. Decision makers, medical and administrative, should not regard laminar airflow as a preventive measure to reduce the risk of SSIs. Consequently, this equipment should not be installed in new operating rooms.

FUNDING

None.

Does laminar flow ventilation reduce the rate of infection?

Aims

To determine whether there is any difference in infection rate at 90 days between trauma operations performed in laminar flow and plenum ventilation, and whether infection risk is altered following the installation of laminar flow (LF).

Patients and Methods

We assessed the impact of plenum ventilation (PV) and LF on the rate of infection for patients undergoing orthopaedic trauma operations. All NHS hospitals in England with a trauma theatre(s) were contacted to identify the ventilation system which was used between April 2008 and March 2013 in the following categories: always LF, never LF, installed LF during study period (subdivided: before, during and after installation) and unknown. For each operation, age, gender, comorbidity, socio-economic deprivation, number of previous trauma operations and surgical site infection within 90 days (SSI90) were extracted from England’s national hospital administrative Hospital Episode Statistics database. Crude and adjusted odds ratios (OR) were used to compare ventilation groups using hierarchical logistic regression. Subanalysis was performed for hip hemiarthroplasties.

Results

A total of 803 065 trauma operations were performed during this time; 19 hospitals installed LF, 124 already had LF, 13 had PV and the type of ventilation was unknown in 28. Patient characteristics were similar between the groups. The rate of SSI90 was similar for always LF and PV (2.7% and 2.4%). For hemiarthroplasties of the hip, the rates of SSI90 were significantly higher for LF compared with PV (3.8% and 2.6%, OR 1.45, p = 0·001). Hospitals installing LF did not see any statistically significant change in the rate of SSI90.

Conclusion

The results of this observational study imply that infection rate is similar when orthopaedic trauma surgery is performed in LF and PV, and is unchanged by installing LF in a previously PV theatre. Cite this article: Bone Joint J 2016;98-B:1262–9.

Infection Control Practices to Reduce Airborne Bacteria During Total Knee Replacement: A Hospital Survey in Four States

Objective:

To describe the use of laminar airflow, body exhaust, and ultraviolet lights during total knee replacement (TKR) in four U.S. states.

Design:

Survey of healthcare facilities.

Setting:

Hospitals in Illinois, North Carolina, Ohio, and Tennessee that performed TKR during 2000 as identified by Medicare claims data.

Participants:

Hospitals responding to a mailed questionnaire.

Results:

Two hundred ninety-five (73%) of 405 eligible hospitals that performed 18,374 primary and revision TKR procedures responded to the questionnaire. Among responding hospitals, 30% reported regular use (for > 75% of procedures) of laminar airflow, 42% reported regular use of body exhaust, and 5% reported regular use of ultraviolet lights. Among hospitals providing complete data, 150 (58%) performing 66% of procedures reported regular use of at least one of these techniques. On regression analyses, laminar airflow was used more often by hospitals with a TKR volume greater than 25 procedures per year (odds ratio [OR], 2.0; 95% confidence interval [CI95], 1.1-3.7) and orthopedic residency programs (OR,2.8;CI95,1.3-6.3), but its use was not significantly related to hospital setting or ownership status.

Conclusions:

Although these clean air practices are not recommended by any U.S. governmental or professional organization, they are used in nearly two-thirds of TKR procedures. Better information about their impact on current practice and more explicit guidelines may aid decisions about the use of these resource-intensive infection control practices.

Current Evidence for the Use of Laminar Flow in Reducing Infection Rates in Total Joint Arthroplasty

Since the introduction of laminar air flow in orthopaedic theatres by Sir John Charnley, it has widely become accepted as the standard during orthopaedic procedures such as joint arthroplasty. We present a review of available current literature for the use of laminar flow operating theatre ventilation during total joint arthroplasty and examines the effectiveness of laminar flow ventilated operating theatres in preventing post-operative wound infection. Results of our findings suggest that while bacterial and air particulate is reduced by laminar air flow systems, there is no conclusive effect on the reduction of post-operative wound infections following total joint arthroplasty. We conclude that a combination of strict aseptic technique, prophylactic antibiotics and good anaesthetic control during surgery remains crucial to reduce post-operative surgical infections.

Deep Infection After Total Knee Replacement: Impact of Laminar Airflow Systems and Body Exhaust Suits in the Modern Operating Room

We investigated the relationship between the risk of deep infection and intraoperative use of laminar airflow systems and body exhaust suits during 8,288 total knee replacements performed in 256 hospitals. The overall 90-day cumulative incidence of deep infection requiring subsequent operation was 0.34% (28 procedures). In all combinations of laminar airflow systems and body exhaust suits, the 90-day cumulative incidence of infection requiring subsequent operation was 0.27%-0.43%. The risk ratio was 1.57 (95% confidence interval, 0.75-3.31) for laminar airflow systems and 0.75 (95% confidence interval, 0.34-1.62) for body exhaust suits suits. The risk was not statistically associated with use of either method, but infections were rare.

Prevention of infection in orthopaedic joint replacement

Infection of a prosthetic joint is a significant adverse event, affecting the patient, the surgical team, and consuming hospital resources. The patient faces multiple operations, a prolonged hospital stay and a more challenging period of rehabilitation. The surgeon must perform longer and more technically demanding revision operations in order to remove the infected prosthesis, increasing the burden on hospital resources. It has been estimated that that the cost of managing an infected total hip replacement (THR) is four times greater than for a primary procedure (Dreghorn & Hamblen 1989). The personal cost to the patient must also be emphasised.

Two-stage revision of infected hip arthroplasty using a shortened post-operative course of antibiotics

INTRODUCTION

We present a series of 30 consecutive patients with 31 infected total hip arthroplasties treated by a single surgeon over a 4-year period in whom a shortened post-operative course of antimicrobial chemotherapy was used.

METHODS

The treatment protocol consisted of a two-stage exchange with removal of infected components, insertion of an interim antibiotic eluting cement spacer and re-implantation of an extensively coated uncemented prosthesis on the femoral side. Systemic antibiotic treatment following each stage consisted of an abridged course of 5 days post-operative intra-venous administration followed by complete cessation of anti-microbial therapy.

RESULTS

At a mean follow-up of 35 months (minimum 24 months), there were no cases of recurrent prosthetic infection and no patient had required revision for aseptic loosening or mechanical instability on the femoral side. The combination of effective-staged surgical joint debridement, a shortened post-operative course of systemic antibiotic treatment and an adequate latent period before re-implantation has led to encourage early results in this series of revised chronic hip joint prosthetic infections.

Principles of a clean operating room environment

Optimizing the operating room environment is necessary to minimize the prevalence of arthroplasty infection. Reduction of bacterial contamination in the operating room should be a primary focus of all members of the operating room team. However, in recent years, there has been a decline in the emphasis of the basic principles of antisepsis in many operating rooms. The purpose of this review is to highlight important considerations for optimizing the operating room environment. These principles should be actively promoted by orthopedic surgeons in their operating rooms as part of a comprehensive approach to minimizing arthroplasty infection.

Case report: cefazolin-induced hemolytic anemia

Antibiotic-induced hemolytic anemia is a rare complication. Prophylactic cephalosporins are widely used in patients having orthopaedic procedures. When there is a precipitous drop in hemoglobin levels, it is important for the clinician to consider the possibility of drug-induced anemia when other causes of blood loss have been excluded. We present a patient with no prior drug allergies who had antibiotic-induced hemolytic anemia develop after total knee arthroplasty.

In vitro testing of antimicrobial activity of bone cement

The purpose of this study was to establish a reliable and cost-effective microplate proliferation assay for in vitro antimicrobial testing of bone cement samples. Cement samples devoid of antimicrobial agents, loaded with 2% gentamicin or with different concentrations of high-porosity silver, were incubated in a 96-well microplate with several staphylococcal, Pseudomonas aeruginosa, and Enterococcus faecium isolates exhibiting different susceptibilities to gentamicin. After being rinsed, the samples were brought into a soy medium in which adherent cells on the cement surface either were killed by the antimicrobial surface or started to release clonal counterparts. The medium was monitored in real time by recording a time proliferation curve for each well. Microplate testing revealed no antibacterial effect of plain bone cement. The antibacterial activity of gentamicin-loaded bone cement was shown by the microplate test to depend on the gentamicin susceptibilities of the strains. The effect of high-porosity silver was dose dependent. Bactericidal activity against all tested strains was found for bone cement loaded with 1% high-porosity silver. The accuracy of this new proliferation assay was shown by the high correlation between the types of proliferation curves and antibiotic susceptibility. In contrast to routine agar diffusion testing, it assesses the dynamic response of microorganisms to antimicrobial agents in biomaterials and allows high-throughput screening and detection of antimicrobial properties of poorly water-soluble compounds like silver.

Efficacy of a single dose of cefazolin as a prophylactic antibiotic in primary arthroplasty

We analyzed the wound infection rate of 1,367 primary total hip and knee arthroplasties performed between 1991 and 1999. Two hundred and fifteen arthroplasties were performed with 3 doses (3 x 750 mg) of cefuroxime, and 1,152 arthroplasties were performed with a single preoperative dose (1 x 1 g) of cefazolin as antimicrobial prophylaxis. All wound infections that occurred within 2 years of the index surgery were analyzed. The deep wound infection rate of total hip arthroplasty was 1.1% (95% confidence interval [CI], 0%-3.3%) in the cefuroxime group and 1.1% (95% CI, 0%-2.2%) in the cefazolin group (Fisher's exact test, P = 1.0). The deep wound infection rate of total knee arthroplasty in the cefuroxime group (1.6%; 95% CI, 0%-3.8%) was not significantly different from the cefazolin group (1.0%; 95% CI, 0.3%-1.7%) (Fisher's exact test, P =.63). We concluded that a single dose (1 g) of cefazolin given at anesthetic induction offered similar protection to 3 doses (3 x 750 mg) of cefuroxime in preventing infection in primary total joint arthroplasty.

[Perioperative antibiotic prophylaxis in hip operations. Penetration into bone, capsule tissue and cartilage exemplified by cefuroxime]

The most serious complication of accident surgery is postoperative osteitis. At the same time, perioperative antibiotic prophylaxis is generally recommended in order to reduce the rate of infection in joint surgery. The criteria for the suitability of a substance as prophylaxis include inter alia the activity spectrum with respect to the expected microorganisms, its retention time in the body and its ability to penetrate the endangered tissue. In the present study, the systemic and local activity levels after a single i.v. dose of 1500 mg cefuroxime was investigated in relation to the time of administration in 30 patients who had to undergo total hip replacement owing to a medial fracture of the neck of the femur. The tissue and serum samples were analyzed by high pressure liquid chromatography (HPLC). The results show that the tissue levels of the intermediary cephalosporin after an i.v. single shot dose are on average still several times higher than the minimum inhibitory concentration (MIC) of the most frequent bacterium. Staphylococcus aureus, as late as 4 hours after application. The optimal time for the administration form selected was immediately prior to the operation and the concentrations measured suggest that several repeat doses of cefuroxime for short-term prophylaxis are not necessary.

Effect of intraoperative blood loss on the serum level of cefazolin in patients managed with total hip arthroplasty. A prospective, controlled study

The effect of intraoperative blood loss on serum levels of cefazolin in patients being managed with total hip arthroplasty was studied. Eighteen patients, thirteen men and five women, with a mean age of sixty-five years (range, forty to eighty-five years) were enrolled in the study. Fifteen had a primary total hip arthroplasty and three, a revision. Each patient served as his or her own control. Baseline clearance of cefazolin was determined at a minimum of forty-eight hours before the operation. Each patient received one gram of cefazolin intravenously. Serial serum concentrations were determined from specimens drawn at zero, five, ten, twenty, thirty, sixty, 120, 240, and 300 minutes after administration. Fifteen minutes before the skin incision was made, each patient again received one gram of cefazolin intravenously. Serum samples were collected at the same time-intervals, and the serum levels of cefazolin were determined with use of capillary electrophoresis. Data regarding intraoperative blood loss as well as replacement of fluid and blood were recorded. The administration of the antibiotic, retrieval of the serum samples, and estimation of the blood loss were performed by the same person in the same manner for all patients. The preoperative and intraoperative creatinine clearances (mean and standard deviation), estimated with use of the formula of Cockcroft and Gault, were 62.06 +/- 21.28 and 74.02 +/- 24.75 milliliters per minute, respectively. The amount of intraoperative blood loss averaged 1137 +/- 436 milliliters (range, 675 to 2437 milliliters). The preoperative and intraoperative cefazolin clearances averaged 0.49 +/- 0.21 and 0.52 +/- 0.30 milliliter per minute per kilogram, respectively. During joint replacement, the commonly accepted interval between doses of cefazolin is four hours. In the present study, the serum level of cefazolin at four hours was forty-five micrograms per milliliter. This corresponds to an osseous concentration that well exceeds the minimum inhibitory concentration for Staphylococcus aureus, which is 0.5 microgram per milliliter. This study suggests that, with blood losses of less [corrected] than 2000 milliliters, it is not necessary to administer cefazolin at intraoperative intervals of less than four hours in order to maintain a concentration of antibiotics that is higher than the minimum inhibitory concentration for the most common infecting organisms.

Preoperative nutritional status of total joint patients. Relationship to postoperative wound complications

The records of 217 consecutive patients who underwent a primary total hip or total knee arthroplasty were reviewed for preoperative and postoperative nutritional status. Fifty-seven patients had a lymphocyte count of less than 1,500 cells/mm3, four patients had an albumin level of less than 3.5 g/dL, and two patients had both, giving a 27% incidence of indices indicative of preoperative nutritional depletion. Patients without wound complications had an average preoperative lymphocyte count of 1,995 (+/- 631), compared to 1,638 (+/- 491) for those with persistent serous drainage from their wounds, and 1,553 (+/- 419) for those patients with a major wound complication (P = .002). The average albumin levels were 4.30 (+/- 0.33), 4.22 (+/- 0.31), and 4.13 (+/- 0.54), respectively. Patients with rheumatoid arthritis were compared to those with osteoarthritis and were found to have significantly lower preoperative albumin levels. They were three times as likely to develop a major wound complication. Patients on immunosuppressive medications had significantly lower preoperative lymphocyte counts, lower albumin levels, and higher complication rates (P = .04). After operation, lymphocyte counts of all patients dropped to an average of 57% of their preoperative values, and albumin levels dropped to 72% of their preoperative values. No nutritional parameters had returned to their preoperative levels by 10 postoperative days. For all patients, a preoperative lymphocyte count of less than 1,500 cells/mm was associated with a five times greater frequency of developing a major wound complication, and an albumin level of less than 3.5 g/dL had a seven times greater frequency.(ABSTRACT TRUNCATED AT 250 WORDS)