Does an Antimicrobial Incision Drape Prevent Intraoperative Contamination? A Randomized Controlled Trial of 1187 Patients.

BACKGROUND: The risk of periprosthetic joint infection (PJI), a serious complication after arthroplasty, has not changed for years. Interventions such as eradication of Staphylococcus aureus and antibiotic bone cement are used to diminish infection risk but despite these efforts, the percentage of infection in TKA remains constant. Antimicrobial drapes have a dual action, acting both as a physical and antimicrobial barrier to counter bacterial contamination of the surgical wound. To study the effect of antimicrobial drapes, we used intraoperative contamination as a proxy for infection in our investigation. QUESTIONS/PURPOSES: (1) Do antimicrobial surgical drapes reduce the risk of intraoperative microbial contamination in patients undergoing primary knee arthroplasty? (2) Are other factors such as sex, season, age, type of arthroplasty and duration of surgery associated with an increased risk of contamination in patients undergoing primary knee arthroplasty? (3) Does loosening of the antimicrobial drape increase contamination risk? METHODS: An investigator-initiated, two-arm, non-blinded, multicenter, randomized, controlled trial was performed at five different hospitals in the capital and central regions of Denmark. Twenty-four surgeons participated in the study. Participants were patients older than 18 years undergoing primary knee arthroplasty. We excluded patients with an iodine allergy, previous open knee surgery, previous septic arthritis, any antibiotics taken 4 weeks before surgery, and if they were unable to understand the implications of study participation. Patients were randomly assigned to operation with an antimicrobial drape (intervention group) or operation without (control group). We screened 1769 patients, of which 100 were ineligible and 10 declined to participate. In all, 94% (1659 of 1769) of patients consented and were randomized to the intervention group (51%, 838 of 1659) and control group (49%, 821 of 1659), respectively. In all, 36% (603 of 1659) of patients in the intervention group and 35% (584 of 1659) patients in the control group were available for final analysis. No crossover was performed, and analysis was done per-protocol. Patients were excluded due to logistic failures like lack of utensils, samples disappearing en route to the laboratory mainly caused by implementation of a new electronic patient chart (EPIC, Verona, WI, USA), and forgetful surgeons. Intraoperatively, we swabbed for bacteria at the surgical site and in a rinse from the surgeons' gloves. All samples were sent for cultivation, and colony forming units (CFUs) counts ≥ 1 were deemed contaminated. The primary outcome measure was the difference in the proportion of contaminated patients between the two randomized groups. Secondary outcome measures were the affiliation of sex, season, age, type of implant used, and duration of surgery on contamination risk. To investigate whether other factors were affiliated with contamination risk, we did a logistic regression to control for confounding variables, including sex, age, season, type of implant and duration of surgery. RESULTS: Use of iodinated drapes reduced contamination, with contamination detected in 10% (60 of 603) procedures where iodinated drapes were used compared with 15% (90 of 584) when they were not (odds ratio 0.61 [95% CI 0.43 to 0.87]; p = 0.005), with a relative risk reduction of 35% (95% CI 12.3 to 52.5) and a number needed to treat of 18 patients. After controlling for confounding variables such as sex, age, type of implant, and duration of surgery, we found that not using an antimicrobial drape increased contamination risk by a factor of 1.6 (95% CI 1.08 to 2.35; p = 0.02). Female sex and undergoing surgery in the central region were associated with lower odds of contamination (OR 0.55 [95% CI 0.39 to 0.8]; p = 0.002 and OR 0.45 [95% CI 0.25 to 0.8]; p = 0.006, respectively). Patients with more than a 10-mm separation of the drape from the skin had higher odds of contamination (OR 3.54 [95% CI 1.64 to 11.05]; p = 0.0013). CONCLUSIONS: The use of an antimicrobial drape resulted in lower contamination risk than operating without an antimicrobial drape. Our findings suggest that antimicrobial drapes are useful in infection prevention, but further studies are needed to investigate the effect of antimicrobial drapes on infection. LEVEL OF EVIDENCE: Level I, therapeutic study.

Hair removal with a clipper and microbial colonisation prior to knee arthroplasty: a randomised controlled trial.

Background: Despite the widely reported success of knee arthroplasty, studies show that 1.6-3 % of patients undergo revision within the first postoperative year predominantly due to infection. Preoperative skin preparation may potentially decrease the bacterial load and consequently, the risk of periprosthetic joint infections. The effects of hair removal on prosthetic joint infection are inconsistent. Our primary aim was to investigate if hair removal with a clipper influenced skin colonisation and bacterial composition. Methods: Forty Caucasian male participants who were planned to undergo knee arthroplasty, (mean age 63.8 years), were included. Patients were randomised to hair removal in a within-person study design. As a control, the opposite leg of the patient was used. Swabs were collected prior to hair removal (baseline), immediately after hair removal (Day 0), and with follow-up after one and seven days. Results: The intervention showed significant decrease in mean log colony-forming units per. cm2 from baseline 2.97 to 2.67 (P<0.01) immediately after hair removal and sustained at Day 1 (P=0.01). At Day 7, the mean was non-significant compared to baseline. The control group did not show any decrease of skin microbiota at follow-up on Day 0, 1 or 7.No significant differences within the bacterial composition were found between the intervention and control leg at baseline among the six most prevalent detected bacterial species: Staphylococcus epidermidis, Micrococcus luteus, S. hominis, S. capitis, S. haemolyticus and S. aureus. The study did not find any changes in the bacterial composition over time. Conclusion: Hair removal with a clipper within 24 hours prior to surgery causes a significant non-selective reduction in skin colonisation.

Revision for periprosthetic joint infection rate stratified by seasonality of operation in a national population of total and unicompartmental knee arthroplasty patients: a register-based analysis.

Aim: The aim of this study was to investigate whether the revision rate for periprosthetic joint infection (PJI) depends on the season of the primary procedure using a national population of knee arthroplasty (KA) patients. Seasonal variation of some surgical procedures has been observed to impact subsequent infection risks, with a higher risk of revision for surgeries performed during summer, but an analysis of PJI rates based on a national arthroplasty register has yet to be completed. We hypothesized that an increased risk of revision due to PJI could be demonstrated in a national population when primary surgery was performed during the summer. Methods: The Danish Knee Arthroplasty Registry (DKR) was used to determine the risk of revision due to PJI within 2 years after primary surgery. All primary KA procedures between 1 January 1997 and 31 December 2014 and revisions until 31 December 2016 were identified. Smoothing spline regression was used to identify possible seasonal pattern effects of the primary procedure on revision risk, and logistic regression was used to calculate risk of infection differences between seasons. Results: A total number of 124 809 primary procedures was registered in the study period. After excluding duplicates and matching primary procedures with the first revisions within 2 years after the primary procedure, 3391 were identified. Of these, 348 cases were recorded with an indication of deep infection requiring revision. Spline regression analyses did not demonstrate any clear seasonal pattern of the primary procedure regarding the risk of revision for infection or any other cause. Logistic regression found a decreased risk of revision for infection when the primary procedure was performed during the summer in the years 1997 to 2005, no influence on the risk of revision for infection in 2005 to 2012, and an increased risk of revision for infection following summer procedures during the years 2013 to 2014. Conclusion: It was not possible to demonstrate a consistent seasonal variation of the risk of revision for PJI following primary KA. This is most likely because the underlying etiologies for PJI are not subject to seasonal variation.

Universal Dermal Microbiome in Human Skin.

Human skin microbiota has been described as a "microbial fingerprint" due to observed differences between individuals. Current understanding of the cutaneous microbiota is based on sampling the outermost layers of the epidermis, while the microbiota in the remaining skin layers has not yet been fully characterized. Environmental conditions can vary drastically between the cutaneous compartments and give rise to unique communities. We demonstrate that the dermal microbiota is surprisingly similar among individuals and contains a specific subset of the epidermal microbiota. Variability in bacterial community composition decreased significantly from the epidermal to the dermal compartment but was similar among anatomic locations (hip and knee). The composition of the epidermal microbiota was more strongly affected by environmental factors than that of the dermal community. These results indicate a well-conserved dermal community that is functionally distinct from the epidermal community, challenging the current dogma. Future studies in cutaneous disorders and chronic infections may benefit by focusing on the dermal microbiota as a persistent microbial community.IMPORTANCE Human skin microbiota is thought to be unique according to the individual's lifestyle and genetic predisposition. This is true for the epidermal microbiota, while our findings demonstrate that the dermal microbiota is universal between healthy individuals. The preserved dermal microbial community is compositionally unique and functionally distinct to the specific environment in the depth of human skin. It is expected to have direct contact with the immune response of the human host, and research in the communication between host and microbiota should be targeted to this cutaneous compartment. This novel insight into specific microbial adaptation can be used advantageously in the research of chronic disorders and infections of the skin. It can enlighten the alteration between health and disease to the benefit of patients suffering from long-lasting socioeconomic illnesses.

[Report: complicated influenza A(H1N1) in a second-trimester pregnancy]. / Kompliceret influenza A (H1N1) hos gravid i andet trimester.

A 27-year-old woman at 25 weeks of gestation was admitted to hospital due to bilateral pneumonia with increasing hypoxia. She was tested positive for influenza A (H1N1) and successfully treated with oral oseltamivir. Nine days after the admission pathological umbilical flows were recorded and an emergency caesarean was performed at 26 weeks + 2 days of gestation. The neonatal period was uncomplicated. Influenza A (H1N1) is especially dangerous in pregnant women and vaccination is important.