Operative environment

Evaluation of Incise Drape Lift Using 2% Chlorhexidine Gluconate/70% Isopropyl Alcohol Preoperative Skin Preparations in a Human Volunteer Knee Model

Background

Before surgery, skin is prepped with antiseptics to reduce risk of surgical site infections. An incise drape can be used as an additional modality to immobilize any remaining bacteria. Good adhesion of this drape is critical for infection prevention.

Methods

This is a randomized controlled study using a human volunteer knee model (n = 30) to evaluate the adhesion performance of an incise drape comparing 2 skin preparations. A new investigational 2% chlorhexidine gluconate/70% isopropyl alcohol skin prep (prep A) was compared with an existing skin prep containing the same active agents (prep B). Two samples of an iodine-impregnated incise drape were placed on each knee after prepping. Knees were flexed in dry conditions, under a saline-soaked gauze, and after saline lavage. The frequency of drape lift was recorded after each challenge.

Results

After dry flex, 4 of 60 samples (6.7%) had lifted on prep A and 0 on prep B (P = .125). After wet flex, 20 of 60 samples (33%) had lifted on prep A, whereas 42 of 60 samples (70%) had lifted on prep B (P < .0001). After lavage, 23 of 60 samples (38%) had lifted on prep A, whereas 48 of 60 samples (80%) had lifted on prep B (P < .0001). Both preps were well tolerated with minimal erythema and no edema, rash, dryness, or denudation observed. No adverse events were reported.

Conclusions

Prep A resulted in reduced frequency of incise drape lift from skin under wet conditions in this model compared with prep B.

Effect of a Clean Surgical Airflow Layer on the Incidence of Infection in Total Hip Arthroplasty

The Center for Health Design estimates that more than 30% of surgical site infections are caused by airborne pathogens. A device that creates a localized clean air field directly adjacent to and surrounding the incision site is meant to shield a surgical site from particulate in the operating room. The purpose of this study was to determine whether the routine use of this device would reduce the rate of infection following total hip arthroplasty (THA). The authors conducted a retrospective review of primary THA cases performed with and without the airflow device. Since July 2013, a total of 1093 primary THA cases were performed with the device at the authors' institution. The incidence of wound dehiscence and deep infection was compared with that of 1171 THA cases performed prior to July 2013 without the airflow device. There were no significant differences between the study groups regarding average patient age, sex, body mass index, or diagnosis. In the airflow group, there were 7 (0.64%) deep infections and 5 (0.46%) cases of wound dehiscence that required a return to the operating room for irrigation and wound revision. In the control group, there were 7 (0.60%) cases of deep infection and 4 (0.34%) wound revisions. The groups were not significantly different in the rates of infection (P=1.0) or wound revision (P=.75). Both groups had a very low incidence of infection and wound revision, with rates below 1%. Despite compelling bench data showing a dramatic reduction of particle load in the wound, the use of the airflow device did not reduce the clinical rate of infection over a large number of cases. [Orthopedics. 2020;43(5):e425-e430.].

Use of Antimicrobial-Impregnated Incise Drapes to Prevent Periprosthetic Joint Infection in Primary Total Joint Arthroplasty: A Retrospective Analysis of 9774 Cases

BACKGROUND

Antimicrobial-impregnated incise drapes are often used despite any literature that demonstrates a reduction in the rate of periprosthetic joint infection (PJI). The aim of this study is to compare the efficacy of antimicrobial-impregnated incise drapes with nonantimicrobial-impregnated incise drapes for the prevention of PJI in patients undergoing total joint arthroplasty (TJA).

METHODS

A retrospective study of 9774 primary TJAs from 2000 to 2012 was performed. Patients who received an antimicrobial-impregnated incise drape (n = 5241) were compared with patients who received a nonantimicrobial-impregnated incise drape (n = 4533). The decision to use an antimicrobial drape was based on the surgeon's discretion. Patients who developed PJI within 1 year after index surgery were identified. Multivariate logistic regression analysis and sensitivity analysis using propensity score matching were performed to control for potential confounders.

RESULTS

The overall PJI rate was 1.14% (60 of 5241) for patients who received an antimicrobial-impregnated incise drape compared with 1.26% (57 of 4533) for those with a nonantimicrobial-impregnated incise drape. There was no difference in the PJI rate between patients with an antimicrobial-impregnated incise drape and those who received nonantimicrobial-impregnated incise drape in the univariate (odds ratio [OR] = 0.91; 95% confidence interval [CI] = 0.63-1.30), multivariate (adjusted OR = 0.92; 95% CI, 0.63-1.34), or propensity score matching analysis (OR = 0.84; 95% CI = 0.52-1.35).

CONCLUSION

Despite the increasing adoption of the use of antimicrobial-impregnated incise drapes in our institute, this study suggests that antimicrobial-impregnated incise drapes do not reduce PJI in patients undergoing primary TJAs.

Incise Draping Reduces the Rate of Contamination of the Surgical Site During Hip Surgery: A Prospective, Randomized Trial

BACKGROUND

Iodophor-impregnated adhesive incise drapes are widely used during surgeries for reducing surgical site contamination. There is little evidence to support the latter belief. This study evaluated the efficacy of iodophor-impregnated adhesive drapes for reducing bacterial contamination and counts at the incision site during hip surgery.

METHODS

In this prospective, randomized clinical trial, we enrolled 101 patients undergoing open joint preservation procedure of the hip. Half the patients had the adhesive drape applied to the skin prior to incision, while the remainder underwent the same surgery without a drape. Culture swabs were taken from the surgical site at 5 points (preskin preparation, after skin preparation, postincision, before subcutaneous closure, prior to dressing application) and sent for culture and colony counts. Mixed-effects logistic regressions were used to estimate effects of time and drape application on contamination rate.

RESULTS

At the conclusion of surgery, 12.0% of incisions with adhesive drapes and 27.4% without adhesive drapes were positive for bacterial colonization. When controlling for preoperative colonization and other factors, patients without adhesive drapes were significantly more likely to have bacteria present at the time of skin closure, and at all time points when swab cultures were taken.

CONCLUSION

It appears that the iodophor-impregnated adhesive draping significantly reduces bacterial colonization of the incision. Bacterial count at the skin was extremely high in some patients in whom adhesive drapes were not used, raising the possibility that a subsequent surgical site infection or periprosthetic joint infection could arise had an implant been utilized.

Single-Dose, Preoperative Vitamin-D Supplementation Decreases Infection in a Mouse Model of Periprosthetic Joint Infection

BACKGROUND

Despite recent advances, infection remains the most common etiology of arthroplasty failure. Recent work suggests that 25-hydroxyvitamin D (25D) deficiency correlates with the frequency of periprosthetic joint infection (PJI). We endeavored to examine whether 25D3 deficiency leads to increased bacterial burden in vivo in an established mouse model of PJI and, if so, whether this effect can be reversed by preoperative 25D3 supplementation.

METHODS

Mice (lys-EGFP) possessing fluorescent neutrophils were fed a vitamin D3-sufficient (n = 20) or deficient (n = 40) diet for 6 weeks. A group of 25D3-deficient mice (n = 20) were "rescued" with 1 intraperitoneal dose of 25D3 at 3 days before surgery. A stainless steel implant was inserted into the knee joint and the joint space was inoculated with bioluminescent Staphylococcus aureus (1 × 10 colony forming units [CFUs]). In vivo imaging was used to monitor bacterial burden and neutrophil infiltration. Blood was drawn to confirm 25D3 levels 3 days before surgery and on postoperative days (PODs) 0 and 14. Mice were killed at POD 21, and CFUs were quantified after culture. Myeloperoxidase (MPO) and β-N-acetylglucosaminidase (NAG) were assayed to look at neutrophil infiltration and activated tissue macrophage recruitment, respectively.

RESULTS

Serum values confirmed 25D3 deficiency and repletion of the 25D3-rescued group. Bacterial bioluminescence and neutrophil fluorescence were significantly greater (p < 0.05) in the 25D3-deficient group. CFU counts from the joint tissue and implant were also significantly greater in this group (p < 0.05). Rescue treatment significantly decreased bacterial burden and neutrophil infiltration (p < 0.05). Compared with the 25D3-sufficient and 25D3-rescued groups, MPO activity was higher (p < 0.02) and NAG activity was lower (p < 0.03) in the 25D3-deficient group.

CONCLUSIONS

This study demonstrated in vivo in a mouse model of PJI that (1) 25D3 deficiency results in increased bacterial burden and neutrophil infiltration, and (2) this effect can be reversed with preoperative repletion of 25D3.

CLINICAL RELEVANCE

Considering that >65% of patients undergoing arthroplasty have insufficient or low levels of total 25D and that 25D levels can be replenished with ease using a U.S. Food and Drug Administration (FDA)-approved, oral 25D3 product, 25D deficiency may be an important modifiable risk factor in humans undergoing joint replacement.

Factors contributing to airborne particle dispersal in the operating room

Background

Surgical-site infections due to intraoperative contamination are chiefly ascribable to airborne particles carrying microorganisms. The purpose of this study is to identify the actions that increase the number of airborne particles in the operating room.

Methods

Two surgeons and two surgical nurses performed three patterns of physical movements to mimic intraoperative actions, such as preparing the instrument table, gowning and donning/doffing gloves, and preparing for total knee arthroplasty. The generation and behavior of airborne particles were filmed using a fine particle visualization system, and the number of airborne particles in 2.83 m³ of air was counted using a laser particle counter. Each action was repeated five times, and the particle measurements were evaluated through one-way analysis of variance multiple comparison tests followed by Tukey–Kramer and Bonferroni–Dunn multiple comparison tests for post hoc analysis. Statistical significance was defined as a P value ≤ .01.

Results

A large number of airborne particles were observed while unfolding the surgical gown, removing gloves, and putting the arms through the sleeves of the gown. Although numerous airborne particles were observed while applying the stockinet and putting on large drapes for preparation of total knee arthroplasty, fewer particles (0.3–2.0 μm in size) were detected at the level of the operating table under laminar airflow compared to actions performed in a non-ventilated preoperative room (P < .01).

Conclusions

The results of this study suggest that surgical staff should avoid unnecessary actions that produce a large number of airborne particles near a sterile area and that laminar airflow has the potential to reduce the incidence of bacterial contamination.

Minimising the risk of infection: a peri-operative checklist

The purpose of this article is to provide the reader with a seven-step checklist that could help in minimising the risk of PJI. The check list includes strategies that can be implemented pre-operatively such as medical optimisation, and reduction of the bioburden by effective skin preparation or actions taking during surgery such as administration of timely and appropriate antibiotics or blood conservation, and finally implementation of post-operative protocols such as efforts to minimise wound drainage and haematoma formation.

Prevention of Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) has moved into the first place as the cause of failure following total knee arthroplasty (TKA). Recent studies have shown that PJI results in higher mortality in patients than many cancers. The economic burden of treating PJI is likely to exceed $1 billion this year in the US. Thus, it is paramount that all efforts are invested to prevent this dreaded complication after total joint arthroplasty (TJA). This article summarizes some of the most effective and proven strategies for prevention of PJI. It is hoped that the article will be of benefit to the readers of the journal.

Sequence types of Staphylococcus epidermidis associated with prosthetic joint infections are not present in the laminar airflow during prosthetic joint surgery

Molecular characterization of Staphylococcus epidermidis isolates from prosthetic joint infections (PJIs) has demonstrated a predominance of healthcare-associated multi-drug resistant sequence types (ST2 and ST215). How, and when, patients acquire these nosocomial STs is not known. The aim was to investigate if sequence types of S. epidermidis associated with PJIs are found in the air during prosthetic joint surgery. Air sampling was undertaken during 17 hip/knee arthroplasties performed in operating theaters equipped with mobile laminar airflow units in a 500-bed hospital in central Sweden. Species identification was performed using MALDI-TOF MS and 16S rRNA gene analysis. Isolates identified as S. epidermidis were further characterized by MLST and antibiotic susceptibility testing. Seven hundred and thirty-five isolates were available for species identification. Micrococcus spp. (n = 303) and coagulase-negative staphylococci (n = 217) constituted the majority of the isolates. Thirty-two isolates of S. epidermidis were found. S. epidermidis isolates demonstrated a high level of allelic diversity with 18 different sequence types, but neither ST2 nor ST215 was found. Commensals with low pathogenic potential dominated among the airborne microorganisms in the operating field during prosthetic joint surgery. Nosocomial sequence types of S. epidermidis associated with PJIs were not found, and other routes of inoculation are therefore of interest in future studies.

Preventing surgical-site infections: measures other than antibiotics

Surgical-site infections (SSIs) due to intra-operative contamination are chiefly ascribable to airborne particles carrying microorganisms, mainly Staphylococcus aureus, which settle on the surgeon's hands and instruments. SSI prevention therefore rests on minimisation of airborne contaminated particle counts, although these have not been demonstrated to correlate significantly with SSI rates. Maintaining clear air in the operating room classically involves the use of ultra clean ventilation systems combining laminar airflow and high-efficiency particulate air filters to create a physical barrier around the surgical table; in addition to a stringent patient preparation protocol, appropriate equipment, and strict operating room discipline on the part of the surgeon and other staff members. SSI rates in clean surgery, although influenced by the type of procedure and by patient-related factors, are consistently very low, of about 1% to 2%. These low rates, together with the effectiveness of prophylactic antibiotic therapy and the multiplicity of parameters influencing the SSI risk, are major obstacles to the demonstration that a specific measure is effective in decreasing SSIs. As a result, controversy surrounds the usefulness of many measures, including laminar airflow, body exhaust suits, patient preparation techniques, and specific surgical instruments. Impeccable surgical technique and operating room behaviour, in contrast, are clearly essential.