Principles of a clean operating room environment

Postoperative Infection Rates After Total Ankle Arthroplasty: A Comparison With and Without the Use of a Surgical Helmet System

Following total joint arthroplasty, surgical site infections (SSI) and periprosthetic joint infections (PJI) are associated with increased patient morbidity and healthcare utilization. Current positive-pressure surgical sterile helmet system (SHS) were developed as a feasible, useful version of the body exhaust system.The use of SHS has not yet been proven to decrease infection rates in the orthopedic literature. The primary purpose of this study is to compare the infection rates between patients who underwent total ankle arthroplasty (TAA) with a surgical team wearing SHS versus without SHS.A retrospective chart review in patients undergoing primary TAA with the surgeon wearing SHS (Group 1) or standard surgical attire (Group 2) was conducted. The primary outcome was postoperative SSI and PJI. The rate of wound complications, revision rates, and associated procedures were also analyzed. We identified 109 patients in Group 1 and 151 patients in Group 2. The rate of SSI was 12.8% in Group 1 and 14.6% in Group 2 (p = .411). The rate of PJI was 0.92% in Group 1 and 2.6% in Group 2 (p = .411). There was no difference in revision rates between the two groups. This study suggests that SHS does not appear to protect against postoperative SSI or PJI after TAA. Conversely, we did not find a higher infection rate compared to standard surgical attire despite recent in-vitro studies suggesting SHS as a source of wound contamination. The utility of SHS does not appear to influence the prevalence of postoperative SSI or PJI.

Multiplanar fracture reducer versus manual traction in the treatment of tibial shaft fractures with intramedullary nails

OBJECT

The purpose of this study was to propose a new traction device, a multiplanar fracture reducer (MFR), for the treatment of tibial shaft fractures with intramedullary nails (IMN). The efficiencies of the multiplanar fracture reducer and manual traction (MT) in the treatment of tibial shaft fractures with IMN were compared.

METHODS

From January 2019 to January 2020, a total of 79 patients were enrolled in this study, among whom 38 were treated with MFR while 41 were treated with MT. Their demographics and fracture characteristics, surgical data, and prognostic data between the two groups were compared.

RESULTS

The mean number of intra-operative fluoroscopies in the MFR group was less than that in the MT group (19.4 vs 21.2, p < 0.001); surgical procedures involving open reduction were more in the MT group than in MFR group (0 vs 5, p = 0.026); there were less assistants in the MFR group than in the MT group (1 vs 1.9, p < 0.001), while the average Lysholm Knee Function Score and knee flexion were 92.7 ± 2.0 and 128.8 ± 1.4 in the MFR group, and 91.9 ± 2.1 and 127.5 ± 1.8 in the MT group, respectively. Both LKFS and knee flexion in the MFR group were significantly better than those in the MT group (p = 0.032 and p < 0.001). The remaining data between the two groups were comparable.

CONCLUSION

MFR is a safe and effective device for the minimal invasive treatment of tibial shaft fractures fixed with IMN.

Application of the multiplanar fracture redactor in the treatment of tibial shaft fractures with intramedullary nails

This prospective study aimed to introduce the application of the multiplanar fracture redactor (MFR) in the treatment of tibial shaft fractures with intramedullary nails (IMNs). From February to June 2018, a total of 18 patients with tibial shaft fractures were recruited. MFR was used to help achieve the reduction of tibial shaft fractures with IMN in all patients. The demographic and fracture characteristics, surgical data, postoperative complications and prognostic indicators of 16 patients were recorded. All operations were performed under closed reduction, excellent radiological and functional outcomes were observed. The average duration of surgery, intraoperative blood loss, intraoperative fluoroscopy times, number of intraoperative assistants, and duration of postoperative hospital stay were 91.2 ± 26.1 min, 95.0 ± 58.3 ml, 19.2 ± 2.3 times, 1 (1-2), and 7.8 ± 2.6 days, respectively. The mean Lysholm Knee Function Score (LKFS), American Orthopaedic Foot and Ankle Society (AOFAS) and visual analogue scale (VAS) scores at one year after surgery were 96.8 ± 2.1, 94.8 ± 2.9, and 1 (0-3), respectively. Wound infection, non-union, malunion or complications associated with MFR were not observed in this study. Thus, MFR was a safe and neater method to achieve and maintain the reduction of tibial shaft fractures with IMN.

Traction methods in the retrograde intramedullary nailing of femur shaft fractures: the double reverse traction repositor or manual traction

OBJECTIVE

The purpose of this prospective study was to compare the double reverse traction repositor (DRTR) and manual traction in retrograde intramedullary nailing (RE-IMN) for femoral shaft fractures.

PATIENTS AND METHODS

Seventy-seven patients with femur shaft fractures were randomized to undergo surgery with either DRTR or manual traction (MT) to facilitate RE-IMN between January 2018 and January 2019. Demographics, fracture characteristics, surgical data, post-operative complications, and functional outcomes were assessed. Data from 72 patients completing the final follow-up (12 months) were analysed in this study.

RESULTS

The average number of intra-operative perspectives in the DRTR group was 27.7, which was significantly reduced compared with that in the MT group (31.3, p < 0.001). Fewer assistants were required in the DRTR group compared with the MT group (1.1 vs 1.9, p < 0.001). Fewer patients with open reduction were discovered in the DRTR group compared with the MT group (2.8 vs 19.4, p=0.024). Demographics, fracture characteristics, other surgical data, and prognostic parameters were comparative between the two groups.

CONCLUSIONS

The DRTR can be effectively and safely used to treat femur shaft fractures with RE-IMN. The DRTR achieves similar results as MT and is also superior to MT in terms of intra-operative perspectives, the number of assistants, and the open reduction rate.

What Preoperative Optimization Should Be Implemented to Reduce the Risk of Surgical Site Infection/Periprosthetic Joint Infection (SSI/PJI) in Patients Undergoing Total Ankle Arthroplasty (TAA)?

RECOMMENDATION

We recommend that patients awaiting total ankle arthroplasty (TAA) be optimized prior to surgery by implementing skin cleansing, nutritional status enhancement, glycemic control, body mass index (BMI) optimization, smoking cessation, and management of immune-modulating comorbidities. At the time of surgery, there is strong evidence that optimal preparation of the surgical site with an alcohol-containing agent, weight-based and timely administration of antibiotic prophylaxis, and reducing operating room traffic should also be put in place.

LEVEL OF EVIDENCE

Moderate.

DELEGATE VOTE

Agree: 100%, Disagree: 0%, Abstain: 0% (Unanimous, Strongest Consensus).

Comparison of air exhausts for surgical body suits (space suits) and the potential for periprosthetic joint infection

BACKGROUND

Periprosthetic joint infection is a major complication of total joint replacement surgery and is associated with significant morbidity, mortality and financial burden. Surgical body suits (space suits), originally designed to reduce the incidence of infection, have paradoxically been implicated in increased periprosthetic joint infection rates recently. Air exhausted from space suits may contribute to this increased rate of periprosthetic joint infection.

AIM

To investigate the flow of air exhausted from space suits commonly used in modern operating theatres.

METHODS

The exhaust airflow patterns of four commercially available space suit systems were compared using a fog machine and serial still photographs.

FINDINGS

The space suit systems tested all air exhausted into the operating room. The single fan systems with a standard surgical gown exhausted air laterally from the posterior gown fold at approximately the level of the surgical field. The single fan system with a dedicated zippered suit exhausted air at a level below the surgical field. The dual fan system exhausted air out of the top of the helmet at a level above the surgical field.

CONCLUSIONS

Space suit systems currently in use in joint replacement surgery differ significantly from traditional body exhaust systems; rather than removing contaminated air from the operating environment, modern systems exhaust this air into the operating room, in some cases potentially towards the sterile instrument tray and the surgical field.

Surgical Head Coverings: A Literature Review

Microorganisms that cause surgical site infections may either be present on the patient's skin or mucous membranes or transmitted to the patient by health care personnel, the environment, or other items in the perioperative setting. This literature review analyzes the evidence used to support the recommendation that perioperative personnel should cover their heads, hair, and ears in the semirestricted and restricted areas. A literature search produced 27 articles related to bacterial shedding from skin and hair, pathogenic organisms present on the hair and ears, and case reports of infectious organisms passed from health care providers to patients. Although there is no conclusive evidence that wearing a head covering can help prevent surgical site infections, the potential benefits to patients when compared with the risks suggest that perioperative team members should cover their heads, hair, and ears in the semirestricted and restricted areas to provide the best possible protection for surgical patients.

Microorganisms in Confined Habitats: Microbial Monitoring and Control of Intensive Care Units, Operating Rooms, Cleanrooms and the International Space Station

Indoor environments, where people spend most of their time, are characterized by a specific microbial community, the indoor microbiome. Most indoor environments are connected to the natural environment by high ventilation, but some habitats are more confined: intensive care units, operating rooms, cleanrooms and the international space station (ISS) are extraordinary living and working areas for humans, with a limited exchange with the environment. The purposes for confinement are different: a patient has to be protected from infections (intensive care unit, operating room), product quality has to be assured (cleanrooms), or confinement is necessary due to extreme, health-threatening outer conditions, as on the ISS. The ISS represents the most secluded man-made habitat, constantly inhabited by humans since November 2000 – and, inevitably, also by microorganisms. All of these man-made confined habitats need to be microbiologically monitored and controlled, by e.g., microbial cleaning and disinfection. However, these measures apply constant selective pressures, which support microbes with resistance capacities against antibiotics or chemical and physical stresses and thus facilitate the rise of survival specialists and multi-resistant strains. In this article, we summarize the available data on the microbiome of aforementioned confined habitats. By comparing the different operating, maintenance and monitoring procedures as well as microbial communities therein, we emphasize the importance to properly understand the effects of confinement on the microbial diversity, the possible risks represented by some of these microorganisms and by the evolution of (antibiotic) resistances in such environments – and the need to reassess the current hygiene standards.

Traction table versus manual traction in the intramedullary nailing of unstable intertrochanteric fractures: A prospective randomized trial

INTRODUCTION

The purpose of this prospective randomized study was to compare traction table with manual traction for the reduction and nailing of unstable intertrochanteric femur fractures.

DESIGN

Prospective, randomized, two-center trial.

MATERIALS AND METHODS

72 elderly patients with AO/OTA 31A2 and 31A3 proximal femur fractures were randomized to undergo surgery with either manual traction (MT) or traction table (TT) facilitated intramedullary nailing. The demographics and fracture characteristics, duration of preparation and surgery, total anaesthesia time, fluoroscopy time, blood loss, number of assistants, early post-operative radiological evaluations and 6th month functional and radiological outcomes were evaluated. Data of 64 patients attending 6th month follow-up examination were evaluated statistically.

RESULTS

No significant differences were observed between groups regarding demographics and fracture characteristics. In the manual traction group, there was a significant time gain in respect of the positioning and preparation period (18.0±1.6min in MT group, 29.0±2.4min in TT group) (p<0.05). In terms of total anaesthesia time (Preparation+surgery) approximately 6min of difference was observed in favor of MT group (72.8±14.0min for MT and 78.6±6.5min for TT, [p<0.05]). Median number of assistants needed was significantly lower in TT group (2 assistants [1-3]) in MT group and (1 assistant [1,2]) in TT group [p<0.05]). There was no significant difference between two groups regarding other surgical and outcome parameters.

CONCLUSIONS

Manual traction reduced the preparation time and total anaesthesia duration, despite an increase in number of surgical assistant.

LEVEL OF EVIDENCE

Level II.

Contamination Relative to the Activation Timing of Filtered-Exhaust Helmets

BACKGROUND

Filtered-exhaust helmet systems are commonplace during total joint arthroplasty, but their ability to limit intraoperative contamination has been questioned. We hypothesized that activation of the airflow system after complete gowning would lead to decreased contamination of the surgical environment.

METHODS

Using a fluorescent particle model, the maximal particle spread from a filtered-exhaust helmet and contamination of the surgical environment based on timing of airflow activation through simulated surgical gowning procedures were evaluated.

RESULTS

Helmet airflow analysis revealed particle spread greater than 5 feet in all trials. Activation before gowning resulted in a significantly greater contamination in the control group compared with the experimental group (P = .014).

CONCLUSIONS

We recommend complete surgical gowning before activation of the airflow system.

The management of periprosthetic infections in the future: a review of new forms of treatment

The number of arthroplasties being undertaken is expected to grow year on year, and periprosthetic joint infections will be an increasing socioeconomic burden. The challenge to prevent and eradicate these infections has resulted in the emergence of several new strategies, which are discussed in this review. Cite this article: Bone Joint J 2015;97-B:1162-9.

Dissatisfied patients after total knee arthroplasty: a registry study involving 114 patients with 8-13 years of followup

BACKGROUND AND PURPOSE

In 2003, an enquiry by the Swedish Knee Arthroplasty Register (SKAR) 2-7 years after total knee arthroplasty (TKA) revealed patients who were dissatisfied with the outcome of their surgery but who had not been revised. 6 years later, we examined the dissatisfied patients in one Swedish county and a matched group of very satisfied patients.

PATIENTS AND METHODS

118 TKAs in 114 patients, all of whom had had their surgery between 1996 and 2001, were examined in 2009-2010. 55 patients (with 58 TKAs) had stated in 2003 that they were dissatisfied with their knees and 59 (with 60 TKAs) had stated that they were very satisfied with their knees. The patients were examined clinically and radiographically, and performed functional tests consisting of the 6-minute walk and chair-stand test. All the patients filled out a visual analog scale (VAS, 0-100 mm) regarding knee pain and also the Hospital and Anxiety and Depression scale (HAD).

RESULTS

Mean VAS score for knee pain differed by 30 mm in favor of the very satisfied group (p < 0.001). 23 of the 55 patients in the dissatisfied group and 6 of 59 patients in the very satisfied group suffered from anxiety and/or depression (p = 0.001). Mean range of motion was 11 degrees better in the very satisfied group (p < 0.001). The groups were similar with regard to clinical examination, physical performance testing, and radiography.

INTERPRETATION

The patients who reported poor response after TKA continued to be unhappy after 8-13 years, as demonstrated by VAS pain and HAD, despite the absence of a discernible objective reason for revision.

Nondrainage decreases blood transfusion need and infection rate in bilateral total knee arthroplasty

This retrospective study enrolled 526 patients undergoing bilateral total knee arthroplasties at our institution. In nondrainage group (Group 1) of 255 patients (510 knees), a disposable elastic sterile exsanguination tourniquet (HemaClear), wound closure in layers and Jones Bandage, without pre-tourniquet removal hemostasis or Hemovac drain were used. In drainage group (Group 2) of 227 patients (454 knees), pneumatic tourniquet, post-deflation hemostasis, a Hemovac drain and Jones bandage were used. The maximal drop in hemoglobin was significantly greater in Group 2 than Group 1 (P < 0.001). Also infection rate was significantly lower in Group 1 (P = 0.017). The use of sterile tourniquet removed after wound closure without Hemovac drain decreases blood transfusion need, infection rate, tourniquet related pain and postoperative complications.

Infection control in operating theatres

The operating theatre complex is the heart of any major surgical hospital. Good operating theatre design meets the functional needs of theatre care professionals. Operating theatre design must pay careful consideration to traffic patterns, the number and configuration of nearby operating rooms, the space required for staff, administration and storage, provisions for sterile processing and systems to control airborne contaminants (Wan et al 2011). There have been infection control issues with private finance initiative built operating theatres (Unison 2003, Ontario Health Coalition 2005). The aim of this article is to address these issues as they relate to infection control and prevention.

Real-time monitoring of non-viable airborne particles correlates with airborne colonies and represents an acceptable surrogate for daily assessment of cell-processing cleanroom performance

BACKGROUND AIMS

Airborne particulate monitoring is mandated as a component of good manufacturing practice. We present a procedure developed to monitor and interpret airborne particulates in an International Organization for Standardization (ISO) class 7 cleanroom used for the cell processing of Section 351 and Section 361 products.

METHODS

We collected paired viable and non-viable airborne particle data over a period of 1 year in locations chosen to provide a range of air quality. We used receiver operator characteristic (ROC) analysis to determine empirically the relationship between non-viable and viable airborne particle counts.

RESULTS

Viable and non-viable particles were well-correlated (r(2) = 0.78), with outlier observations at the low end of the scale (non-viable particles without detectable airborne colonies). ROC analysis predicted viable counts ≥ 0.5/feet(3) (a limit set by the United States Pharmacopeia) at an action limit of ≥ 32 000 particles (≥ 0.5 µ)/feet(3), with 95.6% sensitivity and 50% specificity. This limit was exceeded 2.6 times during 18 months of retrospective daily cleanroom data (an expected false alarm rate of 1.3 times/year). After implementing this action limit, we were alerted in real time to an air-handling failure undetected by our hospital facilities management.

CONCLUSIONS

A rational action limit for non-viable particles was determined based on the correlation with airborne colonies. Reaching or exceeding the action limit of 32 000 non-viable particles/feet(3) triggers suspension of cleanroom cell-processing activities, deep cleaning, investigation of air handling, and a deviation management process. Our full procedure for particle monitoring is available as an online supplement.

Sterility of the personal protection system in total joint arthroplasty

BACKGROUND

Bacteria shed by operating room personnel is a source of wound contamination and postoperative infections. The personal protection system (PPS) was designed to decrease airborne bacteria and intraoperative contamination in total joint arthroplasty.

QUESTIONS/PURPOSES

We determined the microbial contamination rate of the PPS and incidence of contamination with key pathogens, Staphylococcus aureus and coagulase-negative staphylococci.

PATIENTS AND METHODS

We prospectively evaluated PPS contamination in 61 primary THAs and 41 TKAs. The PPS were assumed to be sterile before opening the packs. The initial culture was taken immediately after the hood was placed over the helmet. Four cultures were collected at the conclusion of the procedure. Plates were examined and colonies were classified according to Gram stain results and biochemical tests. S. aureus was classified as methicillin-resistant or -susceptible.

RESULTS

At time zero, 22 of 102 cultures isolated an organism, accounting for a contamination rate of 22%. The bacterial contamination rate of the PPS at the conclusion of the procedure was 47% (48 of 102). The relative percentage of the various organisms found was coagulase-negative staphylococci 50%, Micrococcus sp. 20%, methicillin-susceptible S. aureus 11%, and methicillin-resistant S. aureus (MRSA) 1%.

CONCLUSIONS

The external surface of the PPS cannot be assumed to be sterile after its removal from the original packaging. Of all the PPS studied, the potential pathogens coagulase-negative staphylococcus, S. aureus, and MRSA were found in 43%. This study supports the need to change gloves if the PPS is touched or adjusted during the procedure.

Is repetitive intraoperative splash basin use a source of bacterial contamination in total joint replacement?

Splash basins are used in arthroplasty cases to wash instruments. Several studies in the literature have shown these basins being a potential source of bacterial infection. This study assesses the risk of contamination of intraoperative splash basins used to wash and store instruments. A total of 46 random clean primary arthroplasty cases (32 hips, 13 knees, and 1 unicondylar knee) were studied by taking cultures of sterile splash basins as soon as they are opened (controls) and again at wound closure after instruments and debris have come into contact with the sterile water. All cultures were taken with sterile culture swabs and sent to the laboratory for aerobic, anaerobic, and fungal culture. Outcome measured was any positive culture. A total of 92 cultures from 46 cases were tested. Only 1 (2.17%) control culture, which grew Streptococcus viridans, was positive for bacterial growth. One of 46 samples (2.17%) taken at wound closure was positive for coagulase-negative Staphylococcus. Mean time between basin opening and wound closure was 180±45 minutes. For the 1 infected sample taken at the conclusion of the case, it was 240 minutes. Previous studies show contamination rates as high as 74% for splash basins used intraoperatively. Our study contradicts the belief that splash basins are a high source of infection, with only 2.17% of basins showing contamination. Splash basins can be a potential source of contamination, but the risk is not as high as previously cited in the orthopedic literature.

Sterile surgical helmet system in elective total hip and knee arthroplasty

PURPOSE

To evaluate the sterility of the sterile surgical helmet system (SSHS) during elective total hip and knee arthroplasty in theatres with (n=20) and without (n=20) laminar flow.

METHODS

Three surgeons performed 14 total knee arthroplasties (TKAs) and 6 total hip arthroplasties (THAs) in a laminar flow theatre and 15 TKAs and 5 THAs in a non-laminar flow theatre. An SSHS was used in all the procedures. Samples were taken from the hood at 30-minute intervals during surgery. Swabs were then broken into cooked meat broths for cultivation of organisms. The broths were then directly inoculated onto blood agar and fastidious anaerobic agar for culture of aerobic and anaerobic bacteria, respectively. After 24 hours, these plates were reinoculated with broths that had been incubated for 24 hours. Microbial growth was quantified as 0 (none), 1 (mild), 2 (moderate) and 3 (heavy). Bacterial contamination in the 2 groups at 30, 60 and 90 minutes was compared.

RESULTS

Respectively in the laminar and non-laminar flow theatres, 0 and 9 of the SSHSs showed bacterial growth after direct inoculation, and 14 and 18 of the SSHSs grew 18 and 24 types of organisms in the swab cultures after 24 hours of incubation. Respectively at 30, 60, and 90 minutes, the degree of contamination from direct incubation was significant, but the degree of contamination on swabs after 24 hours of inoculation was not significant. The mean time-dependent contamination after direct inoculation was 0 for the laminar flow group and 0.5, 0.75, and 1.0 for the non-laminar flow group, whereas the corresponding values after 24 hours of incubation were 1.8, 1.8, and 2.6, and 2, 2.75, and 2.95. Coagulase negative Staphylococcus aureus was the most common organism in both groups.

CONCLUSION

80% of SSHSs used were contaminated intra-operatively. Direct contact with the SSHS should be avoided by the operating team during surgery. Routine changing of gloves in case of contact with the SSHS should be practised.

Directed air flow to reduce airborne particulate and bacterial contamination in the surgical field during total hip arthroplasty

This study evaluated the use of a system that delivers a small field of local, directed air from a high-efficiency particulate air (HEPA) filter to reduce airborne particulate and airborne bacteria in the surgical field during total hip arthroplasty. Thirty-six patients were randomized into 3 groups: with directed air flow, with the directed air flow system present but turned off, and control. Airborne particulate and bacteria were collected from within 5 cm of the surgical wound. All particulate and bacterial counts at the surgical site were significantly lower in the directed air flow group (P < .001). The directed air flow system was effective in reducing airborne particulate and colony-forming units in the surgical field during total hip arthroplasty.

A standardized and safe method of sterile field maintenance during intra-operative horizontal plane fluoroscopy

Background

Intra-operative fluoroscopy for orthopaedic procedures frequently involves imaging in the horizontal plane, which requires the lower portion of the C-arm (x-ray tube) to be rotated from an unsterile zone (beneath the table) into the sterile field. To protect the integrity of the sterile field the C-arm must be draped repeatedly throughout the surgical case. The current, un-standardized, practice employs draping procedures which violate the Association of peri-Operative Registered Nurses (AORN) Standards and Recommended Practices, waste time and material, and pose an increased risk for surgical site infection.

Presentation of the hypothesis

Use of a novel sterile C-arm drape (C-armor) that maintains the integrity of the sterile field, will improve operating room efficiency and reduce surgical site infection risk factors. This reduction in risk factors may potentially reduce surgical site infections in orthopaedic surgical cases requiring repeated horizontal x-ray imaging.

Testing the Hypothesis

Savings in time and material and the reduction in surgical site infection risk factors afforded by using C-armor are intuitive to those skilled in the practice of orthopaedic surgery. Testing for a reduction in the number of microorganisms introduced to the surgical site by improved C-arm draping would be challenging due to the multiple confounding factors during a surgical operation. Determination of an absolute reduction in surgical site infections may be possible, but will require accounting for many confounding variables and a large study sample in order to achieve statistical significance.

Implications of the Hypothesis

Improved intraoperative workflow, healthcare savings and a reduction in surgical site infection risk factors will be achieved by utilizing a standardized and safe method of sterile field maintenance during intra-operative horizontal plane fluoroscopy.

Predicting bacterial populations based on airborne particulates: a study performed in nonlaminar flow operating rooms during joint arthroplasty surgery

BACKGROUND

Prevention of postsurgical infection is preferable to treatment. Prevention requires identification and control of the potential sources of microbial contamination. This study investigated whether the density of airborne particulates can predict the density of viable airborne bacteria at the surgery site.

METHODS

A standard particle analyzer was used to measure the number and diameter of airborne particulates during 22 joint arthroplasty surgeries. An impact air sampler and standard culture plates were used to identify and count colony-forming units (CFU).

RESULTS

Particulate density averaged >500,000 particles/m(3) per 10-minute interval, and 1786 CFU were identified, primarily gram-positive cocci. A particle density > or = 10 microm explained 41% of the variation in CFU density. Particle and CFU density increased with longer surgery duration and higher staff counts.

CONCLUSIONS

These findings support the use of environmental controls that isolate and protect the surgical site from airborne particulates and contamination.