Contamination Relative to the Activation Timing of Filtered-Exhaust Helmets

Surgical helmet systems in total joint arthroplasty: assessment of hood sterility and donning technique

BACKGROUND

The incidence of prosthetic joint infection (PJI) is increasing, coincident with the rising volume of joint arthroplasty being performed. With recent controversy regarding the efficacy of surgical helmet systems (SHS) in preventing infection, the focus has turned to the correct donning techniques and usage of surgical hoods. The aim of this study was to compare the bacterial contamination of the operating surgeon's gloves after two common donning techniques of SHS hoods. We also evaluated the baseline sterility of the SHS hoods at the beginning of the procedure.

METHODS

The bacterial contamination rate was quantified using colony-forming units (CFUs), with 50 trials performed per donning technique. Samples were cultured on 5% Columbia blood agar in ambient air at 37 °C for 48 h and all subsequent bacterial growth was identified using a MALDI-TOF mass spectrometer. In Group 1, the operating surgeon donned their colleague's hood. In Group 2, the operating surgeon had their hood applied by a non-scrubbed colleague. After each trial, the operating surgeon immediately inoculated their gloves onto an agar plate. The immediate sterility of 50 SHS hoods was assessed at two separate zones-the screen (Zone 1) and the neckline (Zone 2).

RESULTS

There was no significant difference in contamination rates between the two techniques (3% vs. 2%, P = 0.99) or between right and left glove contamination rates. Immediately after donning, 6/50 (12%) of SHS hoods cultured an organism. Contamination rates at both the face shield and neckline zones were equivalent. The majority of bacteria cultured were Bacillus species.

DISCUSSION

We found no significant difference in the operating surgeon's glove contamination using two common SHS hood-donning techniques when they were performed under laminar airflow with late fan activation. We suggest the SHS hood should not be assumed to be completely sterile and that gloves are changed if it is touched intraoperatively.

Effectiveness of Manual Terminal Cleaning Varies on High-Touch Surfaces Near the Operative Field

Background

Periprosthetic joint infection may result from pathogen to patient transmission within the environment. The purpose of this study is to evaluate the contamination level of selected high-touch surfaces in the operating room (OR) using a blacklight fluorescent marking system after a manual terminal clean.

Methods

Prior to the manual terminal clean, 16 high-touch surfaces were marked using a blacklight fluorescent gel. The marked areas were assessed the next morning for thoroughness of cleaning. Surfaces were categorized based on the average percent of the marks removed as “clean” (>75%), “partially clean” (26%-74%), or poorly cleaned (<25%). This process was repeated randomly 12 times. Terminal cleaning was done in the standard fashion, and the perioperative team was unaware of the initiation of this study.

Results

A total of 936 marks were analyzed. There was a significant difference in the number of marks completely clean (29.1%, 272/936) vs marks that were not touched (40.8%, 382/936), P < .001. Only the OR back table (75%) had a rating of clean. Partially clean areas included Mayfield table (72%), overhead lights (70.1%), infusion pump (61.1%), clock reset button (58.3%), table remote control (50%), tourniquet machine (50%), and the OR table (33.3%). Poorly cleaned surfaces included anesthesia medication cart (21.8%), door handles (20.8%), phone (16.7%), electrocautery unit (16.7%), foot pedal (16.7%), anesthesia cart (16.2%), nurses’ station (14.1%), and supply cabinet doors (6%).

Conclusions

Effectiveness of manual terminal cleaning varied greatly across surfaces. In general, surfaces further from the operative field were less likely to have markings removed.

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.

A back table ultraviolet light decreases environmental contamination during operative cases

BACKGROUND

The purpose of this study is to assess the impact of a germicidal ultraviolet light-emitting diode (LED) on the contamination level of a back table in the operating room (OR) during total joint arthroplasty procedures.

METHODS

Eight Tryptic Soy Agar petri plates were placed on a table located near the operative field and exposed to air. One plate was removed on the hour over an 8-hour time span. The back table had either an UV-LED for disinfection or a sham UV-LED. This process was repeated in 12 different ORs (6 with UV light, 6 with sham device). The plates were then incubated for 48 hours at 36°C ± 1°C . Colony forming units (CFU) were recorded 24 and 48 hours after incubation.

RESULTS

There was a statistically significant difference in total CFUs between the intervention vs sham at 24-hours (27 vs 95, P = .0001) and 48-hours (38 vs 122, P < .0001). The multivariate analysis revealed that the 24-hour and 48-hour count, the predictors UV light (P = .002) and hour of plate removal (P = .050) were statistically significantly associated with CFU counts. Together, the predictor variables explained 15.8% and 23.0% of the variance in CFU counts at 24- and 48-hours, respectively.

CONCLUSIONS

A back table UV-LED may decrease environmental contamination near the operative field. This has potential to lead to a decrease in joint infection.

The Relationship between Bacterial Load and Initial Run Time of a Surgical Helmet

Background

Periprosthetic joint infection (PJI) is a complication of arthroplasty surgery with significant morbidity and mortality. Surgical helmets are a possible source of infection. Pre-existing dust and microorganisms on its surface may be blown into the surgical field by the helmet ventilation system.

Methods

Twenty surgical helmets at our institution were assessed through microscopy and polymerase chain reaction testing. Helmets were arranged with agar plates under the front and rear outflow vents. Helmets ran while plates were exchanged at different time points. Bacterial growth was assessed via colony counts and correlated with fan operating time. Gram staining and 16S sequencing were performed to identify bacterial species.

Results

The primary microbiological contaminate identified was Burkholderia. There was an inverse relationship between colony formation and fan operating time. The highest number of colonies was found within the first minute of fan operating time. There was a significant decrease in the number of colonies formed from the zero-minute to the three (27 vs 5; P = <.01), four (27 vs 3; P = <.01), and five-minute (27 vs 4; P = <.01) time points for the front outflow plates. A significant difference was also observed between the one-minute and four-minute time points ( P = .046).

Conclusion

We observed an inverse relationship between bacterial spread helmet fan operation time, which may correlate with dispersion of pre-existing contaminates. To decrease contamination risk, we recommend that helmets are run for at least 3 min prior to entering the operating room.

Iatrogenic Contamination With a Surgical Helmet System in Orthopedic Surgery

Surgical helmet systems (SHSs) have been used to decrease iatrogenic contamination to prevent periprosthetic joint infections. However, the use of SHSs has been controversial. Therefore, the purpose of this study was to investigate iatrogenic contamination of traditional surgical attire (TSA), SHSs, and SHSs with delayed ventilation (SHS-DV) (helmet fan not turned on until surgeon gowned and gloved). A total of 180 orthopedic surgical procedures were prospectively enrolled and randomized into one of three cohorts. The TSA cohort included any orthopedic procedures, while the SHS and SHS-DV cohorts included arthroplasty procedures. Cultures were obtained from bilateral forearms, axillae, the sternum, and face shields for SHS groups. There were 60 surgeries in each group. The rate of positive cultures was calculated for each cohort and stratified by location and type of microorganism. The positive culture rates were 15% in the TSA, 25% in the SHS, 18% in the SHS-DV cohorts. The positive swab culture rates were 6% in the TSA, 7% in the SHS, and 4% in the SHS-DV cohorts. The positive culture rate was highest from the forearms in the TSA cohort (10%), the face shield in the SHS cohort (20%), and the chest in the SHS-DV cohort (7%). Coagulase-negative Staphylococcus was the most common bacteria cultured. The overall bacterial contamination rates were similar between the TSA and the SHS cohorts, with a lower rate in the SHS-DV cohort. Waiting to initiate airflow in SHSs and treating the shields as contaminated may reduce iatrogenic contamination. [Orthopedics. 2021;44(6):e753-e756.].

Orthopedic Surgical Helmet Systems Significantly Impair Speech Intelligibility

Surgical suits provide protection to orthopedic surgeons, but the suits and fan noise may interfere with communication between operative team members. The goal of this study was to quantify the fan sound and effect of the suit, fan, and N95 mask. Sound levels were measured using a specialized manikin and evaluated using preferred speech interference levels (PSILs), noise criterion (NC) ratings, and comparison with speech sound levels from the literature. Additionally, sound blocking due to the surgical suit was measured and combined effects of the fan and suit were described using a signal to noise ratio (SNR). The noise with the fan at medium and high speed was louder than average speech and the PSILs at these speeds were significantly higher than with the fan off. The fan NC rating of 50 to 60 exceeded the recommended range of 25 to 30 for operating rooms. The N95 mask, space suit, and distance between speaker and receiver all reduced the sound signal at the receiver's ear, with the worst case being full personal protective equipment on both and speaker distanced from receiver. The estimated SNR for the suit and fan system was negative for many frequency bands used in speech, indicating more noise than signal. Multiple measures indicated that the fan noises were at levels associated with speech interference. This noise combined with sound blocking provided by the suit produced SNRs commonly associated with noisy to very noisy environments. This study suggests the combined effects of the suit, fan, and distance may negatively impact operating room communication. [Orthopedics. 2021;44(4):208-214.].

Examination of Surgical Helmet and Surgical Hood Application Methods in Reducing Contamination in Arthroplasty Surgery

Background

Contamination of the surgeon during gowning is a possible risk factor for prosthetic joint infection in arthroplasty surgery. Surgical helmets are a common form of personal protective equipment used during this type of surgery. Increasingly, there is a focus on the methods of application of the surgical hood and gown while wearing these helmets.

Methods

Ultraviolet fluorescent powder was used to represent air-borne contaminant and applied through the airflow inlet of the surgical helmet. Seven methods of helmet and surgical gown application methods were examined. A ultraviolet torch was used to determine the level of contamination across 11 body regions. A single body region with less than 10 particles was classified as minor contamination, and over 10 particles as major contamination.

Results

Early activation of the surgical helmet resulted in significant level of contamination across the majority of body regions. Major contamination also affected the scrub nurse when applying the surgical hood to the surgeon’s helmet. Late activation of helmet system resulted in only minor level of contamination to the surgeon’s shoulders and forearms. Adhesive wrist wraps over the inner gloves did not decrease contamination when added to late activation of the helmet.

Conclusion

It is our recommendation that the surgical hood should be applied by an unsterile theater assistant and that the surgical helmet system should be activated after the surgeon has applied inner gloves to minimize the level of contamination to the surgeon’s gown.

The Orthopaedic Trauma Service and COVID-19: Practice Considerations to Optimize Outcomes and Limit Exposure

The COVID-19 pandemic has presented challenges to healthcare systems, including the cancellation and then staged resumption of elective procedures. The orthopaedic trauma community has continued to provide care to patients with acute musculoskeletal injuries that cannot be delayed in all scenarios. This article summarizes and provides relevant information (orthopaedic trauma service, outpatient fracture clinic, inpatient surgery) to the practicing orthopaedic traumatologist on maximizing outcomes while limiting exposure during the pandemic. LEVEL OF EVIDENCE:: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.

Does the Method of Sterile Glove-Opening Influence Back Table Contamination? A Fluorescent Particle Study

BACKGROUND

Surgical site infections (SSI) may result from inadvertent intraoperative contamination events. This study investigated the method of opening surgical gloves onto the operative field (OF) and potential contamination rates.

METHODS

Twenty surgical glove packets were coated with a commercially available fluorescent particle powder. Two methods of glove openings (10 surgical glove packets in each cohort) were investigated: direct drop (DD) onto the OF vs opening and direct hand-off (DH) to a sterile intermediary (SI). Ultraviolet black light was used to quantify fluorescent particles for dispensed glove packets and the OF in both cohorts. The gloves of the SI were inspected in the DH cohort. A previously used contamination scale for fluorescent particle model contamination was employed: 0: no detectable fluorescent particle specks, 1: 1-5 specks, 2: 5-10 specks, 3: 11-100 specks, 4: >100 specks.

RESULTS

The DD cohort had a median OF contamination of 4 (range, 3-4) vs 3 for the DH trials (range, 1-3; P = .001). Likewise, the median glove contamination was higher in the DD cohort, 3 (range, 2-4) vs 1 for DH (range, 0-3; P = .007). Minimal contamination was found on the hands of the SI. Total fluorescent contamination rates, including the gloves of SI in the DH cohort, revealed greater overall contamination in DD (median, 3.5; range, 2-4) vs DH cohort (median, 1; range, 0-3); (P < .001).

CONCLUSION

Using a fluorescent particle model, there is a greater burden of potential contamination from dispensed glove packets and OF with DD vs DH. The DH method did not show significant fluorescent particle contamination on the SI gloves. These data support the use of the opening of gloves via DH over the DD method in total joint arthroplasty to decrease the risk of potential contamination.

Environment of care: Is it time to reassess microbial contamination of the operating room air as a risk factor for surgical site infection in total joint arthroplasty?

In the modern operating room (OR), traditional surgical mask, frequent air exchanges, and architectural barriers are viewed as effective in reducing airborne microbial populations. Intraoperative sampling of airborne particulates is rarely performed in the OR because of technical difficulties associated with sampling methodologies and a common belief that airborne contamination is infrequently associated with surgical site infections (SSIs). Recent studies suggest that viable airborne particulates are readily disseminated throughout the OR, placing patients at risk for postoperative SSI. In 2017, virtually all surgical disciplines are engaged in the implantation of selective biomedical devices, and these implants have been documented to be at high risk for intraoperative contamination. Approximately 1.2 million arthroplasties are performed annually in the United States, and that number is expected to increase to 3.8 million by the year 2030. The incidence of periprosthetic joint infection is perceived to be low (<2.5%); however, the personal and fiscal morbidity is significant. Although the pharmaceutic and computer industries enforce stringent air quality standards on their manufacturing processes, there is currently no U.S. standard for acceptable air quality within the OR environment. This review documents the contribution of air contamination to the etiology of periprosthetic joint infection, and evidence for selective innovative strategies to reduce the risk of intraoperative microbial aerosols.