Aerosol production during autopsies: The risk of sawing in bone

Diathermy and bone sawing are high aerosol yield procedures

Aims

Orthopaedic surgery uses many varied instruments with high-speed, high-impact, thermal energy and sometimes heavy instruments, all of which potentially result in aerosolization of contaminated blood, tissue, and bone, raising concerns for clinicians' health. This study quantifies the aerosol exposure by measuring the number and size distribution of the particles reaching the lead surgeon during key orthopaedic operations.

Methods

The aerosol yield from 17 orthopaedic open surgeries (on the knee, hip, and shoulder) was recorded at the position of the lead surgeon using an Aerodynamic Particle Sizer (APS; 0.5 to 20 μm diameter particles) sampling at 1 s time resolution. Through timestamping, detected aerosol was attributed to specific procedures.

Results

Diathermy (electrocautery) and oscillating bone saw use had a high aerosol yield (> 100 particles detected per s) consistent with high exposure to aerosol in the respirable range (< 5 µm) for the lead surgeon. Pulsed lavage, reaming, osteotome use, and jig application/removal were medium aerosol yield (10 to 100 particles s-1). However, pulsed lavage aerosol was largely attributed to the saline jet, osteotome use was always brief, and jig application/removal had a large variability in the associated aerosol yield. Suctioning (with/without saline irrigation) had a low aerosol yield (< 10 particles s-1). Most surprisingly, other high-speed procedures, such as drilling and screwing, had low aerosol yields.

Conclusion

This work suggests that additional precautions should be recommended for diathermy and bone sawing, such as enhanced personal protective equipment or the use of suction devices to reduce exposure.

Mechanical Properties of a Bone-like Bioceramic-Epoxy-Based Composite Material with Nanocellulose Fibers

Several composite materials are being investigated as reinforcement fillers for surgery simulations. This study presents an artificial composite material with properties similar to those of the human bone, which may be used in surgery simulations. Moreover, considering the potential toxicity of debris generated during sawing, a safe epoxy-based composite material was synthesized using cellulose nanocrystals (CNCs) and bioceramics (i.e., hydroxyapatite, Yttria stabilized zirconia oxide, Zirconia oxide), which were used to mimic the stiffness of human bone. To examine the change in mechanical properties according to the composition, 1, 3, and 5 wt% of CNCs were mixed with 5 wt% of the bioceramics. When CNCs were added at 1 wt%, there was a confirmed change in the non-linear stiffness and ductility. The CNC-added specimen fractured when forming a nano-network around the local CNCs during curing. In contrast, the specimen without CNCs was more densely structured, and combined to form a network of all specimens such that a plastic region could exist. Thus, this study successfully manufactured a material that could mimic longitudinal and transverse characteristics similar to those of real human bone, as well as exhibit mechanical properties such as strength and stiffness. Bioceramics are harmless to the human body, and can be used by controlling the added quantity of CNCs. We expect that this material will be suitable for use in surgery simulations.

Prevention of the spread of infection during highly infectious autopsy using a craniotomy box

In cranial autopsies, the post-mortem examination requires the use of a saw for the removal of the skull cap. In these procedures, sawing of bone becomes a critical source of infectious aerosols which spread instantaneously in the immediate environment, generating liquid aerosols including droplets of cerebrospinal fluid and blood, and leading to exposure of all autopsy personnel. In high-risk cases like prion disease, tuberculosis, severe acute respiratory syndrome (SARS), COVID-19, etc. where the skull would require sawing, the prime concern is the saw operator's exposure to these pathogens. Therefore, the author suggests the use of an ingenious ergonomic semi-circular craniotomy box during skull cap and brain removal in the autopsy procedure to successfully prevent the contamination of the entire autopsy hall. A transparent acrylic plastic box has been customized, which is semi-circular in shape having three walls, one semi-circular dome without a floor, a front wall with adjustable zipper closure, and a hind wall with circular holes with sleeves made of 5-layer fabrics. The dome contains one outlet for a vacuum suction pipe on the side, two holes on each side of the dome with non-woven fabric arms for the saw operator, and assistants' arms for performing skull opening procedures. The use of this box allowed the author to prevent and limit the spread of the generation of infectious aerosols in the autopsy hall as the bone dust collected in the vacuum ensures the safety of autopsy surgeons.

Particulate matter emissions during autopsies: a method to reduce exposure

Particulate matter emitted during autopsies can serve as a vector for numerous viruses or bacteria and can lead to infections. Reducing the exposure of those particles in indoor working environments is, therefore, an important issue. To assess the health risk for employees in forensic medicine, we measure particulate matter in the ambient air during autopsies by using an aerosol spectrometer. The autopsies were performed with either an ordinary oscillating saw or an adapted saw with a suction unit. The particle emissions from both saws were compared to each other in order to evaluate whether a technical adaption leads to a particle reduction. Furthermore, the particle exposure reduction by wearing a face mask and variations in the background concentration in the room were analyzed. High particle concentrations were measured while using the ordinary saw. By using the adapted saw or wearing a face mask, the particle exposure could mostly be avoided. On the majority of the working days, an increase in the background concentration could be observed. Based on this knowledge, the use of a proper suction unit and wearing a face mask during autopsies is necessary. Besides, it is important to have sufficient ventilation in the room so that long-lasting high background concentrations can be prevented.

Can aerosols-generating dental, oral and maxillofacial, and orthopedic surgical procedures lead to disease transmission? An implication on the current COVID-19 pandemic

Various dental, maxillofacial, and orthopedic surgical procedures (DMOSP) have been known to produce bioaerosols, that can lead to the transmission of various infectious diseases. Hence, a systematic review (SR) aimed at generating evidence of aerosols generating DMOSP that can result in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), further investigating their infectivity and assessing the role of enhanced personal protective equipment (PPE) an essential to preventing the spreading of SARS-CoV-2 during aerosol-generating procedures (AGPs). This SR was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement (PRISMA) guidelines based on a well-designed Population, Intervention, Comparison, Outcomes and Study (PICOS) framework, and various databases were searched to retrieve the studies which assessed potential aerosolization during DMOSP. This SR included 80 studies (59 dental and 21 orthopedic) with 7 SR, 47 humans, 5 cadaveric, 16 experimental, and 5 animal studies that confirmed the generation of small-sized < 5 μm particles in DMOSP. One study confirmed that HIV could be transmitted by aerosolized blood generated by an electric saw and bur. There is sufficient evidence that DMOSP generates an ample amount of bioaerosols, but the infectivity of these bioaerosols to transmit diseases like SARS-CoV-2 generates very weak evidence but still, this should be considered. Confirmation through isolation and culture of viable virus in the clinical environment should be pursued. An evidence provided by the current review was gathered by extrapolation from available experimental and empirical evidence not based on SARS-CoV-2. The results of the present review, therefore, should be interpreted with great caution.

Mapping Biological Risks Related to Necropsy Activities: Old Concerns and Novel Issues for the Safety of Health Professionals

Nowadays only a few studies on biological and environmental risk among healthcare workers are available in literature. The present study aims to assess the health operator’s risk of contact with microorganisms during necropsy activities, to evaluate the efficiency of current protections, to identify possible new sources of contact, and to point out possible preventive measures. In addition, considering the current pandemic scenario, the risk of transmission of SARS-CoV-2 infection in the dissection room is assessed. The objectives were pursued through two distinct monitoring campaigns carried out in different periods through sampling performed both on the corpses and at the environmental level.

Medicolegal death investigator workplace safety hazards: A scoping review of the literature

In the United States, medicolegal death investigation practices and policies pertaining to sudden unexpected deaths are mandated by state government. Practices vary across states, which contributes to inconsistency in job prerequisites and training. In preparation for a study focused on occupational safety and health of medicolegal death investigators in their on-scene and follow-up activities, a scoping review was conducted to document known occupational safety risks and health-related conditions associated with death investigation. Searches used Boolean and subject heading operators both broad and narrow in scope, and search terms included scene responder, hazard, investigator, forensic pathology, injury, and safety. Twenty-five articles met inclusion criteria, which included seventeen survey-mixed method designs, two systematic reviews, five quasi-experimental designs, and one case study. Twelve articles addressed mental health and eleven focused on risks associated with infectious disease. One article addressed the risk of chemical exposure from cyanide among autopsy personnel (including forensic pathologists) and nine included a wide range of employees within the setting of medical examiner or coroner offices. One article, addressing burnout, included employees in a forensic science laboratory setting as well as medicolegal death investigators and two articles included forensic pathologists and medicolegal death investigators. Only one article addressed medicolegal death investigators specifically. Articles addressing occupational and environmental hazards of medicolegal death investigators associated with musculoskeletal, respiratory, cardiovascular, radiological, nuclear, electrical, or explosive threats were not identified. There is little published about safety risks inherent in conducting death investigations. Research is needed to adequately inform health promotion and injury prevention strategies.

Drill splatter in orthopaedic procedures and its importance during the COVID-19 pandemic : an experimental study

AIMS

During the COVID-19 pandemic, drilling has been classified as an aerosol-generating procedure. However, there is limited evidence on the effects of bone drilling on splatter generation. Our aim was to quantify the effect of drilling on splatter generation within the orthopaedic operative setting.

METHODS

This study was performed using a Stryker System 7 dual rotating drill at full speed. Two fluid mediums (Videne (Solution 1) and Fluorescein (Solution 2)) were used to simulate drill splatter conditions. Drilling occurred at saw bone level (0 cm) and at different heights (20 cm, 50 cm, and 100 cm) above the target to simulate the surgeon 'working arm length', with and without using a drill guide. The furthest droplets were marked and the droplet displacement was measured in cm. A surgical microscope was used to detect microscopic droplets.

RESULTS

Bone drilling produced 5 cm and 7 cm droplet displacement using Solutions 1 and 2, respectively. Drilling at 100 cm above the target produced the greatest splatter generation with a 95 cm macroscopic droplet displacement using Solution 2. Microscopic droplet generation was noticed at further distances than what can be macroscopically seen using Solution 1 (98 cm). Using the drill guide, there was negligible drill splatter generation.

CONCLUSION

Our study has shown lower than anticipated drill splatter generation. The use of a drill guide acted as a protective measure and significantly reduced drill splatter. We therefore recommend using a drill guide at all times to reduce the risk of viral transmission in the operative setting. Cite this article: Bone Jt Open 2021;2(9):752-756.

Design and Construction of a Biosafety Level 3 Autopsy Laboratory

CONTEXT.—

Autopsy pathologists, including medical examiners, provide valuable public health support for infectious disease deaths through surveillance for deaths of public health concern including emerging infections, identifying causative organisms for unexplained deaths, and providing insights into the pathology and pathogenesis of novel or unusual infections. However, autopsy poses biosafety risks to workers within and outside the laboratory. The highest rates of laboratory-acquired infections occur in autopsy workers.

OBJECTIVE.—

To design and construct an appropriately biosafe autopsy laboratory.

DESIGN.—

We conducted a biosafety risk assessment for autopsy workers using the process developed by the US Centers for Disease Control and Prevention and National Institutes of Health and applied these findings as the basis of laboratory design and construction.

RESULTS.—

Autopsy workers are unpredictably exposed to a variety of infectious organisms, including hepatitis C virus, HIV, and Mycobacterium tuberculosis. Hazardous autopsy procedures include using and encountering sharp objects and the generation of aerosols from dissection, fluid aspiration, rinsing tissues, and dividing bone with an oscillating saw.

CONCLUSIONS.—

Exposure to blood-borne and airborne pathogens from procedures that can cause cutaneous inoculation and inhalation of aerosols indicates that human autopsies should be performed at biosafety level 3. We designed a large, entirely biosafety level 3 medical examiner autopsy laboratory using design principles and characteristics that can be scaled to accommodate smaller academic or other hospital-based autopsy spaces. Containment was achieved through a concentric ring design, with access control at interface zones. As new autopsy laboratories are planned, we strongly recommend that they be designed to function uniformly at biosafety level 3.

Use of post-mortem chest computed tomography in Covid-19 pneumonia

Background and aim

COVID-19 is an extremely challenging disease, both from a clinical and forensic point of view, and performing autopsies of COVID-19 deceased requires adequately equipped sectorial rooms and exposes health professionals to the risk of contagion. Among one of the categories that are most affected by SARS-Cov-2 infection are the elderly residents. Despite the need for prompt diagnoses, which are essential to implement all isolation measures necessary to contain the infection spread, deceased subjects in long-term care facilities are still are often diagnosed post-mortem. In this context, our study focuses on the use of post-mortem computed tomography for the diagnosis of COVID-19 infection, in conjunction with post-mortem swabs. The aim of this study was to assess the usefulness of post-mortem whole CT-scanning in identifying COVID-19 pneumonia as a cause of death, by comparing chest CT-findings of confirmed COVID-19 fatalities to control cases.

Materials and methods

The study included 24 deceased subjects: 13 subjects coming from long-term care facility and 11 subjects died at home. Whole body CT scans were performed within 48 h from death in all subjects to evaluate the presence and distribution of pulmonary abnormalities typical of COVID-19-pneumonia, including: ground-glass opacities (GGO), consolidation, and pleural effusion to confirm the post-mortem diagnosis.

Results

Whole-body CT scans was feasible and allowed a complete diagnosis in all subjects. In 9 (69%) of the 13 cases from long-term care facility the cause of death was severe COVID 19 pneumonia, while GGO were present in 100% of the study population.

Conclusion

In the context of rapidly escalating COVID-19 outbreaks, given that laboratory tests for the novel coronavirus is time-consuming and can be falsely negative, the post-mortem CT can be considered as a reliable and safe modality to confirm COVID-19 pneumonia. This is especially true for specific postmortem chest CT-findings that are rather characteristic of COVID-19 fatalities.

Robotic-Assisted Surgery for Cadaveric Skull Opening: A New Method of Autopsy Procedure

Background: Sawing of bone is an essential part of an autopsy procedure. An oscillating saw always generates noise, fine infectious dust particles, and the possibility of traumatic injuries, all of which can induce occupational hazard risks to autopsy workers, especially during the COVID-19 pandemic. Objectives: The first goal of this study was to explore the production of noise and bone dust emission, comparing an oscillating saw and a robotic autopsy saw during an autopsy. The second goal was to evaluate the performance of a new robotic autopsy method, used during skull opening. The third goal was to encourage mortuary workers to use robotic technology during the autopsy procedure to protect us away from occupational injuries as well as airborne infections. Materials and Methods: The experiments involved a comparison of noise levels and aerosol production during skull cutting between the oscillating saw and the robotic autopsy saw. Results: The results confirmed that noise production from the robotic autopsy saw was lower than the oscillating saw. However, the bone dust levels, produced by the robotic autopsy saw, were greater than the oscillating saw, but were not greater than the dust concentrations which were present before opening the skull. Conclusions: The use of a new robotic system might be an alternative choice for protecting against occupational damage among the healthcare workers. Further research might attempt to consider other healthcare problems which occur in the autopsy workplace and apply the robotic-assisted technology in autopsy surgery.

Universal Precautions Provide Appropriate Protection during Autopsies of Patients with Infectious Diseases

The current coronavirus disease 2019 (COVID-19) pandemic has raised concerns about the safety of laboratory personnel who handle tissue samples that harbor pathogens, including those performing autopsies. While pathologists have performed autopsies on infected decedents for centuries, universal precaution protocols for limiting exposure to pathogens were not developed until the 20th century. This article reviews the history and effectiveness of universal precautions, with an emphasis on performing autopsies on COVID-19 decedents.

Pathology Trainee Redeployment and Education During the COVID-19 Pandemic: An Institutional Experience

Pathology training programs throughout the United States have endured unprecedented challenges dealing with the ongoing coronavirus disease 2019 pandemic. At Houston Methodist Hospital, the Department of Pathology and Genomic Medicine planned and executed a trainee-oriented, stepwise emergency response. The focus was on optimizing workflows among areas of both clinical and anatomic pathology, maintaining an excellent educational experience, and minimizing trainee exposure to coronavirus disease 2019. During the first phase of the response, trainees were divided into 2 groups: one working on-site and the other working remotely. With the progression of the pandemic, all trainees were called back on-site and further redeployed within our department to meet the significantly increased workload demands of our clinical laboratory services. Adjustments to trainee educational activities included, among others, the organization of a daily coronavirus disease 2019 virtual seminar series. This series served to facilitate communication between faculty, laboratory managers, and trainees. Moreover, it became a forum for trainees to provide updates on individual service workflows and volumes, ongoing projects and research, as well as literature reviews on coronavirus disease 2019–related topics. From our program’s experience, redeploying pathology trainees within our department during the coronavirus disease 2019 pandemic resulted in optimization of patient care while ensuring trainee safety, and importantly, helped to maintain continuous high-quality education through active involvement in unique learning opportunities.

COVID-19: Postmortem Diagnostic and Biosafety Considerations

As a result of the 2019 novel human coronavirus (COVID-19) global spread, medical examiner/coroner offices will inevitably encounter increased numbers of COVID-19-infected decedents at autopsy. While in some cases a history of fever and/or respiratory distress (eg, cough or shortness of breath) may suggest the diagnosis, epidemiologic studies indicate that the majority of individuals infected with COVID-19 develop mild to no symptoms. Those dying with-but not of-COVID-19 may still be infectious, however. While multiple guidelines have been issued regarding autopsy protocol in cases of suspected COVID-19 deaths, there is some variability in the recommendations. Additionally, limited recommendations to date have been issued regarding scene investigative protocol, and there is a paucity of publications characterizing COVID-19 postmortem gross and histologic findings. A case of sudden unexpected death due to COVID-19 is presented as a means of illustrating common autopsy findings, as well as diagnostic and biosafety considerations. We also review and summarize the current COVID-19 literature in an effort to provide practical evidence-based biosafety guidance for medical examiner-coroner offices encountering COVID-19 at autopsy.

COVID-19 pandemic and total knee arthroplasty: the concept of a containment sheet-a frugal innovation

BACKGROUND

The primary purpose of the present study was to assess whether use of proposed containment sheet (so called "a frugal innovation") minimizes the aerosol and splatter dispersion during total knee arthroplasty (TKA).

MATERIAL AND METHOD

A total of 32 patients with knee osteoarthritis who were scheduled to undergo primary and unilateral TKA reported during the COVID-19 pandemic were enrolled into this prospective single-institution cohort study. Demographic and epidemiological data, travel and contact history were collected. Eligible cohort was randomly assigned to a study (TKA using containment sheet) group and a control group (TKA without containment sheet). Radiological and functional outcomes before operation and at the final follow-up were assessed using Western Ontario and Mc-master Universities Osteoarthritis Index score (WOMAC) and the visual analog scale (VAS). The primary outcome was the postoperative effectiveness of containment sheet and face shield, defined as the numbers of countable macroscopic aerosols and/or splatters to naked eyes. The level of significance was set at p < 0.05 levels.

RESULTS

Present cohort was comprised of 14 men (43.75%) and 18 women (56.25%) with an average age of 65.45 ± 4.07 years (range, 62-75 years). There were no statistically significant differences with regard to baseline parameters and perioperative demographics. Functional outcomes for knee function at the last follow-up showed significant improvement in both the groups (p < 0.05). Face shield showed significant number of aerosols/splatters in control group. Highest number/concentration of aerosols/splatters was contained within the sheet.

CONCLUSION

The proposed containment sheet can minimize the dispersion of aerosols and splatters generated during TKA and provide a safe healthcare environment in a cost-effective manner.

Minimizing aerosol bone dust during autopsies

When sawing bone for medical or medico-legal procedures, fine, airborne dust is produced (aerosols) that can pose a health hazard when inhaled. The aim of this study was to determine the influence of saw blade frequency and contact load, bone condition, test environment, and saw blade type, on the production of aerosol particles. A custom test setup was designed, manufactured and used in 8 bone sawing experiments, using a particle counter to determine the production of aerosol particles while varying the 5 chosen parameters. The number of counted particles was highest with higher saw blade frequencies, lower saw blade contact loads, in dry completely skeletonized bone compared to fresh bone, and using an electrical oscillating saw compared to hand-sawing. Under all conditions, the high amount of aerosol counted posed potential health risks. The ventilation system that we tested was adequate in removing the produced particles, but these high-tech systems are not always available in developing countries or emergency situations. The production of aerosols can be reduced by optimizing the sawing parameters. However, even the lowest number of aerosol particles counted during the current study was high enough to cause potential health risks to practitioners. Safety precautions should be taken, such as external ventilation, proper breathing gear, and adequate protocols, to truly minimize the risk in all bone sawing scenarios.