A quantitative evaluation of aerosol generation during tracheal intubation and extubation

Routine Use of Videolaryngoscopy in Airway Management

Tracheal intubation is a fundamental facet of airway management, for which the importance of achieving success at the first attempt is well recognized. Failure to do so can lead to significant morbidity and mortality if there is inadequate patient oxygenation by alternate means. The evidence supporting the benefits of a videolaryngoscope in attaining this objective is now overwhelming (in adults). This has led to its increasing recognition in international airway management guidelines and its promotion from an occasional airway rescue tool to the first-choice device during routine airway management. However, usage in clinical practice does not currently reflect the increased worldwide availability that followed the upsurge in videolaryngoscope purchasing during the coronavirus disease 2019 pandemic. There are a number of obstacles to widespread adoption, including lack of adequate training, fears over de-skilling at direct laryngoscopy, equipment and cleaning costs, and concerns over the environmental impact, among others. It is now clear that in order for patients to benefit maximally from the technology and for airway managers to fully appreciate its role in everyday practice, proper training and education are necessary. Recent research evidence has addressed some existing barriers to default usage, and the emergence of techniques such as awake videolaryngoscopy and video-assisted flexible (bronchoscopic) intubation has also increased the scope of clinical application. Future studies will likely further confirm the superiority of videolaryngoscopy over direct laryngoscopy, therefore, it is incumbent upon all airway managers (and their teams) to gain expertise in videolaryngoscopy and to use it routinely in their everyday practice..

Factors associated with correction of personal protective equipment nonadherence in a multidisciplinary emergency department setting: A retrospective video review

BACKGROUND

Despite local and national recommendations, health care provider adherence to personal protective equipment (PPE) varied during the COVID-19 pandemic. Previous studies have identified factors influencing initial PPE adherence but did not address factors influencing behaviors leading to correction after initial nonadherence.

METHODS

We conducted a retrospective video review of 18 pediatric resuscitations involving aerosol-generating procedures from March 2020 to December 2022 to identify factors associated with nonadherence correction. We quantified adherent and nonadherent providers, instances of PPE nonadherence, and time to correction. We also analyzed correction behaviors, including provider actions and correction locations.

RESULTS

Among 434 providers, 362 (83%) were nonadherent with at least 1 PPE. Only 186 of 1,832 instances of nonadherence were corrected, primarily upon room entry and during patient care. Correction time varied by PPE type and nonadherence level (incomplete vs absent). Most corrections were self-initiated, with few reminders from other providers.

DISCUSSION

Potential barriers to correction include a lack of social pressure and external reminders. Solutions include optimizing PPE availability, providing real-time feedback, and educating on double gloving.

CONCLUSIONS

Most providers were nonadherent to PPE requirements during high-risk infection transmission events. The low correction rate suggests challenges in promoting collective responsibility and maintaining protective behaviors during medical emergencies.

Aerosol generation during pediatric otolaryngological procedures

OBJECTIVES

To assess the extent of staff exposure to aerosol generation in common pediatric otorhinolaryngological procedures (tonsillotomies, adenoidectomies, and tympanostomies) and determine the surgical phases responsible for most aerosol generation in these procedures.

METHODS

Aerosol generation was measured during 35 pediatric otolaryngological procedures using an Optical Particle Sizer that measures aerosol concentrations for particle sizes between 0.3 and 10.0 μm. The different phases of and instruments used in each procedure were logged. Operating room background aerosol levels and coughing were used as references.

RESULTS

Total aerosol concentrations were significantly higher during tonsillotomies and adenoidectomies when compared to tympanostomies (p = 0.011 and p = 0.042) and to empty room background aerosol concentrations (p = 0.0057 and p < 0.001). Aerosol concentration during tonsillotomies did not differ from coughing, which is considered as standard for high-risk aerosol procedures. During tympanostomies, aerosol concentrations were even lower than during perioperative concentrations. No statistically significant difference in aerosol generation comparing suction, electrocautery, cold instruments, and paracentesis was found.

CONCLUSION

According to the results of this study, tympanostomies are low-risk aerosol-generating procedures. On the other hand, pediatric tonsillotomies produced aerosols comparable to coughing, pointing to them being significantly aerosol-producing procedures and viral transmission is theoretically possible intraoperatively.

Aerosol and Droplet Generation from Open Rhinoplasty: Surgical Risk in the Pandemic Era

Introduction: The coronavirus disease 2019 pandemic has led to concerns over transmission risk from head and neck operations including facial cosmetic surgeries. Objectives: To quantify droplet and aerosol generation from rhinoplasty techniques in a human anatomic specimen model using fluorescein staining and an optical particle sizer. Methods: Noses of human anatomic specimens were infiltrated using 0.1% fluorescein. Droplets and aerosols were measured during rhinoplasty techniques including opening the skin-soft tissue envelope, monopolar electrocautery, endonasal rasping, endonasal osteotomy, and percutaneous osteotomy. Results: No visible droplet contamination was observed for any rhinoplasty techniques investigated. Compared with the negative control of anterior rhinoscopy, total 0.300-10.000 μm aerosols were increased after monopolar electrocautery (p < 0.001) and endonasal rasp (p = 0.003). Opening the skin-soft tissue envelope, endonasal osteotomies, and percutaneous osteotomies did not generate a detectable increase in aerosols (p > 0.15). Discussion and Conclusions: In this investigation, droplets were not observed under ultraviolet light, and aerosol generation was noted only with cautery and endonasal rasping.

Reducing airborne transmissible diseases in perioperative environments

The COVID-19 pandemic has transformed our understanding of aerosol transmissible disease and the measures required to minimise transmission. Anaesthesia providers are often in close proximity to patients and other hospital staff for prolonged periods while working in operating and procedure rooms. Although enhanced ventilation provides some protection from aerosol transmissible disease in these work areas, close proximity and long duration of exposure have the opposite effect. Surgical masks provide only minimal additional protection. Surgical patients are also at risk from viral and bacterial aerosols. Despite having recently experienced the most significant pandemic in 100 yr, we continue to lack adequate understanding of the true risks encountered from aerosol transmissible diseases in the operating room, and the best course of action to protect patients and healthcare workers from them in the future. Nevertheless, hospitals can take specific actions now by providing respirators for routine use, encouraging staff to utilise respirators routinely, establishing triggers for situations that require respirator use, educating staff concerning the prevention of aerosol transmissible diseases, and providing portable air purifiers for perioperative spaces with low levels of ventilation.

Ventilator-Associated Pneumonia, Ventilator-Associated Events, and Nosocomial Respiratory Viral Infections on the Leeside of the Pandemic

The COVID-19 pandemic has had an unprecedented impact on population health and hospital operations. Over 7 million patients have been hospitalized for COVID-19 thus far in the United States alone. Mortality rates for hospitalized patients during the first wave of the pandemic were > 30%, but as we enter the fifth year of the pandemic hospitalizations have fallen and mortality rates for hospitalized patients with COVID-19 have plummeted to 5% or less. These gains reflect lessons learned about how to optimize respiratory support for different kinds of patients, targeted use of therapeutics for patients with different manifestations of COVID-19 including immunosuppressants and antivirals as appropriate, and high levels of population immunity acquired through vaccines and natural infections. At the same time, the pandemic has helped highlight some longstanding sources of harm for hospitalized patients including hospital-acquired pneumonia, ventilator-associated events (VAEs), and hospital-acquired respiratory viral infections. We are, thankfully, on the leeside of the pandemic at present; but the large increases in ventilator-associated pneumonia (VAP), VAEs, bacterial superinfections, and nosocomial respiratory viral infections associated with the pandemic beg the question of how best to prevent these complications moving forward. This paper reviews the burden of hospitalization for COVID-19, the intersection between COVID-19 and both VAP and VAEs, the frequency and impact of hospital-acquired respiratory viral infections, new recommendations on how best to prevent VAP and VAEs, and current insights into effective strategies to prevent nosocomial spread of respiratory viruses.

Impact of the Coronavirus Pandemic on Patients Requiring Tracheal Intubation by Helicopter Emergency Medical Services: A Retrospective, Single-Center, Observational Study

Background/Objectives: The impacts of the coronavirus disease 2019 (COVID-19) pandemic on patients using helicopter emergency medical services (HEMS) regarding tracheal intubation and patient management remain unclear. Thus, we aimed to investigate this matter in Japan. Methods: In this retrospective, observational study, we analyzed 2277 patients who utilized HEMS in Tochigi Prefecture during 2018-2022. We included only patients who required tracheal intubation. We categorized patients from February 2020 to January 2022 in the pandemic group and those from February 2018 to January 2020 in the control group. We compared the interval from arrival at the scene to leaving the scene (on-scene time) and secondary variables between the two groups. Results: A total of 278 eligible patients were divided into the pandemic group (n = 127) and the control group (n = 151). The on-scene time was lower during the pandemic than that before (25.64 ± 9.19 vs. 27.83 ± 8.74 min, p = 0.043). The percentage of patients using midazolam was lower (11.8% vs. 22.5%, p = 0.02) and that of patients using rocuronium bromide was higher (29.1% vs. 6.0%, p < 0.001) during the pandemic. In contrast, the type of intervention other than tracheal intubation and the type of transportation to the hospital did not differ between the groups. Conclusions: The COVID-19 pandemic was associated with changes in the mission time of and the frequency of certain drugs administered by the HEMS. However, the type of intervention and the type of transportation did not differ. Further research is needed on changes in patient prognosis and condition due to the effects of the COVID-19 pandemic.

Masks and respirators for prevention of respiratory infections: a state of the science review

SUMMARYThis narrative review and meta-analysis summarizes a broad evidence base on the benefits-and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts-of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.

Airway and respiratory complications during anaesthesia and associated with peri-operative cardiac arrest as reported to the 7th National Audit Project of the Royal College of Anaesthetists

The 7th National Audit Project (NAP7) of the Royal College of Anaesthetists studied complications of the airway and respiratory system during anaesthesia care including peri-operative cardiac arrest. Among 24,721 surveyed cases, airway and respiratory complications occurred commonly (n = 421 and n = 264, respectively). The most common airway complications were: laryngospasm (157, 37%); airway failure (125, 30%); and aspiration (27, 6%). Emergency front of neck airway was rare (1 in 8370, 95%CI 1 in 2296-30,519). The most common respiratory complications were: severe ventilation difficulty (97, 37%); hyper/hypocapnia (63, 24%); and hypoxaemia (62, 23%). Among 881 reports to NAP7 and 358 deaths, airway and respiratory complications accounted for 113 (13%) peri-operative cardiac arrests and 32 (9%) deaths, with hypoxaemia as the most common primary cause. Airway and respiratory cases had higher and lower survival rates than other causes of cardiac arrest, respectively. Patients with obesity, young children (particularly infants) and out-of-hours care were overrepresented in reports. There were six cases of unrecognised oesophageal intubation with three resulting in cardiac arrest. Of these cases, failure to correctly interpret capnography was a recurrent theme. Cases of emergency front of neck airway (6, approximately 1 in 450,000) and pulmonary aspiration (11, approximately 1 in 25,000) leading to cardiac arrest were rare. Overall, these data, while distinct from the 4th National Audit Project, suggest that airway management is likely to have become safer in the last decade, despite the surgical population having become more challenging for anaesthetists.

Association between anesthesia technique and death after hip fracture repair for patients with COVID-19

PURPOSE

Patients with COVID-19 undergoing hip fracture surgeries have a 30-day mortality of up to 34%. We aimed to evaluate the association between anesthesia technique and 30-day mortality after hip fracture surgery in patients with COVID-19.

METHODS

After ethics approval, we performed a retrospective cohort analysis of the American College of Surgeons National Surgical Quality Improvement Program data set from January to December 2021. Inclusion criteria were age ≥ 19 yr, laboratory-confirmed SARS-CoV-2 infection within 14 days preoperatively, and hip fracture surgery under general anesthesia (GA) or spinal anesthesia (SA). Exclusion criteria were American Society of Anesthesiologists Physical Status V, ventilator dependence, international normalized ratio ≥ 1.5, partial thromboplastin time > 35 sec, and platelet count < 80 × 109 L-1. The primary outcome was all-cause 30-day mortality. The adjusted association between anesthetic technique and 30-day mortality was analyzed using multivariable logistic regression.

RESULTS

Of 23,045 patients undergoing hip fracture surgery, 331 patients met the study criteria. The median [interquartile range] age was 82 [74-88] yr, and 32.3% were male. The 30-day mortality rate was 10.0% (33/331) for the cohort (10.7%, 29/272 for GA vs 6.8%, 4/59 for SA; P = 0.51; standardized mean difference, 0.138). The use of SA, compared with GA, was not associated with decreased mortality (adjusted odds ratio, 0.61; 95% confidence interval, 0.21 to 1.8; E-value, 2.49).

CONCLUSION

Anesthesia technique was not associated with mortality in patients with COVID-19 undergoing hip fracture surgery. The findings were limited by a small sample size.

STUDY REGISTRATION

www.

CLINICALTRIALS

gov (NCT05133648); registered 24 November 2021.

A quantitative evaluation of aerosol generation during cardiopulmonary resuscitation

It is unclear if cardiopulmonary resuscitation is an aerosol-generating procedure and whether this poses a risk of airborne disease transmission to healthcare workers and bystanders. Use of airborne transmission precautions during cardiopulmonary resuscitation may confer rescuer protection but risks patient harm due to delays in commencing treatment. To quantify the risk of respiratory aerosol generation during cardiopulmonary resuscitation in humans, we conducted an aerosol monitoring study during out-of-hospital cardiac arrests. Exhaled aerosol was recorded using an optical particle sizer spectrometer connected to the breathing system. Aerosol produced during resuscitation was compared with that produced by control participants under general anaesthesia ventilated with an equivalent respiratory pattern to cardiopulmonary resuscitation. A porcine cardiac arrest model was used to determine the independent contributions of ventilatory breaths, chest compressions and external cardiac defibrillation to aerosol generation. Time-series analysis of participants with cardiac arrest (n = 18) demonstrated a repeating waveform of respiratory aerosol that mapped to specific components of resuscitation. Very high peak aerosol concentrations were generated during ventilation of participants with cardiac arrest with median (IQR [range]) 17,926 (5546-59,209 [1523-242,648]) particles.l-1 , which were 24-fold greater than in control participants under general anaesthesia (744 (309-2106 [23-9099]) particles.l-1 , p < 0.001, n = 16). A substantial rise in aerosol also occurred with cardiac defibrillation and chest compressions. In a complimentary porcine model of cardiac arrest, aerosol recordings showed a strikingly similar profile to the human data. Time-averaged aerosol concentrations during ventilation were approximately 270-fold higher than before cardiac arrest (19,410 (2307-41,017 [104-136,025]) vs. 72 (41-136 [23-268]) particles.l-1 , p = 0.008). The porcine model also confirmed that both defibrillation and chest compressions generate high concentrations of aerosol independent of, but synergistic with, ventilation. In conclusion, multiple components of cardiopulmonary resuscitation generate high concentrations of respiratory aerosol. We recommend that airborne transmission precautions are warranted in the setting of high-risk pathogens, until the airway is secured with an airway device and breathing system with a filter.

Time to intubation with McGrath ™ videolaryngoscope versus direct laryngoscope in powered air-purifying respirator: a randomised controlled trial

INTRODUCTION

During the coronavirus disease 2019 (COVID-19) pandemic, multiple guidelines have recommended videolaryngoscope (VL) for tracheal intubation. However, there is no evidence that VL reduces time to tracheal intubation, and this is important for COVID-19 patients with respiratory failure.

METHODS

To simulate intubation of COVID-19 patients, we randomly assigned 28 elective surgical patients to be intubated with either McGrath™ MAC VL or direct laryngoscope (DL) by specialist anaesthetists who donned 3M™ Jupiter™ powered air-purifying respirators (PAPR) and N95 masks. The primary outcome was time to intubation.

RESULTS

The median time to intubation was 61 s (interquartile range [IQR] 37-63 s) and 41.5 s (IQR 37-56 s) in the VL and DL groups, respectively ( P = 0.35). The closest mean distance between the anaesthetist and patient during intubation was 21.6 ± 4.8 cm and 17.6 ± 5.3 cm in the VL and DL groups, respectively ( P = 0.045). There were no significant differences in the median intubation difficulty scale scores, proportion of successful intubations at the first laryngoscopic attempt and proportion of intubations requiring adjuncts. All the patients underwent successful intubation with no adverse event.

CONCLUSION

There was no significant difference in the time to intubation of elective surgical patients with either McGrath™ VL or DL by specialist anaesthetists who donned PAPR and N95 masks. The distance between the anaesthetist and patient was significantly greater with VL. When resources are limited or disrupted during a pandemic, DL could be a viable alternative to VL for specialist anaesthetists.

A "safety cap" for improving hospital sanitation and reducing potential disease transmission

BACKGROUND

During endotracheal intubation, extubation, tracheotomy, and tracheotomy tube replacement, the splashed airway secretions of patients will increase the risk of transmission of SARS-CoV-2 and many other potential viral and bacterial diseases, such as influenza virus, adenovirus, respiratory syncytial virus, rhinovirus, Middle East respiratory coronavirus syndrome (MERS-CoV), Streptococcus pneumoniae, and Mycobacterium tuberculosis. Therefore, it is necessary to establish a barrier between patients and medical workers to reduce the risk of operators' infection with potentially pathogenic microorganisms.

METHODS

We designed a "safety cap" that can be connected to the opening of an endotracheal tube or tracheotomy tube to reduce the diffusion area of respiratory secretions during the process of endotracheal intubation, extubation and tracheotomy tube replace, so as to reduce the infection risk of medical workers.

RESULTS

Through a series of hydrodynamic simulation analysis and experiments, we demonstrated that the use of "safety cap" can substantially limit the spatter of airway secretions, so as to improve the hospital sanitation.

CONCLUSION

The "safety cap" can effectively limit the dissemination of patients' respiratory secretions, thus reducing the risk of potential diseases transmission and may have certain application prospects.

Airway Management: The Current Role of Videolaryngoscopy

Airway management is usually an uncomplicated and safe intervention; however, when problems arise with the primary airway technique, the clinical situation can rapidly deteriorate, resulting in significant patient harm. Videolaryngoscopy has been shown to improve patient outcomes when compared with direct laryngoscopy, including improved first-pass success at tracheal intubation, reduced difficult laryngeal views, reduced oxygen desaturation, reduced airway trauma, and improved recognition of oesophageal intubation. The shared view that videolaryngoscopy affords may also facilitate superior teaching, training, and multidisciplinary team performance. As such, its recommended role in airway management has evolved from occasional use as a rescue device (when direct laryngoscopy fails) to a first-intention technique that should be incorporated into routine clinical practice, and this is reflected in recently updated guidelines from a number of international airway societies. However, currently, overall videolaryngoscopy usage is not commensurate with its now widespread availability. A number of factors exist that may be preventing its full adoption, including perceived financial costs, inadequacy of education and training, challenges in achieving deliverable decontamination processes, concerns over sustainability, fears over "de-skilling" at direct laryngoscopy, and perceived limitations of videolaryngoscopes. This article reviews the most up-to-date evidence supporting videolaryngoscopy, explores its current scope of utilisation (including specialist techniques), the potential barriers preventing its full adoption, and areas for future advancement and research.

Characterizing Aerosol Generating Procedures With Background Oriented Schlieren

The potential for characterizing aerosol generating procedures (AGPs) using background oriented schlieren (BOS) flow visualization was investigated in two clinical situations. A human-scale BOS system was used on a manikin simulating jet ventilation and extubation. A novel approach to representation of the BOS images using line integral convolution allows direct evaluation of both magnitude and direction of the refractive index gradient field. Plumes issuing from the manikin's mouth were clearly visualized and characterized in both experiments, and it is recommended that BOS be adapted into a clinical tool for risk evaluation in clinical environments.

Aerosol generation with the use of positive pressure ventilation via supraglottic airway devices: an observational study

The amount of aerosol generation associated with the use of positive pressure ventilation via a supraglottic airway device has not been quantified. We conducted a two-group, two-centre, prospective cohort study in which we recruited 21 low-risk adult patients scheduled for elective surgery under general anaesthesia with second-generation supraglottic airway devices. An optical particle sizer and an isokinetic sampling probe were used to record particle concentrations per second at different size distributions (0.3-10 μm) during use as well as baseline levels during two common activities (conversation and coughing). There was a median (IQR [range]) peak increase of 2.8 (1.5-4.5 [1-28.1]) and 4.1 (2.0-7.1 [1-18.2]) times background concentrations during SAD insertion and removal. Most of the particles generated during supraglottic airway insertion (85.0%) and removal (85.3%) were < 3 μm diameter. Median (IQR [range]) aerosol concentration generated by insertion (1.1 (0.6-5.1 [0.2-22.3]) particles.cm^-3 ) and removal (2.1 (0.5-3.0 [0.1-18.9]) particles.cm^-3 ) of SADs were significantly lower than those produced during continuous talking (44.5 (28.3-70.5 [2.0-134.5]) particles.cm^-3 ) and coughing (141.0 (98.3-202.8 [4.0-296.5]) particles.cm^-3 ) (p < 0.001). The aerosol levels produced were similar with the two devices. The proportion of easily inhaled and small particles (<1 μm) produced during insertion (57.5%) and removal (57.5%) was much lower than during talking (99.1%) and coughing (99.6%). These results suggest that the use of supraglottic airway devices in low-risk patients, even with positive pressure ventilation, generates fewer aerosols than speaking and coughing in awake patients.

Aerosol generation during coughing: an observational study

OBJECTIVE

Coronavirus disease 2019 has highlighted the lack of knowledge on aerosol exposure during respiratory activity and aerosol-generating procedures. This study sought to determine the aerosol concentrations generated by coughing to better understand, and to set a standard for studying, aerosols generated in medical procedures.

METHODS

Aerosol exposure during coughing was measured in 37 healthy volunteers in the operating theatre with an optical particle sizer, from 40 cm, 70 cm and 100 cm distances.

RESULTS

Altogether, 306 volitional and 15 involuntary coughs were measured. No differences between groups were observed.

CONCLUSION

Many medical procedures are expected to generate aerosols; it is unclear whether they are higher risk than normal respiratory activity. The measured aerosol exposure can be used to determine the risk for significant aerosol generation during medical procedures. Considerable variation of aerosol generation during cough was observed between individuals, but whether cough was volitional or involuntary made no difference to aerosol production.

Aerosol Generation During Nasal Airway Instrumentation

OBJECTIVE

Airborne aerosol transmission, an established mechanism of SARS-CoV-2 spread, has been successfully mitigated in the health care setting through the adoption of universal masking. Upper airway endoscopy, however, requires direct access to the face, thereby potentially exposing the clinic environment to infectious particles. This study quantifies aerosol production during rigid nasal endoscopy (RNE) and RNE with debridement (RNED) as compared with intubation, a posited gold standard aerosol-generating procedure.

STUDY DESIGN

Prospective cross-sectional study.

SETTING

Subspecialty single-center clinic and surgical study.

METHOD

Three aerosol detectors (NANOSCAN-3910, OPS-3330, and APS-3321) with a particle size sensitivity of 10 to 20,000 nm were utilized to detect particulate production during the clinical care of 209 patients undergoing RNE/RNED and 25 patients undergoing intubation.

RESULTS

RNE and RNED produced statistically significant particles over baseline in 29.3% and 51.0% of subjects (P = .003-.049 and .002-.047, respectively). Intubation produced statistically significant particles in 31.2% (P = .001-.015). The mean ± SD particle diameter in all tests was 69.9 ± 10.5 nm with 99.7% <300 nm. There were no statistical differences in particle production among RNE, RNED, and intubation. The presence of concomitant cough, sneeze, or prolonged speech similarly did not significantly affect particle production during any procedure.

CONCLUSIONS

Instrumentation of nasal airway produces airborne aerosols to a similar degree of those seen during intubation, independent of reactive patient behaviors such as cough or sneeze. These data suggest that an improved understanding is necessary of both the definition of an aerosol-generating procedure and the functional consequences of procedural aerosol generation in clinical settings.

The effect of clinical face shields on aerosolized particle exposure

Background

Face shields protect healthcare workers (HCWs) from fluid and large droplet contamination. Their effect on smaller aerosolized particles is unknown.

Materials & methods

An ultrasonic atomizer was used to simulate particle sizes equivalent to human breathing and forceful cough. Particles were measured at positions correlating to anesthetic personnel in relation to a patient inside an operating theatre environment. The effect of the application of face shields on HCW exposure was measured.

Results & Conclusion

Significant reductions in particle concentrations were measured after the application of vented and enclosed face shields. Face shields appear to reduce the concentration of aerosolized particles that HCWs are exposed to, thereby potentially conferring further protection against exposure to aerosolized particles in an operating theatre environment.

High-impact papers in the field of anesthesiology: a 10-year cross-sectional study

PURPOSE

This study was performed to evaluate trends in and provide future direction for anesthesiology education, research, and clinical practice.

METHODS

We collected high-impact papers, ranking in the top 10% in the field of anesthesiology and published from 2011 to 2020, by the InCites tool based on the Web of Science Core Collection. We analyzed the trends, locations, distribution of subject categories, research organizations, collaborative networks, and subject terms of these papers.

RESULTS

A total of 4,685 high-impact papers were included for analysis. The number of high-impact papers increased from 462 in 2011 to 520 in 2020. The paper with the highest value of category normalized citation impact (115.95) was published in Anesthesia and Analgesia in 2018. High-impact papers were mainly distributed in the subject categories of "Anesthesiology," "Clinical Neurology," "Neurosciences," and "Medicine General Internal." They were primarily cited in "Anesthesiology," "Clinical Neurology," "Neurosciences," "Medicine General Internal," and "Surgery." Most of these high-impact papers came from the USA, UK, Canada, Germany, and Australia. The most productive institutions were the League of European Research Universities, Harvard University, University of Toronto, University of London, University of California System, and University Health Network Toronto. Research collaboration circles have been formed in the USA, UK, and Canada. Subject-term analysis indicated postoperative analgesia, chronic pain, and perioperative complications were high-interest topics, and COVID-19 became a new hot topic in 2020.

CONCLUSIONS

The current study provides a historical view of high-impact papers in anesthesiology in the past ten years. High-impact papers were mostly from the USA. Postoperative analgesia, chronic pain, and perioperative complications have been hot topics, and COVID-19 became a new topic in 2020. These findings provide references for education, research, and clinical practice in the field of anesthesiology.

Compound lidocaine/prilocaine cream combined with tetracaine prevents cough caused by extubation after general anaesthesia: a randomised controlled trial

BACKGROUND

Coughing caused by tracheal extubation is common following general anaesthesia. Heavy aerosol production by coughing during recovery from general anaesthesia in patients with respiratory infections (especially COVID-19) may be one of the highest risk factors for infection in healthcare workers. The application of local anaesthetics to the endotracheal tube is an effective method to reduce coughing. The most commonly used anaesthetics are compound lidocaine/prilocaine cream and tetracaine spray. However, coughing still occurs when the two anaesthetics are used alone. We speculated that the application of compound lidocaine/prilocaine combined with tetracaine spray would better prevent coughing caused by tracheal extubation.

METHODS

Patients scheduled for laparoscopic cholecystectomy or cholecystectomy combined with common bile duct exploration under general anaesthesia were randomly assigned to Group C (saline spray), Group L (2 g compound lidocaine/prilocaine cream contains 5 mg of lidocaine and 5 mg prilocaine)), Group T (tetracaine) and Group F (compound lidocaine/prilocaine cream combined with tetracaine). The incidence of coughing, the endotracheal tube tolerance assessment, the incidence of agitation, the active extubation rate, the incidence of postoperative pharyngeal pain and the incidence of postoperative cough were recorded and analysed. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), and the plasma concentrations of epinephrine and norepinephrine were measured immediately before extubation and 1 min after extubation.

RESULTS

A total of 211 patients were randomly assigned to Group C (53 cases), Group L (52 cases), Group T (52 cases) and Group F (54 cases). The primary result is assessment of the incidence of cough. The patients emerged from general anaesthesia, 96% of Group C had cough, which was significantly reduced in Group L (61.5%, P < 0.001), Group T (75%, P < 0.05) and Group F (22.2%, P < 0.001). Group F had a significantly reduced incidence of cough compared to Group L and Group T (P < 0.05 or P < 0.01, respectively). The secondary results were assessed. The endotracheal tube tolerance score in Group C ((1, 3) 4, P < 0.001) was higher than Group L ((0, 1) 2), Group T ((0, 1.25) 3) and Group F ((0, 0) 1). Group F had a significantly lower score than Group L and Group T (P < 0.05, P < 0.01, respectively). The incidence of agitation and the active extubation rate were also higher in Group C (96.2% and 71.7%, respectively, P < 0.001) than Group L (48.1% and 15.4%, respectively), Group T (61.5% and 26.9%, respectively) and Group F (17.3% and 7.7%, respectively). Blood pressure, HR and plasma concentrations of epinephrine and norepinephrine were significantly higher in Group C than in all other groups at the time of extubation and 1 min after extubation (P < 0.001). Group F exhibited significantly reduced blood pressure, heart rate and plasma concentrations of epinephrine and norepinephrine compared to Group L and Group T (P < 0.05, P < 0.01 or P < 0.001, respectively). The incidence of postoperative pharyngeal pain and the incidence of postoperative cough were not significantly different among the groups.

CONCLUSIONS

Compound lidocaine/prilocaine cream combined with tetracaine may be a more effective approach for preventing coughing and stabilising circulation during extubation following general anaesthesia. This may play an important role in preventing medical staff from contracting respiratory infectious diseases.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR2200058429 (registration date: 09-04-2022) "retrospectively registered".

Risk of Bacterial Exposure to the Anesthesiologist's Face During Intubation and Extubation

Introduction

Anesthesiologists are exposed to the risk of infection from various secretions or droplets from the respiratory tract of patients. We aimed to determine bacterial exposure to anesthesiologists' faces during endotracheal intubation and extubation.

Methods

Six resident anesthesiologists performed 66 intubation and 66 extubation procedures in patients undergoing elective otorhinolaryngology surgeries. Sampling was performed by swabbing the face shields twice in an overlapping slalom pattern, before and after each procedure. Samples for pre-intubation and pre-extubation were collected immediately after wearing the face shield at the time of anesthesia induction and at the end of the surgery, respectively. Post-intubation samples were collected after the injection of anesthetic drugs, positive pressure mask ventilation, endotracheal intubation, and confirmation of intubation success. Post-extubation samples were collected after endotracheal tube suction, oral suction, extubation, and confirmation of spontaneous breathing and stable vital signs. All swabs were cultured for 48 h, and bacterial growth was confirmed by colony forming unit (CFU) count.

Results

There was no bacterial growth in either pre- or post-intubation bacterial cultures. In contrast, while there was no bacterial growth in pre-extubation samples, 15.2% of post-extubation samples were CFU+ (0/66 [0%] vs 10/66 [15.2%], p=0.001). All the CFU+ samples belonged to 47 patients with post-extubation coughing, and the CFU count was correlated with the number of coughing episodes during the process of extubation (P < 0.01, correlation coefficient= 0.403).

Conclusion

The current study shows the actual chance of bacterial exposure to the anesthesiologist's face during the patient awakening process after general anesthesia. Given the correlation between the CFU count and the number of coughing episodes, we recommend anesthesiologists to use appropriate facial protection equipment during this procedure.

Design and quantitative evaluation of 'Aerosol Bio-Containment Device (ABCD)' for reducing aerosol exposure during infectious aerosol-generating events

The Coronavirus Disease 2019 (COVID-19) pandemic renewed interest in infectious aerosols and reducing risk of airborne respiratory pathogen transmission, prompting development of devices to protect healthcare workers during airway procedures. However, there are no standard methods for assessing the efficacy of particle containment with these protective devices. We designed and built an aerosol bio-containment device (ABCD) to contain and remove aerosol via an external suction system and tested the aerosol containment of the device in an environmental chamber using a novel, quantitative assessment method. The ABCD exhibited a strong ability to control aerosol exposure in experimental and computational fluid dynamic (CFD) simulated scenarios with appropriate suction use and maintenance of device seals. Using a log-risk-reduction framework, we assessed device containment efficacy and showed that, when combined with other protective equipment, the ABCD can significantly reduce airborne clinical exposure. We propose this type of quantitative analysis serves as a basis for rating efficacy of aerosol protective enclosures.

Asymptomatic screening for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) as an infection prevention measure in healthcare facilities: Challenges and considerations

Testing of asymptomatic patients for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) (ie, "asymptomatic screening) to attempt to reduce the risk of nosocomial transmission has been extensive and resource intensive, and such testing is of unclear benefit when added to other layers of infection prevention mitigation controls. In addition, the logistic challenges and costs related to screening program implementation, data noting the lack of substantial aerosol generation with elective controlled intubation, extubation, and other procedures, and the adverse patient and facility consequences of asymptomatic screening call into question the utility of this infection prevention intervention. Consequently, the Society for Healthcare Epidemiology of America (SHEA) recommends against routine universal use of asymptomatic screening for SARS-CoV-2 in healthcare facilities. Specifically, preprocedure asymptomatic screening is unlikely to provide incremental benefit in preventing SARS-CoV-2 transmission in the procedural and perioperative environment when other infection prevention strategies are in place, and it should not be considered a requirement for all patients. Admission screening may be beneficial during times of increased virus transmission in some settings where other layers of controls are limited (eg, behavioral health, congregate care, or shared patient rooms), but widespread routine use of admission asymptomatic screening is not recommended over strengthening other infection prevention controls. In this commentary, we outline the challenges surrounding the use of asymptomatic screening, including logistics and costs of implementing a screening program, and adverse patient and facility consequences. We review data pertaining to the lack of substantial aerosol generation during elective controlled intubation, extubation, and other procedures, and we provide guidance for when asymptomatic screening for SARS-CoV-2 may be considered in a limited scope.

BIS-guided sedation prevents the cough reaction of patients under general anaesthesia caused by extubation: a randomized controlled trial

Background

The multiple modes of SARS-CoV-2 transmission including airborne, droplet, contact and faecal–oral transmissions that cause coronavirus disease 2019 (COVID-19) contribute to a public threat to the lives of people worldwide. Heavy aerosol production by coughing and the big peak expiratory flow in patients with respiratory infections (especially SARS-CoV-2) during recovery from general anaesthesia are the highest risk factors for infection in healthcare workers. To perform sedation before extubation significantly reduced the incidence of coughing during recovery from general anaesthesia. However, there are few studies on endotracheal tube removal under BIS-guided sedation in postanaesthesia care unit (PACU). We speculated that the BIS-guided sedation with dexmedetomidine and propofol would better prevent coughing caused by tracheal extubation and reducing peak expiratory flow.

Methods

Patients with general anaesthesia were randomly assigned to Group S (dexmedetomidine was infused in the operating room for 30 min, and the bispectral index (BIS) value was maintained 60–70 by infusion propofol at 0.5~1.5 μg/ml in the PACU until the endotracheal tubes were pulled out) and Group C (no dexmedetomidine and propofol treatment, replaced with the saline treatment). The incidence of coughing, agitation and active extubation, endotracheal tube tolerance and the peak expiratory flow at spontaneous breathing and at extubation were assessed.

Results

A total of 101 patients were randomly assigned to Group S (51 cases) and Group C (50 cases). The incidence of coughing, agitation and active extubation was significantly lower (1(51), 0(51) and 0(51), respectively) in Group S than (11(50), 8(50) and 5(50), respectively) in Group C (p < 0.05 or p < 0.01, respectively); the scores of cough were significantly reduced (1(1, 1)) in Group S than (1(1, 2)) in Group C (p < 0.01); and the endotracheal tube tolerance was significantly improved (0(0, 1)) in Group S than (1(1, 3)) in Group C (p < 0.001). The peak expiratory flow at spontaneous breathing and at extubation was significantly reduced (5(5, 7) and 6.5(6, 8), respectively) in Group S than (8(5, 10) and 21(9, 32)) in Group C (p < 0.001).

Conclusions

BIS-guided sedation with dexmedetomidine and propofol significantly prevented coughing and reduced peak expiratory flow during recovery from general anaesthesia, which may play an important role in preventing medical staff from contracting COVID-19.

Trial registration

Chinese Clinical Trial Registry: ChiCTR2200058429 (registration date: 09-04-2022) “retrospectively registered”.

Impact of Pandemic Response on Training Experience of Anesthesiology Residents in an Academic Medical Center: A Retrospective Cohort Study

Background The impact of the coronavirus disease 2019 (COVID-19) pandemic substantially altered operations at hospitals that support graduate medical education. We examined the impact of the pandemic on an anesthesiology training program with respect to overall case volume, subspecialty exposure, procedural skill experience, and approaches to airway management. Methods Data for this single center, retrospective cohort study came from an Institutional Review Board approved repository for clinical data. Date ranges were divided into the following phases in 2020: Pre-Pandemic (PP), Early Pandemic (EP), Recovery 1 (R1), and Recovery 2 (R2). All periods were compared to the same period from 2019 for case volume, anesthesia provider type, trainee exposure to Accreditation Council for Graduate Medical Education (ACGME) index case categories, airway technique, and patient variables. Results 15,087 cases were identified, with 5,598 (37.6%) in the PP phase, 1,570 (10.5%) in the EP phase, 1,451 (9.7%) in the R1 phase, and 6,269 (42.1%) in the R2 phase. There was a significant reduction in case volume during the EP phase compared to the corresponding period in 2019 (-55.3%; P < .001) that improved but did not return to baseline by the R2 phase (-17.6%; P < .001). ACGME required minimum cases were reduced during the EP phase compared to 2019 data for pediatric cases (age < 12 y, -72.1%; P < .001 and age < 3 y, -53.5%; P < .006) and cardiopulmonary bypass cases (52.3%, P < .003). Surgical subspecialty case volumes were significantly reduced in the EP phase except for transplant surgery. By the R2 phase, all subspecialty volumes had recovered except for plastic surgery (14.9 vs. 10.5 cases/week; P < .006) and surgical endoscopy (59.2 vs. 40 cases/week; P < .001). Use of video laryngoscopy (VL) and rapid sequence induction and intubation (RSII) also increased from the PP to the EP phase (24.6 vs. 79.6%; P < .001 and 10.3 vs. 52.3%; P < .001, respectively) and remained elevated into the R2 phase (35.2%; P < 0.001 and 23.1%; P < .001, respectively). Conclusions The COVID-19 pandemic produced significant changes in surgical case exposure for a relatively short period. The impact was short-lived, with sufficient remaining time to meet the annual ACGME program minimum case requirements and procedural experiences. The longer-term impact may be a shift towards the increased use of VL and RSII, which became more prevalent during the early phase of the pandemic.

Pharmacologic methods to minimise coughing during extubation in the era of COVID-19

BACKGROUND/AIM

Given the current severe acute respiratory syndrome coronavirus 2 pandemic, coughing at the time of extubation is at risk of creating aerosolisation. This may place health care workers at risk of nosocomial infection during the perioperative period. This study aims to summarise the current pharmacologic methods to minimise cough at the time of extubation, and to determine whether some strategies could be more beneficial than others.

METHODS

This is a summary of systematic reviews. A comprehensive search through MEDLINE was performed. Thirty-three publications were screened for eligibility. Only the manuscripts discussing pharmacologic methods to minimise coughing on extubation were included in this review.

FINDINGS

Many pharmacological agents have been proposed to decrease the incidence of cough at the time of extubation. Of these, intravenous administration of dexmedetomidine (relative risk 0.4; 95% CI: 0.4-0.5) or remifentanil (RR 0.4; 95% CI: 0.4-0.5) seems to have the largest effect to reduce cough on extubation.

CONCLUSION

The available data in the current literature is sparse. Yet, dexmedetomidine and remifentanil seem to be the most efficient agents to decrease the incidence of emergence coughing.

Epidemiology and Outcome of Out-of-Hospital Cardiac Arrests during the COVID-19 Pandemic in South Korea: A Systematic Review and Meta-Analyses

PURPOSE

To evaluate the effect of coronavirus disease 2019 (COVID-19) on out-of-hospital cardiac arrest (OHCA) outcomes in South Korea, we conducted systematic review and meta-analysis.

MATERIALS AND METHODS

MEDLINE, Embase, KoreaMed, and Korean Information Service System databases were searched up to June 2022. We included observational studies and letters on OHCA during the COVID-19 pandemic and compared them to those before the pandemic. Epidemiologic characteristics, including at-home OHCA, bystander cardiopulmonary resuscitation, unwitnessed arrest, use of an automated external defibrillator (AED), shockable cardiac rhythm, and airway management, were evaluated. Survival and favorable neurological outcomes were extracted. We conducted a meta-analysis of each characteristic and outcome.

RESULTS

Six studies including 4628 OHCA patients were included in this study. The incidence of at-home OHCA significantly increased and the AED use decreased during the COVID-19 pandemic compared to before the pandemic [odds ratio (OR), 1.29; 95% confidence interval (CI), 1.08-1.55; I²=0% and OR, 0.74; 95% CI, 0.57-0.97; I²=0%, respectively]. Return of spontaneous circulation after OHCA, survival, and favorable neurological outcomes during and before the pandemic did not differ significantly (OR, 0.90; 95% CI, 0.71-1.13; I²=37%; OR, 0.74; 95% CI, 0.43-1.26; I²=72%; OR, 0.77; 95% CI, 0.43-1.37; I²=70%, respectively).

CONCLUSION

During the COVID-19 pandemic in South Korea, the incidence of at-home OHCA increased and AED use decreased among OHCA patients. However, survival and favorable neurological outcomes did not significantly differ from before the pandemic. This insignificant effect of the pandemic on OHCA in South Korea could be attributed to the slow increase in patient count in the early days of the pandemic. OSF Registry (DOI: 10.17605/OSF.IO/UGE9D).

Re-evaluating our language when reducing risk of SARS-CoV-2 transmission to healthcare workers: Time to rethink the term, “aerosol-generating procedures”

The term, "aerosol-generating procedures” (AGPs), was proposed during the prior SARS-CoV-1 epidemic in order to maximise healthcare worker and patient protection. The concept of AGPs has since expanded to include routine therapeutic processes such as various modes of oxygen delivery and non-invasive ventilation modalities. Evidence gained during the SARS-CoV-2 pandemic has brought into question the concept of AGPs with regard to intubation, airway management, non-invasive ventilation and high flow nasal oxygen delivery. Although encounters where these procedures occur may still be associated with increased risk of infectious transmission, this is a function of the clinical context and not because the procedure itself is aerosol-generating.

Strategies from A Multi-National Sample of Electroconvulsive Therapy (ECT) Services: Managing Anesthesia for ECT during the COVID-19 Pandemic

Electroconvulsive therapy (ECT) is important in the management of severe, treatment-resistant, and life-threatening psychiatric illness. Anesthesia supports the clinical efficacy and tolerability of ECT. The COVID-19 pandemic has significantly disrupted ECT services, including anesthesia. This study documents strategies for managing ECT anesthesia during the pandemic. Data were collected between March and November 2021, using a mixed-methods, cross-sectional, electronic survey. Clinical directors in ECT services, their delegates, and anesthetists worldwide participated. One hundred and twelve participants provided quantitative responses to the survey. Of these, 23.4% were anesthetists, and the remainder were ECT clinical directors. Most participants were from Australia, New Zealand, North America, and Europe. Most were located in a public hospital, in a metropolitan region, and in a ‘medium/high-risk’ COVID-19 hotspot. Half of the participants reported their services made changes to ECT anesthetic technique during the pandemic. Services introduced strategies associated with anesthetic induction, ventilation, use of laryngeal mask airways, staffing, medications, plastic barriers to separate staff from patients, and the location of extubation and recovery. This is the first multi-national, mixed-methods study to investigate ECT anesthesia practices during the COVID-19 pandemic. The results are vital to inform practice during the next waves of COVID-19 infection, ensuring patients continue to receive ECT.

Aerosol concentrations and size distributions during clinical dental procedures

Background

Suspected aerosol-generating dental instruments may cause risks for operators by transmitting pathogens, such as the SARS-CoV-2 virus. The aim of our study was to measure aerosol generation in various dental procedures in clinical settings.

Methods

The study population comprised of 84 patients who underwent 253 different dental procedures measured with Optical Particle Sizer in a dental office setting. Aerosol particles from 0.3 to 10 μm in diameter were measured. Dental procedures included oral examinations (N = 52), restorative procedures with air turbine handpiece (N = 8), high-speed (N = 6) and low-speed (N = 30) handpieces, ultrasonic scaling (N = 31), periodontal treatment using hand instruments (N = 60), endodontic treatment (N = 12), intraoral radiographs (N = 24), and dental local anesthesia (N = 31).

Results

Air turbine handpieces significantly elevated <1 μm particle median (p = 0.013) and maximum (p = 0.016) aerosol number concentrations as well as aerosol particle mass concentrations (p = 0.046 and p = 0.006) compared to the background aerosol levels preceding the operation. Low-speed dental handpieces elevated >5 μm median (p = 0.023), maximum (p = 0.013) particle number concentrations,> 5 μm particle mass concentrations (p = 0.021) and maximum total particle mass concentrations (p = 0.022). High-speed dental handpieces elevated aerosol concentration levels compared to the levels produced during oral examination.

Conclusions

Air turbine handpieces produced the highest levels of <1 μm aerosols and total particle number concentrations when compared to the other commonly used instruments. In addition, high- and low-speed dental handpieces and ultrasonic scalers elevated the aerosol concentration levels compared to the aerosol levels measured during oral examination. These aerosol-generating procedures, involving air turbine, high- and low-speed handpiece, and ultrasonic scaler, should be performed with caution.

Clinical significance

Aerosol generating dental instruments, especially air turbine, should be used with adequate precautions (rubber dam, high-volume evacuation, FFP-respirators), because aerosols can cause a potential risk for operators and substitution of air turbine for high-speed dental handpiece in poor epidemic situations should be considered to reduce the risk of aerosol transmission.

Aerosol and droplet generation in upper and lower GI endoscopy: whole procedure and event-based analysis

BACKGROUND AND AIMS

Aerosol-generating procedures have become an important healthcare issue during the coronavirus disease 2019 (COVID-19) pandemic because the severe acute respiratory syndrome coronavirus 2 virus can be transmitted through aerosols. We aimed to characterize aerosol and droplet generation in GI endoscopy, where there is little evidence.

METHODS

This prospective observational study included 36 patients undergoing routine peroral gastroscopy (POG), 11 undergoing transnasal endoscopy (TNE), and 48 undergoing lower GI (LGI) endoscopy. Particle counters took measurements near the appropriate orifice (2 models were used with diameter ranges of .3-25 μm and 20-3000 μm). Quantitative analysis was performed by recording specific events and subtracting background particles.

RESULTS

POG produced 1.96 times the level of background particles (P < .001) and TNE produced 2.00 times (P < .001), but a direct comparison showed POG produced 2.00 times more particles than TNE. LGI procedures produced significant particle counts (P < .001) with 2.4 times greater production per procedure than POG but only .63 times production per minute. Events that were significant relative to the room background particle count were POG, with throat spray (150.0 times, P < .001), esophageal extubation (37.5 times, P < .001), and coughing or gagging (25.8 times, P < .01); TNE, with nasal spray (40.1 times, P < .001), nasal extubation (32.0 times, P < .01), and coughing or gagging (20.0, P < .01); and LGI procedures, with rectal intubation (9.9 times, P < .05), rectal extubation (27.2 times, P < .01), application of abdominal pressure (9.6 times, P < .05), and rectal insufflation or retroflexion (7.7 times, P < .01). These all produced particle counts larger than or comparable with volitional cough.

CONCLUSIONS

GI endoscopy performed through the mouth, nose, or rectum generates significant quantities of aerosols and droplets. Because the infectivity of procedures is not established, we therefore suggest adequate personal protective equipment is used for all GI endoscopy where there is a high population prevalence of COVID-19. Avoiding throat and nasal spray would significantly reduce particles generated from upper GI procedures.

Effect of two barrier devices on the time taken and ease of intubation of a paediatric intubation manikin - A randomised cross-over simulation study

Background and Aims

During the present COVID-19 pandemic, several inventions have been employed to protect personnel involved in intubation from inhalational exposure to the virus. In this study, we compared the effect of two barrier devices, Intubation Box versus Plastic Drape, on the time taken and difficulty in intubating a pediatric manikin.

Material and Methods

Nineteen experienced anesthesiologists performed six different intubations: without barrier, with intubation box, with plastic drape; with and without a bougie, using the Latin Square Design for randomizing order of intubations. The time taken for intubation (TTI) was compared using Student's t test, and nonparametric values were analyzed using Chi-square test with Yates correction.

Results

Both barrier devices increased the TTI from 14.8 (3.5) s to 19.8 (6.8) s with intubation box (P = 0.068) and 19.3 (8.9) s with plastic drape (P = 0.099). Use of bougie significantly prolonged TTI to 25.8 (6.7) s without barrier (P = 0.000), 32.5 (13.3) with intubation box (P = 0.000), and 29.8 (7.3) s with plastic drape (P = 0.000). The number of attempts was not different (P = 0.411), and the visibility was slightly impaired with both barriers (P = 0.047). The ease of intubation, even without the bougie, was significantly different compared to default, with P values of 0.009 and 0.042 for intubation box and plastic drape, respectively. The highest significance was with intubation box with bougie with a P value of 0.00017.

Conclusion

Both the intubation box and plastic drape increased the time taken as well as difficulty in intubation. The extra protection afforded should be balanced against risks of hypoxia in the patient.

Preventing spread of aerosolized infectious particles during medical procedures: A lab-based analysis of an inexpensive plastic enclosure

Severe viral respiratory diseases, such as SARS-CoV-2, are transmitted through aerosol particles produced by coughing, talking, and breathing. Medical procedures including tracheal intubation, extubation, dental work, and any procedure involving close contact with a patient's airways can increase exposure to infectious aerosol particles. This presents a significant risk for viral exposure of nearby healthcare workers during and following patient care. Previous studies have examined the effectiveness of plastic enclosures for trapping aerosol particles and protecting health-care workers. However, many of these enclosures are expensive or are burdensome for healthcare workers to work with. In this study, a low-cost plastic enclosure was designed to reduce aerosol spread and viral transmission during medical procedures, while also alleviating issues found in the design and use of other medical enclosures to contain aerosols. This enclosure is fabricated from clear polycarbonate for maximum visibility. A large single-side cutout provides health care providers with ease of access to the patient with a separate cutout for equipment access. A survey of medical providers in a local hospital network demonstrated their approval of the enclosure's ease of use and design. The enclosure with appropriate plastic covers reduced total escaped particle number concentrations (diameter > 0.01 μm) by over 93% at 8 cm away from all openings. Concentration decay experiments indicated that the enclosure without active suction should be left on the patient for 15-20 minutes following a tracheal manipulation to allow sufficient time for >90% of aerosol particles to settle upon interior surfaces. This decreases to 5 minutes when 30 LPM suction is applied. This enclosure is an inexpensive, easily implemented additional layer of protection that can be used to help contain infectious or otherwise potentially hazardous aerosol particles while providing access into the enclosure.

Maintaining Prehospital Intubation Success with COVID-19 Personal Protective Precautions

Background:

Tracheal intubation is a high-risk intervention for exposure to airborne infective pathogens, including the novel coronavirus disease 2019 (COVID-19). During the recent pandemic, personal protective equipment (PPE) was essential to protect staff during intubation but is recognized to make the practical conduct of anesthesia and intubation more difficult. In the early phase of the coronavirus pandemic, some simple alterations were made to the emergency anesthesia standard operating procedure (SOP) of a prehospital critical care service to attempt to maintain high intubation success rates despite the challenges posed by wearing PPE. This retrospective observational cohort study aims to compare first-pass intubation success rates before and after the introduction of PPE and an altered SOP.

Methodology:

A retrospective observational cohort study was conducted from January 1, 2019 through August 30, 2021. The retrospective analysis used prospectively collected data using prehospital electronic patient records. Anonymized data were held in Excel (v16.54) and analyzed using IBM SPSS Statistics (v28). Patient inclusion criteria were those of all ages who received a primary tracheal intubation attempt outside the hospital by critical care teams. March 27, 2020 was the date from which the SOP changed to mandatory COVID-19 SOP including Level 3 PPE – this date is used to separate the cohort groups.

Results:

Data were analyzed from 1,266 patients who received primary intubations by the service. The overall first-pass intubation success rate was 89.7% and the overall intubation success rate was 99.9%. There was no statistically significant difference in first-pass success rate between the two groups: 90.3% in the pre-COVID-19 group (n = 546) and 89.3% in the COVID-19 group (n = 720); Pearson chi-square 0.329; P = .566. In addition, there was no statistical difference in overall intubation success rate between groups: 99.8% in the pre-COVID-19 group and 100.0% in the COVID-19 group; Pearson chi-square 1.32; P = .251.

Non-drug-assisted intubations were more than twice as likely to require multiple attempts in both the pre-COVID-19 group (n = 546; OR = 2.15; 95% CI, 1.19-3.90; P = .01) and in the COVID-19 group (n = 720; OR = 2.5; 95% CI, 1.5-4.1; P = <.001).

Conclusion:

This study presents simple changes to a prehospital intubation SOP in response to COVID-19 which included mandatory use of PPE, the first intubator always being the most experienced clinician, and routine first use of video laryngoscopy (VL). These changes allowed protection of the clinical team while successfully maintaining the first-pass and overall success rates for prehospital tracheal intubation.

Anaesthetists' current practice and perceptions of aerosol-generating procedures: a mixed-methods study

The evidence base surrounding the transmission risk of 'aerosol-generating procedures' has evolved primarily through quantification of aerosol concentrations during clinical practice. Consequently, infection prevention and control guidelines are undergoing continual reassessment. This mixed-methods study aimed to explore the perceptions of practicing anaesthetists regarding aerosol-generating procedures. An online survey was distributed to the Membership Engagement Group of the Royal College of Anaesthetists during November 2021. The survey included five clinical scenarios to identify the personal approach of respondents to precautions, their hospital's policies and the associated impact on healthcare provision. A purposive sample was selected for interviews to explore the reasoning behind their perceptions and behaviours in greater depth. A total of 333 survey responses were analysed quantitatively. Transcripts from 18 interviews were coded and analysed thematically. The sample was broadly representative of the UK anaesthetic workforce. Most respondents and their hospitals were aware of, supported and adhered to UK guidance. However, there were examples of substantial divergence from these guidelines at both individual and hospital level. For example, 40 (12%) requested respiratory protective equipment and 63 (20%) worked in hospitals that required it to be worn whilst performing tracheal intubation in SARS-CoV-2 negative patients. Additionally, 173 (52%) wore respiratory protective equipment whilst inserting supraglottic airway devices. Regarding the use of respiratory protective equipment and fallow times in the operating theatre: 305 (92%) perceived reduced efficiency; 376 (83%) perceived a negative impact on teamworking; 201 (64%) were worried about environmental impact; and 255 (77%) reported significant problems with communication. However, 269 (63%) felt the negative impacts of respiratory protection equipment were appropriately balanced against the risks of SARS-CoV-2 transmission. Attitudes were polarised about the prospect of moving away from using respiratory protective equipment. Participants' perceived risk from COVID-19 correlated with concern regarding stepdown (Spearman's test, R = 0.36, p < 0.001). Attitudes towards aerosol-generating procedures and the need for respiratory protective equipment are evolving and this information can be used to inform strategies to facilitate successful adoption of revised guidelines.

Aerosol Generation During Otologic Surgery

OBJECTIVE

To assess whether aerosol generation occurs during otologic surgery, to define which instruments are aerosol generating, and to identify factors that enhance safety in protection against airborne pathogens, such as severe acute respiratory syndrome coronavirus 2.

STUDY DESIGN

An observational prospective study on aerosol measurements during otologic operations recorded between August and December 2020.

SETTING

Aerosol generation was measured with an Optical Particle Sizer as part of otologic operations with anesthesia. Particles with a size range of 0.3 to 10 μm were quantified. Aerosol generation was measured during otologic operations to analyze aerosols during drilling in transcanal and transmastoid operations and when using the following instruments: bipolar electrocautery, laser, suction, and cold instruments. Coughing is known to produce significant concentration of aerosols and is commonly used as a reference for high-risk aerosol generation. Thus, the operating room background concentration and coughing were chosen as reference values.

PATIENTS

Thirteen otologic operations were included. The average drilling time per surgery was 27.00 minutes (range, 2.00-71.80 min).

INTERVENTION

Different rotation speeds during drilling and other instruments were used.

MAIN OUTCOME MEASURES

Aerosol concentrations during operations were recorded and compared with background and cough aerosol concentrations.

RESULTS

Total aerosol concentrations during drilling were significantly higher than background ( p < 0.0001, d = 2.02) or coughing ( p < 0.0001, d = 0.50). A higher drilling rotation speed was associated with higher particle concentration ( p = 0.037, η2 = 0.01). Aerosol generation during bipolar electrocautery, drilling, and laser was significantly higher than with cold instruments or suction ( p < 0.0001, η2 = 0.04).

CONCLUSION

High aerosol generation is observed during otologic surgery when drill, laser, or bipolar electrocautery is used. Aerosol generation can be reduced by using cold instruments instead of electric and keeping the suction on during aerosol-generating procedures. If drilling is required, lower rotation speeds are recommended. These measures may help reduce the spread of airborne pathogens during otologic surgery.

Pulmonary function testing during SARS-CoV-2: An ANZSRS/TSANZ position statement

The Thoracic Society of Australia and New Zealand (TSANZ) and the Australian and New Zealand Society of Respiratory Science (ANZSRS) commissioned a joint position paper on pulmonary function testing during coronavirus disease 2019 (COVID-19) in July 2021. A working group was formed via an expression of interest to members of both organizations and commenced work in September 2021. A rapid review of the literature was undertaken, with a 'best evidence synthesis' approach taken to answer the research questions formed. This allowed the working group to accept findings of prior relevant reviews or societal document where appropriate. The advice provided is for providers of pulmonary function tests across all settings. The advice is intended to supplement local infection prevention and state, territory or national directives. The working group's key messages reflect a precautionary approach to protect the safety of both healthcare workers (HCWs) and patients in a rapidly changing environment. The decision on strategies employed may vary depending on local transmission and practice environment. The advice is likely to require review as evidence grows and the COVID-19 pandemic evolves. While this position statement was contextualized specifically to the COVID-19 pandemic, the working group strongly advocates that any changes to clinical/laboratory practice, made in the interest of optimizing the safety and well-being of HCWs and patients involved in pulmonary function testing, are carefully considered in light of their potential for ongoing use to reduce transmission of other droplet and/or aerosol borne diseases.

Airborne Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospitals: Effects of Aerosol-Generating Procedures, HEPA-Filtration Units, Patient Viral Load, and Physical Distance

BACKGROUND

Transmission of coronavirus disease 2019 (COVID-19) can occur through inhalation of fine droplets or aerosols containing infectious virus. The objective of this study was to identify situations, patient characteristics, environmental parameters, and aerosol-generating procedures (AGPs) associated with airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus.

METHODS

Air samples were collected near hospitalized COVID-19 patients and analyzed by RT-qPCR. Results were related to distance to the patient, most recent patient diagnostic PCR cycle threshold (Ct) value, room ventilation, and ongoing potential AGPs.

RESULTS

In total, 310 air samples were collected; of these, 26 (8%) were positive for SARS-CoV-2. Of the 231 samples from patient rooms, 22 (10%) were positive for SARS-CoV-2. Positive air samples were associated with a low patient Ct value (OR, 5.0 for Ct <25 vs >25; P = .01; 95% CI: 1.18-29.5) and a shorter physical distance to the patient (OR, 2.0 for every meter closer to the patient; P = .05; 95% CI: 1.0-3.8). A mobile HEPA-filtration unit in the room decreased the proportion of positive samples (OR, .3; P = .02; 95% CI: .12-.98). No association was observed between SARS-CoV-2-positive air samples and mechanical ventilation, high-flow nasal cannula, nebulizer treatment, or noninvasive ventilation. An association was found with positive expiratory pressure training (P < .01) and a trend towards an association for airway manipulation, including bronchoscopies and in- and extubations.

CONCLUSIONS

Our results show that major risk factors for airborne SARS-CoV-2 include short physical distance, high patient viral load, and poor room ventilation. AGPs, as traditionally defined, seem to be of secondary importance.

Ear, Nose, and Throat Foreign Bodies in the Paediatric Population: Did the COVID-19 Lockdown Change Anything?

Background

In the pediatric population, the ear, nose, and throat (ENT) foreign body is a common presentation for emergency departments (ED) and ENT units. COVID-19 has led to a significant impact on the health care system and the overall mental well-being of the general population. With the health care system under significant strain, we noted a continued presence of children with foreign bodies, with some requiring removal under a general anesthetic.

Aim

We aimed to assess if lockdown measures increased or decreased the incidence of children presenting to the hospital with ear, nose, and throat foreign bodies and to evaluate their management by the ED and ENT specialties.

Method

A retrospective data of children presenting with a foreign body in the ear, nose, and throat from March 2020 to August 2020 was compared with the data for the same period in 2019.

Results

Our study showed an overall decrease in children presenting with foreign bodies in 2020 compared to 2019 (n=90 and n=106, respectively). However, the number of children needing general anesthetic remained the same, and those presenting with foreign bodies in the upper aerodigestive tract were higher in 2020.

Conclusion

Children with foreign ear, nose, and throat bodies continued to present to the hospital during the COVID-19 lockdown. Our study shows an overall decrease in the number of children presenting with Ear, Nose, and Throat foreign body during the lockdown, but not statistically significantly different.

What were the historical reasons for the resistance to recognizing airborne transmission during the COVID-19 pandemic?

The question of whether SARS-CoV-2 is mainly transmitted by droplets or aerosols has been highly controversial. We sought to explain this controversy through a historical analysis of transmission research in other diseases. For most of human history, the dominant paradigm was that many diseases were carried by the air, often over long distances and in a phantasmagorical way. This miasmatic paradigm was challenged in the mid to late 19th century with the rise of germ theory, and as diseases such as cholera, puerperal fever, and malaria were found to actually transmit in other ways. Motivated by his views on the importance of contact/droplet infection, and the resistance he encountered from the remaining influence of miasma theory, prominent public health official Charles Chapin in 1910 helped initiate a successful paradigm shift, deeming airborne transmission most unlikely. This new paradigm became dominant. However, the lack of understanding of aerosols led to systematic errors in the interpretation of research evidence on transmission pathways. For the next five decades, airborne transmission was considered of negligible or minor importance for all major respiratory diseases, until a demonstration of airborne transmission of tuberculosis (which had been mistakenly thought to be transmitted by droplets) in 1962. The contact/droplet paradigm remained dominant, and only a few diseases were widely accepted as airborne before COVID-19: those that were clearly transmitted to people not in the same room. The acceleration of interdisciplinary research inspired by the COVID-19 pandemic has shown that airborne transmission is a major mode of transmission for this disease, and is likely to be significant for many respiratory infectious diseases.

Measuring SARS-CoV-2 aerosolization in rooms of hospitalized patients

Objective

Airborne spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a significant risk for healthcare workers. Understanding transmission of SARS-CoV-2 in the hospital could help minimize nosocomial infection. The objective of this pilot study was to measure aerosolization of SARS-CoV-2 in the hospital rooms of COVID-19 patients.

Methods

Two air samplers (Inspirotec) were placed 1 and 4 m away from adults with SARS-CoV-2 infection hospitalized at an urban, academic tertiary care center from June to October 2020. Airborne SARS-CoV-2 concentration was measured by quantitative reverse transcription polymerase chain reaction and analyzed by clinical parameters and patient demographics.

Results

Thirteen patients with COVID-19 (eight females [61.5%], median age: 57 years old, range 25-82) presented with shortness of breath (100%), cough (38.5%) and fever (15.4%). Respiratory therapy during air sampling varied: mechanical ventilation via endotracheal tube (n = 3), high flow nasal cannula (n = 4), nasal cannula (n = 4), respiratory helmet (n = 1), and room air (n = 1). SARS-CoV-2 RNA was identified in rooms of three out of three intubated patients compared with one out of 10 of the non-intubated patients (p = .014). Airborne SARS-CoV-2 tended to decrease with distance (1 vs. 4 m) in rooms of intubated patients.

Conclusions

Hospital rooms of intubated patients had higher levels of aerosolized SARS-CoV-2, consistent with increased aerosolization of virus in patients with severe disease or treatment with positive pressure ventilation through an endotracheal tube. While preliminary, these data have safety implications for health care workers and design of protective measures in the hospital.

Level of Evidence

2.

Aerosol-Generating Procedures and Virus Transmission

During the early phase of the COVID-19 pandemic, many respiratory therapies were classified as aerosol-generating procedures. This categorization resulted in a broad range of clinical concerns and a shortage of essential medical resources for some patients. In the past 2 years, many studies have assessed the transmission risk posed by various respiratory care procedures. These studies are discussed in this narrative review, with recommendations for mitigating transmission risk based on the current evidence.

Prevention of SARS-CoV-2 and respiratory viral infections in healthcare settings: current and emerging concepts

PURPOSE OF REVIEW

COVID-19 has catalyzed a wealth of new data on the science of respiratory pathogen transmission and revealed opportunities to enhance infection prevention practices in healthcare settings.

RECENT FINDINGS

New data refute the traditional division between droplet vs airborne transmission and clarify the central role of aerosols in spreading all respiratory viruses, including Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), even in the absence of so-called 'aerosol-generating procedures' (AGPs). Indeed, most AGPs generate fewer aerosols than talking, labored breathing, or coughing. Risk factors for transmission include high viral loads, symptoms, proximity, prolonged exposure, lack of masking, and poor ventilation. Testing all patients on admission and thereafter can identify early occult infections and prevent hospital-based clusters. Additional prevention strategies include universal masking, encouraging universal vaccination, preferential use of N95 respirators when community rates are high, improving native ventilation, utilizing portable high-efficiency particulate air filters when ventilation is limited, and minimizing room sharing when possible.

SUMMARY

Multifaceted infection prevention programs that include universal testing, masking, vaccination, and enhanced ventilation can minimize nosocomial SARS-CoV-2 infections in patients and workplace infections in healthcare personnel. Extending these insights to other respiratory viruses may further increase the safety of healthcare and ready hospitals for novel respiratory viruses that may emerge in the future.