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.

Impact of personal protective equipment attached powered air-purifying respirator on nursing-skill performance and psychosocial stress of intensive care unit COVID-19 nurses: A cross-sectional study

AIM

To investigate how personal protective equipment with an attached powered air-purifying respirator worn by intensive care unit nurses caring for COVID-19 patients in Korea impacts nursing-skill performance and psychosocial stress.

DESIGN

A cross-sectional descriptive study was designed using purposive sampling.

REVIEW METHODS

Online data collection was conducted from 3 March 2021-20 March 2021on 181 nurses who had worked for more than 1 month in COVID-19 critical care settings wearing personal protective equipment with a powered air-purifying respirator. A structured questionnaire was used to gather data on sociodemographic characteristics, attitude toward personal protective equipment, nursing-skill performance wearing personal protective equipment and psychosocial stress.

DATA SOURCES

Data was sourced from structured questionnaire responses.

RESULTS

Nursing skill performance decreased to 63.4%, compared with normal performance. Subjects' perceptions and attitudes related to PPE scored 3.56 out of 5; 44.7% of subjects reported severe psychosocial stress, which was significantly affected by attitude toward personal protective equipment usage, nursing performance, experience caring for COVID-19 patients and length of personal protective equipment usage per shift.

CONCLUSION

Greater negative attitude toward usage of personal protective equipment with a powered air-purifying respirator, results in lower nursing-skill performance and higher the psychosocial stress of nurses responding to COVID-19 outbreaks.

IMPLICATIONS FOR THE PROFESSION AND/OR PATIENT CARE

High negative attitude toward PPE and low nursing-skill performance due to PPE with an attached PAPR results in significant and debilitating psychosocial stress in ICU nurses responding to COVID-19 outbreaks. To respond effectively to future infectious disease outbreaks and improve nursing performance, minimising the inconvenience and restrictions experienced by nurses wearing personal protective equipment is critical.

REPORTING METHOD

We adhered to relevant EQUATOR guidelines to report.

PATIENT OR PUBLIC CONTRIBUTION

No patient or public contribution.

High-Risk Aerosol-Generating Procedures in COVID-19: Respiratory Protective Equipment Considerations

The correct selection and utilization of respiratory personal protective equipment is of the utmost importance in the current COVID-19 pandemic. This is especially true for health care workers exposed to high-risk aerosol-generating procedures, including otolaryngologists, ophthalmologists, neurosurgeons, maxillofacial surgeons, and laparoscopic surgeons. This communication provides a review of approved forms of respiratory protection and compares their characteristics, including surgical masks, N95 respirator, elastomeric respirators, powered air-purifying respirators, and controlled air-purifying respirators. For standard airborne precautions, N95 respirator are appropriate for respiratory protection. However, high-risk aerosol-generating procedures may create aerosolization of high viral loads that represent increased risk to health care workers. In these situations, enhanced respiratory protection with filters certified as 99, 100, or HEPA (high-efficiency particulate air) may be appropriate.

Assessment of Two Personal Breathing Recording Devices in a Simulated Healthcare Environment

BACKGROUND

In the field of respiratory protection for healthcare workers (HCWs), few data are available on respiratory airflow rate when HCWs are performing their work activities. The objective of this study was to assess the performance of two wearable breathing recording devices in a simulated healthcare environment.

METHODS

Breathing recording devices from two different manufactures "A" and "B" were assessed using 15 subjects while performing a series of simulated healthcare work activities (patient assessment; vitals; IV treatment; changing linen; carrying weight while walking; normal breathing while standing). The minute volume (MV, L/min), mean inhalation flow (MIF, L/min), peak inhalation flow (PIF, L/min), breathing frequency (f, breaths/min), and tidal volume (TV, L/min) measured by each device were analyzed. Bland-Altman method was applied to explore the variability of devices A and B. Duncan's multiple range test was used to investigate the differences among activity-specific inspiratory flow rates.

RESULTS

The average MV, MIF and PIF reported by device A were 23, 54, and 82 L/min with 95% upper confidence intervals (CIs) of 25, 60 and 92 L/min; the mean differences of MV, MIF and PIF presented by the two units of device A were 0.9, 1.3, and 2.8 L/min, respectively. The average values and mean differences of MV, MIF and PIF found with device B were significantly higher than device A (P<0.05), showing a high variability. During non-speech activities, the PIF/MV and MIF/MV ratios were >3.14 and >2, while with speech, the ratios increased to >6 and >3. The f during speech (15 breaths/min) was significantly lower than non-speech activities (20-25 breaths/min). Among different simulated work activities, the PIF of "patient assessment" was the highest.

CONCLUSIONS

This study demonstrated a novel approach to characterize respiratory flow for healthcare workers using an innovative wearable flow recording device. Data from this investigation could be useful in the development of future respirator test standards.

Aerosol Generation During Bone-Sawing Procedures in Veterinary Autopsies

Bone-sawing procedures are routinely performed during veterinary and human autopsies and represent an important source for infectious aerosols. Here we investigate the generation of aerosols during bone-sawing procedures using 5 different saws regularly used in veterinary and human pathology. In particular, the electrical bone band saw produced vast amounts of aerosolized particles less than 5 µm in diameter, which spread rapidly throughout the entire autopsy hall, leading to an exposure of all personnel. Other sawing devices tested were a diamond-coated cut grinder, an oscillating saw, a reciprocating saw, and a hand bone saw. Although these saws, especially the handsaw, generated fewer aerosolized particles than the band saw, the level of exposure of the saw operator would still be of concern in cases where infectious material would require sawing. Contamination of the entire autopsy area was successfully prevented by the construction of a separately ventilated sawing cabin inside the existing autopsy room. Saw operators in this cabin, however, were exposed to even higher aerosol concentrations. Protection of saw operators was achieved by using a powered air-purifying respirator. In conclusion, our results demonstrate that all bone-sawing procedures applied in veterinary and human pathology can generate aerosols that are of concern for the health of autopsy personnel. To reduce the risk of aerosol infections from bone-sawing procedures, efficient and properly designed ventilation systems to limit the spread of aerosols and appropriate personal protective equipment against aerosols for exposed personnel should be implemented.

Development of a Manikin-Based Performance Evaluation Method for Loose-Fitting Powered Air-Purifying Respirators

OBJECTIVE

Loose-fitting powered air-purifying respirators (PAPRs) are increasingly being used in healthcare. NIOSH has previously used advanced manikin headforms to develop methods to evaluate filtering facepiece respirator fit; research has now begun to develop methods to evaluate PAPR performance using headforms. This preliminary study investigated the performance of PAPRs at different work rates to support development of a manikin-based test method.

METHODS

Manikin penetration factors (mPF) of three models of loose-fitting PAPRs were measured at four different work rates (REST: 11 Lpm, LOW: 25 Lpm, MODERATE: 48 Lpm, and HIGH: 88 Lpm) using a medium-sized NIOSH static advanced headform mounted onto a torso. In-mask differential pressure was monitored throughout each test. Two condensation particle counters were used to measure the sodium chloride aerosol concentrations in the test chamber and also inside the PAPR facepiece over a 2-minute sample period. Two test system configurations were evaluated for returning air to the headform in the exhalation cycle (filtered and unfiltered). Geometric mean (GM) and 5th percentile mPFs for each model/work rate combination were computed. Analysis of variance tests were used to assess the variables affecting mPF.

RESULTS

PAPR model, work rate, and test configuration significantly affected PAPR performance. PAPR airflow rates for the three models were approximately 185, 210, and 235 Lpm. All models achieved GM mPFs and 5th percentile mPFs greater than their designated Occupational Safety and Health Administration assigned protection factors despite negative minimum pressures observed for some work rate/model combinations.

CONCLUSIONS

PAPR model, work rate, and test configuration affect PAPR performance. Advanced headforms have potential for assessing PAPR performance once test methods can be matured. A manikin-based inward leakage test method for PAPRs can be further developed using the knowledge gained from this study. Future studies should vary PAPR airflow rate to better understand the effects on performance. Additional future research is needed to evaluate the correlation of PAPR performance using advanced headforms to the performance measured with human subjects.

Effects of a powered air-purifying respirator intervention on indium exposure reduction and indium related biomarkers among ITO sputter target manufacturing workers

This study aimed to evaluate the efficacy of powered air-purifying respirators (PAPRs) worn by the workers, and to investigate the effect of this application on exposure and preclinical effects in terms of workplace measuring and biomarker monitoring in ITO sputter target manufacturing plants and workers, respectively. Fifty-four workers were recruited and investigated from 2010-2012, during which PAPRs were provided to on-site workers in September 2011. Each worker completed questionnaires and provided blood and urine samples for analysis of biomarkers of indium exposure and preclinical effects. Area and personal indium air samples were randomly collected from selected worksites and from participants. The penetration percentage of the respirator (concentration inside respirator divided by concentration outside respirator) was 6.6%. Some biomarkers, such as S-In, SOD, GPx, GST, MDA, and TMOM, reflected the decrease in exposure and showed lower levels, after implementation of PAPRs. This study is the first to investigate the efficacy of PAPRs for reducing indium exposure. The measurement results clearly showed that the implementation of PAPRs reduces levels of indium-related biomarkers. These findings have practical applications for minimizing occupational exposure to indium and for managing the health of workers exposed to indium.