The COVID-19 pandemic: implications for the head and neck anesthesiologist

High Frequency Jet Ventilation or Mechanical Ventilation for Panendoscopy for Cervicofacial Cancer: A Retrospective Study

Introduction-the upper airway panendoscopy, performed under general anesthesia, is mandatory for the diagnosis of cervicofacial cancer. It is a challenging procedure because the anesthesiologist and the surgeon have to share the airway space together. There is no consensus about the ventilation strategy to adopt. Transtracheal high frequency jet ventilation (HFJV) is the traditional method in our institution. However, the COVID-19 pandemic forced us to change our practices because HFJV is a high risk for viral dissemination. Tracheal intubation and mechanical ventilation were recommended for all patients. Our retrospective study compares the two ventilation strategies for panendoscopy: high frequency jet ventilation (HFJV) and mechanical ventilation with orotracheal intubation (MVOI). Methods-we reviewed all panendoscopies performed before the pandemic in January and February 2020 (HFJV) and during the pandemic in April and May 2020 (MVOI). Minor patients, patients with a tracheotomy before or after, were excluded. We performed a multivariate analysis adjusted on unbalanced parameters between the two groups to compare the risk of desaturation. Results-we included 182 patients: 81 patients in the HFJV group and 80 in the MVOI group. After adjustments based on BMI, tumor localization, history of cervicofacial cancer surgery, and use of muscle relaxants, the patients from the HFJV group showed significantly less desaturation than the intubation group (9.9% vs. 17.5%, OR_a = 0.18, p = 0.047). Conclusion-HFJV limited the incidence of desaturation during upper airway panendoscopies in comparison to oral intubation.

Tubeless Anesthesia in Subglottic Stenosis: Comparative Review of Apneic Low-Flow Oxygenation With THRIVE

OBJECTIVE

Managing the shared airway in subglottic stenosis presents a unique challenge. Tubeless anesthesia with apneic oxygenation is increasingly being adopted as it overcomes the limitations of access to and visualization of the narrowed subglottis. Low-flow oxygenation (LFO) and transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) are two delivery techniques. We sought to compare their utility in this patient cohort.

STUDY DESIGN

Retrospective cohort study.

METHODS

Thirty-five cases of endoscopic debridement of subglottic stenosis were retrospectively studied. Operative technique was consistent among the cases. Oxygen was delivered at low-flow rates at the laryngeal inlet with LFO (n = 23) or high-flow rates at the nares with THRIVE (n = 12). Data regarding apnea time, the need for rescue ventilation, and relevant patient and disease factors were recorded for analysis.

RESULTS

Median apnea time for LFO and THRIVE were 34 and 25 minutes, respectively. Rescue with intermittent supraglottic jet ventilation was required more often with LFO than THRIVE (61% vs 33%) and was sufficient for the case to be completed in all but one instance. Elevated BMI was the sole significant predictor of early oxygen desaturation (24.8 vs 37.95 kg/m² , P = .002) with LFO. Median stenosis diameter was 6 mm (range 2-14).

CONCLUSION

Apneic techniques are safe and feasible for the endoscopic management of subglottic stenosis of all severities. Elevated BMI is the only significant predictor for early oxygen desaturation. In the many healthcare settings where THRIVE is not available, LFO is a valid alterative in the nonobese patient. Laryngoscope, 2021.

The Impact of COVID-19 on Speech-Language Pathologists Engaged in Clinical Practices With Elevated Coronavirus Transmission Risk

Purpose This study assessed and described potential clinical practice changes secondary to COVID-19 that emerged as an early response to the pandemic for speech-language pathologists (SLPs) engaged in voice, alaryngeal, and swallowing activities that may increase the risk of virus transmission. Method SLPs from the United States and Canada (n = 665) who were engaged in clinical activities that might elevate the risk of COVID-19 exposure completed an online survey regarding their clinical practices. Topics assessed included potential clinical service modifications, COVID-19 testing and health, and potential financial impacts in the early time period of the pandemic. Results The percentage of SLPs completing the most endoscopic procedures prepandemic (≥ 10/week) was reduced from 39% of respondents to 3% due to the pandemic. Those who completed the most tracheoesophageal puncture voice prosthesis changes (≥ 5/week) reported a reduction in frequency from 24% to 6%. Twenty-five percent of SLPs reported that they were tested for COVID-19, and 6% reported a positive result. Descriptive statistics suggest that COVID-19 testing rates of SLPs, the percentage of SLPs experiencing a financial impact, and the percentage who were furloughed varied across SLP work setting. Conclusions These findings provide the first data characterizing the impact on COVID-19 on clinical practice for SLPs engaged in procedures such as endoscopy and laryngectomy care. The results indicate that, as frontline workers, SLPs were directly impacted in their practice patterns, personal health, safety, and financial security, and that these reported impacts occurred differently across SLP work settings.

Aerosol Generation During Laryngology Procedures in the Operating Room

OBJECTIVE

Severe acute respiratory syndrome coronavirus-2 spreads through respiratory fluids. We aim to quantify aerosolized particles during laryngology procedures to understand their potential for transmission of infectious aerosol-based diseases.

STUDY DESIGN

Prospective quantification of aerosol generation.

METHODS

Airborne particles (0.3-25 μm in diameter) were measured during live-patient laryngology surgeries using an optical particle counter positioned 60 cm from the oral cavity to the surgeon's left. Measurements taken during the procedures were compared to baseline concentrations recorded immediately before each procedure. Procedures included direct laryngoscopy with general endotracheal anesthesia (GETA), direct laryngoscopy with jet ventilation, and carbon dioxide (CO₂ ) laser use with or without jet ventilation, all utilizing intermittent suction.

RESULTS

Greater than 99% of measured particles were 0.3 to 1.0 μm in diameter. Compared to baseline, direct laryngoscopy was associated with a significant 6.71% increase in cumulative particles, primarily 0.3 to 1.0 μm particles (P < .0001). 1.0 to 25 μm particles significantly decreased (P < .001). Jet ventilation was not associated with a significant change in cumulative particles; when analyzing differential particle sizes, only 10 to 25 μm particles exhibited a significant increase compared to baseline (+42.40%, P = .002). Significant increases in cumulative particles were recorded during CO₂ laser use (+14.70%, P < .0001), specifically in 0.3 to 2.5 μm particles. Overall, there was no difference when comparing CO₂ laser use during jet ventilation versus GETA.

CONCLUSIONS

CO₂ laser use during laryngology surgery is associated with significant increases in airborne particles. Although direct laryngoscopy with GETA is associated with slight increases in particles, jet ventilation overall does not increase particle aerosolization.

LEVEL OF EVIDENCE

III Laryngoscope, 2021.

Transnasal humidified rapid-insufflation ventilatory exchange ('THRIVE') in the coronavirus disease 2019 pandemic

Background

Since the start of the coronavirus disease 2019 pandemic, transnasal humidified rapid-insufflation ventilatory exchange (‘THRIVE’) has been classified as a high-risk aerosol-generating procedure and is strongly discouraged, despite a lack of conclusive evidence on its safety.

Methods

This study aimed to investigate the safety of transnasal humidified rapid-insufflation ventilatory exchange usage and its impact on staff members. A prospective study was conducted on all transnasal humidified rapid-insufflation ventilatory exchange cases performed in our unit between March and July 2020.

Results

During the study period, 18 patients with a variety of airway pathologies were successfully managed with transnasal humidified rapid-insufflation ventilatory exchange. For each case, 7–10 staff members were present. Appropriate personal protective equipment protocols were strictly implemented and adhered to. None of the staff involved reported symptoms or tested positive for coronavirus disease 2019, up to at least a month following their exposure to transnasal humidified rapid-insufflation ventilatory exchange.

Conclusion

With strictly correct personal protective equipment use, transnasal humidified rapid-insufflation ventilatory exchange can be safely employed for carefully selected patients in the current pandemic, without jeopardising the health and safety of the ENT and anaesthetic workforce.