Video-stylet vs. channeled hyperangulated videolaryngoscope: Efficacy in simulated Ludwig's angina randomized cadaver trial.

INTRODUCTION: Ludwig's angina (LA) is a life-threatening infection that can affect the floor of the mouth and neck, potentially causing serious airway obstruction. In such cases, rescue airway management and oxygenation can be challenging due to swelling of the mouth floor, trismus, and limited mouth opening. The aim of this study was to assess the efficacy of the Trachway video-stylet (VS) and Pentax AWS hyperangulated videolaryngoscope with channel (HAVL-C) compared to the standard geometric video-laryngoscope (SGVL, Macintosh 3, Trachway) in simulating Ludwig's angina with cadavers. METHODS: Three fresh frozen cadavers were prepared with varying degrees of difficulty to simulate the airway conditions of patients with LA, including mouth floor swelling, restricted mouth opening, and trismus. Fifty-five second-year resident physicians from various specialties participated in the study and received training in airway management using SGVL, VS, and HAVL-C devices. Participants were randomly assigned to intubate simulated LA with cadavers using the three devices in a random order, and intubation times and success rates were recorded. Participants also rated the difficulty of intubation using a visual analogue scale (VAS) score. The primary outcome assessed the first-pass intubation success or failure, while the secondary outcomes measured the intubation time and subjective difficulty using a visual analogue scale with different laryngoscopes. RESULTS: The success rates for intubation within 90 s were 40% for SGVL, 82% for VS, and 76% for HAVL-C. VS and HAVL-C had significantly higher success rates than SGVL, with hazard ratios of 3.4 and 2.7, and 95% confidence intervals (CI) of 2.0-5.7 and 1.6-4.6, p < 0.001, respectively. The odds ratios of successful intubation for VS and HAVL-C were 8.1 and 6.3, respectively, with a 95% CI of 3.7-17.8 and 2.4-16.7, p < 0.001, compared to SGVL. The VAS score was significantly correlated with intubation success rate and time. CONCLUSIONS: In cases of LA, the use of VS and HAVL-C is preferable over SGVL. These findings suggest that using VS and HAVL-C can improve intubation success rates and reduce intubation time in patients with LA.

Continuous aerosol monitoring and comparison of aerosol exposure based on smoke dispersion distance and concentrations during oxygenation therapy.

This study evaluated the aerosol exposure risks while using common noninvasive oxygenation devices. A simulated mannequin was designed to breathe at a minute ventilation of 20 L/min and used the following oxygen-therapy devices: nasal cannula oxygenation (NCO) at 4 and 15 L/min, nonrebreathing mask (NRM) at 15 L/min, simple mask at 6 L/min, combination of NCO at 15 L/min and NRM at 15 L/min, high-flow nasal cannula (HFNC) at 50 L/min, and flush rate NRM. Two-dimension of the dispersion distance and the aerosol concentrations were measured at head, trunk, and foot around the mannequin for over 10 min. HFNC and flush-rate NRM yielded the longest dispersion distance and highest aerosol concentrations over the three sites of the mannequin than the other oxygenation devices and should use with caution. For flow rates of < 15 L/min, oxygenation devices with mask-like effects, such as NRM or NCO with NRM, decreased aerosol dispersion more effectively than NCO alone or a simple mask. In the upright position, the foot area exhibited the highest aerosol concentration regardless of the oxygenation device than the head-trunk areas of the mannequin. Healthcare workers should be alert even at the foot side of the patient while administering oxygenation therapy.