Clinical evaluation of the Trachospray device for upper airway anaesthesia

Topical Anaesthesia Using a Soft Mist Spray Device Allows Comfortable Awake Visualisation of the Airway via Self-Videolaryngoscopy in Volunteers

Background: During endotracheal intubation, there is a 10% incidence of difficult laryngoscopy, which may result in serious complications. It is important to obtain as much information about the visibility of laryngeal structures before the patient is anaesthetised. Performing awake (video-) laryngoscopy on a patient is uncomfortable and can trigger gagging and coughing reflexes, making visualisation nearly impossible. The objective of this study is to evaluate the effectiveness of a soft mist spray device for airway anaesthesia during awake (video-) laryngoscopy. Methods: Twenty healthy volunteers inhaled through the Trachospray device, which was placed in their mouths. Two 2 mL syringes containing lidocaine at 4% were sprayed into the airway during inspiration. After several minutes, the subjects were asked to perform a videolaryngoscopy on themselves until the glottic structures and the vocal cords were visible. Upon completion of the procedure, all participants were asked to fill out a feedback form. Results: The duration of the videolaryngoscopy to visualisation of the vocal cords averaged 17 ± 13 s. After analysing the data, three distinct groups emerged as follows: Group 1 (70% of participants) showed no response, allowing for easy insertion of the videolaryngoscope. Group 2 (25% of participants) exhibited a light response but still permitted easy insertion and visualisation. One patient demonstrated a clear response with noticeable laryngeal contraction, requiring slightly more effort and discomfort for insertion. In 80% of the participants, the laryngeal structures were visualised according to Cormack-Lehane grade 1. All participants reported a high level of comfort, with an average rating of NRS 8. The anaesthesiologist assessed the level of anaesthesia as good to very good. No adverse events were observed. Conclusions: The Trachospray provided good, reliable, comfortable, and safe topical anaesthesia for awake videolaryngoscopy. This enables a direct visual assessment of the airway and may assist in making decisions regarding airway management for tracheal intubation.

Advances in soft mist inhalers

INTRODUCTION

Soft mist inhalers (SMIs) are propellant-free inhalers that utilize mechanical power to deliver single or multiple doses of inhalable drug aerosols in the form of a slow mist to patients. Compared to traditional inhalers, SMIs allow for a longer and slower release of aerosol with a smaller ballistic effect, leading to a limited loss in the oropharyngeal area, whilst requiring little coordination of actuation and inhalation by patients. Currently, the Respimat® is the only commercially available SMI, with several others in different stages of preclinical and clinical development.

AREAS COVERED

The primary purpose of this review is to critically assess recent advances in SMIs for the delivery of inhaled therapeutics.

EXPERT OPINION

Advanced particle formulations, such as nanoparticles which target specific areas of the lung, Biologics, such as vaccines, proteins, and antibodies (which are sensitive to aerosolization), are expected to be generally delivered by SMIs. Furthermore, repurposed drugs are expected to constitute a large share of future formulations to be delivered by SMIs. SMIs can also be employed for the delivery of formulations that target systemic diseases. Finally, digitalizing SMIs would improve patient adherence and provide clinicians with fundamental insights into patients' treatment progress.