The utility of the pretracheal stethoscope in detecting ventilatory abnormalities during propofol sedation in children

Wireless broadband acousto-mechanical sensing system for continuous physiological monitoring

The human body generates various forms of subtle, broadband acousto-mechanical signals that contain information on cardiorespiratory and gastrointestinal health with potential application for continuous physiological monitoring. Existing device options, ranging from digital stethoscopes to inertial measurement units, offer useful capabilities but have disadvantages such as restricted measurement locations that prevent continuous, longitudinal tracking and that constrain their use to controlled environments. Here we present a wireless, broadband acousto-mechanical sensing network that circumvents these limitations and provides information on processes including slow movements within the body, digestive activity, respiratory sounds and cardiac cycles, all with clinical grade accuracy and independent of artifacts from ambient sounds. This system can also perform spatiotemporal mapping of the dynamics of gastrointestinal processes and airflow into and out of the lungs. To demonstrate the capabilities of this system we used it to monitor constrained respiratory airflow and intestinal motility in neonates in the neonatal intensive care unit (n = 15), and to assess regional lung function in patients undergoing thoracic surgery (n = 55). This broadband acousto-mechanical sensing system holds the potential to help mitigate cardiorespiratory instability and manage disease progression in patients through continuous monitoring of physiological signals, in both the clinical and nonclinical setting.

A novel system that continuously visualizes and analyzes respiratory sounds to promptly evaluate upper airway abnormalities: a pilot study

Although respiratory sounds are useful indicators for evaluating abnormalities of the upper airway and lungs, the accuracy of their evaluation may be limited. The continuous evaluation and visualization of respiratory sounds has so far been impossible. To resolve these problems, we developed a novel continuous visualization system for assessing respiratory sounds. Our novel system was used to evaluate respiratory abnormalities in two patients. The results were not known until later. The first patient was a 23-year-old man with chronic granulomatous disease and persistent anorexia. During his hospital stay, he exhibited a consciousness disorder, bradypnea, and hypercapnia requiring tracheal intubation. After the administration of muscle relaxant, he suddenly developed acute airway stenosis. Because we could not intubate and ventilate, we performed cricothyroidotomy. Subsequent review of our novel system revealed mild stridor before the onset of acute airway stenosis, which had not been recognized clinically. The second patient was a 74-year-old woman who had been intubated several days earlier for tracheal burn injury, and was extubated after alleviation of her laryngeal edema. After extubation, she gradually developed inspiratory stridor. We re-intubated her after diagnosing post-extubation laryngeal edema. Subsequent review of our novel system revealed serially increased stridor after the extubation, at an earlier time than was recognized by healthcare providers. This unique continuous monitoring and visualization system for respiratory sounds could be an objective tool for improving patient safety regarding airway complications.

Comparing two airway management strategies for moderately sedated patients undergoing awake craniotomy: A single-blinded randomized controlled trial

BACKGROUND

In the monitored anesthesia care (MAC) setting for awake craniotomy (AC), maintaining airway patency in sedated patients remains challenging. This randomized controlled trial aimed to compare the validity of the below-epiglottis transnasal tube insertion (the tip of the tube placed between the epiglottis and vocal cords) and the nasopharyngeal airway (simulated by the above-epiglottis transnasal tube with the tip of the tube placed between the epiglottis and the free edge of the soft palate) with respect to maintaining upper airway patency for moderately sedated patients undergoing AC.

METHODS

Sixty patients scheduled for elective AC were randomized to receive below-epiglottis (n = 30) or above-epiglottis (n = 30) transnasal tube insertion before surgery. Moderate sedation was maintained in the pre- and post-awake phases. The primary outcome was the upper airway obstruction (UAO) remission rate (relieved obstructions after tube insertion/the total number of obstructions before tube insertion).

RESULTS

The UAO remission rate was higher in the below-epiglottis group [100% (12/12) vs 45% (5/11); P = .005]. The tidal volume values monitored through the tube were greater in the below-epiglottis group during the pre-awake phase (P < .001). End-tidal carbon dioxide (EtCO₂ ) monitored through the tube was higher in the below-epiglottis group at bone flap removal (P < .001). During the awake phase, patients' ability to speak was not impeded. No patient had serious complications related to the tube.

CONCLUSION

The below-epiglottis tube insertion is a more effective method to maintain upper airway patency than the nasopharyngeal airway for moderately sedated patients undergoing AC.