Doctor of Philosophy

dissertationDrug-induced respiratory depression and airway obstruction are the primary causes of morbidity associated with sedation and analgesia. Most agents used to sedate patients during unpleasant procedures can depress ventilatory function. Sedation can cause two forms of respiratory depression: central ventilatory depression and obstructed breathing. This research aims to identify methods to reduce both of these forms of respiratory depression through 3 phases: (1) testing the ability of continuous positive airway pressure (CPAP) to prevent apnea in the clinical setting during procedural sedation for colonoscopies, (2) testing bi-level positive airway pressure (BiPAP) on patients undergoing general anesthesia, and (3) developing and demonstrating feasibility of a prototype ventilator that can address the clinical needs identified in phase 1 and 2 for a broad range of routine use scenarios. The culmination of this work is the design and testing of the electric blower-based mask ventilator (EBMV) in phase 3. It was designed to address the specific clinical problem of respiratory depression and apnea that results from sedation. The EBMV provides CPAP to prevent the airway from obstructing due to soft tissue collapse and it provides robust and real-time respiratory monitoring. In the event of central ventilatory depression, it can provide BiPAP breaths until the patient can resume regular breathing. The EBMV provides reliable and continuous respiratory support and monitoring even in the presence of large or varying leaks around the patient's face mask, allowing it to be a iv universal-fit option suitable for any patient that receives sedation. This technology aims to reduce respiratory depression by making sophisticated respiratory monitoring and support more widely available to patients undergoing sedation