Imposed Work of Breathing of Airway Adjuncts
Abstract
This bench study investigated the imposed work of breathing (WOB(I)) of an endotracheal tube (ETT), Laryngeal Mask Airway (LMA(R)), Streamlined Liner of the Pharyngeal Airway (SLIPA (R)), and Cobra Perilaryngeal Airway (CobraPLA(R)). A surrogate measure of imposed work maximum negative inspiratory pressure (MNIP), was used as the primary measure. Pressure-volume (PV) curves were compared qualitatively. A spontaneous breathing simulator was used to generate simulated spontaneous breaths. The devices were placed into an intubating mannequin modified by connecting the trachea to the simulator. A pneumotachograph was interposed between the airway device and the simulator. Simulated breathing conditions: spontaneously breathing patient receiving one minimum alveolar concentration of isoflurane (Cond 1) and spontaneous breathing of an adult emerging from general anesthesia (Cond 2). MNIP average and SD were calculated for 5 breaths. For Cond 1, MNIP (cm water) range: -0.6 (SLIPA(R)) to -2.0 (ETT); Cond 2, MNIP (cm water) range: -3.1 (SLIPA(R)) to -7.1 (ETT). ANOVA indicated statistically significant differences in MNIP for both conditions (p < 0.05). Post hoc tests indicated MNIP differences between all of the devices. PV curves were confirmatory. while there were statistically significant differences in WOB(I) of the devices, these differences are not likely clinically significant at the simulated inspiratory flow rates except for the WOB(I) of the ETT with the patient emerging from anesthesia. Selection should be made on factors including patient status and cost. The findings should aid future developers of these devices. The views expressed in this abstract are those of the authors and do not reflect the official policy or position of the Uniformed Services University of the Health Sciences, United States Air Force, Department of Defense or the US Government.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 16, 2004
- Accession Number
- ADA428809
Entities
People
- Brian A. Molloy
- Gary A. Wells
- Joseph C. Skinner Jr.
- Paul N. Austin
- William D. Gilmer
Organizations
- Uniformed Services University of the Health Sciences