1. Emergency Airway Modification Combination Catheter for Transtracheal Jet Ventilation and Retrograde Intubation Friedrich W. Haimberger 1 Advisor: Steven J. White, M.D. 2 1.Department of Biomedical Engineering, Vanderbilt University; Nashville, Tennessee 2.Department of Emergency Medicine, Vanderbilt University Medical Center (VUMC); Nashville, Tennessee The Problem Currently, two punctures must be made for separate catheters to complete these two rescue airway procedures. This effectively doubles the risk of hemorrhaging from the puncture site, inadvertent puncture of the esophagus, and inadvertent extra-tracheal catheter malplacement. Additionally, access to the cricothyroid membrane for insertion of the RI catheter may be difficult while TTJV is being performed. Background The standard method of placing a breathing tube into the trachea using a laryngoscope is sometimes impossible to achieve. Due to the brain’s dependence on oxygen, other emergency measures must sometimes be employed to insure a constant flow of the life-sustaining gas. Transtracheal jet ventilation (TTJV) and retrograde intubation (RI), described below, are two rescue airway methods that can provide oxygen to support the brain’s requirements. First, a catheter directed toward the lungs is used to puncture the cricothyroid membrane. During and after puncture, the catheter is aspirated for free-flow of air to confirm correct placement within the trachea. The catheter is then attached to the jet ventilator to provide immediate ventilation of the patient’s lungs. Following this procedure, but while the patient is still being ventilated emergently by TTJV, a separate task of retrograde intubation may be undertaken. A second catheter, aimed toward the head, is used to puncture the cricothyroid membrane again. A wire is passed through this catheter, fed up through the trachea and out the mouth at which point an endotracheal (ET) tube is positioned over the wire and guided down into position. This provides for a definitive airway, despite taking much longer to perform than either the TTJV procedure or standard intubation with a laryngoscope. Transtracheal Jet Ventilation Procedure Retrograde Intubation Procedure Project Definition Develop one device that conforms to the following requirements:  Provides rapid temporary airway with manual jet ventilator  Provides the means to perform retrograde intubation  Allows simultaneous jet ventilation of the lungs through one lumen while a wire is inserted into the second lumen to accomplish retrograde intubation.  Safely combines these two sequential procedures (one being rapid and temporizing while the other is more time-consuming yet definitive) into one step that significantly decreases the composite risk Market Analysis   Possibility for use in any emergency department, as well as EMS advanced life support units, air medical helicopters, Army field medic units, and hospital critical care units  Any case with upper airway compromise  Total cost, disposable and non-disposable equipment approaches $1,000  Disposable (tubes, catheters) = $250-300  Non-disposable (laryngoscope blades, oxygen regulator, jet ventilator) = $600  Projected annual sales (catheter only) for the U.S. without markup = $225,000  Patent Search (as recent as 13 April 2005) shows no current device for this procedure www.cookgroup.com www.med-worldwide.com/ jet-ventilator.html www.cookgroup.com www.images.md Cost/Benefit Analysis Costs/Benefits Current MethodAfter Implementation Time expenditure 1+5 minutes (2 procedures) 3-4 minutes Amount of Materials All mentioned aboveOne less catheter and introducer needle Catheter Cost $200 total for TTJV and RI ~ $150 for combination Bodily Harm Potential--- 50% of previous Practicality/Efficacy Difficult to combine both procedures due to anatomic access Combination of procedures is easy / provides improved safety margin for RI TTJV Catheter Jet Ventilator Setup Retrograde Intubation Kit Proposed Solutions Solution #1   Similar to catheter from Martech Medical  Double Lumen Split Catheter  Short (<1cm) insertion needle  Inserted perpendicular to cricothyroid membrane  One lumen flexes towards lungs, one towards mouth  Instant ventilation and wire insertion capability www.martechmedical.com Double Lumen Split Catheters Solution #2   Typical marked double lumen, central line-type catheter  Must be semi-rigid to prevent kinking at flex point  Entirely rigid until slightly proximal of lumen exit  Inserted toward the head  Normal retrograde intubation possible  Catheter pulled out slightly, then flexed to point hole/lumen toward the lungs  Catheter pushed back in for immediate ventilation  Wire inserted next to provide for retrograde intubation Feasibility Testing  Testing done in VUMC Emergency Room  Used VUMC jet ventilators, oxygen sources, and other disposables  No exact baseline for determining lung inflation  Different size catheters (14G – 24G) were tested  Inflation capability tested on endotracheal tube attached to latex glove (trachea and lung simulator)  Capability measured by Dr. White and his many years’ experience  Determined that sufficient inflation was possible from 14 – 20G catheter  Glove barely inflated with 22G and 24G catheters Acknowledgements I would like to thank Dr. White for his continued support throughout our work on my senior project. His openness to allowing me to help him with a project that has been on his mind for years in addition to his willingness to meet with me and allow me to shadow him in the ER whenever I needed or wanted merely exemplify his devotion to his profession. Without him, this project would not have been possible. www.cookcriticalcare.com Double Lumen Central Line Catheter www.images.md ET Tube Positioning over Guide Wire Conclusions  Solution #1 will most likely be more feasible since fewer steps are needed for procedural completion  Solution #2 requires more of a delay prior to ventilation, though the time is likely clinically insignificant  Future work includes prototyping with a catheter extrusion company and clinical testing during Summer 2005