Emergency Airways
Modification of Transtracheal Jet Ventilation and Retrograde Intubation Techniques
Fritz Haimberger
14 October 2004
BME 272 Senior Design Project NCIIA Proposal
Background
Currently, IV catheters or transtracheal jet ventilation (TTJV) catheters (Figure 1) are used to perform the ventilation procedure. The IV catheter is useful for protection against disease, while the TTJV catheter is larger and armored to prevent breakage. It is difficult to find an IV catheter with a syringe pre-attached to provide aspiration during the puncture process – due tothe possibility of blood-borne pathogen transmission, it is simply not practical. First, a catheter directed toward the lungs is used to puncture the cricothyroid membrane. During and after puncture, the catheter is aspirated to provide immediate rescue ventilation to the patient. Following this procedure, but while the patient is still being ventilated emergently by TTJV, a separate task of retrograde intubation is undertaken. Another catheter, aimed cephalad, is used to puncture the cricothyroid membrane a second time. 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, even though it takes much longer than the TTJV procedure. Currently, puncture holes for two separate catheters must be made to complete these two rescue airway procedures. This significantly increases the possibility for infection at the insertion site, the probability of bruising around the puncture site, the bleeding that ensues as a result of the procedure, the likelihood for inadvertent puncture of the esophagus, and inadvertent extra-tracheal catheter placement to occur upon catheter insertion.
Description of Project
The purpose of this project is to provide for an easier method of securing a patent airway using these two methods. It is proposed that a single device be designed to conform to the following criteria:
1.First provides a rapid, temporary airway for ventilation with a manual jet ventilator, with gas flow directed toward the lungs
2.Following that, provides a means to accomplish retrograde intubation to secure a definitive airway
3.Accomplishes the retrograde intubation through a separate lumen in the catheter that allows for insertion of a wire that would eventually be withdrawn from the mouth and used for ET tube insertion
4.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 Potential
As it stands now, the total cost of materials for these two procedures is in upwards of $1,000, including disposable and non-disposable equipment. The disposable portion of these procedures (catheters, ET tube, patient connecting tube) in and of itself costs at least $250 (Susquehana Micro, Inc), and this does not account for any markup. The non-disposable supplies as seen in Figure 2 (oxygen regulator, jet ventilator, laryngoscope blade and handles) cost approximately $600 (Gall’s, Inc. and Life-Assist, Inc). The potential market for the proposed device is quite sizeable – any hospital that deals with a significant amount of trauma (most likely a level 1 trauma center), has the potential for encountering a good deal of patients with compromised upper airways requiring an intervention such as the one proposed here. The competitive advantages of this procedure are to simply offer a faster, safer means of establishing a patent airway in a patient with severe airway trauma.
Group Composition
The only member of this group is Fritz Haimberger, a senior biomedical engineering student at VanderbiltUniversity. He is an emergency medical technician with a local rescue squad and a former firefighter, and he is very familiar with airway stabilization as it pertains to rapid intervention. He will be performing all research duties, observations in the emergency room at Vanderbilt University Medical Center, device development, and testing of the proposed device. He will be supervised by Steven J. White, MD, an assistant professor of emergency medicine at Vanderbilt University Medical Center (VUMC).
Timeline
The following timeline is listed by month with the culmination of the project occurring simultaneously with the completion of the BME 272/273 design class in April of 2005. During November and December, the student will research techniques on TTJV and retrograde intubation and will observe these in action at the VUMC Emergency Department. The months of December and January will concentrate on brainstorming the engineering aspects of the current devices used to determine a course of design for the proposed single device. February will entail performing risk assessments of design possibilities gained from these brainstorming sessions to determine a path of construction. During the latter part of February and the month of March, development of the actual device will take place along with testing on simulators and possibly animals. April will conclude the testing and troubleshooting phase, followed by the analysis and presentation of our findings.
Equipment and Resources Required
VanderbiltUniversity should provide all necessary analysis and computational tools through the computing labs. The mechanical engineering shop may be used to gain a prototype of the proposed device, and the testing of the device may occur in conjunction with the VUMC advanced skills laboratory or animal testing facilities. It is suspected that since the basis for this device is already approved for use by the FDA, testing will be done primarily based on the double lumen design and the retroflexion of the catheter. FDA mandates must be taken into consideration, but it must be kept in mind that this device is merely an improvement on an already-present technology. Due to the nature of the Department of Biomedical Engineering at this university and its accompanying medical center, the acquisition of these tools and facilities for testingshould not be an issue in the least. It is hoped that the cost for use of the advanced skills lab and animal testing will be minimal, and the prototyping machine that is due next semester in the shop will also require very little money to operate for such a small device (on the order of 1cm in diameter and 7cm in length).
References
Susquehana Micro, Inc. Date of Access: 1 November 2004
(cost of TTJV equipment)
Galls, Inc. Date of Access: 13 November 2004
(cost of intubation equipment, photos)
Life-Assist, Inc. Date of Access: 13 November 2004
(photos)