ACUTE PULMONARY PRESSURIZATION DEVICE AND METHOD OF USE

Abstract

A system and method for relief of negative lung pressure during acute laryngospasm or upper airway obstruction, providing a non-toxic gas cartridge capable of supplying between 0.5-5 liters of gas during a procedure, a valve adapted to commence and stop gas release, and a trans-cricothyroid cartilage inflation needle for acutely relieving the negative pressure in the chest. The needle may also be used to insert a guidewire to assist in endotracheal tube insertion.

Claims

1. A thoracic inflation device, comprising: a canister having a non-toxic gas pressurized to at least 120 psi; a hollow inflation needle having an elongated axis and a sharp tip configured to pierce through human skin and cartilage into the larynx or trachea of a human with minimal tissue trauma; a valve, configured to control a rate of release of the non-toxic gas from the canister through the hollow inflation needle to a rate of between 1-60 liters per minute into the larynx or trachea; and an insertion depth stop surface extending normal to the elongated an axis of the hollow inflation needle from on an exterior of the hollow inflation needle, configured to establish an insertion limit for the inflation needle with respect to the human skin.

2. The thoracic inflation device according to claim 1, wherein the valve is configured to automatically release between 0.5 and 2.0 liters of the non-toxic gas per activation.

3. The thoracic inflation device according to claim 1, wherein the valve comprises a finger trigger.

4. The thoracic inflation device according to claim 1, wherein the valve is configured control the rate of release of the non-toxic gas through the hollow inflation needle to a rate of 3-20 liters per minute.

5. The thoracic inflation device according to claim 1, further comprising a sensor configured to detect a subatmospheric pressure in the larynx or trachea.

6. The thoracic inflation device according to claim 5, wherein the value is further configured to automatically supply the non-toxic gas until the subatmospheric pressure is relieved.

7. The thoracic inflation device according to claim 1, wherein the valve has an finger-activated trigger, is limited to provide between 0.5-1.5 liters per finger activation, and requires a reset before supply of more non-toxic gas.

8. The thoracic inflation device according to claim 1, wherein the hollow inflation needle comprises a dual lumen cannula having a first lumen configured to supply the non-toxic gas to the larynx or trachea, and a second lumen configured to sense a pressure within the larynx or trachea, wherein an initial flow of the non-toxic gas is emitted through the second lumen to ensure that it is clear.

9. The thoracic inflation device according to claim 1, wherein the hollow inflation needle has a closed tip and a side exhaust port for the non-toxic gas.

10. The thoracic inflation device according to claim 1, wherein the non-toxic gas is anoxic.

11. The thoracic inflation device according to claim 1, wherein the valve comprises a timer configured to limit a duration of flow of the non-toxic gas through the hollow inflation needle.

12. The thoracic inflation device according to claim 1, wherein the hollow inflation needle has a lumen aligned with the long axis, with a terminal inclined surface configured to deflect an inserted guidewire out through a sidewall aperture of the hollow inflation needle.

13. A thoracic inflation method, comprising: providing an inflation device comprising: a canister having a non-toxic gas pressurized to at least 120 psi; a hollow inflation needle having an elongated axis and a sharp tip configured to pierce through human skin and cartilage into the larynx or trachea of a human with minimal tissue trauma; a valve, configured to control a rate of release of the non-toxic gas from the canister through the hollow inflation needle to a rate of between 1-60 liters per minute into the larynx or trachea; and an insertion depth stop surface extending normal to the elongated an axis of the hollow inflation needle from on an exterior of the hollow inflation needle, configured to establish an insertion limit for the inflation needle with respect to the human skin; determining that a human has an obstructive apnea; inserting the hollow inflation needle through the skin and larynx or trachea of the human, until the insertion depth stop contacts the human skin; activating the valve, to inject the non-toxic gas into the larynx or trachea, in a sufficient amount to alleviate a negative pressure within the larynx or trachea; and removing the hollow inflation needle from the larynx or trachea.

14. The method according to claim 13, further comprising restoring patency of the upper airway of the human.

15. The method according to claim 13, wherein the valve is automatically releases between 0.5 and 2.0 liters of the non-toxic gas per activation into the larynx or trachea, at a rate of 3-20 liters per minute.

16. The method according to claim 13, further detecting a subatmospheric pressure in the larynx or trachea, and automatically controlling the valve to permit the flow of the non-toxic gas until the subatmospheric pressure is alleviated.

17. The method according to claim 13, wherein the valve has a trigger and is limited to provide between 0.5-1.5 liters per activation, requiring a reset before supply of more non-toxic gas, the method further comprising: activating the trigger a first time to supply between 0.5-1.5 liters of the non-toxic gas; resetting the trigger; and activating the trigger a second time to supply between 0.5-1.5 liters of the non-toxic gas.

18. The method according to claim 13, wherein the hollow inflation needle comprises a dual lumen cannula having a first lumen configured to supply the non-toxic gas to the larynx or trachea, and a second lumen configured to sense a pressure within the larynx or trachea; the method further comprising: after insertion through the human and larynx or trachea, providing an initial flow of the non-toxic gas through the second lumen to ensure that it is clear; providing a subsequent flow of the non-toxic gas through the first lumen; sensing a pressure in the second lumen to monitor the pressure in the larynx or trachea; and automatically ceasing inflation selectively dependent on the pressure in the larynx or trachea.

19. The method according to claim 13, wherein the hollow inflation needle has a lumen aligned with the long axis, with a terminal inclined surface configured to deflect a guidewire in the lumen out through a sidewall aperture of the hollow inflation needle, the method further comprising: after activating the valve and before removing the hollow inflation needle from the larynx or trachea, inserting the guidewire through the lumen of the hollow inflation needle; feeding a looped end of the guidewire through the lumen, and towards an upper airway obstruction; attaching a breathing tube to the looped end of the guidewire; pulling the breathing tube past the upper airway obstruction by retracting the guidewire from the hollow inflation needle; disconnecting the looped end of the guidewire from the breathing tube; and removing the hollow inflation needle and guidewire from the larynx or trachea.

20. A thoracic inflation device, comprising: a hollow inflation needle having an elongated axis, a hollow lumen, a sharp tip configured to pierce through human skin and cartilage into the larynx or trachea of a human with minimal tissue trauma, and a side port continuous with the hollow lumen; an insertion depth stop surface extending normal to the elongated an axis of the hollow inflation needle from on an exterior of the hollow inflation needle, configured to establish an insertion limit sharp tip of the inflation needle respect to the human skin; and a valve, configured to receive a gas from a canister having a pressure in excess of 120 psi, and to control a flow of the gas into the larynx or trachea to a rate of release between 3-20 liters per minute and an amount of the gas between 0.5 and 2 liters.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 shows graphs of rapid desaturation during seizure-induced laryngospasm.

[0045] FIG. 2 shows a severe reduction in oxygen saturation during upper airway obstruction and persistence of decreased oxygen saturation after obstruction is cleared.

[0046] FIG. 3 shows the prevention of persistent oxygen desaturation problems by lung inflation with pure oxygen or other gas.

[0047] FIGS. 4A-4B shows a prior art cartridge inflation kit for repair of bicycle tires.

[0048] FIG. 5A shows a prior art needle inflation valve for a sports ball.

[0049] FIG. 5B shows a needle for chest inflation according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0050] FIG. 1 shows the rapid oxygen desaturation during seizure-induced laryngospasm. The short tune-course for hypoxic changes in ECG (within tens of seconds), indicates the extremely short timeframe for intervention. In the top panel, an episode of obstructive apnea is shown as evidenced by the absence of airflow on head-out plethysmography and the hypoxic ECG changes within tens of seconds. For comparison, a period of seizure-induced central apnea (where the airway is open) is shown that presents no such hypoxic changes even though the animal is not breathing. Airway closure from laryngospasm to produce obstructive apnea was fatal in 7/7 rats.

[0051] FIG. 2 shows severe reduction in oxygen saturation during upper airway obstruction and persistence of decreased oxygen saturation after obstruction is cleared. Shown to the left (blue bars) are the results from control animals (N=4), and to the right are the obstructed animals. Urethane-anesthetized rats received a tracheal tube that was tightly sealed in the tracheal below the larynx. Control animals received no further manipulation, but the obstructed animals were obstructed by occluding the tracheal tube for a period of 100 seconds or until the animal displayed respiratory arrest. Animals were immediately resuscitated (as necessary) by chest compressions. The set of bars for each group represent: (1) the baseline oxygen saturation as derived from the average of 5 points separated by 10 seconds; (2) the minimum oxygen saturation value during the period of obstruction; (3) the average saturation during the 60-sec period of 1 to 2 minutes after the obstruction was removed; and (4) the average saturation during the 60-sec period of 9-10 minutes after the obstruction was removed.

[0052] A 2-way repeated measures ANOVA showed significant effects for condition and for group (condition: F (3,21)=6.070, P=0.0038; group: F (1, 7)=44.69, P=0.0003) with significant differences for the obstruction minimum and at 1-2 minutes post-obstruction (P=6.838453 e-006, P=0.00257923, respectively).

[0053] To test the impact of the lung inflation method according to the present technology, rats under the same conditions as shown in FIG. 1 were studied. Lung inflation was tested with 100% oxygen gas, 100% nitrogen gas, or room air.

[0054] As shown in FIG. 2, all three gas inflation methods eliminated the persistent lower oxygen saturation after the obstruction was cleared. All animals with inflation (irrespective of the gas used for inflation) rapidly and persistently returned to baseline levels of oxygen saturation, indicating protection from persistent oxygen absorption derangements. Inflation with oxygen had the added benefit of delaying the desaturation and reducing tis minimum during the period of obstruction.

[0055] FIG. 3 shows the prevention of persistent oxygen desaturation problems by lung inflation with pure oxygen or other gas. The impact of lung inflation is two-fold: inflation with any gas prevents the persistent lower oxygen saturation after the upper airway obstruction is cleared, and delays and decreases the desaturation during obstruction. Only inflation with oxygen or nitrogen shown.

[0056] Evident from the data shown in FIG. 3 is the need for intervention in less than a minute. This is far too short for a call for emergency services and treatment by an emergency specialist. The volumes of air used for protection in the proof-of-concept experiments are 2-3 times the tidal volume. In rats the volume for inflation was 4.5 to 6.5 ml. In humans, where the tidal volume is reported to be about 0.5 liters, 1.0-1.5 liters would be comparable to the volumes used in the rat experiments (well below the total lung capacity of 4-6 liters).

Example 1

[0057] Jet Inflation Device

[0058] The present technology provides a simple emergency intervention based on inflation of the lungs with a modest volume of oxygen or other gas to protect a human or animal from rapid oxygen desaturation, to restore oxygen saturation levels to safe levels, and to reduce post-obstructive pulmonary edema due to a temporary upper airway obstruction or to permit longer times for clearing an obstruction. The ability to activate this intervention within seconds is critical for saving lives. Whereas the device relates to transtracheal jet ventilation, transtracheal jet ventilation is contraindicated in complete upper airway obstruction because transtracheal jet ventilation is intended for ventilation over many minutes or longer [Yealy D M, Menegazzi J J, Ward. KR. Transtracheal jet ventilation and airway obstruction. Am J Emerg Med. 1991 Mar. 9(2):200]. The proposed device is intended for immediate life support over a period of up to several minutes during complete airway obstruction due to laryngospasm.

[0059] To quickly force a volume of about 2 liters into the trachea, below an upper airway obstruction, a device is provided that resembles a device used for emergency repair of bicycle tires, as shown in FIG. 4A. A 16 gram CO.sub.2 cartridge (20 nil internal volume), shown in FIG. 4B, contains about 5 liters of gas at atmospheric pressure and room temperature, and can fill a bicycle tire to about 120 psi. Nitrogen, Oxygen and air (12 grams) may be provided in a similar size cartridge. These cartridges are sealed and stored stably under normal temperatures, and can typically be shipped by ground. A simple regulator screws or presses onto the cylinder, and is used to both regulate the rate at which gas is released. The regulator typically has a threaded or clamped attachment for an inflation cannula or valve stem attachment.

[0060] The present device has a similar configuration, with a typical canister capacity of 2-6 liters (standard temperature and pressure) for a single use, or larger to permit multiple inflations. Because of their physiologic effects carbon dioxide, oxygen, nitrogen or air are the preferred gasses, but carbon dioxide may be used in some cases.

[0061] FIG. 4A shows a prior art, commercially available cartridge inflation kit for repair of bicycle tires. This may employ carbon dioxide or nitrogen cartridges, shown in FIG. 4B. See, Genuine Innovations “Tire Repair and Inflation Kit”, Microflate Nano EBTB 50, Accessories Marketing, Inc., Div. of ITW Inc., San Luis Obisbo Calif., SKU 708162025816, which has a cap that screws onto the threaded cartridge to break the frangible metal cartridge seal. Unscrewing the cap starts and regulates the rate of flow. Other models have trigger actuated valves.

[0062] Most needles used to fill inflatable balls are just over 1 mm in outside diameter with outlets on the side of the tip and at the end of a blunt tip. See FIG. 5A. The needle design according to the present technology is similar in that it can be clamped or screwed into the regulator cap similar to the inflation needle for a ball, but the tip opening is closed and pointed with a conical tip (not the cutting tips of conventional hypodermic needles), as shown in FIG. 5B. This allows entry with a minimum of tissue damage. The opening is on the side, occupying about 90 degrees of arc so that the airflow can be directed down the trachea toward the lungs.

[0063] An inflation needle may thus be inserted into the cap, which provides about a 1 mm diameter cannula, with a side port and a sharpened tip for insertion through the skin, connective tissue and cartilage into the lumen of the trachea, below the vocal chords. The inflation needle may have a stop formed about one half inch from the tip, to prevent over-insertion of the needle into the trachea and into the dorsal wall of the trachea. (The internal diameter of the adult human trachea is about 1 inch.) The stop may be a plate or disk, and may be adjustable along the shaft of the needle, to accommodate different size patients. For example, the stop may be a transparent silicone rubber disk that press fits around the needle, which provides visibility for the caregiver during the procedure, while also preventing backsplash of body fluids.

[0064] A medical version of this system requires minimal modifications. Of course, the canister and valve cap should be clean and sterile, and avoid any liquid or powder lubricants. A medical valve cap would typically provide a Luer lock connector, though it is not required, and indeed incompatibility with intravenous tube sets may be an advantage.

[0065] The valve cap preferably has a trigger for activation, and may be limited to provide 0.5-1.5 liters per activation, and requiring a reset and second activation for more gas. A dual lumen cannula may be provided to permit feedback sensing of the gas pressure within the chest. In some cases, a single lumen may be used for both inflation and sensing. In this case, the regulator may automatically inflate the chest when the pressure is subatmospheric. In order to ensure that the gas is not injected accidentally, the initial blast of air may exhaust through the sensing port, ensuring that it is clear.

[0066] The needle preferably has a sharpened tip, e.g., having a conical or triangular profile (similar to the profile used in trochars), with an exhaust port facing downward. The stop/shield may have markings to show alignment, to ensure that the caregiver knows which way the port is facing.

[0067] The keys for inflation are a needle that can be safely inserted into the trachea between the cricoid and thyroid cartilages with a minimal chance of erroneous placement (too deep, not deep enough) and an opening that allows rapid filling at relatively low pressures without a sharply focused stream, to minimize the chance of tissue damage or penetration of the airway by an air jet. The space between the cricoid and thyroid cartilages is readily identifiable even in individuals with short necks, the space is relatively avascular to minimize complications, and it is the point at which the distance from skin surface to the interior of the airway is minimal. This insertion is technically into the larynx since it is between the thyroid and cricoid cartilages, not the trachea, but it will be below the point of obstruction due to laryngospasm or similar upper airway obstruction. Penetration through the rings of the trachea is variable and could lead to complications.

[0068] The goal is to deliver the full volume of gas quickly and allow it to pressurize the airway. When the obstruction is cleared, by whatever mechanism, the gas will be cleared by normal respiratory activity.

[0069] The acute intervention pulmonary inflation device is used as follows:

[0070] The device works to prevent pulmonary edema and, when using oxygen for inflation, to protect against hypoxemia during acute upper airway obstruction that can be life threatening within tens of seconds.

[0071] Because of the simplicity of design and use, it can be deployed by users of comparatively average skill, especially with some simple instructions. This is in contrast to the sophisticated intubation efforts performed in an emergency setting by highly trained physicians or technicians.

[0072] The device may have a system which presents prerecorded audio instructions, with a self-contained battery, activation button or sensor, speaker, and electronic integrated semiconductor “chip” device to produce the audible instructions.

[0073] Alternately, the device may be packaged with printed instructions in a kit, which also includes the gas cartridge, inflation valve, and needle. Because of the time criticality of the procedure, preferably, the device is preassembled, in a tray with a sealed membrane cover. The tray is preferred because the sharp needle requires protection, though a syringe-type cover may be used to protect the needle and the caregiver during preparation.

[0074] In some cases, the inflation device is reusable, though the needle is disposable. A reusable inflation device may have a disposable clear plastic sheet cover, like a bag, to ensure that it does not become soiled during use. When reusable, a canister or cartridge larger than 12-16 grams may be provided.

[0075] The device supports the individual for minutes, which means that a canister of gas plus the injection port can be small enough for high portability. In some cases, the device may be self-administered, though when the cause of the laryngospasm is a seizure, this may not be possible. The device is in any case meant for use “in the field” so that it can be deployed within the incredibly short time window before respiratory and/or cardiac arrest. Availability within medical facilities may of course be provided. The device may be provided along with automatic electronic defibrillator kits, or as part of a more generalized emergency kit.

[0076] Further, the intervention can be deployed in the field within the time that is likely to save a life. Cardiac rhythm changes occur within tens of seconds and respiratory and/or cardiac arrest in about 1 minute. Only a simple, portable intervention can be practical in this time frame.

[0077] In the case of seizure-induced laryngospasm that can be fatal, support needs to last several minutes before the obstruction spontaneously resolves. In the case of a choking incident, the intervention provides minutes for the work to remove the obstruction. In the case of acute airway obstruction in response to an allergic reaction, the device can be repeatedly used to support the individual for a longer period until a more stable solution can be established by trained emergency professionals.

[0078] Procedurally, the lung inflation device is used as follows:

[0079] 1. As quickly as possible after recognizing that an upper airway obstruction exists, enable the gas canister/inflation needle.

[0080] 2. Apply topical anesthetic around the point of entry (this is unnecessary if the individual has already lost consciousness, but useful in conscious individuals to minimize movements that may result in unnecessary trauma during insertion).

[0081] 3. Insert the needle between the thyroid and cricoid cartilages, i.e. just below the lower border of the cartilage that forms the Adam's apple in the midline, to its built-in stop, ensuring that the needle tip is safely in the trachea.

[0082] 4. Release the gas and hold the unit in place.

[0083] 5. Release a second burst of gas after 2 minutes if obstruction is not cleared.

[0084] 6. Release additional bursts of gas only if there seems to be leakage of gas as evidenced by actual gas leakage from the mouth or clear evidence of the chest returning to an uninflated size.

Example 2

[0085] An advanced version of the device permits the passage of a guide wire from the trachea up into the pharynx to facilitate rapid intubation of an individual with laryngospasm.

[0086] A guidewire with a loop (or blunt tip) may be extended from the needle upward, toward the larynx, past the vocal cords, which are constricted due to laryngospasm. As the guidewire emerges through the larynx, a caregiver may grasp and extend it, and then use the guidewire to properly place an endotracheal tube.

[0087] The portability of the device and intent for its use “in the field” by users of comparatively average skill rather than an emergency setting by highly trained physicians or technicians. This means that the risk of error is likely to be higher, and the end user will not be as equipped to deal with complications as emergency professionals.

[0088] The advanced version will therefore be typically used by medical professionals (EMT, emergency physicians, etc.) and requires training.

[0089] This more advanced version of the device performs the same function of penetrating the larynx and inflating the lungs, but also adds a feature that would facilitate the “reverse intubation” of a patient whose airway was closed by laryngospasm. In this version of the device, the kit contains a guide wire with a loop at the end, and a number 5 or 6 anode/corrugated endotracheal tube, and a 10 ml syringe.

[0090] After the initial burst of oxygen and hyperinflation, while chest compressions are done, the device is rotated 180 degrees so the opening points upward to the larynx and upper airway. The guide wire is passed through the opening until it reaches the pharynx. The EMT/operator bagging the patient can perform a finger sweep and retrieve the guide wire.

[0091] The eye of the flexible endotracheal tube is hooked to the loop of the guide wire, and the endotracheal tube pulled into the trachea and the lung inflation needle removed. The cuff of the ET tube is then inflated and the patient ventilated through it. The whole process should take less than 4 minutes afforded by the initial oxygen burst of the lung inflation device.

[0092] The guidewire/endotracheal tube option may be provided as part of an “Airway Kit” that could be kept at all places where AEDs are available. All hospital and health care personnel would be trained during CPR training in the use of this kit.

[0093] While several embodiments of the disclosure have been shown in the drawings and/or discussed herein, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto. All references discussed herein are expressly incorporated herein by reference in their entirety.

REFERENCES

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