Patent Application
20190314591
This disclosure is protected under United States and/or International Copyright Laws.© 2018, 2019 Dr. John Allen Pacey. All Rights Reserved. A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and/or Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The current disclosure is directed to secretion clearing endotracheal tubes and related devices and techniques.
The evolution of a new belief that secretion clearing capability can, and should, be built into Ventilating systems is supported by the notion that having repeated passages of suction apparatus into the airway can only increase the risk of transmission of bacteria into the trachea and lungs. The principle causes of Ventilator Acquired Pneumonia are the commensal bacteria that exist in the patient normally but also those common in ICU and Hospital environs (such as MRSA), the accumulation of airway secretions which act as a growth medium, and the periodic suctioning necessary to clear such secretions.
Secretion clearing strategies have been attempted in the past such as the suction system of Fry above the ETT cuff and later the Mallincrodt Evac® endotracheal tube which features a subglottic suction port that has been placed just above the endotracheal tube cuff. This has been tested pre-clinically by ventilation of a Porcine subject and was shown to be effective by removal of pooled secretions residing above the cuff. The current belief is that the periodic escape of fluid past the cuff downward into the trachea is a contributing cause of contamination of the airway. Early studies demonstrated a modest benefit in reducing VAP using these suction devices above the cuff but this is questioned in some current studies.
The Evac tube was the first specialized endotracheal tube that has been recognized to reduce VAP. This strategy of suctioning just above the cuff proved less effective than other interventions and is replaced by the tapered cuff and other strategies as by Perez in U.S. Pat. No. 9,907,920.
In some aspects, the purpose of the described devices and related methods is to create conditions that tend to clear secretions during the normal conduct of ventilation by having an exclusive outflow channel and/or to use a programed cuff leak combined with PEEP to protect the airway. One significant benefit of described devices and methods is the relative simplicity of production which has benefits providing low cost of goods for manufacture. The system is largely automated in that it uses forces usual for the airway such as PEEP for its successful operation. It is noteworthy that great expense and great research efforts have been expended to upgrade and perfect the Ventilator systems but virtually nothing has been expended to improve the final connection of the Ventilating system to the patient. Therefore for 100 years or more we have been extending the use of single lumen endotracheal tubes without questioning whether improvements can or should be made.
This application is intended to describe one or more embodiments of the present disclosure. It is to be understood that the use of absolute terms, such as “must,” “will,” and the like, as well as specific quantities, is to be construed as being applicable to one or more of such embodiments, but not necessarily to all such embodiments. As such, embodiments of the disclosure may omit, or include a modification of, one or more features or functionalities described in the context of such absolute terms. In addition, the headings in this application are for reference purposes only and shall not in any way affect the meaning or interpretation of the present disclosure.
In some variants, the SCET may include a pharyngeal suction component 125 that is positioned at least partially along the inflow path 105, the outflow path 110, or a combination thereof. The pharyngeal suction component 125 may optionally perform pharyngeal suction, which may improve visibility and scavenge hazardous smoke produced from the surgery, for example. In some aspects, the pharyngeal suction component may be activated periodically or based on need to suction Saliva and Esophageal reflux secretions to keep the Pharynx free of contaminants and to collect that which is expelled by PEEP air flow passing through the controlled leak from the cuff.
In some examples, the pharyngeal suction component 125 may be made of PVC and may have a 3 mm to 5 mm internal diameter. This internal diameter may be beneficial because some secretions are viscous and may come about in considerable volume. Blood may also contaminate the airway with associated clotting residues. Blood may especially be a product of micro laryngeal or laser surgery. In some aspects, the pharyngeal suction component and may operate by application of external suction as required. The pharyngeal position of the suction may prevent fluids from gathering following reflux, and intercept fluids that may be expelled by a “Programmed Cuff Leak” described herein. The “Programmed Cuff Leak” is controllable, for example, by variations of PEEP, Cuff Pressure, Monitoring leak % on the ventilator, and variations of FIO2.
In some aspects, the SCET 100 may also include one or more x-ray markers 130. In many cases, the accurate placement of the Secretion clearing tube (SCET) 100 may be important because the cuff must lay in the tracheal lumen without resting on the laryngeal cords and the area of the bifurcation likewise best not be in contact with the cords for an extended period of time. The ETT 135 of the SCET 100 may have a number of Radiographic or x-ray markers 130 at 1 cm intervals to locate cuff position with respect to the vocal cords. In other examples, various numbers of markers 135 may be used, for example, depending on different spacing of the markers 135, total length of the SCET 100, and for various other design reasons. The marker spacing may, in some cases, be more or less than 1 cm, such as a single market designed to target the Vocal cords exactly. Other spacing may be selected for pediatrics or special applications. The markers 130 may enable accurate placement of the SCET 100 upon x-ray examination of the chest and neck of the patient. An alternative method of confirming the position may be performed using Video Laryngoscopy, for example, when Video Laryngoscopy is used to initially place the endotracheal tube (ETT) 135.
In some cases, multiple radiographic markers may be implemented that identify the location of the Bifurcation and also the cuff itself such that the vocal cords are positioned midway from the Cuff to the Bifurcation.
As further illustrated in
In some examples, the cuff flap 145 may be made of PVC, and may be 1 to 2 mcm in size or length. The cuff flap 145 may have a durometer that assures protection. In other cases, the cuff flap 145 may be constructed as a ball valve type of occlusion secured to the cuff. The main security will be provided by modest PEEP.
In some aspects, the cuff crease feature positioned on the posterior aspect of the cuff may allow some limited leakage of the Gas delivered by the ventilator so that secretions may bypass the cuff and pass into the pharynx. In some cases, the cuff crease may be designed so that the amount of leakage permitted is generally 10% or less of the Total inspired volume so that a slow continuous liberation of secretions may pass along with CO2 and air.
In some aspects, the cuff crease may include a one-way way flap or ball valve that permits fluid to exit but not pass back below the cuff. In some cases, the cuff crease may be powered or driven or moved by clinical PEEP or constant positive airway pressure.
In some examples, the cuff crease may be controlled to allow 0-10% of inspired volume to pass by means of increasing or decreasing cuff pressure. In some cases, the cuff crease may be designed for the Tapered Endotracheal tube Cuff series.
In some aspects, the ETT may be coated or covered or made of conventional wrapping metals. In some aspects, the metal layer be up to 1.5 mm thick. In some aspects, only a portion of the ETT may be covered or made of metal, such as the portion of single lumen design that will be transiting through the vocal cord area, or approximately the distal 50%.
There are a multitude of additional benefits that may be provided by one or more features of the described Secretion Clearing tube over the use of traditional mono lumen tubes. Some, but by no means all, of the beneficial uses of the described device is provided below.
In some aspects, the SCET may be used as a “T-Piece” replacement. For example, the SCET may be used as a “Classic T-Piece” for weaning patients from Mechanical Ventilation (MV), for example, with the advantage that there is minimal dead space and the flow of enriched oxygenated air passes down to a lower level of the ventilation catheter while the patient breaths from his/her own volition. This is done by at once passively introducing humidified oxygen enriched air via the inflow limb of the (SCET) and allowing exhausted air to pass out via the exhaust limb. This is usually done with a classical mono-lumen ETT and the “T Piece” is an external cap that is placed over the open end of the ETT when the tube is disconnected from a ventilator. The process allows caregivers to evaluate the strength of patient breathing activity while medication is withheld. The SCET has the advantage of promoting mixing of inflow and outflow gas to make the transition to non-mechanically assisted breathing more likely to succeed while also aiding the patient to clear secretions that might otherwise accumulate in the mono-lumen tube during such a trial due to the continuous passage of ventilating air and oxygen.
In some cases, the SCET may be equipped with the optional pharyngeal suction which would be an advantage to improve pharyngeal secretions management.
In some examples, the SCET may also be used for PSV during weaning from ventilator care. The PSV may provide benefits over the “T Piece” implementations. PSV is an alternative to the use of a “T-Piece” strategy wherein a mechanical assist for the weaning may be more effective in preserving patient strength.
In some aspects, the SCET may be used as an aid to Microlaryngeal surgery. For example, a surgeon doing micro-laryngeal surgery requires ventilation that allows an un-hurried operating environment but also benefits from the use of a small caliber tube passing through the operative field. The SCET will permit a smaller size tube to be used because the inflow/outflow gasses will pass more readily through the shorter dead space zone and will have a more enriched oxygen to deliver. The size can be expected to go down by 1-2 mm, for example, from 6 to 5 or 4 mm. The Secretion clearing tube may have a selection of small diameter distal single lumen segments that have small 4, 5, 6 mm, diameters that are designed for microlaryngeal surgical procedures. This may greatly add to the convenience of the surgeon. This allows some use also for upper tracheal surgery where stenosis or other abnormality make a smaller tube diameter an advantage. In some cases, use of some PEEP coupled with a modest cuff leak may keep the airway more completely oxygenated and may clear CO2 more completely.
In some cases, the SCET may be used as an armoured ETT. For example, the use of the SCET to replace classic armoured tubes may be effective. The upper double lumen portion of the SCET is stronger and very resistant to kinking during patient positional change. The position of the tube with respect to the cords should be known at all times.
In some cases, the secretion clearing tube may be protected from endotracheal tube obstruction by the presence of a controlled cuff leak which acts as a relief valve for any blockage of the exhalation limb of the secretion clearing tube. This may prevent barotrauma to the lungs. In yet some instances, the secretion clearing tube which may be used for ventilation with sub-standard FiO2 in the range of 15-20% and may be used in a way that will produce a modest High CO2 environment (40-50 mmhg.) that will be less likely to support combustion.
Cleaning strategies: there are cleaning devices available that are very effectively designed to clear secretions that may be too viscous or bloody to be cleared by normal means. This may be applied to the exhaust limb of the tube. Such a device is the Endo Clear device.
In some aspects, it is possible to run an anesthetic safely with a low oxygen high CO2 environment in or with the described SCET. For example, by running the anesthetic in the SCET (e.g., the inflow path, the outflow path, or the pharyngeal suction component), low oxygen levels, such as between 10-20%, which is the typical percentage in ambient air, may be present to provide a safe environment. This may substantially reduce the risk of an airway fire when using a laser for surgery, for example.
In some aspects, the SCET may utilize and include a flexible ski tip to assist with endotracheal tube passage (as described in U.S. Pat. No. 5,873,362 to Parker, which is hereby incorporated by reference as if fully set forth herein). This may provide the added benefit of hosting a micro atomizer feature incorporated in the tip for airway cleaning. In some cases, an airway pressure sensor may be included on or proximate to the flexible ski tip to permit periodic adjustment of cuff pressures and ventilator performance
In some aspects, the SCET may include or incorporate a fluidic passage for saline or periodic use of perflurocarbon and/or a separate suction channel.
The embodiments of the disclosure in which an exclusive property or privilege is claimed are defined as follows:
The following references are also incorporated by reference in their entireties as if fully set forth herein:
This application claims priority to Provisional Application No. 62/659,055 filed Apr. 17, 2018; the contents of this application are hereby incorporated by reference as if fully set forth herein. The following patent applications are hereby incorporated by reference in their entireties as if fully set forth herein: U.S. application Ser. No. 14/284,799 filed May 22, 2014, titled “SECRETION CLEARING VENTILATION CATHETER AND AIRWAY MANAGEMENT SYSTEM”; U.S. application Ser. No. 16/351,392 filed Mar. 12, 2019, titled “SECRETION CLEARING VENTILATION CATHETER AND AIRWAY MANAGEMENT SYSTEM”; and “U.S. Pat. No. 9,839,755 filed Jan. 27, 2014, titled “SECRETION CLEARING PATIENT AIRWAY MANAGEMENT SYSTEM.”
| Number | Date | Country | |
|---|---|---|---|
| 62659055 | Apr 2018 | US |
