JPH0317503B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to endotracheal tubes and tracheostomy tubes (hereinafter collectively referred to as tracheal tubes) for medical or veterinary use. More specifically, the present invention relates to a cuffed tracheal tube for use in artificial respiration by intubating the trachea through the oral cavity, nasal cavity, or tracheostomy, and connecting an artificial respirator to the lungs.

[Prior Art] The cuff of a cuffed endotracheal tube inserted into the trachea of a person and used for ventilation prevents vomit from entering the trachea from the esophagus, etc., and connects the tube. The space between the inner wall of the trachea and the endotracheal tube is airtight to ensure adequate ventilation when performing intermittent positive pressure breathing, etc., while also preventing gas leakage between the inner wall of the trachea and the endotracheal tube. However, when a conventional cuffed endotracheal tube is connected to a ventilator to control the patient's breathing, it can be Since it is necessary to increase the pressure of the inspiratory gas several times higher than the normal internal cuff pressure, a cuff with a cuff that should lightly adhere to the inner wall of the trachea at the desired pressure to maintain airtightness is required. The endotracheal tube cuff becomes deformed due to the pressure difference between the pulmonary and laryngopharyngeal sides of the airway and becomes displaced with each positive pressure ventilation, eventually damaging the airtightness between the cuff and the inner wall of the trachea. This can lead to serious consequences such as insufficient ventilation due to leakage of insufflation gas or movement of the endotracheal tube.

One way to prevent this is to raise the internal pressure of the cuff in advance to a level much higher than the required maximum airway pressure. As a result, the capillaries on the inner wall of the trachea were compressed, obstructing blood flow, and the mucosal cells in contact with the cuff were left with functional impairment, sometimes leading to necrosis.

To solve this problem, the cuff pressure is also increased when necessary, that is, when the intrapulmonary pressure increases.
If the cuff pressure could be lowered to the minimum necessary level when the intrapulmonary pressure decreases, expiration would be possible even if the inner wall of the trachea is temporarily compressed as the cuff pressure increases and blood flow in the capillaries is obstructed. Based on the idea that the cuff pressure decreases due to the decrease in intrapulmonary pressure due to the pattern during the phase, the blood flow in the capillaries on the inner wall of the trachea is improved, and damage to the inner wall of the trachea can be prevented. A cuff roller (manufactured by Respironics, USA, trade name) used in conjunction with an endotracheal tube, and a respiratory pressure superimposition type cuff pressure adjustment device (patent application published in 1983).
-029098) and other inventions have been made.

Here, Kafuto Lola can be briefly explained as follows.
As shown in FIG. 2, an air bag 23 pressed by a spring is airtightly arranged in a small case 21 having a connection port 26, and the air bag 23 has a gas inlet 24 equipped with a check valve 25. A connection port 27 that connects to the cuff C of the endotracheal tube T is formed. When the connection port 27 and the cuff C are connected, and gas is injected from the gas inlet 24 during use, the air bladder 23 communicating with the cuff C also expands and the spring 22 is pushed. The pushing force of the spring 22 is made to be a force corresponding to the desired pressure of the cuff C, so that the pushing force of the spring 22 at the desired cuff pressure falls within the operating stroke of the spring 22. On the other hand, by communicating the connection port 26 of the small case 21 with the airway of the endotracheal tube T, pressure changes in the airway are transmitted to the air sac 23, so that the desired cuff pressure of the endotracheal tube T can be maintained. Airway pressure is added to the airway. However, this method
The problem is that the price increases due to the installation of expensive devices that are disposable.

In addition, the respiratory pressure superimposition type cuff pressure adjustment device is a method that uses oxygen gas or compressed air from medical gas piping as a power source to add airway internal pressure to the cuff pressure. Because it uses gas, it cannot be used in areas without pressurized gas.

[Problems to be solved by the invention] The present invention has been made in view of the above problems.
The mechanism is simple and safe, and the cuff of the cuffed tracheal tube is reliably raised and lowered in synchronization with the intrapulmonary pressure, while always maintaining the cuff pressure level above the minimum necessary level. An object of the present invention is to provide an economical cuffed tracheal tube that is less susceptible to deformation or displacement of the cuff.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a cuffed endotracheal tube and a tracheostomy tube.
Near the distal end of the tracheal insertion tube, there is provided one or more vent holes that communicate between the inside and outside of the tube wall of the tube, and a substantially cylindrical or Pear-shaped thin membranes are arranged in double layers on the inside and outside,
Both ends of each of the double membranes are airtightly attached to the outer periphery of the tube to form an inner and outer double cuff, and the air formed between the membranes of the double cuff is A structure is adopted in which a cuff inflation tube is provided for freely inflating and deflating the outer cuff by injecting and discharging gas into the chamber.

[Operation of the Invention] Since the cuffed tracheal tube of the present invention is constructed as described above, to explain it with reference to FIG. The outer cuff (hereinafter referred to as the tracheal sealing cuff) 5 has the function of inflating when gas is injected from the cuff inflation tube 6 and closely contacting the tracheal inner wall 7 to seal between the trachea and the tracheal tube 1. has. On the other hand, the inner cuff (hereinafter referred to as the cuff for adding intratracheal pressure) 4 is activated when the gas pressure in the airway gas passage 2 increases to exceed the pressure in the air chamber 9.
Gas in the airway gas passage 2 flows in from the airway pressure introduction port 3, and the airway pressure adding cuff 4 that separates this airway gas from the gas in the air chamber 9 is closed until the respective pressures are balanced. push away Therefore, the tracheal sealing cuff 5 presses the inner wall 7 of the trachea of the patient, etc. at a pressure corresponding to the airway pressure at that time through the gas in the cuff, so the cuff position changes due to the increased intratracheal pressure. It rarely shifts. In this case, since the airway internal pressure is transmitted through the gas, the tracheal sealing cuff 5 is evenly pressed from the inside, so it is hardly distorted and the position of the cuff 5 is less likely to shift.

[Example] Next, an example of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing a tracheal tube according to a preferred embodiment of the present invention.

The tracheal tube of the present invention is a cuffed tracheal tube that is inserted into the trachea of a patient etc. for the purpose of respiratory management, and a preferred example thereof is shown in FIG. An airway pressure introduction port 3 that opens to the outside from the airway gas passage 2 is provided in a part of the vicinity, and the airway pressure introduction port 3
A cuff 4 for adding airway pressure is installed in the shape of an air sac around the outer periphery of the endotracheal tube 1, which is provided with a cuff 4 for adding airway pressure, and the cuff 4 for adding airway pressure is further airtightly wrapped from the outside by a cuff 5 for sealing the trachea. ing. Then, the tracheal sealing cuff 5 is inflated by injecting or discharging gas into the tracheal sealing cuff 5 through the cuff inflation tube connection passage 8 formed on the wall surface of the endotracheal tube 1. A cuff inflation tube 6 for deflation is connected and communicates with an air chamber 9 formed between the two cuffs 4 and 5.

The endotracheal tube 1 is made of a flexible resin such as soft vinyl chloride resin, silicone rubber, polyurethane, etc., and has appropriate flexibility and elasticity. The endotracheal tube 1 has an airway gas passage 2 with a large inner diameter that is open at both ends, and a small inner diameter gas passage that is closed at the distal end (patient side) and opened at an appropriate portion on the proximal end (operator side). A cuff inflation tube connection passage 8 is formed, and a bevel is formed at the tip of the endotracheal tube 1 to facilitate insertion into the trachea.A cuff 4 for applying airway pressure is formed near the tip of the endotracheal tube 1. One or more small airway pressure introduction ports 3 serving as ventilation holes communicating between the inside and outside of the wall of the endotracheal tube 1 are bored in the surrounded portion.

The cuff 4 for applying airway pressure and the cuff 5 for sealing the trachea are made of flexible resin such as soft vinyl chloride resin, silicone rubber, polyurethane, etc., and are formed into a cylindrical shape, and are attached to the endotracheal tube so as to form an air sac-like thin film when inflated. It is arranged and formed on the outer periphery of 1. The inner airway pressure adding cuff 4 communicates with the airway gas passage 2 via the airway pressure introduction port 3.
It has a function of expanding when the airway internal pressure becomes higher than the pressure in the air chamber 9 and applying the airway internal pressure to the tracheal sealing cuff 5, while the tracheal sealing cuff 5 is injected with gas in advance from the cuff inflation tube 6. It is inflated by this and has the function of lightly compressing the inner wall 7 of the trachea and sealing between the trachea and the endotracheal tube 1.

The cuff inflation tube 6 is made of a flexible resin such as soft vinyl chloride resin, silicone rubber, polyurethane, polyethylene, etc., and has a small diameter.
One end of the cuff inflation tube connection passage 8 is inserted into the opening of the cuff inflation tube connection passage 8.
is airtightly glued and fixed. Cuff inflation tube 6
The other end is a connection end to a gas supply means (not shown), and is formed in a shape that can be connected to the tip of a syringe. A pilot balloon 10 is provided for confirmation from the ground.

Next, an example of the use of the cuffed tracheal tube for applying airway pressure according to the present invention will be described.

After testing the airtightness of the tracheal sealing cuff 5 by injecting and discharging gas with the cuff inflation tube 6 as necessary, the gas inside is discharged and deflated, and then the cuff for applying airway pressure is attached. A tracheal tube is inserted and placed at a desired position within the trachea of a patient. Then, using the cuff inflation tube 6, gas is injected until the compression pressure of the tracheal sealing cuff 5 against the tracheal inner wall 7 reaches the desired pressure, and then the cuff inflation tube 6 is occluded and a ventilator, etc. (not shown) is used. The proximal end of the endotracheal tube 1 is connected to the tracheal tube (not shown), and the patient's breathing is managed using intermittent positive pressure ventilation or the like. In this case, the breathing pattern that corresponds to the inspiratory phase in natural breathing corresponds to the action of mechanically pressurizing breathing gas and pushing it into the lungs in pressurized breathing. Therefore, at this time, as a matter of course, the intrapulmonary pressure and the gas pressure within the airway gas passage 2 of the endotracheal tube 1 communicating therewith rise.

When the gas pressure in the airway gas passage 2 rises and exceeds the pressure in the air chamber 9, the gas in the airway flows in from the airway pressure introduction port 3, and the gas in the airway and the gas in the air chamber 9 are combined. The airway internal pressure adding cuff 4 that separates the airway is pushed to the point where the respective pressures are balanced.
That is, the tracheal sealing cuff 5 presses the tracheal inner wall 7 of the patient, etc., at a pressure corresponding to the airway internal pressure at that time, via the gas inside the cuff. Moreover, since the tracheal sealing cuff 5 is configured to be pressed evenly from the inside in a concentric and symmetrical manner, even if the pressure difference between the lung side and the laryngopharynx side of the airway becomes large, the tracheal sealing cuff 5 can be pressed evenly from the inside. 5 is hardly distorted, and the position of the cuff 5 is hardly displaced.

Furthermore, when the gas pressure in the airway gas passage 2 becomes lower than the set pressure in the air chamber 9, the airway pressure adding cuff 4 is pressed against the outer periphery of the endotracheal tube 1 by the pressure in the air chamber 9. However, since the hole diameter of the airway pressure introduction port 3 is sufficiently small, and if necessary, there are a plurality of holes, the thin film of the airway pressure adding cuff 4 does not enter into the intratracheal gas passage 2. Therefore, the movement of the airway internal pressure adding cuff 4 is stopped at this position, so that the pressure in the air chamber 9 settles to the desired pressure set initially. That is, even if the pressure in the airway gas passage 2 drops below the pressure in the air chamber 9, the compressive force of the tracheal sealing cuff 5 against the tracheal inner wall 7 can be maintained at the desired set pressure. Airtightness is maintained.

Therefore, the compressive pressure on the tracheal inner wall 7 of the patient, etc. becomes the initial set pressure of the tracheal sealing cuff 5 when the pressure in the airway gas passage 2 is low,
The pressure inside the airway gas passage 2 is reduced by the tracheal sealing cuff 5.
When the pressure becomes higher than the initial set pressure of the tracheal sealing cuff 5, the airway pressure becomes the current airway pressure. The compression operation is repeated variably within the range of pressure. However, it is desirable to create the cuffs 4 and 5 in a suitable shape so that they inflate evenly, so that the elasticity required to inflate the cuffs appropriately is as small as possible.

[Effects of the Invention] As is clear from the above explanation, the cuffed tracheal tube for applying airway pressure according to the present invention has the following advantages.

(1) The mechanism is simple, so there are few components.
Furthermore, it is economical because it does not require a special power source.

(2) Conventional cuffs with low pressure and large volume are preferred because they apply soft pressure to the inner wall of the trachea, but the airway pressure on the lung side pushes the cuff membrane from the lung side within the trachea, deforming the cuff and increasing the cuff inner pressure. Therefore, the cuff is distorted and pushed every time you take a pressurized breath, causing it to shift.
This friction easily damages the ciliated mucosa on the inner wall of the trachea, and the endotracheal tube is also susceptible to movement, and the connection parts of the absorption tubes and connectors that connect to the endotracheal tube and form the breathing circuit move constantly. However, by using the endotracheal tube of the present invention, such accidents can be largely prevented.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention, and FIG.
The figure is an explanatory diagram of a conventional example. (Main symbols in the drawing), 1: Endotracheal tube,
2: Airway gas passage, 3: Airway pressure introduction port, 4:
Cuff for adding airway pressure, 5: Cuff for tracheal sealing,
6: Cuff inflation tube, 8: Cuff inflation tube connection passage, 9: Air chamber.

Claims (1)

[Claims] 1. A tracheal insertion tube is provided with one or more vent holes that communicate between the inside and outside of the tube wall near the tip of the tube, and a substantially cylindrical or Pear-shaped flexible thin membranes are arranged in double layers with the inner and outer parts separated, and both ends of each of the double membranes are airtightly attached to the outer periphery of the tube to form a double inner and outer cuff, It is characterized by being connected to a cuff inflation tube for inflating and deflating the outer cuff as desired by injecting and discharging gas into the air chamber formed between the membranes of the double cuff. A tracheal tube with a cuff for adding airway pressure.