RU2772752C1 - Needle for guiding and securing an epidural catheter in a subcutaneous canal during epidural anaesthesia and epidural analgesia - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to the field of medicine, namely to anaesthesiology and intensive care. Guide needle for guiding and securing an epidural catheter in a subcutaneous canal as part of the conducted epidural anaesthesia is made of steel, has a length of 145 mm, a needle body diameter of 1.2 mm, a sharpened distal end of the needle with pencil-type sharpening at an angle of 12°, a length of the proximal end of the needle of 5 mm and a diameter of 0.45 mm for a G 20 epidural catheter and 0.7 mm for a G 19 epidural catheter, at the proximal end of the needle, to facilitate the entry of the needle into the lumen of the epidural catheter, a truncated conical part is made at an angle of 15° with a length of 0.5 mm.

EFFECT: use of the invention provides a possibility of guiding and securing an epidural catheter in a subcutaneous canal with a low injury rate, to a great distance from the point of entry of the epidural catheter into the epidural space, thereby additionally reducing the risk of infection of the epidural space with prolonged standing of the epidural catheter, the risk of migration of the epidural catheter is reduced.

1 cl, 2 dwg

Description

The invention relates to medicine, namely to anesthesiology and intensive care.

Epidural anesthesia is a method without which it is impossible to imagine the conduct of surgical interventions in many areas of surgery and traumatology. Highly traumatic surgical interventions objectively require prolonged postoperative analgesia. This task is successfully handled by the constant, for several days, the introduction of a local anesthetic into the epidural space (Koryachkin V.A. Neuraxial blockades. St. Petersburg ELBI-SPb 2013). The presence of an epidural catheter (EC) in the subcutaneous canal makes it safe to stand for a long time. The risk of infection of the epidural space is reduced - the further the site of exit of EC from the skin from the point of entry into the epidural space, the lower the risk of infection of the epidural space. The location of the EC in the subcutaneous canal also makes it convenient for medical personnel to care for the catheter (treatment of the skin at the site of the EC and change of the aseptic sticker). In this case, the EC is less at risk of dislocation - falling out of the epidural space.

There are three devices designed to perform EC in the subcutaneous canal.

The first device is a non-modified Tuohy epidural needle. In the invention described by the authors Kuzmin Vyacheslav Valentinovich and Egorov Vladimir Mikhailovich (Patent RU 2309772 C1, class IPC A61M 19/00 dated November 10, 2007), an unmodified Tuohy epidural needle is used to conduct EC in the subcutaneous canal. Using this device, it is difficult to accurately hit the small post-puncture hole in the skin where the EC is located. There is a risk of injury to the EC. You can cut, damage the EC.

The second device is a modified Tuohy needle. The epidural needle is modified (the pavilion of the needle is broken off) and passed under the skin from the exit site of the EC in the lateral direction (Patent RU 2301083 C2, class IPC A61M 19/00 dated 06/20/2007). There is no risk of damaging the EC, since the needle is not inserted towards the EC, and away from it. But there are also a number of disadvantages when using this device. Modifying an epidural is quite difficult. The modification of the epidural needle consists in the fact that a mandrin is inserted into the needle, after which the pavilion is broken off with gentle breaking movements in the area of the needle pavilion to the right, left, down and up. The disadvantage is that it is not so easy to break off the pavilion of the epidural needle with the mandrel inserted into it, since the mandrel of a modern disposable needle is made of plastic. And in the modified needle, after breaking off the pavilion, a sharp inner edge is formed, which reduces the lumen of the needle, making it difficult to pass the EC through its lumen, and there is a risk of damage to the EC.

Also, the disadvantages of the described two devices is that the Tuohy needle has a large outer diameter G 18-1.3 mm and G 16-1.7 mm, which leads to greater tissue trauma during the passage of the epidural needle and the creation of a subcutaneous canal of a larger diameter than EC . For a G 16 needle with an outer diameter of 1.7 mm, the EC has an outer diameter of G 19-1.05 mm, and for a G 18 needle with an outer diameter of 1.3 mm, the EC G 20 has an outer diameter of 0.85 mm. In addition, the standard, unmodified Tuohy needle is 80 mm long, while the modified one is 76 mm. Accordingly, the channel length is limited by the long needle and cannot be more than 75-80 mm when using an unmodified epidural needle and 70 mm using a modified epidural needle. The longer and narrower the channel in which the EC is located, the lower the risk of infectious complications and the lower the risk of dislocation of the catheter from the epidural space. Also, the disadvantage of these two devices is that the Tuohy epidural needle has a blunt curved end, which is solely for the convenience of perforating the ligamentum flavum. It is quite difficult to perforate the skin with this needle. Often, anesthesiologists make a small incision in the skin at the site of the intended epidural puncture to facilitate the passage of the epidural needle through the skin. Therefore, perforating the skin with such a needle, especially a modified one with a broken pavilion, is a rather difficult task.

The third device is a modified spinal needle. Authors Marchenko A.P., Yamshchikov O.N., Emelyanov S.A. (Patent RU No. 2727234 C1 class IPC A61 19/00 dated 07/21/2020) a modified spinal needle is used after spinal anesthesia in a complex of combined two-level spinal-epidural anesthesia. When modifying the spinal needle, the pavilion of the needle is broken off and the proximal end of the EC is fixed at the proximal end of the needle (the needle is inserted into the lumen of the EC, the outer diameter of the needle G 26 corresponds to the inner diameter of the EC G 20 and is 0.45 mm.). The advantages of this device are that the modified spinal needle has a small outer diameter, due to which the modification (breaking off the pavilion of the needle) is very easy, the needle is very sharp and thin, which makes it less traumatic to conduct EC in the subcutaneous canal. The disadvantages of this device are that it takes time to modify the spinal needle (about 10 seconds), the needle is very thin, and when it is inserted into the subcutaneous canal in patients with increased body weight, due to an excessive increase in subcutaneous fat, there are difficulties in determining the distal end of the needle under the skin and, accordingly, it is difficult to carry out the exit of the needle from the skin to the outside. To exit the needle with the EC fixed on it, it is required to perform an additional puncture of the skin with a guide needle of a larger diameter over the spinal needle, since the outer diameter of the spinal needle is less than the outer diameter of the EC. The guide needle developed by us relieves the method of conducting EC in the subcutaneous canal from all these disadvantages listed above.

The technical problem solved by the invention is the creation of a conductor needle, which will be designed for safe and convenient EC in the subcutaneous canal during epidural anesthesia.

The needle is made of steel grade 12X18H10T GOST 5632-72. The length of the needle is 145 mm, the diameter of the needle body is 1.2 mm - G 18. The proximal end of the needle has a diameter of 0.45 mm for EC G 20 (Fig. 1) and a diameter of 0.7 mm for EC G 19 (Fig. 2) and a length of 5 mm. At the proximal end of the needle, there is a truncated conical part at an angle of 15°, 0.5 mm long, which serves to facilitate the entry of the needle into the EC lumen using the “catheter on the needle” method. The fixation is very strong, since the outer diameter of the proximal end of the needle corresponds to the inner diameter of the EC (0.45 mm for EC G 20 and 0.7 mm for EC G 19). The distal end of the needle is sharply sharpened, sharpening type "pencil", at an angle of 12°. Pencil sharpening reduces the risk of injury to vessels located under the skin, respectively, reduces the risk of bleeding and the formation of subcutaneous hematomas. Also, the hole that is formed on the skin after a puncture with a pencil sharpened needle is much smaller than the diameter of this needle (the diameter of the hole decreases due to the elastic properties of the skin). The outer diameter of the guide needle is 0.35 mm larger than the outer diameter of the EC G 20-0.85 mm and 0.15 mm larger than the outer diameter of the EC G 19-1.05 mm. The conductor needle offered by us is applied as follows. After catheterization of the epidural space, below the epidural needle, a skin incision 3-4 mm long is made with a pointed scalpel. In order to create a convenient access for passing the needle, the incision on the skin is expanded with a surgical clamp. The epidural needle is removed. EC is retracted upward, in the cranial direction. We perform anesthesia of the skin and subcutaneous fat, below the EC, with a solution of Lidocaine 4 mg / ml at a distance of 120-130 mm, lateral to the place of standing of the EC, at an angle of 90% to the axial axis. Next, we need to put the EC on the proximal end of the guide needle. With the help of a surgical clamp, while holding the guide needle with EC put on it, with translational movements we advance the guide needle with EC under the skin of the lumbar region in the lateral direction from the epidural puncture site. After perforation of the skin (the needle is very sharp and the perforation of the skin is very easy), the guide needle moves up to a distance of no more than 10 mm above the skin surface. Subsequently, we take the guide needle by the distal end with a surgical clamp and smoothly remove the needle with the EC put on it. Extraction is easy, since the outer diameter of the guide needle is larger than the outer diameter of the EC. At the junction of the guide needle and EC, we cut the catheter with scissors. We extract the EC, while carefully placing it in the wound in the area of the epidural puncture, making sure that there are no kinks in the EC. We apply aseptic stickers on the skin at the site of the epidural puncture and on the exit site of the EC on the skin of the lumbar region.

The advantages of the conductor needle developed by us are as follows:

- its use for conducting EC in the subcutaneous canal allows you to carry out and fix the EC in the subcutaneous canal at a greater distance - 110-120 mm from the exit site of the EC;

- this conductor needle is thinner than the epidural needle, longer and sharper than it, the length is 145 mm, and the length of the spinal needle is 88 mm, the epidural is 80 mm;

- the needle does not require modification during anesthesia, it is a finished product; - fixation of EC on the conductor needle is strong;

- for easier removal of the needle with EC, no additional perforation is required on the skin, which makes it less traumatic and quick to perform EC in the subcutaneous canal.

The guide needle developed by us makes it possible to carry out and fix EC in the subcutaneous canal with a low degree of trauma, at a great distance from the place where the EC enters the epidural space. The performance of this manipulation becomes simpler and faster, the risk of infection of the epidural space during prolonged standing of EC decreases, and the risk of EC migration decreases.

Claims (1)

Guide needle for insertion and fixation of the epidural catheter in the subcutaneous canal during epidural anesthesia, made of steel, having a length of 145 mm, a needle body diameter of 1.2 mm, a sharply sharpened distal end of the needle with a pencil type sharpening at an angle of 12°; the proximal end of the needle 5 mm long and 0.45 mm in diameter for the G 20 epidural catheter and 0.7 mm for the G 19 epidural catheter; at the proximal end of the needle, to facilitate the entry of the needle into the lumen of the epidural catheter, a truncated conical part is made at an angle of 15°, 0.5 mm long.

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