WO1992018193A1

WO1992018193A1 - Indwelling vein cannula

Info

Publication number: WO1992018193A1
Application number: PCT/EP1992/000879
Authority: WO
Inventors: Ludger Meyer
Original assignee: Ludger Meyer
Priority date: 1991-04-22
Filing date: 1992-04-21
Publication date: 1992-10-29
Also published as: EP0535204A1; DE4113045C1; CA2085978A1; JPH05509254A; AU1648792A

Abstract

The invention concerns an indwelling vein cannula with a cannula body comprising essentially a plastic cannula and a handle attachment, and with an inner puncture cannula comprising a metal cannula (stylet), the cannula body (2) including a flexing section (11) in the region of the handle attachment (3).

Description

Vein indwelling cannula

The invention relates to a vein-indwelling cannula with a cannula body consisting essentially of a plastic cannula and a handle attachment and with a puncture inner cannula having a metal cannula (male).

The intravenous injection and the intravenous continuous drip infusion are indispensable for all medical therapy. They developed in many small steps and over a long period of time. Methods for bloodletting and for the purpose of administering medication have been known for a long time.

With the discovery of the blood circulation at the beginning of the 17th century, the anatomical-physiological basis for infusion and transfusion was created. The first attempts at infusion soon began, first in animals and later also in humans, which, however, were initially unable to achieve a therapeutic effect or progress in knowledge. Since the reason for the initial failures was probably the septic one As a result of the circumstances, it was only in the 19th century that the injection syringe was invented, which paved the way for modern injection therapy. However, a new chapter in transfusion theory only began after the blood group discovery at the beginning of this century. Only now could the decisive basics and techniques be developed, which, stimulated by the two world wars and the development of internal medicine and anesthesiology, are still largely valid to this day. In the meantime, intravenous therapy for parenteral medication or for the replacement of blood by means of transfusion or infusion has become established.

All disease states in which the medication is to act quickly or cannot be administered in any other way are considered to be an indication for intravenous injection. Especially in connection with the latter case, long-term medication is often necessary, so that the administration of the

REPLACEMENT LEAF indicated intravenous drip infusion solution. Vein indwelling cannulas are used here, the function of which will be described in detail below.

Depending on the duration of use and the rate of infusion, a suitable vein is selected first. In the case of prolonged infusion therapy, it is expedient first to select veins that are as distal as possible, so that in the event of thrombosis later, continuous proximal veins can be used. In any case, veins in the area of the joints (wrist, elbow, etc.) must be avoided because otherwise injuries or even punctures of the vein wall can occur during movements despite the fixation of the cannula. With increasing frequency of use of intravenous fluid therapy, a large number of further developments of cannulas have been used in the past decades. In particular, plastic indwelling cannulas, of which the so-called Braunüle (registered trademark of B. Braun Melsungen AG) is the most widespread, is enjoying growing popularity.

The known plastic vein cannulas shown at the beginning consist first of all of a puncture inner cannula whose actual cannula consists of metal (so-called stylet), which has a conically ending, tight-fitting plastic cannula pushed onto it. The length of the plastic cannula is slightly shorter than the stylet and the transition on the conical part in the area of the cannula tip is infinitely variable due to precise processing, so that a deformation of the conical (plastic) cannula tip complicating the penetration of the tissue is correct when correct Handling is excluded.

The handling of a known vein indwelling cannula will be described in the following: After the cannula has been inserted into the vein lumen about ¹ / z to 1 cm, the metal stylet is withdrawn so far that its tip lies completely inside the plastic cannula. As a result, the chamber at the end of the plastic cannula fills with blood, which enables the position of the indwelling vein cannula to be checked. Then the plastic cannula is completely encased by the

REPLACEMENT LEAF pushed into the vein lumen with the vein still congested. This prevents the metal tip of the manhole from damaging the vein wall when the indwelling cannula is inserted, but the plastic cannula retains the necessary rigidity so that it is not bent by the skin resistance when being pushed forward. Finally, the indwelling vein cannula is fixed to the support wings provided on the cannula body by adhesive strips or the like on the skin, and the injection syringe or the infusion system is connected.

As stated above, the known venous cannula is already very well developed with regard to its use. However, complications can also arise after placement, which are due to the fact that reliable fixation is achieved in the area of the actual cannula, but the transition between the cannula chamber and the mouth of the infusion tube does not permit optimal fixation. Even in the case of small and therefore shorter venous cannulas, this part of the venous cannula protrudes from the attached "triangle" (puncture site - right support wing - left support wing) as an extension of the cannula longitudinal axis. In the event of careless or unconscious movement of the patient, e.g. B. while sleeping, there is therefore the possibility of a displacement of this end of the cannula. The infusion tube can detach itself from the venous stay cannula or - due to the leverage of this protruding free end of the cannula - injuries in the actual access area or inside the vein.

The invention is therefore based on the object of designing and developing the aforementioned venous cannula so that the aforementioned disadvantages are avoided and that the venous cannula is improved in its entirety. Furthermore, it is desirable to facilitate the handling of the venous indwelling cannula or to improve its function without having to forego the known advantages.

REPLACEMENT LEAF The vein-indwelling cannula according to the invention, in which the above-described object is achieved, is initially and essentially characterized in that the cannula body is provided with a flexure in the region of the handle attachment. This configuration according to the invention ensures that movements transmitted via the infusion tube to the vein cannula can no longer be transmitted to the plastic cannula located in the vein. In particular, according to the invention, the indwelling vein cannula in the area between the puncture point and the receiving opening for the injection syringe or the infusion tube can no longer act as a rigid lever, so that the possibility of undesired injuries can be reliably excluded.

The size, shape, material selection and technical conception of the above-mentioned and the claimed components described in the exemplary embodiments and to be used according to the invention are not subject to any special exceptional conditions, so that the selection criteria known in the respective application area can be used without restriction, in particular, they can also advantageously be used independently of one another to solve the task or at least one subtask.

There are now various possibilities for developing and developing the teaching of the invention, for which reference is made on the one hand to the subclaims and on the other hand to the following explanation of a preferred exemplary embodiment of the venous indwelling cannula according to the invention with reference to the drawing. The drawing shows:

1 is a side view of the venous residence cannula according to the invention in the assembled state with protective hood,

2 shows a side view of the venous cannula according to the invention in the pulled-apart state with the protective hood removed,

SPARE BLADE 3 shows a top view of the venous cannula according to the invention from FIG. 2,

4 shows a side view of part of the venous cannula according to the invention from FIG. 2,

5 shows a top view of the part of the venous indwelling cannula according to the invention from FIGS. 4 and

Fig. 6 shown enlarged, a section of. Vein indwelling cannula according to the invention according to the dash-dotted circle from FIGS. 3 and 5.

1 shows a side view of the venous indwelling cannula according to the invention, designated as a whole by 1. The vein indwelling cannula 1, which is regularly designed as a one-time cannula, is in this assembled state before it is used for the first time. For a better overview, the vein indwelling cannula 1 is shown in FIGS. 2 and 3 as a side view or top view in its individual components.

Specifically, the vein indwelling cannula 1 according to the invention initially has the cannula body 2 with a handle attachment 3 and a plastic cannula 4 molded thereon. Molded support wings 5 also serve as adhesive and support surfaces for attaching the vein cannula 1 to the skin. Their undersides are often provided with notches in order to better adapt to the contour of an arm, for example.

1 to 3 also show that inside the cannula body 2 made of plastic there is a puncture inner cannula 6, which is provided with a metal cannula, the so-called male 7. The tip of the stylet 7 is ground, as can be seen particularly clearly from FIGS. 2 and 3. The puncture inner cannula 6 is equipped with a holding web 8 for better handling. The vein indwelling cannula 1 is closed with a stylet closure 9, which is designed so that it can also serve to close the cannula body 2 after removal of the stylet 7. For this purpose - and of course for receiving an injection (not shown)

REPLACEMENT LEAF syringe or an infusion tube (not shown) - both the cannula body 2 and the puncture inner cannula 6 are designed like a hollow cylinder at their end facing away from the tip. Finally, from FIGS. 2 and 3 it can be seen that the vein indwelling cannulas 1 are provided with a protective hood 10 for protection against injuries and damage.

According to the invention facing away from the tip end of the body 2 Kanülen¬ is provided in the region of the handle neck 3 with a flexure 11, so that the course of the injection syringe bz w ^'. the tip of the infusion tube no longer has to point in the direction of the cannula longitudinal axis (not particularly emphasized in the drawing).

The function of this flexure 11, which is known per se from other areas, can be seen clearly from FIGS. 4 and 5, which show the cannula body 2 in a side view and a top view. According to a further teaching of the invention, the flexure 11 is designed in terms of its type and length in such a way that it enables angling over 90 °. In this way, for example, an infusion tube can be fastened perpendicular to the arm (and thus also perpendicular to the vein) in the venous cannula 1 according to the invention. Possible movements of the infusion tube are transmitted far less to the cannula body 2 than with conventional indwelling cannulas.

In a further embodiment of the invention, the cannula body 2 is provided with a finger plate 12 in the region of the handle attachment 3. It is particularly advantageous if, according to a further teaching of the invention, the finger plate 12 is adapted to the anatomy of the fingertip of an index finger, is arched and / or is provided with elevations 13. Slipping of the fingertip on the cannula body 2 can thus be reliably avoided. The above-described configuration enables the vein indwelling cannula 1 according to the invention to be handled particularly well, since it can be guided safely and yet sensitively with three fingers. The index finger rests on the finger plate 12 and the thumb and middle finger laterally clamp the retaining web 8 of the puncture inner cannula 6. Also shows here the particular advantage of the above-described configuration of the venous indwelling cannula 1 according to the invention, since a very frequent - albeit harmless in most cases - complication is puncturing the vein when the vessel is punctured. It is taught to "keep the vein indwelling cannula" so that you can clearly feel the resistance of the vein wall or to guide the injection needle as delicately as possible in order to fix it immediately when blood drips into the cannula can. This recommendation is supported by the previously described version.

It is not shown that indwelling vein cannulas are often provided with second accesses - for example in order to enable the cannula to be rinsed - these are generally arranged on the handle attachment of the cannula body at the level of the support wings. It is therefore expedient for the finger plate in the vein indwelling cannula designed according to the invention to simultaneously form the cover of the second access.

Finally, a further teaching of the invention is that the plastic cannula 4 has at least one transverse bore 14 in the region of its tip. For better illustration, the area in the dot-dash circle K from FIGS. 3 and 5 is shown enlarged in FIG. 6. In the illustrated and preferred embodiment, the plastic cannula 4 according to the invention, which is only shown in the area of its tip, has a transverse bore 14, but designs with several transverse bores are also conceivable. A uniform flow behavior is achieved by means of these transverse bores and blockages (for example due to blood clots, by contacting the tip of the cannula against the vein wall or mechanical damage to the sensitive, conically tapering tip of the cannula etc.) can be reliably ruled out.

REPLACEMENT LEAF

Claims

dP claims:

1. indwelling vein cannula with a cannula body consisting essentially of a plastic cannula and a handle attachment and with a puncture inner cannula having a metal cannula (stylet), characterized in that the cannula body (2) in the area of the handle attachment (3) with a flexure ( 11) is provided.

2. indwelling vein cannula according to claim 1, characterized in that the flexure (11) is designed in its type and length so that angling up to 90 ° are possible.

3. indwelling vein cannula according to claim 1 or 2, characterized in that the cannula body (2) in the region of the handle attachment (3) is provided with a finger plate (12).

4. indwelling vein cannula according to claim 3, characterized in that the finger plate (12), adapted to the anatomy of a fingertip, is curved.

5. indwelling vein cannula according to claim 3 or 4, characterized in that on the finger plate (12) elevations (13) are provided.

6. indwelling vein cannula according to one of claims 3 to 5, characterized in that the finger plate (12) forms the lid of a second access.

7. indwelling vein cannula according to one of claims 1 to 6, characterized in that the plastic cannula (4) has at least one transverse bore (14) in the region of its tip.

REPLACEMENT LEAF