WO2007066100A1

WO2007066100A1 - Cricothyroidotomy device

Info

Publication number: WO2007066100A1
Application number: PCT/GB2006/004550
Authority: WO
Inventors: Kanagasabaphy Chandradeva
Original assignee: Kanagasabaphy Chandradeva
Priority date: 2005-12-05
Filing date: 2006-12-05
Publication date: 2007-06-14
Also published as: GB2422550A; GB0524805D0

Abstract

Apparatus for performing cricothyroidotomy or similar procedures, comprising a syringe (26), a needle (4), a cannula (6), a guidewire (18) and a branched conduit (8) comprising a tubular member with an opening (10, 12) at each end and a further opening (14) at the outer end of an intermediate branch member (15), allowing a guidewire to be used to locate the cannula correctly without removing the syringe.

Description

Cricothyroidotomy device

This invention relates to a device for performing cricothyroidotomy, in particular to a device for performing cannula cricothyroidotomy (CC).

The main prior art device for performing cannula cricothyroidotomy comprises a "cannula-over-needle set" which includes a syringe attached to a needle, the needle being surrounded by a cannula. The role of cannula cricothyroidotomy (CC) in the management of the difficult airway is increasingly recognised. CC may be used for percutaneous transtracheal jet ventilation during 'can't intubate, can't ventilate' situation, (1) assisting retrograde intubation (2) and direct laryngoscopy intubation (3). This technique is also very useful during airway surgery (4). Anaesthetists who do not undertake CC on a regular basis seem to encounter difficulties in performing this procedure. It has been shown in a study that anaesthetists, both senior and junior, needed retraining to retain this life-saving skill ^"(5).

The procedure of CC involves two stages. Firstly, identifying the intratracheal space by being able to aspirate air and demonstrate a capnograph trace. The second involves advancing the cannula over a needle or guidewire and placing it securely in the intratracheal space. In the cannula-over-needle technique, when the cannula is advanced, the tip may impinge on the tracheal wall and become kinked by the ridges on the inner surface of the trachea. When a kink-resistant cannula is employed, impediment or increased resistance to advancement of the cannula may be experienced. Recurrent attempts increase the risk of haemorrhage and multiple punctures of the tracheal wall could increase the risk of barotrauma and surgical emphysema, as gas could be forced into these puncture sites during jet ventilation. Above all, any delay in oxygenation will have catastrophic consequences for the patient.

Even when a kink resistant cannula is used, there can be the problem that when the cannula is advanced into the trachea it can impinge on the tracheal wall thereby blocking the opening at the tip of the cannula, for this reason it is known to use the Seldinger technique to advance the cannula over a guidewire inside the trachea. The Seldinger technique involves removing the needle from the syringe and inserting a long J-shaped guidewire through the needle, into the trachea. The curve at the bottom of the wire prevents the cannula from impinging on the ridges in the trachea and allows it to be pushed a few centimetres into the trachea such that part of it becomes substantially parallel with the trachea. At this point the cannula is pushed into the trachea over the guidewire so as to be substantially parallel with the trachea. Once the cannula is in this position the opening will not be blocked by ridges in the trachea. At this point the guidewire is removed.

In order to facilitate and shorten the time taken to carry out this procedure it is the object of this invention to provide an improved device for performing cannula cricothyroidotomy.

According to one aspect of the invention there is provided a cannulation device according to claim 1.

According to another aspect of the invention there is provided a set of parts according to claim 12. An embodiment of the invention will now be described with reference to the following drawings, in which

Figure 1 shows the apparatus according to the invention.

Figure 2 shows the apparatus according to the invention in use in four stages.

Referring to Figure 1 the equipment according to the invention consists of a cannula-over-needle set [2], the diameter of the cannula preferably between 1OG and 25G, more preferably between 15G and 2OG and most preferably 18G (1.30mm); the needle [4] having a length of preferably between 2cm and 10cm, more preferably between 3cm and 7cm and most preferably 5cm and being slightly longer than the length of the cannula [6]. The cannula-over-needle set [2] is provided with a bifurcated hub [8] which comprises a branched conduit. In the preferred embodiment the bifurcated hub [8] comprises a substantially tubular member having two coaxial ports or openings [10], [12], the first port [10] accepting a syringe and the second port [12] attached to the needle [4] and a third port [14] at the end of the branch member [15] having an acute angle with respect to the tubular member and on the same side of the cannula-over- needle set [2] as the bevel [16] of the needle [4]. The apparatus also includes a J-shaped guidewire [18] having a curved section

[20] and an appropriate diameter to fit inside the needle, preferably between 0.5 and 1.5 mm, more preferably between 0.75 and 1mm and most preferably 0.88 mm; the guidewire is made of a resilient flexible material, such as wound wire and has a length of preferably between 10 and 50cm, more preferably between 15 and 30cm and most preferably of 20cm. The guidewire is preferably provided with a stopper [22] at the uncurved end, having a diameter greater than that of the third port [14] and a guidewire straightener [24] which comprises a substantially cylindrical tube having an inside diameter slightly greater than that of the guidewire and made of a material that is not readily flexible. It will be understood by the skilled man that the above mentioned sizes are appropriate for adult humans and that different lengths of needle can be prepared for use in children, obese people, and other sizes may be appropriate for use in animals.

Although not shown in figure 1 , for simplicity, it can be seen in figure 2 that the cannula [6] can be attached to a connector device [32] which has two coaxial tubular connectors, the inner connector for connection to a syringe (or the hub of the invention) and the outer connector for connection to a breathing system. As can be seen from the figures, the connector piece [32] is so shaped that it has a much larger diameter than the cannula and therefore stops the cannula from slipping into the trachea, it can also be seen that the connector device [32] is bevelled in order that the cannula enters the trachea at the appropriate angle. Not shown on the drawings are laterally extending members which are, in use, attached to a collar which keeps the cannula in the correct position on the patient's neck.

In order to understand the way in which the apparatus is used there follows a description with reference to figure 2. A rolled towel is placed beneath the patient's neck to support and extend it. With the thumb and index finger of the non-dominent hand to stabilize the thyroid cartilage, the cricothyroid membrane [28] is palpated with the index finger of the dominant hand. The cricothyroid membrane is infiltrated with local anaesthetics, preferably with adrenaline in order to minimise bleeding. A saline-filled syringe [26] is connected to the first port [10] with the branch member or side-hub [15] facing the ceiling; the syringe is held approximately 60 degrees from the horizontal. The opening [14] of the side-hub [15] can be closed with an appropriate cap or the thumb of the operator. Alternatively, it can be connected to a capnograph monitor [not shown]. The cricothyroid membrane [28] is punctured and the needle [4] together with the cannula [6] advanced caudally. The intratracheal space is identified by the aspiration of air and demonstration of a capnograph trace. The needle is advanced into the trachea [30] no more than 1.0 cm and is held firmly by the operator. The lubricated, J-shaped guidewire [18] is then introduced through the side-hub [15] into the trachea by the operator or by an assistant; the straightener [24] is placed at the advancing end of the guidewire [20] in order to ease entry into the side hub [15]. Once the appropriate length of the guidewire [18] is inserted, the stopper [22] avoids the risk of the guidewire being lost in the intratracheal space; the cannula [6] is then advanced over the needle [4] and guidewire [18] into the trachea. Following placement of the cannula, the needle [4] and guidewire [18] can be removed together. If the guidewire [18] or the cannula [6] cannot be advanced they should be removed en masse and the procedure repeated.

The technique described here exhibits a number of desirable features. Although a guidewire is used, the duration of this technique should be shorter than that of the Seldinger technique as it involves fewer steps. Unlike the Seldinger technique, the provision of a stopper allows a much shorter guidewire to be used whist still avoiding losing the guidewire in the intratracheal space. The shorter guidewire is less cumbersome, more convenient to handle in emergency resuscitation and unlikely to get knotted in the intratracheal space. This technique also permits the monitoring of carbon dioxide as the air aspiration test is performed and allows advancement of the cannula following the insertion of the guidewire in rapid sequence. In addition, the provision of the branched member [15] in the same plane as the bevel of the needle means that when the needle is introduced into the body with the sharp end first, the third port [14] will be easily accessible to aid insertion of the guidewire. Furthermore, it will make it easier for the user to ensure the needle is entered into the body in the correct way simply by making sure the third port is facing upwards. References

1. Henderson JJ, Popat MT, Latto IP, Pearce AC. Special article. Difficult Airway Society guidelines for management of the unanticipated difficult intubation.

Anaesthesia 2004; 59: 675-94

2. Ovassapian A. Management of the difficult airway. In: Ovassapian A, ed.

Fibreoptic Endoscopy, the Difficult Airway, 2^nd edn. Philadelphia: Lippincott- Raven, 1996: 201-30

3. Chandradeva K, Palin C, Ghosh SM, Pinches SC. Percutaneous transtracheal jet ventilation as a guide to tracheal intubation in severe upper airway obstruction from supraglottic oedema. BrJ Anaes 2005; 94: 683-6

4. Bourgain JL, Desruennes E, Fischler M, Ravussin P. Transtracheal high

frequency jet ventilation for endoscopic airway surgery: a multicentre study. Br J Anaes 2001 ; 87: 870-5

5. Standley TDA, Spears FD. Teaching cannula cricothyroidotomy. Anaesthesia 2004; 59: 1138-9

Claims

1. A cannulation device for performing cricothyroidotomy comprising:

a branched conduit comprising a tubular member with an opening at each end and a further opening at the outer end of an intermediate branch member, and

a cannula, the cannula being attached at one end to a connector piece having a larger diameter than the diameter of the cannula.

2. A device according to claim 1 wherein said conduit comprises

a first opening at one end adapted to retain a syringe

a second opening at the other end co-axial with the first opening and connected to or integral with a needle; and

a third opening comprising the further opening at the outer end of the

intermediate branched member.

3. A device according to claim 1 or claim 2 wherein the third opening is at an acute angle with respect to the tubular member.

4. A device according to claim 2 or 3 in which said needle has a bevelled tip and; said third opening is in the same plane as the bevel.

5. A device according to any one of the preceding claims, together with a guidewire.

6. The apparatus according to claim 5 wherein the guidewire is J-shaped.

7. The apparatus according to claim 5 or claim 6 wherein said guidewire is less than 20cm long.

8. The apparatus according to claim 5 or claim 6 wherein said guidewire is less than 15cm long.

9. The apparatus according to claim 5 or claim 6 wherein said guidewire is 10cm long.

10. The apparatus according to any one of claims 5 to 9 wherein said guidewire has a stopper at one end.

11. The apparatus according to claim 10 when dependent on any one of claim 6 or a claim dependent on claim 6; wherein the stopper is at the straight end of the J shaped guidewire.

12. A set of parts for performing cannula cricothyroidotomy comprising:

a syringe

a needle

a cannula, attached at one end to a connector device having a diameter larger than that of the cannula

a guidewire

a branched conduit comprising a tubular member with an opening at each end and a further opening at the outer end of an intermediate branch member.

13. A set of parts according to claim 12 wherein the guidewire is J-shaped.

14. A set of parts according to claim 12 or 13 wherein said guidewire is less than 20cm long.

15. A set of parts according to claim 12 or claim 13 wherein said guidewire is less than 15cm long.

16. A set of parts according to claim 12 or 13 wherein said guidewire is 10cm long.

17. A set of parts according to any one of claims 12 to 16 wherein said guidewire has a stopper at one end.

18. A set of parts according to claim 17 when dependent on any one of claim 13 or a claim dependent on claim 13; wherein the stopper is at the straight end of the J shaped guidewire.