INTRAVENOUS ACCESS DEVICE

Abstract

The invention provides a device for application to the skin of a patient to facilitate intravenous access, e.g. via needles, syringes, cannulas or catheters, the device having an upper surface and a lower surface, wherein the lower surface is suitable for contacting the skin of the patient at the location of a vein to be accessed. The device comprises a heat patch, an organic nitrate vasodilator agent and an amino based anaesthetic agent which is an amino ester or amino amide. The device is configured and arranged such that in use the device can be activated by the application of pressure to the patch so as to initiate an exothermic chemical reaction in the heat patch which heats the patch to a temperature of from 50 to 55 degrees Celsius for a period of time of one minute or more. Further, the device is configured and arranged such that when the device is applied to the skin of the patient, with the lower surface contacting the skin of the patient, the vasodilator agent and the anaesthetic agent are released from the lower side of the device onto the patient's skin at the location of a vein to be accessed.

Claims

1. A device for application to the skin of a patient to facilitate intravenous access, the device having an upper surface and a lower surface, wherein the lower surface is suitable for contacting the skin of the patient at the location of a vein to be accessed, the device comprising a heat patch, an organic nitrate vasodilator agent and an amino based anaesthetic agent which is an amino ester or amino amide, wherein the device is configured and arranged such that in use the device can be activated by the application of pressure to the patch so as to initiate an exothermic chemical reaction in the heat patch which heats the patch to a temperature of from 50 to 55 degrees Celsius for a period of time of one minute or more, and wherein the device is configured and arranged such that when the device is applied to the skin of the patient, with the lower surface contacting the skin of the patient, the vasodilator agent and the anaesthetic agent are released from the lower side of the device onto the patient's skin at the location of a vein to be accessed.

2. The device of claim 1 wherein the exothermic chemical reaction is a crystallization of a supercooled aqueous salt solution.

3. The device of claim 2 wherein the exothermic chemical reaction is a crystallization of a sodium acetate solution.

4. The device of claim 2, wherein the heat patch comprises a trigger which is a metal or mineral strip or disc, which initiates the exothermic chemical reaction when pressed or flexed.

5. The device of claim 1 wherein the organic nitrate vasodilator agent is selected from the group consisting of glyceryl trinitrate, isosorbide dinitrate, isosorbide mononitrate, erythritol tetranitrate, pentaerythritol tetranitrate, and combinations thereof.

6. The device of claim 5 wherein the organic nitrate vasodilator agent comprises glyceryl trinitrate.

7. The device of claim 1 wherein the amino ester or amino amide anaesthetic agent is selected from the group consisting of procaine, chloroprocaine, tetracaine, cocaine, benzocaine, dibucaine, lidocaine, mepivacaine, prilocaine, bupivacaine, levobupivacaine, ropivacaine, articaine, and etidocain, and combinations thereof.

8. The device of claim 7 wherein the anaesthetic agent is selected from the group consisting of lidocaine, prilocaine, tetracaine, prilocaine, dibucaine, benzocaine and combinations thereof.

9. The device of claim 8 wherein the anaesthetic agent is lidocaine, prilocaine or tetracaine or a combination thereof.

10. The device of claim 1 wherein the lower surface of the device has a surface area of 50 cm.sup.2 or less.

11. The device of claim 10 wherein the lower surface of the device has a surface area of 35 cm.sup.2 or less.

12. The device of claim 1 wherein when the heat patch is activated to initiate the exothermic chemical reaction, the lower surface of the device is, as a consequence, heated to a temperature of from 40 to 46 degrees Celsius.

13. The device of claim 1 wherein the heat patch, when activated, is heated to a temperature of from 50 to 55 degrees Celsius heat for a period of time of less than 15 minutes.

14. The device of claim 13 wherein the heat patch, when activated, is heated to a temperature of from 50 to 55 degrees Celsius heat for a period of time of from one minute to ten minutes.

15. The device of claim 1 wherein the device comprises (i) a topical composition that includes both the vasodilator agent and the amino based anaesthetic agent; or (ii) a first topical composition that provides the vasodilator agent and a second topical composition that provides the amino based anaesthetic agent.

16. The device of claim 15 wherein the amount of organic nitrate vasodilator agent in the topical composition or in the combined first and second topical compositions is: a) 20 w/w % or less; or b) from 0.01 to 20 w/w %; or c) from 0.1 to 20 w/w %.

17. The device of claim 15 wherein the amount of organic nitrate vasodilator agent in the topical composition or in the combined first and second topical compositions is: a) 8 w/w % or less; or b) from 0.01 to 8 w/w %; or c) from 0.1 to 8 w/w %.

18. The device of claim 15 wherein the amount of amino based anaesthetic agent in the topical composition or in the combined first and second topical compositions is: a) 20 w/w % or less; or b) from 0.01 to 20 w/w %; or c) from 0.1 to 20 w/w %.

19. The device of claim 18 wherein the amount of amino based anaesthetic agent in the topical composition or in the combined first and second topical compositions is: a) 8 w/w % or less; or b) from 0.01 to 8 w/w %; or c) from 0.1 to 8 w/w %.

20. The device of claim 1 wherein the weight ratio of organic nitrate vasodilator agent to anaesthetic agent is: (a) from 3:1 to 1:5; or (b) from 2:1 to 1:5.

21. The device of claim 1 wherein the device comprises an amount of organic nitrate vasodilator agent of: (a) from 1 mg to 50 mg; or (b) from 3 mg to 30 mg; or (c) from 5 mg to 20 mg.

22. The device of claim 1 wherein the device comprises an amount of amino based anaesthetic agent of: (a) from 3 mg to 75 mg; or (b) from 5 mg to 60 mg; or (c) from 10 mg to 40 mg.

23. A method of facilitating intravenous access to a selected vein in a patient, the method comprising: i) placing a device onto the skin of the patient at a location proximal to the selected vein, wherein the device has an upper surface and a lower surface, wherein the lower surface is suitable for contacting the skin of the patient at the location of a vein to be accessed, the device comprising a heat patch, an organic nitrate vasodilator agent and an amino based anaesthetic agent which is an amino ester or amino amide, wherein the device is configured and arranged such that in use the device can be activated by the application of pressure to the patch so as to initiate an exothermic chemical reaction in the heat patch which heats the patch to a temperature of from 50 to 55 degrees Celsius for a period of time of one minute or more, and wherein the device is configured and arranged such that when the device is applied to the skin of the patient, with the lower surface contacting the skin of the patient, the vasodilator agent and the anaesthetic agent are released from the lower side of the device onto the patient's skin at the location of a vein to the accessed; ii) activating the device so as to initiate the exothermic chemical reaction in the heat patch to heat the patch to a temperature of from 50 to 55 degrees Celsius; wherein steps i) and ii) can be carried out in any order, and then iv) removing the device from the patient's skin.

24. A kit comprising a device for application to the skin of a patient to facilitate intravenous access, the device having an upper surface and a lower surface, wherein the lower surface is suitable for contacting the skin of the patient at the location of a vein to be accessed, the device comprising a heat patch, an organic nirate vasodilator agent and an amino based anaesthetic agent which is an amino ester or amino amide, wherein the device is configured and arranged such that in use the device can be activated by the application of pressure to the patch so as to initiate an exothermic chemical reaction in the heat patch which heats the patch to a temperature of from 50 to 55 degrees Celsius for a period of time of one minute or more, and wherein the device is configured and arranged such that when the device is applied to the skin of the patient, with the lower surface contacting the skin of the patient, the vasodilator agent and the anaesthetic agent are released from the lower side of the device onto the patient's skin at the location of a vein to be accessed; and an intravenous access device.

25. The kit of claim 24 where in the intravenous access device is selected from needles, syringes, cannulas and catheters.

Description

DESCRIPTION OF THE DRAWINGS

[0156] The invention can be further understood from the non-limiting drawings, in which:

[0157] FIG. 1 shows a perspective view of a device according to the invention without a release sheet present.

[0158] FIG. 2 shows a side view of the device of FIG. 2.

[0159] FIG. 3 shows a view from below of the device of FIG. 1 when a release sheet is present.

[0160] FIG. 4 shows intravenous access devices, one or more of which may be provided together with the device as shown in FIGS. 1-3 in the form of a kit.

[0161] The device 1 is a sterile device which comprises a top layer which provides the upper surface 1a of the device, and a bottom layer, which provides the lower surface 1b of the device.

[0162] A heat patch 2 is included in the device, at or near to the upper surface.

[0163] The lower surface 1b of the device is coated with about 0.5 g of a first composition comprising 2% by weight of glyceryl trinitrate and is further coated with about 0.5 g of a second composition that comprises 4% by weight of tretacaine or that comprises 2% by weight lidocaine and 2% by weight prilocaine). It will be appreciated that a single layer could alternatively be used, where this layer is a mixture of the first and second compositions. It will be appreciated that the amounts of composition and the concentrations of active agent therein could also be varied, in accordance with the teachings above regarding the total amount of active agent present.

[0164] The heat patch 2 is a crystallization type heat patch comprising a flexible container wherein a supercooled aqueous sodium acetate solution and a trigger are contained. The trigger is a metallic disc 3, such as a stainless steel disc, and is immersed in the solution. The flexible container is made from a material which is not affected by the sodium acetate solution and which is impermeable to the sodium acetate solution and which is stable at temperatures up to and above 55 degrees Celsius, such as a suitable polymeric material.

[0165] The heat patch may be of the type described in U.S. Pat. No. 4,077,390.

[0166] The device is provided with an adhesive border 4 around the perimeter of the lower surface, which can be used to releasably adhere the device to the skin of a patient, in a similar manner to a sticking plaster product that is used for wound dressings. The border is shown to extend around the entire perimeter of the device, but it will be appreciated that as an alternative it may be in the form of discrete tabs.

[0167] The adhesive border 4 is provided with a release sheet 5 that covers the adhesive and prevents it from curing before the device is used. The release sheet is removed before the device is applied to the skin of the patient. The release sheet 5 also covers the layers of composition and prevents release of the agents before the device is used.

[0168] Thus in the illustrated embodiment, a single release sheet covers both the adhesive border and the lower surface. However, it will be appreciated that there could be one release sheet for the adhesive and another release sheet for the layers of composition.

[0169] Thus when the release sheet 5 is removed, the border 4 of adhesive is exposed on the lower surface of the device, and can be used to temporarily and releasably secure the device to the skin of the patient. The layers of composition are exposed and thus there is release of the agents onto the skin of the patient.

[0170] The heat patch 2 is activated such that there is also heating to 50 to 55 degrees C.

[0171] The present device is not a pain relief treatment. Instead, the device uses the combination of the organic nitrate vasodilator agent and the amino based anaesthetic agent and the exothermic chemical reaction heats the patch to a temperature of from 50 to 55 degrees Celsius to prepare the skin for cannulation. The device is not designed for treating pain in a subject, whereby prolonged treatment timeframes would be used to ensure pain relief for the subject. Instead, the device provides a short (e.g. 10 minutes or less) preparation treatment that improves the subsequent cannulation process. Unexpectedly, when this preparation treatment is used, the time taken to cannulate and the number of attempts to reach successful cannulation can be significantly reduced. As can be seen from the examples, the results are a notable improvement in terms of the time taken to cannulate and the number of attempts to reach successful cannulation can be significantly reduced

[0172] The device 1 is therefore used to prepare the skin for intravenous access, e.g. cannulation, and can be provided in the form of a kit in combination with an intravenous access device. Such access devices are illustrated in FIG. 4, which shows a cannula 10, a syringe 11, and a catheter 12.

[0173] The invention will now be further described, by means of illustration only, by means of the following non-limiting examples.

EXAMPLES

Example 1

[0174] Example 1 illustrates an exemplary device according to the present invention.

[0175] The device is a sterile device which comprises a top layer, which provides the upper surface of the device, a bottom layer, which provides the lower surface of the device, and a heat patch in a layer between the top layer and the bottom layer.

[0176] The device is not limited to any particular shape. The device may, for example, have an elliptical or circular shape, or a quadrilateral shape, or any other shape mentioned in the present specification.

[0177] The layers are each made of a flexible material. The top and bottom layers are sealed together about their perimeters to hold the heating patch therebetween. The layers can be sealed together using any mechanism known in the art, for example they may be laminated together or secured together with adhesive.

[0178] The lower surface of the device is coated with about 0.5 g of a first composition comprising 2% by weight of glyceryl trinitrate and is further coated with about 0.5 g of a second composition that comprises 4% by weight of tretacaine or that comprises 2% by weight lidocaine and 2% by weight prilocaine). It will be appreciated that a single layer could alternatively be used, where this layer is a mixture of the first and second compositions. It will be appreciated that the amounts of composition and the concentrations of active agent therein could also be varied, in accordance with the teachings above regarding the total amount of active agent present.

[0179] The lower surface of the device is provided with a release sheet that covers these layers of composition and prevents release of the agents before the device is used. The release sheet is removed before the device is applied to the skin of the patient.

[0180] The heat patch is a crystallization type heat patch comprising a flexible container wherein a supercooled aqueous sodium acetate solution and a trigger are contained. The trigger is a metallic disc, such as a stainless steel disc, and is immersed in the solution. The flexible container is made from a material which is not affected by the sodium acetate solution and which is impermeable to the sodium acetate solution and which is stable at temperatures up to and above 55 degrees Celsius, such as a suitable polymeric material.

[0181] The heat patch may be of the type described in U.S. Pat. No. 4,077,390.

[0182] The device is provided with an adhesive border around the perimeter of the lower surface, which can be used to releasably adhere the device to the skin of a patient, in a similar manner to a sticking plaster product that is used for wound dressings. The border may extend around the entire perimeter, or may be in the form of discrete tabs.

[0183] The adhesive border is provided with a release sheet that covers the adhesive and prevents it from curing before the device is used. The release sheet is removed before the device is applied to the skin of the patient.

[0184] It will be appreciated that a single release sheet could cover both the adhesive border and the lower surface.

[0185] Prior to carrying out venepuncture, e.g. by a syringe for the withdrawal of blood from a vein, or by cannulation, the release sheets are removed. The device is then attached to the skin of a patient at a location proximal to the selected vein.

[0186] The device is activated either just before or just after the device is located on the skin; preferably within a two minute window before or after that steps of locating the device on the skin. This activation comprises applying pressure, such that the trigger initiates crystallisation. The exothermic reaction will produce temperatures in the range of 50 to 55 degrees Celsius and the active agents will contact the skin and be absorbed. The device can be left on the skin for 1 to 10 minutes and then removed.

Example 2

[0187] A study was conducted to evaluate the advantageous effects on patient when a device based on the present invention is used before cannulation. This utilised a layer of a composition comprising 2% by weight of glyceryl trinitrate (Percutol Glyceryl Trinitrate 2% Ointment by Aspire Pharma) and a layer of a composition comprising 2% by weight of lidocaine (Anbesol Gel by Alliance Pharmaceuticals) and a heat patch which generates heat due to crystallisation and which is based on supercooled sodium acetate aqueous solution (ClickHeat by Helios). Once activated by pressure, this heats to 52-54 degrees Celsius with a lower surface temperature of 43 degrees Celsius and it remains hot for up to 10 minutes.

[0188] The study included 25 patients with ages between 19 and 52 and from different ethnic groups. Two of the patients had body mass indexes (BMI) above 30 which classify them in the obese category. Consent was obtained and a history of allergies/medical conditions was elicited. Conditions noted included hypertension, asthma and eczema.

[0189] A junior doctor performed the cannulation process for all of the patients over two sessions; he had three years of experience in cannulation.

[0190] For the right hand of each patient cannulation was performed without using the aid of the device of the invention. A tourniquet was applied, starting the process of searching for a vein; timing began from this point to the insertion of a successful cannula. A 22 gauge blue cannula was used.

[0191] For the left hand of the patient, a device based on the invention was used to assist cannulation. Once the heat patch was activated the device was applied to the skin of to the left hand and remained there for two minutes before being removed.

[0192] A tourniquet was then applied, starting the process of searching for a vein; timing began from this point to the insertion of a successful cannula. A 22 gauge blue cannula was used.

[0193] The success in cannulation in each hand was recorded by the junior doctor in terms of whether or not cannulation was achieved. The number of attempts required for successful cannulation (up to a maximum of three), and the perceived ease of cannulation (easy/moderate/difficult) was also recorded for every attempt in each hand.

[0194] The time in seconds that was taken from applying the tourniquet up to the insertion of a successful cannula was also recorded, and a comparison was made between the time for each patient in relation to the left hand and right hand to see the extent to which using the device.

Results

[0195]

TABLE-US-00001 Successful Unsuccessful Success of cannulation 96% 4% with the device Success of cannulation 88% 12% without the device

[0196] The three subjects in whom cannulation was unsuccessful (no cannulation after three attempts) in one or both hands were excluded from the remaining data.

TABLE-US-00002 Success on Success on 1st attempt 2nd attempt Attempts before successful 86.3% 13.6% cannulation with the device Attempts before successful 72.7% 27.2% cannulation without the device

[0197] The time taken for cannula insertion showed that in 77.2% of the patients the time taken to achieve successful cannulation was shorter when using the device of the invention than when not using the device.

[0198] The doctor conducting the procedure reported that when using the device, cannulation was easy in 72.7%, moderate in 22.7% and difficult in 4.5%. Without the device, cannulation was reported as easy in 59%, moderate in 27.2% and difficult in 13.6% of patients.