Method and device for administering a humidified aerosol to a patient interface

Abstract

A method and device are used for administering a humidified aerosol to a patient interface by providing and guiding a first gas flow having a humidified aerosol, a second gas flow having humidified respiratory gases, and a liquid flow of a thermally balancing liquid, thermally balancing the first and second gas flow by parallel guiding the first and second gas flow such that the first and second gas flow are guided in a manner that they are at least partially surrounded by the liquid flow of the thermally balancing liquid, mixing the first and second gas flow to obtain enriched respiratory gases having the humidified aerosol, and administering the enriched respiratory gases to the patient interface. The method and the device avoid the administration of dry or re-dried powdered aerosols and unwanted accumulation of and blockage by powdered material. The device is useful in respiratory support of preterm infants.

Claims

1. A method for administering a humidified aerosol to a patient interface, comprising the following steps: a) providing and guiding a first gas flow comprising the humidified aerosol; b) providing and guiding a second gas flow comprising humidified respiratory gases; c) providing and guiding a liquid flow of a thermally balancing liquid; d) thermally balancing the first gas flow and the second gas flow by parallel guiding the first gas flow and the second gas flow, wherein the first gas flow and the second gas flow are guided in a manner that they are at least partially surrounded by the liquid flow of the thermally balancing liquid; e) mixing the first gas flow and the second gas flow, whereby enriched respiratory gases comprising the humidified aerosol are obtained; and f) administering the enriched respiratory gases comprising the humidified aerosol to the patient interface.

2. The method of claim 1, wherein the second gas flow is guided in a manner that it at least partially surrounds the first gas flow.

3. The method of claim 1, wherein the first gas flow is provided pursuant to step a) at a first temperature, wherein the second gas flow is provided pursuant to step b) at a second temperature, wherein the first gas flow and the second gas flow are mixed pursuant to step e) at a common temperature, wherein the common temperature is lower than the first temperature and the second temperature.

4. The method of claim 3, wherein the common temperature is adjusted to a temperature determined for a breath of a patient at least partially ventilated by the ventilatory circuit.

5. The method of claim 1, wherein the first gas flow is provided pursuant to step a) at 100% relative humidity, wherein the second gas flow is provided pursuant to step b) at 100% relative humidity, and wherein the first gas flow and the second gas flow are mixed pursuant to step e) at 100% relative humidity.

6. The method of claim 1, wherein the liquid flow of the thermally balancing liquid is guided by applying a lower pressure in a flow direction.

7. The method of claim 1, wherein the thermally balancing liquid is selected from one of water, an aqueous solution, a non-aqueous liquid, or a non-aqueous solution.

8. The method of claim 1, wherein dry aerosol is humidified prior to step a) and wherein dry respiratory gases are humidified prior to step b).

9. The method of claim 1, wherein the humidified aerosol is administered in respiratory support of preterm infants.

10. A device for administering a humidified aerosol to a patient interface, comprising: at least one first tube for receiving and guiding a first gas flow comprising the humidified aerosol; at least one second tube for receiving and guiding a second gas flow comprising humidified respiratory gases; at least one third tube for receiving and guiding a liquid flow comprising a thermally balancing liquid; wherein the first tube, the second tube and the third tube are provided in a coaxial arrangement with respect to each other, wherein the third tube covers the first tube and the second tube; and at least one mixing chamber for receiving and mixing the first gas flow and the second gas flow and obtaining enriched respiratory gases comprising the humidified aerosol, the mixing chamber having at least one outlet for administering the enriched respiratory gases comprising the humidified aerosol.

11. The device of claim 10, wherein the first tube is located inside the second tube.

12. The device of claim 10, wherein the third tube forms a jacket directly or indirectly covering the first tube and the second tube.

13. The device of claim 10, wherein the first tube has a first central axis, the second tube has a second central axis, and the third tube has a third central axis, wherein the first central axis, the second central axis, and the third central axis coincide with respect to each other.

14. The device of claim 10, wherein the third tube comprises at least one inlet for receiving the thermally balancing liquid and at least one outlet for dispensing the thermally balancing liquid, wherein the device further comprises a pump being designed for applying a lower pressure at the outlet compared to the pressure at the inlet.

15. The device of claim 10, wherein at least one of the first tube, the second tube and the third tube is a flexible tube.

16. The device of claim 10, wherein at least one of the first tube, the second tube and the third tube comprises a constant cross section along their length.

17. The device of claim 10, further comprising at least one first humidifier configured to humidify dry aerosol and at least one second humidifier configured to humidify dry respiratory gases.

Description

SHORT DESCRIPTION OF THE FIGURES

(1) Further optional features and embodiments of the invention will be disclosed in more detail in the subsequent description of preferred embodiments, preferably in conjunction with the dependent claims. Therein, the respective optional features may be implemented in an isolated fashion as well as in any arbitrary feasible combination, as the skilled person will realize. It is emphasized that the scope of the invention may not be restricted by the preferred embodiments. The embodiments are schematically depicted in the Figures. Therein, identical reference numbers in these Figures refer to identical or functionally comparable elements.

(2) In the Figures:

(3) FIGS. 1A and 1B schematically illustrate a profile (FIG. 1A) and a cross section (FIG. 1B), respectively, of an exemplary device for administering a humidified aerosol to a patient interface according to the present invention;

(4) FIGS. 2A and 2B schematically illustrate two different embodiments each comprising humidifiers attached to the exemplary device of FIGS. 1A and 1B; and

(5) FIGS. 3A and 3B show a comparison between images of cross sections of patient interfaces in form of nasal prongs inserted in a holder which are comparable to those that are, typically, used in respiratory support of preterm infants for administering a humidified aerosol to the patient interface without using the method and the device according to the present invention (FIG. 3A; state of the art) or by using the method and the exemplary device according to FIG. 1 or 2, respectively (FIG. 3B).

DETAILED DESCRIPTION OF THE EMBODIMENTS

(6) FIG. 1A schematically shows a profile of an exemplary device 110 for administering a humidified aerosol 112 to a patient interface 114 according to the present invention. The device 110 may, in particular, be used for patients, including but not limited to preterm infants, who are subject to mechanical ventilation or to ventilatory support.

(7) As depicted in FIG. 1A, the exemplary device 110 comprises a first tube 116 which is configured according to step a) for receiving and guiding a first gas flow 118 that comprises the humidified aerosol 112 to a mixing chamber 120. For this purpose, the first gas flow 118 may, preferably, be provided at a first inlet 122 of the first tube 116 at a first temperature T.sub.1 and at 100% relative humidity.

(8) As further shown in FIG. 1A, the exemplary device 110 further comprises a second tube 124 which is configured according to step b) for receiving and guiding a second gas flow 126 that comprises humidified respiratory gases 128 to the mixing chamber 120. Herein, the humidified respiratory gases 128 may comprise a composition which may be suitable for ventilation of the patient, in particular, air or oxygen-enriched air. For this purpose, the second gas flow 126 may, preferably, be provided at a second inlet 130 of the second tube 124 at a second temperature T.sub.2 but also at 100% relative humidity.

(9) As further illustrated in FIG. 1A, the exemplary device 110 further comprises a third tube 132 which is configured according to step c) for receiving and guiding a liquid flow 134 that comprises a thermally balancing liquid 136. Herein, the thermally balancing liquid 136 which refers to a liquid substance that is, generally, adapted for being used as a support in achieving a thermal balance between the first gas flow 118 and the second gas flow 126. For this purpose, the thermally balancing liquid 136 may, in particular, be selected from one of water or an aqueous solution. However, other kinds of liquid substances, such as a non-aqueous liquid or a non-aqueous solution, may also be feasible for this purpose.

(10) Preferably, the third tube 132 may, as further schematically depicted in FIG. 1A, comprise an inlet 138 for receiving the thermally balancing liquid 136 and an outlet 140 for dispensing the thermally balancing liquid 136. In a particularly preferred embodiment, the device 110 may further comprise a pumping unit (not depicted here) which may be adapted for applying a pressure p.sub.2 at the outlet 140 of the third tube 132 which may be lower compared to the pressure p.sub.1 which may prevail at the inlet 138 of the third tube 132. In this manner the liquid flow 134 of the thermally balancing liquid 136 may be guided in a sucking motion through the third tube 132 instead of pressing it into the third tube 132. As a result, the arrangement as shown in FIG. 1A may, thus, help avoiding that the thermally balancing liquid 136 may intrude into the first tube 116 and/or into the second tube 124 and, eventually, into the patient interface 114 which may, otherwise, result in a suffocation of the patient.

(11) As further schematically depicted in FIG. 1A, the liquid flow 134 may be applied in form of a counter flow arrangement in which the liquid flow 134 may assume an opposite direction compared to the directions of the first flow 118 and of the second flow 126, thus, allowing increasing an effectivity of the thermal balancing. However, a parallel flow of the first gas flow 118, the second gas flow 126 and the liquid flow 134 (not depicted here) may also be feasible.

(12) Any or, preferably, all of the first tube 116, the second tube 124 and the third tube 132 may be selected from a rigid tube, such as a pipe, or, preferably, from a semi-rigid or, more preferred, from a flexible tube, such as a hose or a sleeve. By using the flexible tube, the device 110 may, advantageously, more easily be adjustable to the requirements of the patient. In particular, any or, preferably, all of the first tube 116, the second tube 124 and the third tube 132 may comprise a substantially constant cross section along their length, especially, for allowing the first gas flow 118, the second gas flow 126 and/or liquid flow 134 to move in a substantially constant manner through the first tube 116, thereby reducing a risk of depositions, in particular of the aerosol 112 comprised by the first gas flow 118.

(13) FIG. 1B schematically shows a cross section of the device 110 for administering the humidified aerosol to the patient interface 114 of the device 110 as illustrated in FIG. 1A. As depicted there, the first tube 116, the second tube 124 and the third tube 132 are provided in a coaxial arrangement with respect to each other, wherein the third tube 132 covers the first tube 116 and the second tube 124. In the exemplary embodiment as shown here; the first tube 116 has a first axis, the second tube 124 has a second axis, and the third tube 132 has a third axis, wherein the first axis, the second axis, and the third axis coincide with respect to each other, thus, resulting in a triaxial arrangement of the tubes 116, 124, 132. However, other arrangements may still be feasible.

(14) Returning to FIG. 1A, it is illustrated there that, in accordance with the present invention, the second gas flow 126 is guided through the second tube 124 in a manner that it may at least partially surround the first gas flow 118 which is guided through the first tube 116. This arrangement may, preferably, be achieved by locating the first tube 116 inside the second tube 124, in particular, in a coaxial manner as shown in FIG. 1B. This embodiment may particularly be advantageous when the first tube 116 which is configured for receiving and guiding the humidified aerosol 112 may exhibit a smaller flow volume compared to the second tube 124 being configured for receiving and guiding the humidified respiratory gases 128.

(15) The arrangement as illustrated in FIGS. 1A and 1B, thus, allows thermally balancing the first gas flow 118 and the second gas flow 126 according to step d) by parallel guiding the first gas flow 118 and the second gas flow 126. Herein, the first gas flow 118 and the second gas flow 126 may be guided in a manner that they are at least partially surrounded by the liquid flow 134 of the thermally balancing liquid 136. For this purpose, the third tube 132 may, preferably, have a form of a jacket or a sheath which may be designated for covering both the second tube 124 and, consequently, also the first tube 116 which is located inside the second tube 124 in the exemplary embodiment of FIGS. 1A and 1B. This kind of arrangement may, in particular, allow achieving an effective cooling of both the first gas flow 118 and the second gas flow 126 along their corresponding paths via the first tube 116 and the second tube 124 through which they are guided, respectively.

(16) As further illustrated in FIG. 1A, the exemplary device 110 further comprises the mixing chamber 120 which, according to step e), is designed, on one hand, for receiving the first gas flow 118 from a first outlet 146 of the first tube 116 and the second gas flow 126 from a second outlet 148 of the second tube 124 and, on the other hand, for mixing the received first gas flow 118 and the received second gas flow 126, whereby enriched respiratory gases 142 which comprise the humidified aerosol 112, which may, preferably, be distributed across the entire volume of the respiratory gases 128 in a uniform and finely dispersed form, can be generated and provided via one or more outlets 150 according to step f).

(17) As schematically depicted in FIG. 1A, the mixing chamber 120 may, in this particularly preferred embodiment, be identical with the patient interface 114 which, thus, comprises the outlets 150 for directly or indirectly administering the enriched respiratory gases 142. Herein, additional parts (not depicted here) may, in general, be introduced between the patient interface 114 and the respiratory tracks of the patient. In this particular embodiment, the patient interface 114 may, preferably, be comprise a further outlet 144, the further outlet 144 being configured for outputting exhaled gases as received from the patient.

(18) In an alternative embodiment (not depicted here), the patient interface 114 may be attached in form of a separate unit to the outlets 150 of the mixing chamber 120. Also here, additional parts may, in general, be introduced between the mixing chamber 120 and the patient interface 114 and/or between the patient interface 114 and the respiratory tracks of the patient.

(19) Considering that the first gas flow 118 assumes a third temperature T.sub.3 at the first outlet 146 of the first tube 116 and the second gas flow 126 assumes a fourth temperature T.sub.4 at the second outlet 148 of the second tube 124, the first gas flow 118 and the second gas flow 126 are mixed, preferably, in the mixing chamber 120 at a common temperature T.sub.c. In a particularly preferred embodiment, the common temperature T.sub.c may equal both the third temperature T.sub.3 and the fourth temperature T.sub.4 but, due to cooling of both the first gas flow 118 and the second gas flow 126 along their respective tubes 116, 124, the common temperature T.sub.c may be lower than both the first temperature T.sub.1 at the first inlet 12 of the first tube 116 and the second temperature T.sub.2 at the second inlet 130 of the second tube 124.

(20) In addition to the adjustment of the temperatures as described herein, the first gas flow 118 and the second gas flow 126 may, most preferred, be mixed in accordance with step e) at 100% relative humidity of all participating gas glows 118, 126. In order to arrive at this particularly preferred embodiment, the thermally balancing of both the first gas flow 118 and the second gas flow 126 according to step d) may be applied in the manner that the humidity and the common temperature T.sub.c in the mixing chamber 120 may assume the mentioned values.

(21) As indicated above, this particularly preferred embodiment may ensure that practically no accumulation of powdered material may occur, thus, avoiding a blockage of a tube or of an airway in the respiratory tract. In order to further improve this advantage of the present invention, the thermally balancing of both the first gas flow 118 and the second gas flow 126 according to step d) can, additionally, be applied in a manner that the common temperature T.sub.c may be adjusted to a breath temperature T.sub.b, wherein the breath temperature T.sub.b may be determined for a breath of a patient who is at least partially ventilated via the patient interface 114. In this regard, a thermometer or a thermocouple may be used for determining the breath temperature T.sub.b. In this further improved embodiment any differences between the temperature of the breath of the actually ventilated patient and the temperature of the flow of the enriched respiratory gases 142 may disappear, thus, further contributing to avoiding a deposition in the patient interface 114.

(22) As illustrated in FIGS. 2A and 2B, the exemplary device 110 may further comprise a first humidifier 152 configured to humidify a dry aerosol 154 and a second humidifier 156 configured to humidify dry respiratory gases 158. As already mentioned above, the term “dry” with respect to the dry aerosol 154 and the dry respiratory gases 158 refers to a condition of the aerosol and the respiratory gases which may comprise less than 100% relative humidity, thus, allowing the aerosol and the respiratory gases to be at least further humidified. Preferably, the dry aerosol 154 may be humidified prior to step a) and, subsequently, be guided as the humidified aerosol 112 to the first inlet 122 of the first tube 116 as shown in FIG. 1A. Similarly, the respiratory gases 158 may, preferably, be humidified prior to step b) and, subsequently, be guided as the humidified respiratory gases 128 to the second inlet 130 of the second tube 124 as further shown in FIG. 1A.

(23) In the particular embodiments as depicted in FIGS. 2A and 2B, both the first humidifier 152 and the second humidifier 156 have been chosen in an arrangement as proposed in WO 2015/132172 A1. Accordingly, the humidifiers 152, 156 may each have a water compartment 160 comprising water which may be designated for humidifying the dry aerosol 154 or the dry respiratory gases 158, respectively. For further details, reference may be made to WO 2015/132172 A1, which is incorporated here by reference. However, other kinds of humidifiers and alternative arrangements may also be feasible.

(24) FIGS. 3A and 3B provide a comparison between cross sections of airways 162 comprised by a nasal prong 164 which is designed for being used as the patient interface 114 in respiratory support of preterm infants.

(25) As shown in FIG. 3A, administering the humidified aerosol 112 to the patient interface 114 of the infant in accordance with the state of the art without application of the method and the device 110 according to the present invention, a considerable degree of unwanted powdered material deposition 166 may lead to a blockage of the airways 162 of the nasal prong 164. As illustrated here, this effect may, especially, be dangerous since it may lead to a high risk of suffocation of the infant.

(26) In contrast hereto, practically no depositions can be observed when the dry aerosol 154 is humidified by applying the method and the device 110 for administering the humidified aerosol 112 to the patient interface 114 of the infant according to the present invention. Consequently, the method and the device 110 according to the present invention can effectively be applied even in this sophisticated case in order to avoid an at least partial redrying of the humidified aerosol 112 on its path to the patient interface 114.

LIST OF REFERENCE NUMBERS

(27) 110 device 112 humidified aerosol 114 patient interface 116 first tube 118 first gas flow 120 mixing chamber 122 first inlet 124 second tube 126 second gas flow 128 humidified respiratory gases 130 second inlet 132 third tube 134 liquid flow 136 thermally balancing liquid 138 inlet 140 outlet 142 enriched respiratory gases 144 further outlet 146 first outlet 148 second outlet 150 outlets 152 first humidifier 154 dry aerosol 156 second humidifier 158 dry respiratory gases 160 water compartment 162 airway 164 nasal prong 166 deposition