ASSEMBLY FOR TRACHEAL INSTILLATION OF FLUID MEDICAMENTS IN INFANTS SUPPORTED BY NON-INVASIVE VENTILATION

Abstract

This assembly for tracheal instillation of fluid medicaments, particularly in preterm infants supported by non-invasive ventilation, comprises a microcatheter, a guidewire and a gripper. The microcatheter consists of a very small gauge soft composite tube with a proximal connector and a distal rounded tip. Three circumferential color-coded bands near the rounded tip and a scale in one-centimeter increments on the soft composite tube guide the insertion depth positioning of the rounded tip under direct laryngoscopy. The slidably receptive guidewire within the central lumen of the microcatheter stiffens the soft composite tube for introduction and restores softness thereto after removal. Additionally, the guidewire is locked to the microcatheter during the introduction into the trachea to avoid injury. A gripper attached to the soft composite tube improves manipulation as well as estimated insertion depth control. Once the guidewire is removed, the fluid agent (e.g. surfactant) is slowly instilled into the neonatal trachea.

Claims

1. An assembly (1) for the instillation of one or more fluid medicaments into the trachea (T) of a person while spontaneous breathing is allowed, particularly the person being a newborn or premature infant M supported by CPAP (C) and receiving pulmonary surfactant (S), the assembly (1) comprising: a microcatheter (2), the microcatheter (2) consisting of a rigid connector (8) and a soft composite tube (3) with proximal and distal ends and a central lumen open at the proximal and distal ends, the soft composite tube (3) being characterized by straight, uniform outer diameter (11) not exceeding 1 mm (≤3 Fr), allowing for optimal CPAP (C) transmission in the newborn (P), the distal end terminating in a coextruded rounded tip (9), avoiding airway injury and detachment of foreign bodies during introduction of the microcatheter (2) into the trachea (T), the coextruded rounded tip (9) bearing a central end-hole (10), the central end-hole (10) being in fluid communication with the central lumen, a sequence of color-coded circumferential bands (14-16) near the coextruded rounded tip (9), ensuring positioning of the coextruded rounded tip (9) at the optimum height (H) inside the trachea (T) under direct laryngoscopy (19), sized and arranged according to different body weights of the newborn (P), and a scale in one-centimeter increments (13) along the surface; a guidewire (4), the guidewire (4) characterized by being stiff-flexible and slidably receptive into the microcatheter (2), to stiffen the soft composite tube (3) during introduction of the microcatheter (2) into the trachea (T) and restore softness thereto after removal, having proximal and distal ends and length relative to the microcatheter (2), the proximal end being welded to a threaded plastic cap (5), and the distal end being rounded; and a gripper (17), the gripper (17) being characterized by the reversible attachment to any point of the soft composite tube (3) of the microcatheter (2), when stiffened internally by the guidewire (4), through a longitudinal medial groove (20) on its rear, the longitudinal medial groove (20) being sized to engage within it a portion of the soft composite tube (3).

2. The assembly (1) as in claim 1, wherein the connector (8) being hollow, made of clear rigid material and with proximal and distal ends, the proximal end being configured to allow connection of the threaded plastic cap (5) and of a means (23) for instillation of pulmonary surfactant (S) and other fluid medicaments, the distal end being welded to the proximal end of the soft composite tube (3) and in fluid communication with the central lumen of the soft composite tube (3).

3. The assembly (1) as in claim 1, wherein the sequence of color-coded circumferential bands (14-16) on the soft composite tube (3) comprising: a first color-coded circumferential band (14), the first color-coded circumferential band (14) ensuring the position of the coextruded rounded tip (9) at the optimum height (H) within the trachea (T) for newborn (P) weighing ≤1 kg, characterized by being preferably of bright purple and extending 1.8 cm proximally along the surface of the composite tube soft (3) from the central end hole (10) of the coextruded rounded tip (9); a second color-coded circumferential band (15), the second color-coded circumferential band (15) ensuring the position of the coextruded rounded tip (9) at the optimum height (H) within the trachea (T) for newborn (P) weighing between 1 kg and 2 kg, characterized by being preferably of bright yellow and extending 0.5 cm proximally along the surface of the composite tube soft (3) from the proximal edge of the first color-coded circumferential band (14); and a third color-coded circumferential band (16), the third color-coded circumferential band (16) ensuring the position of the coextruded rounded tip (9) at the optimum height (H) within the trachea (T) for newborn (P) weighing ≥3 kg, characterized by being preferably of bright red and extending 0.5 cm proximally along the surface of the composite tube soft (3) from the proximal edge of the second color-coded circumferential band (15).

4. (canceled)

5. (canceled)

6. The assembly (1) as in claim 1, wherein the soft composite tube (3) having the outer diameter (11) preferably 0.8 mm (2.4 Fr), to allow optimal CPAP (C) transmission in the very and extremely low birth weight newborn (P), and wherein the sequence of color-coded circumferential bands (14-16) being colored with complementary colors.

7. The assembly (1) as in claim 1, wherein the walls of the soft composite tube (3) of the microcateter (2) are clear or blue colored, to improve visualization during the introduction of the microcatheter (2) into the trachea (T) under direct laryngoscopy (19).

8. The assembly (1) as in claim 1, wherein the guidewire (4) having straight, uniform outer diameter not exceeding 0.7 mm (≤2.1 Fr), preferably 0.53 mm (1.6 Fr), and wherein the locking (6) of the guidewire (4) to the connector (8), obtained by screwing the threaded plastic cap (5) around the proximal end of the connector (8), and the rounded distal end of the guidewire (4) preventing airway injury and ruptures of the soft composite tube (3) during the introduction of the microcatheter (2) into the trachea (T).

9. The assembly (1) as in claim 1, wherein the guidewire (4) being made of rigid material, preferably metal such as tungsten or nitinol, to facilitate the introduction of the microcatheter (2) into the trachea (T), and wherein the removal of the guidewire (4) avoiding anatomical distortion of the trachea (T) during the instillation of pulmonary surfactant (S) and other fluid medicaments into the trachea (T) by restoring softness to the soft composite tube (3), and further wherein being colored, preferably of blue, if the walls of the soft composite tube (3) are clear, to improve visualization during the introduction of the microcatheter (2) into the trachea (T) under direct laryngoscopy (19).

10. The assembly (1) as in claim 1, wherein the guidewire (4) being coated with a thin biocompatible silicone film, preferably during manufacturing, to prevent the walls of the soft composite tube (3) from kinking during its removal from the microcatheter (2).

11. The assembly (1) as in claim 1, wherein the attachment of the gripper (17) on the soft composite tube (3) facilitates handling of the microcatheter (2) during the introduction the microcatheter (2) into the trachea (T) under direct laryngoscopy (19).

12. The assembly (1) as in claim 1, wherein the attachment of the gripper (17) on the soft composite tube (3), using the scale in one-centimeter increments (13) as a reference, allowing the operator to maintain constant control of the estimated insertion depth (18) during the introduction of the microcatheter (2) into the trachea (T) under direct laryngoscopy (19).

13. The assembly (1) as in claim 1, wherein the gripper (17) being preferably made of semi-hard rubber.

14. The assembly (1) as in claim 1, wherein the soft composite tube (3) being made of biocompatible material, preferably polyurethane, or polyvinyl chloride, or high-density polyethylene or flexible polyamide without plasticizer, and wherein being between 15 and 25 cm in length.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0049] The foregoing aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawings, wherein:

[0050] FIG. 1 is an elevation view illustrating the features of the assembly of the present invention prepared for introduction into the infant's trachea. The gripper is shown attached to the soft composite tube of the microcatheter at a distance between its distal edge and the rounded tip corresponding to 6 centimeters plus the weight (expressed in kilograms) of the infant who will receive PS via the LISA method. The guidewire is shown within the central lumen of the microcatheter to stiffen the soft composite tube for introduction of the assembly into the infant's trachea and is visible throughout the length of the clear wall of the microcatheter. The threaded plastic cap welded to the proximal end of the guidewire is screwed around the proximal connector of the microcatheter to secure the guidewire for safe introduction. Also shown are three circumferential color-coded bands on the surface of the soft composite tube near the rounded tip, the scale in one-centimeter increments on the surface of the soft composite tube, the outer diameter of the soft composite tube and the inner diameter of the central lumen/end hole at the rounded tip;

[0051] FIG. 2 FIG. 2 is an elevation view, similar to FIG. 1, illustrating the guidewire partially withdrawn from the central lumen of the microcatheter once the threaded plastic cap has been unscrewed from the proximal connector of the microcatheter by unlocking the guidewire therefrom;

[0052] FIG. 3 is a perspective view of the distal portion of the soft composite tube of the microcatheter with the guidewire inserted within its central lumen, illustrating the sequence of three color-coded circumferential bands used for positioning the rounded tip of the microcatheter within the tracheal lumen. These bands are located near the rounded tip having a central end hole, sized according to three different weights (from s 1 kilogram to z 3 kilograms) and arranged from the smallest to the largest weight starting from the central end hole of the rounded tip and extending proximally along the soft composite tube;

[0053] FIG. 4 is an elevation view of the rear of the gripper illustrating the longitudinal medial groove for the attachment to any point of the soft composite tube of the microcatheter;

[0054] FIG. 5 is an elevation view of the rear part of the gripper showing a section of the soft composite tube of the microcatheter, internally stiffened by the guidewire, housed within the longitudinal medial groove of the gripper;

[0055] FIG. 6 is a cross-sectional view of the upper airway and esophagus of an autonomously breathing infant with NRDS supported by CPAP via a nasal interface applied to the nostrils. The optimal height within the tracheal lumen for positioning of the rounded tip of the soft composite tube of the microcatheter for effective PS delivery, avoiding asymmetric distribution into the bronchial tree and esophageal spillage is shown;

[0056] FIG. 7 is a cross-sectional view of the same infant of FIG. 6, after a laryngoscope has been placed into his/her mouth, illustrating the rounded tip of the soft composite tube of the microcatheter, as shown in FIG. 1, reaching the correct position within the tracheal lumen for effective PS administration;

[0057] FIG. 8 is a cross-sectional view of the same infant of FIG. 7, after the laryngoscope has been removed from his/her mouth, illustrating the soft composite tube of the microcatheter, as shown in FIG. 2, adapting to the infant's airway as the guidewire is withdrawn from the microcatheter;

[0058] FIG. 9 is a cross-sectional view of the same infant of FIG. 7 after removal of the guidewire from the microcatheter, as shown in FIG. 8, has been fully carried out, illustrating a syringe filled with the prescribed amount of PS connected to the microcatheter for slow tracheal instillation through the central lumen according to the LISA method.

DETAILED DESCRIPTION OF THE INVENTION

[0059] The invention provides, among other things, an assembly for easily and quickly instilling one or more fluid medicaments into a conduit of a person supported by NIV modalities, in particular into the trachea of a newborn or preterm infant supported by nasal CPAP while spontaneous breathing is allowed. In the following, the invention will be more particularly described in the case of the tracheal instillation of PS preferably in very and extremely low birth weight infant. However, this is not limiting as the assembly can be used for instilling other types of fluid medicaments and/or be used for adults.

[0060] In this section, we shall explain this invention with reference to the appended drawings. Moreover, in the following description, “proximal” will denote a part that is located near the operator when the latter uses the assembly of the invention, while “distal” will denote a part that is away from the operator during this use.

[0061] Referring herein mainly to FIG. 1-2 until otherwise indicated, the assembly 1 of this disclosure comprises a microcatheter 2, a guidewire 4 and a gripper 17.

[0062] The microcatheter 2 consists of a soft composite tube 3 of straight, uniform and very small gauge (outer diameter 11≤1 mm), with transparent walls, having a proximal and a distal end and a central lumen open at the proximal and distal ends. The proximal end of the soft composite tube 3 is provided with a proximal connector 8 in fluid communication with the central lumen of the soft composite tube 3. The proximal connector 8 is configured to cooperate with the tip of a syringe comprising PS, as shown in FIG. 9, and to allow connection of a threaded plastic cap 5, as shown in FIG. 1 and FIG. 7. The proximal connector 8 can be of the Luer, Luer Lock type or any connector conforming to the standards in force. Suitable material for the proximal connector 8 is preferably clear rigid plastic. The distal end of the soft composite tube 3 ends in a rounded tip 9 having a central end hole 11, which has an inner diameter 12 not exceeding 0.7 mm. The rounded tip 9 is coextruded with the distal end of the soft composite tube 3 and the central end hole 10 is in fluid communication with the distal end of the central lumen of the soft composite tube 3. Suitable biocompatible materials for the soft composite tube 3 include polyurethane, polyvinyl chloride, high-density polyethylene and flexible polyamide without plasticizer.

[0063] Due to its very small gauge, the soft composite tube 3 of the microcatheter 2 ensures the optimal airway patency for CPAP C transmission with minimal increase in airway resistance, thus lowering the respiratory workload during the LISA procedure, particularly in very and extremely low birth weight infant, as shown in FIG. 7-9. The coextruded rounded tip 9 of the soft composite tube 3 of the microcatheter 2 prevents airway injury and eliminates the risk of its detachment into the trachea during the introduction of the assembly 1, respectively. Moreover, once the guidewire 4 is removed from the microcatheter 2, the soft composite tube 3 adapts to the infant's airway avoiding significant anatomical distortions during PS instillation, thus increasing tolerability for the procedure, as shown in FIG. 8 and FIG. 9.

[0064] The guidewire 4 has a straight, uniform and very small gauge with an outer diameter ≤0.7 mm, a proximal and a distal end and a length relative to the microcatheter 2. The guidewire 4 is stiff-flexible and slidably receptive into the central lumen of the microcatheter 2. The proximal end of the guidewire 4 is welded to a threaded plastic cap 5 and the distal end has a rounded shape. The threaded plastic cap can be screwed around the proximal connector 8 of the microcatheter 2, as shown in FIG. 1 and in FIG. 7, or unscrewed therefrom, as shown in FIG. 2 and in FIG. 8. By screwing the threaded plastic cap 5 around the proximal connector 8 of the microcatheter 2 the guidewire 4 is locked 6 for safe introduction. The guidewire 4 is preferably of blue color to improve visualization of the assembly 1 under direct laryngoscopy 19, as shown in FIG. 7. The most suitable material for guidewire 4 is metal, especially tungsten or nitinol.

[0065] The guidewire 4 stiffens the soft composite tube 3 of the microcatheter 2 for easy and quick introduction of the assembly 1 into the infant's trachea without the need for additional aids, even in very and extremely low birth weight infant, avoiding significantly kinking and/or bending. Due to its small gauge, the guidewire 4 is also enough flexible to avoid airway injury during the introduction. The operator can also shape the assembly 1 by bending it distally in the most difficult cases, exploiting the rigidity of the guidewire 4. The locking 6 of the guidewire 4 to the proximal connector 8 of the microcatheter 2 prevents the distal end from coming out of the central end hole 10 of the rounded tip 9 during the introduction of the assembly 1 into the infant's airway under direct laryngoscopy 19, as shown in FIG. 7, further avoiding potential airway injury. Moreover, the rounded shape of the distal end of the guidewire 4 prevents potential ruptures of the thin-walled soft composite tube 3.

[0066] FIG. 4 shows the rear part of the gripper 17, preferably of semi-hard rubber, with the longitudinal medial groove 20 suitable for hooking a portion of the soft composite tube 3 when internally stiffened by the guidewire 4. The gripper 17 can be attached in a reversible way to any point of the soft composite tube 3 of the microcatheter 2 by pressing a portion of the soft composite tube 3 against the longitudinal medial groove 20 until completely seated inside, as more clearly shown in FIG. 5. In fixing the gripper 17 on the soft composite tube 3, care should be taken in placing the distal edge 21 of the gripper 17 at a distance 18 from the rounded tip 9 equal to 6 cm plus the infant's weight (expressed in kilograms), using the scale 13 in one-centimeter increments of the soft composite tube 3 as a reference, as shown in FIG. 1-2. If this is adhered to, it will prevent the rounded tip 9 of the soft composite tube 3 of the microcatheter 2 from being inserted too distally into the infant's airway, because the gripper 17 stops any further advancement of the assembly 1 once reached the labial commissure of the mouth M of the infant P, as shown in FIG. 7-9. Similarly, a deficit of insertion should always be considered and ruled out when the distal edge 21 of the gripper 17 is positioned too far from the infant's mouth after the introduction of the microcatheter 2 into the infant's trachea. If necessary, adjustments of the insertion depth of the rounded tip 9 can be performed using the scale 13 in one-centimeter increments on the surface of the soft composite tube 3 as a reference.

[0067] The gripper 17 provides also a valid reference device on the soft composite tube 3 of the microcatheter 2 that helps the operator not to lose the control of the estimated insertion depth 18 of the rounded tip 9 while introducing the assembly 1 into the infant's airway under direct laryngoscopy 19, as well as facilitating the manipulation of the microcatheter 2.

[0068] FIG. 3 illustrates, with more detail respect to FIG. 1-2, 7-9, the sequence of the circumferential color-coded bands (preferably three) 14 15 16 on the distal portion of the soft composite tube 3 for determining the insertion depth of the rounded tip 9 under direct laryngoscopy. These bands 14 15 16 are sized according to three different weights (from ≤1 kilogram to ≥3 kilograms) and arranged from the smallest to the largest weight starting from the central end hole 10 of the rounded tip 9 and extending proximally on the soft composite tube 3.

[0069] The color choice and arrangement of the three circumferential color-coded bands 14 15 16 depend on their optimal visibility under direct laryngoscopy 19, as shown in FIG. 7, due to the mutual improvement of brightness of the complementary colors by proximity. The circumferential color-coded bands 14 15 16 aim to ensure the correct placement of the rounded tip 9 at the optimal height H within the tracheal lumen T, which prevents asymmetrical administration of PS into the tracheobronchial tree B (due to a deep positioning) and esophageal spillage E (due to a high positioning), as shown in FIG. 6-9. The sizes of the three circumferential color-coded bands 14 15 16 shown in FIG. 1-3, 7-9 are borrowed from the distal markers of the commonly used neonatal tracheal tubes that are available for different weights (from s 1 kilogram to Z 3 kilograms). Proceeding proximally from the rounded tip 9 on the soft composite tube 3 of the microcatheter 2, the arrangement of the circumferential color-coded bands 14 15 16 follows this order:

[0070] the first circumferential color-coded band 14, preferably of bright purple, extends 1.8 cm proximally along the surface of the composite tube soft 3 from the central end hole 10 of the rounded tip 9, representing the optimal insertion depth H inside the tracheal lumen T below the laryngeal vocal cords V for an infant weighing 1,000 grams or less, as shown in FIG. 6-9;

[0071] the second circumferential color-coded band 15, preferably of bright yellow, extends 0.5 cm proximally along the surface of the composite tube soft 3 from the proximal edge of the first circumferential color-coded band 14, representing the optimal insertion depth H inside the tracheal lumen T below the laryngeal vocal cords V for an infant weighing between 1,000 to 2,000 grams, as shown in FIG. 6-9;

[0072] the third circumferential color-coded band 16, preferably of bright red, extends 0.5 cm proximally along the surface of the composite tube soft 3 from the proximal edge of the second circumferential color-coded band 15, representing the optimal insertion depth H inside of the tracheal lumen T below the laryngeal vocal cords V for an infant weighing 3,000 grams or more, as shown in FIG. 6-9.

[0073] Herein it is briefly described the LISA method performed with the assembly 1 of this disclosure.

[0074] FIG. 6 illustrates a spontaneously breathing infant P of 1 kilogram supported by CPAP C through an interface I applied to the nostrils N who will receive PS via the LISA method to treat NRDS. Anatomical landmarks as vocal cords V, main bronchial tree B, esophagus E and optimal height H within the tracheal lumen T where the distal tip of the device used should be positioned for effective PS delivery are shown.

[0075] The assembly 1 of this disclosure is prepared for introduction into the infant's airway by inserting the guidewire 4 into the proximal connector 8 and sliding it into the central lumen of the microcatheter 2 until the threaded plastic cap 5 meets the proximal connector 8. At this point, the operator screws it 5 around proximal connector 8 to lock 6 the guidewire 4 for safe introduction of the assembly 1, as shown in FIG. 1. Thereafter, the operator attaches the gripper 17 to the microcatheter 2 by pressing a portion of the soft composite tube 3 stiffened by the guidewire 4 against the longitudinal medial groove 20 on its rear until completely seated inside, as shown in FIG. 5. In doing this, the operator pays particular attention in placing the distal edge 21 of the gripper 17 at a distance 18 equal to 7 cm from the rounded tip 9 using the scale 13 in one-centimeter increments on the surface of the soft composite tube 3 as a reference, as shown in FIG. 1-2. This, among other things, will help the operator maintain control of the estimated insertion depth 18 while introducing the assembly 1 into the infant's trachea under direct laryngoscopy 19.

[0076] Referring now to FIG. 7, the operator introduces the laryngoscope blade 22 using the left-hand L into the mouth M of the same infant P of FIG. 6 to visualize the laryngeal vocal cords V under direct laryngoscopy 19 without interrupting CPAP C support applied to the nostrils N via the interface I. By grasping the assembly 1 at the gripper 17 with the right-hand R, the operator slides the rounded tip 9 of the soft composite tube 3 of the microcatheter 2 between the vocal cords V of the newborn and enters the tracheal lumen T. Once the proximal edge of the first circumferential color-coded band 14 disappears under the vocal cords V, the operator stops any further advancement of the assembly 1, as the rounded tip 9 is now positioned at the optimum height H within the tracheal lumen T that avoids both asymmetric administration into the bronchial tree B and esophageal leakage E of PS.

[0077] Referring now to FIG. 8, the operator takes off the laryngoscope blade 22 from the mouth M of the same infant P of FIG. 7 using the left-hand L, while firmly holding the gripper 17 at the labial commissure of the infant's mouth M with the right-hand R. At this point, the operator checks the position of the distal edge 21 of the gripper 17 relative to the labial commissure of the mouth M of the infant P. If necessary, a further refinement of the insertion depth of the rounded tip 9 can be now performed, based on the estimated insertion depth 18, as shown in FIG. 1-2, using the scale 13 in one-centimeter increments on the surface of the soft composite tube 3 as a reference. Once confirmed that the rounded tip 9 has been placed at the optimum height H within the tracheal lumen T to avoid either asymmetric administration B or esophageal leakage E of PS, the operator unscrews the threaded plastic cap 5 from the proximal connector 8 to unlock 7 the guidewire 4. Thereafter, the operator removes the guidewire 4 from the microcatheter 2 using the left-hand L, while still holding firmly the gripper 17 to the labial corner of the mouth M of the newborn P with the right-hand R, always without interrupting the CPAP C support applied to the nostrils N through the interface I.

[0078] Referring now to FIG. 9, the tip of a syringe 23 filled with the prescribed amount of PS heated to body temperature plus an additional 1 ml of air is connected to the proximal connector 8 of the microcatheter 2. PS is then slowly delivered S at the rounded tip 9 of the soft composite tube 3 of the microcatheter 2 within the tracheal lumen T in 1-2 minutes, while the spontaneously breathing infant P remains supported by CPAP C applied to the nostrils N through the interface I. At the end of the procedure, the microcatheter 2 is removed and the infant P remains supported by CPAP C, as shown in FIG. 6.

[0079] In the preceding detailed description, specific embodiments are described. As various modifications and changes could be made thereto without departing from the broader spirit and scope of the invention, it is intended that all matter contained in the description above or shown in the accompanying drawings should be interpreted as illustrative and not in a limiting sense.