Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M1/00—Suction or pumping devices for medical purposes; Devices for carrying-off, for treatment of, or for carrying-over, body-liquids; Drainage systems
  • A61M1/14—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis
  • A61M1/16—Dialysis systems; Artificial kidneys; Blood oxygenators ; Reciprocating systems for treatment of body fluids, e.g. single needle systems for hemofiltration or pheresis with membranes
  • A61M1/1698—Blood oxygenators with or without heat-exchangers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2205/00—General characteristics of the apparatus
  • A61M2205/33—Controlling, regulating or measuring
  • A61M2205/3331—Pressure; Flow
  • A61M2205/3334—Measuring or controlling the flow rate
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M2240/00—Specially adapted for neonatal use

Definitions

• Extracorporeal support has been proposed both for adults and neonates.
• Such systems utilize an oxygenator to exchange oxygen and carbon dioxide with blood from the patient’s body.
• a method of oxygenating neonatal blood can include receiving deoxygenated arterial blood from an umbilical cord of a neonate within a pumpless extracorporeal circuit.
• the extracorporeal circuit can include a membrane oxygenator.
• the deoxygenated arterial blood can have a blood-flow rate RF.
• the method can include flowing a blended sweep gas through the membrane oxygenator at a blended sweep gas flow rate of at least 2RF or greater.
• the blended sweep gas can comprise oxygen and at least about 1% carbon dioxide by volume.
• the method can include receiving with a gas blender, a first gas from a first source and a second gas from a second source, the first gas different from the second gas, and blending the first gas and the second gas to form the blended sweep gas.
• the first source can be a first gas tank and the second source can be a second gas tank.
• the first source can be a wall line and the second source can be at least one of a second wall line and a gas tank.
• a pumpless oxygenation circuit can include a mixer adapted configured to receive oxygen-containing gas from an oxygen source, receive carbon-dioxide-containing gas from a carbon-dioxide source, output a blended sweep gas comprising oxygen and at least about 1% carbon dioxide by volume.
• the pumpless oxygenation circuit can include a flow controller, a membrane oxygenator, and a blood-flow sensor.
• the flow controller can be fluidically coupled to the output of the mixer, the flow controller adapted to permit a blended sweep gas flow rate of the blended sweep gas through the flow controller.
• the membrane oxygenator can be adapted for connecting to the flow controller and a pumpless neonatal blood circuit.
• the blood-flow sensor can be positioned along the pumpless neonatal blood circuit, the blood-flow sensor adapted and configured to measure a neonatal -blood-flow rate RF.
• the flow controller can control the blended sweep gas flow rate to be at least 2RF or greater.
• the pumpless oxygenation circuit can include a controller communicatively coupled with the flow controller and the blood-flow sensor.
• the pumpless oxygenation circuit can include a blood-gas sensor positioned along the pumpless neonatal blood circuit, the bloodgas sensor communicatively coupled to the controller.
• the controller can control the mixer to titrate a composition of the blended sweep gas to reflect neonatal blood-gas values and provide a sufficient partial pressure of carbon dioxide to maintain normocapnia.
• the blended sweep gas flow rate can be between about 2RF and about 20RF.
• the blended sweep gas flow rate can be between about 2RF and about 16RF.
• the blended sweep gas flow rate can be between about 120 mL/minute and about 800 mL/minute.
• the blended sweep gas can include between about 3% and about 6% carbon dioxide by volume.
• FIG. 1 illustrates a schematic of an extracorporeal support system according to an aspect of the disclosure.
• FIG. 6 illustrates an isometric view of a gas exchanger according to another aspect of the disclosure.
• a system 10 is configured to provide extracorporeal support to a neonate.
• the system 10 may be configured to provide a system environment that is similar to an environment the neonate would experience in utero. Viability of a neonate that is removed from the uterine environment (e.g., due to preterm birth) and that is, for example, between about 22 weeks to about 28 weeks gestation, may be increased by placing the neonate in the system environment.
• the oxygenation circuit 400 may include an oxygenator 500 (shown in FIG. 1 as an extracorporeal membrane oxygenation (ECMO)) for providing gas exchange functionality, particularly of oxygen (to) and carbon dioxide (from), to the neonate 5.
• ECMO extracorporeal membrane oxygenation
• One oxygenator contemplated for use is described in PCT application number filed September 14, 2022 titled “Oxygenating and Neonatal Extracorporeal Support Devices and Systems” the disclosure of which is hereby incorporated by reference as if set forth in its entirety herein.
• the oxygenator 500 can be removably connected to the neonate 5 and, optionally, to other components of the oxygenation circuit 400 and the system 10.
• the oxygenator 500 is connected with the neonate 5 via two or more fluid lines and includes at least a drain line 440 and an inlet line 445.
• the system 10 can include a medication supply line 114 that introduces medication into the neonate blood in the drain line 440.
• a sensor 120 can analyze blood flow through the drain line. The sensor 120 can also perform a gas analysis on the sweep gas returning to the oxygenator 500 in the drain line 440.
• the medication supply line 114 can also introduce medication into the neonate blood in the inlet line 445. Medication can also be introduced into the oxygenator 500 though the medication supply line 114.
• the blood then flows through the oxygenator 500 and returns to the neonate 5 via the inlet line 445.
• the oxygenation level of the blood that flows out of the oxygenator and in through the inlet line 445 are substantially equivalent.
• the oxygenation level of the blood is measured using a gas analyzer 110, such as a ML206 Gas Analyzer from AD Instruments, which uses an infrared sensor and an optical or visible spectrum absorption to measure the levels of CO2 and O2 in the blood, respectively.
• a first gas analyzer 110 can analyze sweep gas flowing to the oxygenator 500.
• a second gas analyzer 110 can analyze oxygenation levels in the blood.
• a sampler 112 can sample flow rate of the sweep gas. In this or other embodiments, the sampling pump flow rate ranges from about 35 to about 200 milliliter per minute (ml/min).
• the remaining gas within the blood comprises nitrogen (N2).
• Housing 502 has an interior volume to house the gas exchanger 550.
• multiple blood inlet ports 504 may be configured to receive, either altematingly or simultaneously, blood from the neonate 5.
• the blood inlet port 504 is connected to drain line 440, through which the blood moves from the neonate 5 to the oxygenator 500.
• the blood outlet port 508 is connected to the inlet line 445, through which the blood moves from the oxygenator 500 to the neonate 5.
• the number of blood outlet ports 508 may be equal to the number of blood inlet ports 504, or it may be different.
• One or more additional ports may be disposed on or adjacent to the blood outlet port 508 or in-line with the inlet line 445.
• the pressure transducer 528 can measure the pressure of the blood exiting the oxygenator 500.
• a sampling port (not shown) may also be disposed on or adjacent to the blood outlet port 508 or the inlet line 445 to allow for a portion of the blood exiting the oxygenator 500 to be removed from the oxygenation circuit 400 to be analyzed or tested.
• the sampling port at the exit of the oxygenator 500 may also be used to inject or infuse medicine or nutrition directly into the blood.
• the one or more additional ports may have any suitable connection means, such as a Luer connector.
• the flow rate is adjusted from entry at 524 to exit at 528 by partially closing the caliber of the tubing (or reducing the diameter of the tubing) to increase the resistance to slow the flow therethrough.
• the resistance of oxygenator inherently controls the gas flow.
• the neonate can regulate the gas flow by increasing heart rate.
• the flow rate can be sensed via a sensor.
• the sensor is a pressure sensor.
• the sensor is a velocity flow sensor, volumetric flow meter, or mass flow meter.
• a gas exhaust port 516 is disposed on the housing 502 for emitting the sweep gas from the oxygenator 500.
• An additional port (not shown) may be disposed on or adjacent to the gas exhaust port 516, and a portion of the sweep gas exiting the oxygenator 500 may be removed for analysis or testing.
• the additional port may have any suitable connection means, such as a Luer connector.
• the oxygenation circuit 400 is configured such that the blood moves therethrough without actuation from an external pump (e.g., a mechanical pump). Instead, blood is circulated through the drain line 440, the oxygenator 500, the inlet line 445, and any other components by the neonate’s heart. That is, the oxygenation circuit 400 is a passive or a pumpless circuit.
• the priming volume of the oxygenator 500 may be lessrange from about 20 mL to about 200 mL, or from about 30 mL to about 100 mL, or from about 40 mL to about 85 mL or from about 50 mL to about 75mL. than about 200 100 mL, less than about 85 mL, less than about 75 mL, less than about 50 mL, less than about 40 mL, or less than about 30 mL. In some aspects, it may be preferable to have a priming volume between aboutranging from about 20 mL and to about 50 mL or between from about 20 mL and to about 40 mL or from about 25 mL to about 30mL.
• the desired temperature can range from about 36 degrees Celsius to about 39 degrees Celsius.
• a heating element 600 is neither needed nor desired within the oxygenator 500. Excluding the heating element 600 from the oxygenator 500 allows the oxygenator 500 to be smaller, require fewer fibers 554, impose less blood-flow resistance, and require a smaller amount of priming material to operate. It is important to note that an oxygenator within an extracorporeal circuit generally requires a heating element to maintain the desired temperature of the blood traveling therethrough. Failure to do this may result in damage to the blood, shock to the patient, or other health hazards.
• decreasing the total size and volume of the oxygenator 500 also decreases the transit time of the blood as it moves through the oxygenator 500. Increased transit time may lead to thrombosis and clot formation, and decreasing the size of the oxygenator 500 decreases the transit time of the blood flowing therethrough, reducing the chance of clot formation.
• the blood flow rate through the oxygenator 500 may depend on the age and size of the neonate 5. For example, in some aspects, a neonate weighing approximately 500 grams would have a flow rate ranging from about 40 mL/min to about 60 mL/min. In some aspects, a 24-week-old neonate may have a flow rate ranging from about 60 mL/min to about 90 mL/min. The flow rate may be higher in a more developed and larger neonate and will depend, in part, on the weight of the neonate. Suitable flow rates may range from about 75 mL/kg/min to about 175 mL/kg/min.
• a controller 1012 and flow controller 1004 is in electrical communication with a controller 1012 and flow controller 1004 to adjust the amount(s) of O2, N2, CO2, and other components within the sweep gas via the gas blender 1002, optionally separating out the excess amount of CO2 using the CO2 separator, and providing the oxygenated blood to the neonate 5 in the neonatal chamber 100.
• the neonatal blood flow can be measured in real-time or periodically.
• the neonatal blood flow can be measured using a flow sensor 1006 such as an ultrasonic flow sensor that can, e.g., be clamped-on a component of the blood-flow circuit such as tubing.
• Suitable sensors 1006 are available from Spectrum Medical of Gloucester, United Kingdom.
• the sweep gas contains an elevated proportion of carbon dioxide relative to that typically used in extracorporeal support, thereby maintaining normocapnia.
• the composition of sweep gas can be adjusted by changing the CO2 level of the sweep gas to achieve the desired maintain normocapnia.
• the initial CO2 level of the sweep gas can initially be equal to a desired CO2 level in the neonatal blood.
• the CO2 level of the sweep gas can then be adjusted based on detected CO2 levels in the neonatal blood.
• a sweep gas contains from about 1% to about 6% CO2 by volume based upon 100%, more preferably from about 3% to about 6% CO2 by volume, e.g., from about 3.0% to about 3.5%, from about 3.5% to about 4.0%, from about 4.0% to about 4.5%, from about 4.5% to about 5.0%, from about 5.0% to about 5.5%, from about 5.5% to about 6.0%, and the like.
• percentages of CO2 in the sweep gas according to embodiments of the invention are two orders of magnitude greater than typically used in extracorporeal support, which typically blend pure oxygen with medical air.
• atmospheric dry air contains 0.04% CO2.
• the sweep gas contains from about 0% to about 10%, about 10% to about 20%, about 20% to about 30%, about 30% to about 40%, or about 40% to about 50% O2.
• the particular sweep gas flow rate and CO2 composition can be adjusted based on the fiber surface area, transmissivity, and other properties of the oxygenator 500 and/or sensor readings (e.g., blood sensors 1006 and/or sweep-gas sensors as described and depicted in the context of FIGS. 1-8) to achieve and maintain desired blood oxygen and carbon dioxide levels.
• a controller 1012 can be communicatively coupled to each sensor (e.g., 1006) and gas blender 1002 and flow controller 1004.
• the principles of how to use feedback e.g., from blood oxygen and carbon dioxide sensors
• the concentration of CO2 in the sweep gas entering the oxygenator 500 may change over time (e.g., by feedback or by a non- feedback-based model) to reflect “wear” of an oxygenator, growth of the neonate, and the like.

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• Health & Medical Sciences (AREA)
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• 2022
  • 2022-09-14 EP EP22785871.9A patent/EP4587076A1/de active Pending
  • 2022-09-14 WO PCT/US2022/043509 patent/WO2024058775A1/en not_active Ceased
  • 2022-09-14 AU AU2022478491A patent/AU2022478491A1/en active Pending
  • 2022-09-14 CA CA3267672A patent/CA3267672A1/en active Pending
  • 2022-09-14 JP JP2025515684A patent/JP2025529469A/ja active Pending

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