JP4380165B2 - Extracorporeal circuit and circulator for low weight patients - Google Patents

Description

【００２９】
【発明の効果】
本発明により血液量が少ない低体重の患者に対しても、感染の危険性のある輸血や肺水腫の原因となる大量の輸液を必要としない、安全で利便性の高い体外循環が可能な体外循環用血液回路および体外循環装置を提供することが可能となった。これにより新生児等の低体重の患者の血液浄化治療がより安全に施行することが可能となった。
【図面の簡単な説明】
【図１】低容量血液回路と該回路を組み込んだ小型軽量血液循環装置の概略図。
【符号の説明】
Ｉ：血液回路の血液循環ポンプおよびカラム部分（患者の近くの場所に設置可能な部分）
１ａ：ポンプ入口のドリップチャンバー
１ｂ：カラム入口のドリップチャンバー
１ｃ：カラム出口のドリップチャンバー
２：カラム
３：血液循環ポンプ
II：血液回路の血液循環ポンプ、カラム以外の部分
（患者から離れた場所に設置可能な部分）
４：透析液循環ポンプ
５：回路内圧測定装置
６：抗凝固剤注入装置
Ａ：回路脱血側
Ｂ：回路送血側[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a medical blood circuit that can be used for extracorporeal blood circulation treatment of a low-weight patient such as a newborn baby, and an extracorporeal blood circulation apparatus for using the circuit.
[0002]
[Prior art]
Until now, various blood processing columns have been developed as medical techniques for the purpose of treatment such as dialysis, diafiltration, or immunoadsorption, and an extracorporeal circuit incorporating the same has also been developed (see Patent Document 1). As for dialyzers and the like, small columns having a membrane surface area of 0.1 square meter have been developed. However, since only a blood circuit with a capacity suitable for adults has been developed for the entire blood circuit, a large volume of fluid or blood replacement (blood transfusion) is required at the same time when used in low-weight patients with low blood volume, especially in newborns. There was a need to do. For this reason, blood for blood transfusion is required, and further, there is a risk of fever and infection due to blood transfusion, and a large amount of infusion is a major factor causing pulmonary edema (see Non-Patent Document 1).
[0003]
In addition, the blood circulation device is usually placed on the floor away from the bed because the pump device and the in-circuit pressure measurement device portion are integrated to increase the overall weight of the blood circulation device. I do not get. For this reason, the blood circuit has to be large, which has been a cause of hindering application to low-weight patients.
[0004]
There is an example of producing a low-volume blood circuit using a three-way stopcock in animal experiments, etc., but in this example there is a risk of inflow of bubbles into the body, and in order to measure the circuit internal pressure from the three-way stopcock Remains a problem that it is necessary to switch the stopcock and cannot perform continuous measurement (see Non-Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent No. 3361588 [0006]
[Non-Patent Document 1]
Harada Hideaki et al., “Examination of 4 cases of inborn errors of metabolism with blood purification”, 47th Annual Meeting of the Japan Premature Newborn Society, Japan Premature Newborn Society, 2002, 14, 3, page 240.
[0007]
[Non-Patent Document 2]
C. J. et al. RYAN et al., Br. J. et al. exp. Path "Activated Charcoal Haemoperfusion Via An Extracorporal Circuit In The Unrestricted And Unanaesthetized Rat", 1979, 60, 400.
[0008]
[Problems to be solved by the invention]
Therefore, the present invention provides a blood circuit that can be applied to a low-weight patient such as a newborn baby and the like, and a blood circuit that has a reduced volume, and is installed at a position close to the patient to form the reduced blood circuit. It is an object of the present invention to provide a blood circulation device that can be used.
[0009]
[Means for Solving the Problems]
In order to solve the above problems, the present invention has the following components.
(1) An extracorporeal circuit having a blood volume of 20 ml or less to be taken from a patient, comprising a drip chamber, an in-circuit pressure measurement unit, a column, a blood circulation pump, and an anticoagulant administration unit. Extracorporeal circuit.
(2) The extracorporeal circuit for low-weight patients according to (1), wherein the volume of the blood circuit excluding the column volume is 10 ml or less.
(3) The low weight according to (1) or (2), wherein at least one drip chamber is installed on the circuit blood feeding side from the column, and the distance from the column to the drip chamber is 30 cm or less Extracorporeal circuit for patients.
(4) The low drip chamber according to (1) or (2), wherein at least one drip chamber is installed on the circuit blood removal side of the blood circulation pump, and the distance from the patient to the drip chamber is 50 cm or less. Extracorporeal circuit for weight patients.
(5) The extracorporeal circuit for low-weight patients according to any one of (1) to (4), comprising three or more drip chambers having an internal volume of 5 ml or less.
(6) For low-weight patients having a drip chamber, an in-circuit pressure measuring device, a column, a blood circulation pump, and an anticoagulant administration device, and the volume of the blood flow path portion of the entire device is 20 ml or less Extracorporeal circulation device.
(7) The extracorporeal circulation apparatus for low-weight patients according to (6), wherein the blood flow circulates at 3 ml / min or less.
(8) The extracorporeal circulation apparatus for a low-weight patient according to (6) or 7, wherein the in-circuit pressure measurement device and the blood circulation pump are independent.
(9) A dialysate circulation pump is further provided, the dialysate circulation pump and the blood circulation pump are independent, and the dialysate circulation pump and the circuit internal pressure measuring device are integrated (6 The low-weight patient circulation apparatus according to any one of (8) to (8).
(10) The body for a low-weight patient according to any one of (6) to (9), wherein the blood circulation pump is fixed to the support and the distance from the patient to the blood circulation pump is 50 cm or less. Circulation device.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
The extracorporeal circuit for low-weight patients according to the present invention enables extracorporeal circulation when the amount of blood taken from the patient is 20 ml or less, and the drip chamber 1, column 2, blood circulation pump 3, circuit pressure measuring device 5, and anticoagulant injection An extracorporeal blood circuit for a low-weight patient having the device 6, (1) a blood volume taken from the patient can be circulated with 20 ml or less, and (2) a drip chamber as a safety device or a continuous pressure measurement site Preferably, it has two or more locations.
[0011]
In general, the blood volume that can be safely taken out of the body without transfusion is 10% or less of the total blood volume. For example, when used for a low-weight patient with a body weight of 3 kg, the blood volume is 20 ml or less. For this reason, the amount of blood taken out from a low-weight patient needs to be 20 ml or less including the column for purification, and 10 ml, which is a half of the circulation device, is desirable.
[0012]
FIG. 1 shows an example of an embodiment of a circulation circuit according to the present invention. Hereinafter, a description will be given with reference to FIG.
[0013]
The material of the circulation circuit of the present invention is not particularly limited. Each component is connected by a tube through which blood flows, and it is preferable to use vinyl chloride having flexibility for the tube portion and silicon for the pump contact portion.
[0014]
In order to reduce the amount of blood taken from the patient, it is important to determine the tube volume. To reduce the inner volume of the tube, the inner diameter of the tube may be reduced. However, if the diameter is made too small, the flow resistance when flowing blood increases and the risk of destroying blood cells increases. Therefore, it is desirable that the inner diameter of the tube is 1.5 mm or more and less than 2.0 mm.
[0015]
A known drip chamber (1a, 1b, 1c) in the present invention can be used. As described above, the drip chamber (1a, 1b, 1c) functions not only as a safety device for preventing bubbles from entering the circulating blood but also as a part for continuously measuring pressure. In the present invention, the volume of the drip chamber (1a, 1b, 1c) is preferably 2 ml or more and 5 ml or less. At least one drip chamber is required in the circulation circuit, and it is preferable to have three or more drip chambers. When there is one drip chamber, the installation position is preferably one location (drip chamber 1c) between the column 2 and the circuit blood supply side B, and then one location between the circuit blood removal side A and the blood circulation pump 3. It is preferable to install (drip chamber 1a). In the case of three, it is preferable to install in one place (drip chamber 1b) between the blood circulation pump 3 and the column 2. When the drip chamber 1c is installed between the column 2 and the circuit blood supply side B, the distance from the patient to the drip chamber 1c is preferably 30 cm or less, and between the circuit blood removal side A and the blood circulation pump 3 When installing the drip chamber 1a, the distance from the patient to the drip chamber 1a is preferably 50 cm or less. The distance from the patient to the drip chambers 1a and 1c is the maximum length when the blood volume in the blood circuit is set within 10 ml, and is set in consideration of the operability of the blood circulation device.
[0016]
The column 2 in the present invention is a blood processing device for extracorporeal circulation, and includes, for example, an adsorption column and a dialysis column. When the column 2 is a dialysis column, a dialysate circulation pump 4 is connected to the column 2 so that the dialysate can be circulated.
[0017]
As the blood circulation pump 3 in the present invention, various pumps such as a roller pump can be used. The blood flow rate during blood circulation is not particularly limited as long as it does not affect the patient, but the blood flow rate is preferably 3 ml / min or less from the viewpoint of the flow resistance in the tube and each component. For example, when using a roller pump that is most widely used as a pump, the diameter of the portion in contact with the pump roller is 1 so that the blood flow rate can be reduced to 3 ml or less and the blood can be pumped stably. It is preferable that the length is 0.5 mm and the length is 15 cm.
[0018]
As the in-circuit pressure measuring device 5 in the present invention, a digital differential pressure gauge, such as a manometer, can be used. By connecting the apparatus to the drip chambers 1a, 1b, and 1c, the circuit internal pressure can be continuously monitored.
[0019]
As the anticoagulant charging device 6 of the present invention, a syringe pump or the like can be used. By connecting the device to the drip chamber 1a, it is possible to continuously inject the anticoagulant into the circuit.
[0020]
A blood circuit having a volume of blood taken from a patient of 20 ml or less is constituted by the above components. For example, in FIG. 1, it is sufficient to connect the drip chamber 1a to the pump 3 near the patient, the pump 3 to the drip chamber 1b, and the column 2 and the drip chamber 1c with tubes having an inner diameter of 2 mm and a length of 15 cm. It is. The total volume of all these parts is 9.6 ml even when the distance between the patient and the device is connected by a tube with an inner diameter of 2 mm and a length of 50 cm, that is, the part other than the column of the blood circuit It is possible to reduce the amount of blood taken out from the patient to 20 ml or less even when the column has an internal volume of 10 ml.
[0021]
In addition, the blood circulation device for forming the blood circuit of the present invention is not particularly limited as long as it has each component of the blood circuit of the present invention and the volume of the blood flow path portion of the circulation device is 20 ml or less. . However, since it is necessary to reduce the size and weight in order to install it inside an incubator, etc., as a result of considering the reduction in size and weight, it is preferable that at least the circuit internal pressure measuring device and the blood circulation pump are independent, and further the circulation Of the elements constituting the circuit, only blood circulation pump 3 and column 2 are installed near the patient, and in-circuit pressure measurement device 5, dialysate circulation pump 4 and anticoagulant injection device 6 are located away from the patient. It was found that extracorporeal circulation of low-weight patients can be performed without impairing conventional functions. Here, “independent” means that the device is not integrated and can be installed in different places. There are no particular limitations on the method of connecting the blood circulation pump 3 and the column 2 and other components, that is, the in-circuit pressure measurement device 5, the dialysate circulation pump 4, and the anticoagulant injection device 6. That is, even if the capacity of the tube connecting these portions is somewhat increased, there is no significant effect on the amount of blood taken from the patient. However, considering the necessity of operating the apparatus at the same time, the distance between the blood circulation pump 3 and the column 2 and the in-circuit pressure measurement device 5, the dialysate circulation pump 4 and the anticoagulant injection device 6 is suitably within 1 m. More preferably, it is within 60 cm. In addition, the distance from the patient to the blood circulation pump is preferably 30 cm or more and 50 cm or less from the viewpoint of preventing the length of the tube of the blood circuit and the treatment for treatment. Furthermore, fixing the blood circulation pump to the support column is preferable because a treatment space can be secured.
[0022]
The details of the present invention will be described below using examples.
[0023]
【Example】
Example 1:
The produced circulation circuit is shown in FIG.
[0024]
The inside diameter of the tube made of vinyl chloride is 1.5mm, the capacity of the drip chamber made of vinyl chloride is 3 places in 2ml, and the roller pump (Peristaltic pump PST-100N, made by Iwaki) is used as the pump 3. A 2 mm 15 cm long silicon tube, drip chamber 1 a to pump 3, pump 3 to drip chamber 1 b, and column 2 to drip chamber 1 c each have an inner diameter of 1.5 mm and a length of 15 cm vinyl chloride This is a blood circuit composed of a tube made of vinyl chloride having a diameter of 1.5 mm and a length of 50 cm from the patient to the drip chamber 1a and the drip chamber 1c to the patient. As the column 2, a dialysis column having a capacity of 10 ml was used. In-circuit pressure measurement device 5 (MANO METER DMS-760 comfix) and dialysate circulation pump 4 (peristaltic pump PST-100N, manufactured by Iwaki) and anticoagulant injection device 6 (syringe pump STC-525, Terumo), the pump 3 and the column 2 were separated to form respective devices (I and II in FIG. 1), and the whole was constituted.
[0025]
Example 2:
Using the apparatus prepared in Example 1, extracorporeal circulation was performed on a rabbit weighing 3 kg. The capacity of the connected column is 10 ml. The rabbits were anesthetized with sodium pentobarbital and then fixed on a fixed table. After tracheotomy, an endotracheal intubation tube was inserted and connected to a ventilator (RESPIRATOR Model '665' HARVARD APPARATUS, laboratory animal anesthesia device SN-487, manufactured by Shinano Manufacturing Co., Ltd.). Artificial respiration was performed with room air, and 1% isoflurane was mixed as gas anesthesia. Thereafter, the right femoral artery and vein were surgically exposed, and then an 18G intravenous indwelling needle was inserted. From the vein side, 0.5 ml of 1000 units / ml heparin was injected as an anticoagulant, and then the circuit inlet was connected to the arterial indwelling needle and the circuit outlet side was connected to the vein indwelling needle. At this time, the circuit was filled with physiological saline containing 10 units / ml heparin. After connecting the circuit, the pump was operated to start extracorporeal circulation at a blood flow rate of 3 ml / min. During extracorporeal circulation, 100 units / ml physiological saline of heparin was injected as an anticoagulant from the drip chamber 1a at a rate of 3 ml / hour. In this case, blood circulation was performed directly, and the dialysate was not circulated.
[0026]
Thereafter, the blood pressure of the rabbit was measured from the drip chamber 1a, from the column inlet pressure drip chamber 1b, and from the drip chamber 1c.
[0027]
Table 1 shows the results of measurement of blood pressure and arterial oxygen saturation in rabbits after 4 hours of extracorporeal circulation. As shown in Table 1, it was shown that rabbits were able to safely perform extracorporeal circulation for 4 hours without exhibiting a decrease in blood pressure or hypoxemia.
[0028]
[Table 1]

[0029]
【The invention's effect】
The present invention enables a safe and convenient extracorporeal circulation that does not require a large amount of infusion that causes transfusion or pulmonary edema, even for low-weight patients with low blood volume. It has become possible to provide a blood circuit for circulation and an extracorporeal circulation device. As a result, blood purification treatment for low-weight patients such as newborns can be performed more safely.
[Brief description of the drawings]
FIG. 1 is a schematic view of a low-capacity blood circuit and a small and lightweight blood circulation device incorporating the circuit.
[Explanation of symbols]
I: Blood circulation pump and column part of blood circuit (part that can be installed near patient)
1a: drip chamber 1b at pump inlet: drip chamber 1c at column inlet: drip chamber 1 at column outlet 2: column 3: blood circulation pump
II: Parts other than blood circulation pumps and columns of blood circuit (parts that can be installed away from patients)
4: Dialysate circulation pump 5: In-circuit pressure measuring device 6: Anticoagulant injection device A: Circuit blood removal side B: Circuit blood supply side

Claims (4)

A drip chamber, an in-circuit pressure measurement device, a column, a blood circulation pump, and an anticoagulant administration device, and the volume of the blood flow path portion of the entire device is 20 ml or less,
Said circuit pressure measuring device and the blood circulation pump, not integrated as a unit, Ru can der be installed in separate locations, underweight patient for extracorporeal circulation apparatus.   The extracorporeal circulation apparatus for low-weight patients according to claim 1, wherein the blood flow circulates at 3 ml / min or less. Furthermore, it has a dialysate circulation pump, the dialysate circulation pump and the blood circulation pump are independent,
The extracorporeal circulation apparatus for low-weight patients according to claim 1 or 2, wherein the dialysate circulation pump and the in-circuit pressure measurement apparatus are integrated.   The extracorporeal circulation apparatus for low-weight patients according to any one of claims 1 to 3, wherein the blood circulation pump is fixed to a support column, and a distance from the patient to the blood circulation pump is 50 cm or less.

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