Extracorporeal membrane oxygenator, as an extracorporeal life support system, is an effective and special auxiliary means for life support based on the extracorporeal circulation system and using extracorporeal circulation technology. Its main purpose is to pump blood into the extracorporeal membrane lung device for adequate blood oxygenation and elimination of carbon dioxide to ensure effective blood supply throughout the body. Compared with traditional extracorporeal circulation auxiliary means, it has the advantages of long maintenance time, only low-intensity anticoagulation, and can support respiratory and circulatory functions at the same time. At present, it is mainly used for critically ill patients with severe cardiopulmonary failure and traditional treatment methods are ineffective.
Although early clinical studies showed that the use of ECMO did not achieve significant efficacy, with the continuous development of oxygenator devices, anticoagulation strategies and other technologies and the accumulation of clinical experience, the scope of ECMO use continues to expand, and the clinical efficacy continues to improve. , so that it can be more widely used in clinical critical care first aid and has good development prospects.
However, there is still a lack of sufficient clinical experience for this emerging auxiliary device, and there are also many serious complications , so the clinical application of ECMO needs to be carefully chosen. In future clinical research, more large-scale clinical studies are needed to further clarify the best indications for ECMO as well as prevention and treatment strategies for related complications. At the same time, in order to ensure the smooth and effective operation of ECMO, it is key to form an excellent ECMO team.
ECMO use safety risk analysis
(1) ECMO function application risks
ECMO equipment mainly includes drive pumps, gas exchange devices, heat exchangers and some monitoring devices. The following is a brief introduction to the components in detail to analyze the existing risks:
Figure ECMO structural diagram
The drive pump provides power for the entire circulation pipeline. At present, there are two drive pumps used in ECMO treatment, namely centrifugal pump and roller pump. The risks of centrifugal pumps include: ① Excessive negative pressure will cause the formation of serious bubbles; ② The blood flow is unstable, and when the blood flow is reduced, it will aggravate hemolysis ; ③ If the centrifugal pump exceeds the indicated recommended range, the centrifugal pump may cause Failure, reduced pump flow, leakage, excessive blood damage, degradation or corrosion of blood contact materials, and may be transmitted to the patient through the blood; ④ A large number of air embolism entering the centrifugal pump will cause the centrifugal pump to fail, causing the blood flow to stop, and the air After the plug is introduced into the patient's body, it may cause death or serious injury; ⑤ The inlet of the centrifugal pump is blocked, which will form negative pressure inside some pipelines; ⑥ When the flow is stopped, the outlet pipe of the centrifugal pump and the patient's intravenous catheter must be closed to prevent The patient has lost blood, and partial occlusion of the outlet tube for an extended period of time may cause blood damage. Complications such as infection, mechanical failure, hemolysis and thromboembolism may still occur during use of
. In this case, there is also a risk of cascade reactions being activated if human blood or blood cells come into contact with other foreign surfaces. Other risks include gas and particle embolism due to accidental blood reflux during venovenous use, accidental disconnection, and coagulation in extracorporeal circulation . thrombi are formed in the vascular system. Adjusting mechanical ventilation or oxygen supply flow according to the removal capacity of CO2 will cause the risk of hypocapnia. Insufficient blood flow, thrombus and pseudomembrane formation in the oxygenator (such as fat, fibrinogen or coagulation products) will lead to loss of oxygenator function (reduced carbon dioxide removal and/or oxygenation capacity), causing Hypoxemia risk.
Battery life, the console must be connected to a suitable power source and must be used with a fully charged battery pack installed. A depleted battery pack must be charged immediately. Please connect the console to external power for at least 6h before use. Loss of power during treatment could result in serious injury or death to the patient.
Other risks include: running the safety protection mode for a long time may increase the damage to blood cells; the risk of pump tube rupture, the risk of gas in the pipeline, the risk of oxygenator damage, the risk of power supply damage, the risk of intubation pullout, etc.
(2) Environmental risks of ECMO use
ECMO pipeline connection diagram
1. Electromagnetic Compatibility This device is classified as medical electrical equipment and therefore requires special precautions regarding electromagnetic compatibility (EMC). The device must be installed and operated in accordance with the EMC section of these instructions for use. If the device is used near magnetic fields (e.g. magnetic resonance therapy), it may be affected by portable or mobile wireless communications equipment.
2． Ambient temperature: Excessive ambient temperature can damage the equipment. Make sure the system is well ventilated and keep the vents clear at all times. Prolonged exposure to direct sunlight can cause the device to overheat. Devices with compromised functionality may endanger the patient's life.
3． Gas Environment Not suitable for use in environments containing flammable anesthetic gases mixed with air or oxygen or with nitrous oxide .
4． Device Compatibility The blood perfusion system can only be used with centrifugal pumps recommended by the device manufacturer, and the relevant devices used must be compatible with the manufacturer's devices or components.
5． Aseptic Technique Aseptic technique should be used when operating the sterile fluid pathways of centrifugal blood pumping systems. The centrifugal pump as well as the disposable flow glass tubes of the blood flow monitoring system are packaged as sterile products and are intended for single use only. If reused or resterilized, serious injury or death may result. Generally supplied sterile and pyrogen-free. Sterility can only be guaranteed if the packaging has not been opened or damaged and the use-by date has not been exceeded. The product must be stored in the original packaging in a dark, dry place at room temperature.
6. Do not allow centrifugal pumps to come into contact with chemicals. Chemicals can affect the integrity of these devices. Some anesthetic solutions can degrade polycarbonate plastic . Avoid letting such solutions come into contact with centrifugal pumps.
7． Systemic heparin antagonism caused by administration of protamine during in vitro procedures may result in coagulation/coagulation and loss of in vitro system performance.
8． Airtightness of the oxygenator. Check the airtightness of the oxygenator before precharging: recirculate the water flow in the heat exchanger for at least 5 minutes to detect whether the heat exchanger structure is airtight and whether there is any liquid leaking from the water flow side into the gas exchange chamber. . If there is a leak in the heat exchange unit of the oxygenator, the oxygenator gas exchange fiber bed will slowly fill with water. To do this, check the lower area of the oxygenator. Leaking oxygenators must not be used and must be replaced. Even if only a small amount of visible gas appears in the oxygenator, it must be exhausted through the oxygenator exhaust port. The oxygenator can be tapped and shaken to completely remove the gas from the oxygenator. During this process, the maximum pressure on the blood side shall not exceed 600mmHg (80kPa).
9． When high blood flow rates are used, convection may cause hypothermia in the patient. Patients can be proactively rewarmed while taking appropriate temperature control measures to address such risks.
10． For products containing phthalates , animal experiments have shown that phthalates (such as DEHP) have potential reproductive toxicity. The materials and components of this medical device may contain the plasticizer (such as DEHP). The possibility of the materials used in this medical device releasing any organic substances, including DEHP, into the patient's blood during clinical application is extremely low because it only occurs when isopropyl alcohol is used as the extraction medium for chemical analysis. DEHP detected. In addition, this medical device has a coating that minimizes the risk of DEHP entering the patient's bloodstream. The risk of not taking the required action is far greater than the risk of exposure to DEHP. The benefits of using this medical device outweigh the possible side effects of DEHP in patients. For precautionary reasons, medical products containing phthalates (such as DEHP) should not be used by pregnant or breastfeeding women.
(3) Risks to ECMO users
1. It is prohibited to place the liquid level sensor below the manufacturer's recommended minimum operating liquid level. Never put your fingers inside the remote tube closure device. Serious injury may occur if fingers are pinched when closing the remote pipe clamp .
2． During maintenance or cleaning, the centrifugal pump must not be disconnected from the AC power supply , otherwise electric shock may occur.
3． Do not adjust, modify, repair or touch the internal pipelines at will. These actions may cause injury to the patient, may cause injury to the operator, and may cause the automatic clamping device interface module to operate incorrectly.
4． When using the defibrillator , ensure that no electrical circuits are formed between the patient, doctor and immediately adjacent personnel being defibrillated and the ground or metal parts of the bed or operating table. The correct polarity and correct polarity must first be checked and maintained. Grounding integrity, otherwise electric shock or burns may occur to the operator or patient. The device must be plugged directly into an electrical outlet, extension cords and power strips are prohibited. Do not touch the patient and metal parts of the console and live components (such as power contacts) at the same time as this may cause electric shock or burns to the operator or patient.
This article is excerpted from the "Quality Control Management Guidelines for First Aid and Life Support Medical Equipment" to learn more about the use safety and quality control management of the extracorporeal membrane oxygenator ECOM.
