HEMOFILTERS.pptx hemofiltration in detail

Ppt

1. HEMOFILTERS … SUBMITTED BY- ABHISHEK NAIR SUBMITTED TO -MUSKAN MA'AM

2. What is Hemofilters Hemofilter is Also known as ultrafilters or hemoconcentrators, these contain semipermeable membranes (hollow fibers) that permit passage of water and electrolytes out of blood. They are normally connected to the CPB circuit at a high pressure port or line, such as the systemic flow line, to provide a driving force for blood through the device. This allows blood to be filtered before being returned to the patient. Fluid removal is usually 30 to 50 ml/minute, and depending on the membrane used, molecules of up to 20 000 Daltons are removed. Hemofiltration may be used during or after CPB, mainly to manage hyperkalemia or acidosis, but also to concentrate the blood if the hematocrit (HCT) is low and circulating volume is adequate

3. Principles of Hemofiltration and its Mechanisms Hemofiltration relies on the principles of convection and diffusion to selectively remove unwanted substances from the patient's blood during cardiopulmonary bypass. The process utilizes a semipermeable membrane that allows the passage of water and small molecules, while retaining larger blood components like proteins and cells. The driving force behind hemofiltration is a pressure gradient, which pushes the patient's blood across the membrane. This convective transport results in the removal of excess fluid, metabolic waste, and electrolytes, while preserving the essential blood constituents necessary for the patient's well-being during the critical surgical procedure.

4. Techniques of Ultrafiltration Ultrafiltration is a critical technique used during cardiopulmonary bypass (CPB) procedures. There are four major types of ultrafiltration that can be employed: Pre-Bypass Ultrafiltration (PBUF) Conventional Ultrafiltration (CUF) Modified Ultrafiltration (MUF) Zero-Balanced Ultrafiltration (Z-BUF) Each of these techniques plays a unique role in regulating fluid balance and removing waste products during complex heart surgeries. Understanding the differences between these approaches is key to optimizing patient outcomes.

5. PRE- BYPASS ULTRAFILTRATION [PBUF]. Pre-bypass ultrafiltration (PBUF) is a technique that filters priming blood before cardiopulmonary bypass (CPB) to make electrolyte, glucose, and lactate values more physiologic and standardized . PBUF can also reduce inflammatory, metabolic, and electrolyte disturbances. The advantages of the PBUF is reduced cardiac impairment & pulmonary dysfunction.

6. CONVENTIONAL ULTRAFILTRATION[CUF] It's a convective process, traditionally performed during the rewarming phase while on CPB to reduce excess TBW(total body water) and Edema. Post oxygenator, some blood is shunted through an UF membrane extracting discardable filtrate by hydrostatic pressure. Concentrated blood is then returned to venous reservoir. Membrane pore size- 65kDa. Drawback: Continuous volume removal lead to volume depletion in venous reservoir and also of some heparin.

7. MODIFIED ULTRA FILTRATION[MUF]. In this method, the arterial line is connected to the inlet of the ultrafilter and the venous line is connected to the outlet of the ultrafilter in the CPB circuit. The inlet of the filter was clamped throughout the CPB As the patient is separated from the CPB, the clamp is removed from the inlet of the filter, allowing the blood to flow through the arterial line to the filter (10-15 mL/kg/min), and finally from the cardioplegic cannula, as a venous line returns to the right atrium It was first described and still commonly used in A-V (aorta/arterial to RA/venous) configuration

8. ZERO-BALANCE (Z-BUF) Zero-balance ultrafiltration (Z-BUF) is the process by which a solution (replacement fluid) is infused into the CPB circuit and an equal volume of fluid is removed via an ultrafiltration column. This process allows small molecules to be removed from the blood, while cells and most proteins remain. Usually performed after the rewarming phase by administering a replacement fluid into the venous reservoir. The amount added is equal to the volume of ultrafiltrate. The most common replacement fluids are Plasmalyte, dialysate isotonic electrolyte solution. High volume Z-BUF allows control of blood potassium, glucose and lactate levels during CPB.

9. Intraoperative Use of Hemofilter Hemofilters is extensively utilized during the intraoperative phase of cardiopulmonary bypass (CPB) procedures. It helps maintain fluid balance, electrolyte levels, and remove waste products from the patient's blood throughout the surgical process. Fluid Management: Hemofilter allows for precise control of the patient's fluid status, preventing excessive fluid accumulation that can lead to complications. Metabolic Regulation: The filtration process removes metabolic waste products, such as urea and creatinine, to support organ function during the bypass. Electrolyte Balance: Hemofilters ensures appropriate levels of essential electrolytes, like sodium, potassium, and calcium, are maintained throughout the procedure.

10. Postoperative Use of Hemofiltre Hemofilters continues to play a vital role in the postoperative management of patients undergoing cardiopulmonary bypass (CPB) procedures. It helps maintain fluid balance, remove waste products, and support organ function during the critical recovery phase. Fluid Regulation: Hemofilter helps prevent fluid overload and edema, which can compromise respiratory and cardiac function in the postoperative period. Metabolic Control: The filtration process removes excess metabolic waste, such as urea and creatinine, to support the patient's renal and hepatic function. Electrolyte Balance: Hemofilters ensures that essential electrolytes, like sodium, potassium, and calcium, are maintained at optimal levels during the recovery phase.

11. Advantages of Hemofilter in CPB 1 Improved Fluid Balance Hemofilter allows for precise control of the patient's fluid status during CPB, preventing complications from fluid overload or depletion. 2 Metabolic Regulation The filtration process removes excess waste products, supporting organ function and metabolic stability throughout the procedure. 3 Electrolyte Homeostasis Hemofilter maintains optimal levels of essential electrolytes like sodium, potassium, and calcium, crucial for cardiac and neurological function. 4 Reduced Inflammatory Response By removing inflammatory mediators, hemofiltration can help mitigate the body's systemic inflammatory reaction during CPB.

12. Disadvantages of Hemofilter in CPB 1 Potential Complications Hemofilter carries a risk of complications such as bleeding, clotting, and infection, which can compromise patient safety during the delicate CPB procedure. 2 Technical Complexity The setup and operation of the hemofiltration system can be technically challenging, requiring specialized training and expertise from the surgical team. 3 Additional Costs The use of hemofilter equipment and consumables can add significant costs to the overall CPB procedure, which may impact healthcare budgets. 4 Limited Accessibility Hemofiltration technology may not be readily available in all healthcare facilities, limiting its use in certain clinical settings.

13. Conclusion: Summary and Key Takeaways In summary, hemofilters plays a vital role in cardiopulmonary bypass (CPB) procedures. It helps maintain fluid balance, regulate electrolytes, and remove metabolic waste, supporting optimal patient outcomes throughout the surgical process and during recovery. Precise Fluid Management: Hemofilter allows for accurate control of the patient's fluid status, preventing complications from over- or under-hydration. Metabolic Optimization: The filtration process removes excess waste products, supporting organ function and maintaining metabolic stability. Electrolyte Homeostasis: Hemofilter ensures essential electrolytes are maintained at optimal levels, crucial for cardiac and neurological function. Reduced Inflammatory Response: By removing inflammatory mediators, hemofiltration can help mitigate the body's systemic inflammatory reaction during CPB.

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