The advantage of hemofiltration is usually compared with dialysis, and the advantage compared with normal dialysis is that it is done more slowly. dialysis is completed in 2-3 hours, and there may be thousands of ml of fluid in and out in a short period of time, and if there is cardiac insufficiency, cardiac insufficiency is likely to occur, and shock may also occur. But hemofiltration is very slow, the blood flow rate is basically similar to the body condition, about 100-150 ml/min. so the impact on the patient’s blood pressure and heart is very small. In fact, when the blood pressure is very low, for example, 80/40mmHg, hemofiltration can still be done, and the risk to the patient is much smaller, although it takes longer, but it is relatively safer for critically ill patients.