With the advancement and widespread application of blood purification technology, the quality of life of patients with end-stage kidney disease has been improving year by year. How to improve the dialysis quality of hemodialysis patients and control dry weight is one of the key factors to improve their quality of life. When the dry weight does not meet the standard, it may cause complications such as hypertension, edema, heart failure, and increase the mortality rate of patients. Therefore, every dialysis patient should know their dry weight, understand how to determine dry weight, water intake, and their clinical significance. Knowing these knowledge is very important.
1、 What is dry weight? Dry weight refers to the weight of a patient after dialysis when all or most of the excess fluid in the body is cleared, which is the normal weight when there is no excess water in the body. After dialysis, the patient's weight reaches dry weight, which can remove excess water from the body to a relatively clean state without dehydration, and will not cause symptoms such as low blood pressure, fatigue, edema, muscle spasms, etc. Of course, dry weight can also vary depending on the patient's condition, nutritional status, consumption, season, etc. It is best to conduct a dry weight assessment once a month.
2、 The hazards of inadequate dry weight
Each dialysis treatment requires determining the amount of dehydration based on dry weight. Medical staff will choose the appropriate dialyzer, ultrafiltration volume, and dialysis time according to dry weight to achieve or approach dry weight after dialysis. If the dry weight is set too high and the weight increases after dialysis, it may cause complications such as hypertension and heart failure, affecting the patient's survival rate. If the weight after dialysis is lower than dry weight, it may cause symptoms such as low blood pressure, vomiting, muscle spasms, and increase the risk of vascular obstruction. Low blood pressure may also cause complications such as cerebral ischemia and epilepsy, seriously affecting physical health and quality of life.
3、 Criteria for determining dry weight
① Symptoms: If the weight can be reduced to the ideal dry weight after dialysis, patients generally feel comfortable, without shortness of breath, difficulty breathing, edema, muscle spasms, hearing loss, tinnitus and other symptoms.
② Signs: Relevant signs can also be used to determine that when the dry weight reaches the ideal state, the patient has no symptoms such as jugular vein distension, hepatomegaly, wheezing, or wet rales in both lungs. At the same time, blood pressure will remain relatively stable and normal, and there will be no significant hypotension during dialysis.
③ Inspection and examination: Other auxiliary examinations can also be used to determine whether the ideal dry weight has been achieved. In an ideal state, chest X-rays should show no signs of pulmonary congestion or pleural effusion, and the cardiothoracic ratio should be less than 50% for males and less than 53% for females, which is normal; Echocardiography shows normal heart size; The human body composition analyzer can also assist in determining dry weight.
In addition, there are multiple factors involved in determining dry weight, and it should be consulted with a doctor to comprehensively assess whether dry weight is appropriate.
4、 The principle of controlling water intake
Controlling liquid intake is one of the most important methods to control dry weight. The amount of water a patient drinks per day is related to the number of dialysis sessions per week. The specific calculation method is as follows: ① For those who undergo blood dialysis three times a week: 500ml/day+urine output from the previous day;
② For those who undergo hemodialysis twice a week: 300ml/day+urine output from the previous day.
During two hemodialysis sessions, weight gain should be controlled within the range of 3% to 5% of dry weight, and weight gain should not exceed 2-3kg. Hemodialysis patients need to strictly record their daily urine output, water intake, and medication intake, and pay attention to weighing.
Do not eat Century egg, dried tofu, pickles, bean curd jelly served with sauce and other foods with high sodium content at ordinary times. The daily sodium intake should be less than 2g. At ordinary times, pay attention to controlling the water intake in porridge, soup noodles, milk and other foods. Moreover, dry weight is not constant, and dialysis patients should regularly measure their weight at home and self control their water intake. It is recommended to evaluate dry weight, volume control, and blood pressure control at least once every 2-4 weeks.