1. Preparation of dialysis equipment: Dialyzer is a place for material exchange, and the most commonly used dialyzer is hollow fiber dialyzer. Hollow fiber is a kind of synthetic semi-permeable membrane. Blood passes through the cavity and dialysate is outside. Hemodialysis machine can control the flow, temperature, dehydration and blood flow of dialysate. , and has various monitoring systems for cardiopulmonary bypass. Nurses should be familiar with the operation of the dialysis machine, and pay attention to the fact that dialysis can only start after all the indicators are stable after starting the machine. Dialysis equipment also includes dialysis water supply system, dialysis pipeline, puncture needle and preparation of dialysate. Dialysis fluid can be divided into acetate and bicarbonate. First, the dialysate with a concentration of 35 times is prepared, which flows into the dialyzer after being diluted by the machine.

2. Preparation of dialysis drugs: including dialysis drugs (saline, heparin, 5% sodium bicarbonate), first aid drugs, hypertonic glucose injection, 10% calcium gluconate, dexamethasone and dialysate.

3. Patient preparation: mainly the preparation of vascular access. If arteriovenous fistula is used, be familiar with the puncture and protection methods of internal fistula; If arteriovenous fistula is used, you should be familiar with its use method, and pay attention to observe whether there is slippage, bleeding, embolism and infection, and keep the catheter clean and sterile. In addition, the nutritional problems of dialysis patients are also very important, and attention should be paid to supplementing protein (intake is 1.2 ~ 1.4g/(kg? 6? 1d), in addition, it is especially necessary to control the water intake, that is, the patient's weight gain does not exceed 2.5kg during dialysis.

4. Psychological care: As uremia patients and their families are unfamiliar with hemodialysis treatment, they are prone to fear and psychological pressure. They should be introduced and explained to make them understand the necessity, methods and precautions of hemodialysis, and try to eliminate the fear and tension of patients before dialysis.

Second, the nursing in the process of dialysis

1. Nursing of vascular access:

(1) Temporary vascular access: Temporary vascular access is a method used for emergency hemodialysis when permanent vascular access is not established and immature. Including internal jugular vein intubation, subclavian vein intubation, femoral vein intubation and direct arterial puncture.

1) Nursing care of intravenous intubation: keep the local area clean and dry, change the dressing every day to prevent infection; The fixation should be firm and the activity should be moderate to prevent falling off; Keep the pipeline unobstructed. After each HD, the pipeline was sealed with heparin saline (2mL containing heparin 500 ~ 1500IU) to prevent anticoagulation and pipeline blockage. Before each hemodialysis, heparin saline and possible blood clots are extracted with a syringe to ensure adequate blood flow.

2) Nursing care of arterial puncture: try to puncture successfully once and fix it firmly to prevent the needle from coming out. At the end of HD, the pressing time should be long, about 20 ~ 30 min. But this method is gradually being eliminated.

(2) Permanent vascular access: it is to anastomose the adjacent arteries and veins of patients' limbs through surgery to make them become blood flow channels, through which arterial blood flows to veins. Nursing points are as follows:

1) Check whether it is unobstructed, and the vein side should feel tremor and hear murmur. It will take 4 ~ 6 weeks to use. Non-dialysis blood collection or injection, blood pressure measurement, hanging heavy objects, etc. It is forbidden on the blood vessels on the side of internal fistula.

2) The puncture point should be more than 5cm away from the fistula anastomosis. The needle gauge is more than 8 ~ 10 cm, so as to hit the nail on the head. If conditions permit, the blood vessels will be stressed evenly by rope ladder puncture, and no false aneurysm will occur.

3) 3) When pulling out the puncture needle after HD, the hemostasis method should be correct and effective, so as not to form hematoma and block the fistula.

4) Pay attention to keep the local area clean and dry to prevent infection. Apply hirudoid every day to relieve inflammation and soften blood vessels.

At the same time, the puncture of blood vessels should be strictly aseptic, and the movements should be skilled and light to minimize the pain of patients.

2. Monitoring of machines in hemodialysis

Hemodialysis machine can be divided into dialysate supply system, blood circulation control system and ultrafiltration control system according to its functions.

(1) dialysate supply system and ultrafiltration control system: the main monitoring contents are as follows:

1) The conductivity of dialysate is 13.5 ~ 14.5 ms/cm.

2) The temperature of dialysate is 36 ~ 37℃.

3) Blood leak detector function, once dialysis breaks the membrane and blood seeps into the dialysate side, the machine will automatically give an alarm.

4) dialysate flow, the setting range is 500+/-50ml/min.

5) The negative pressure of dialysate is set automatically by manual or machine according to dialysis time, dehydration amount and dialyzer used.

(2) Monitoring of blood circulation system: The monitoring contents include arterial pressure, venous pressure and air alarm.

1) Increased arterial pressure: venous puncture point blocked, venous tube blocked, and blood coagulation in dialyzer.

2) Decreased arterial pressure: hypotension, incomplete fistula blockage or poor indwelling catheter, distorted arterial blood circuit, too fast blood pump or insufficient blood flow, needle slippage, etc.

3) Increased venous pressure: swelling caused by external venous needle puncture, poor venous pipeline, venous spasm, venous needle clinging to the pipe wall, vein stenosis near the heart, blood clot in the degassing cavity at the venous end, decreased dialysate lateral pressure and posture change.

4) Decreased venous pressure: low blood pressure, improper position of arterial needle, twisted arterial channel, slippage of puncture needle, insufficient blood flow, membrane rupture of dialyzer, etc.

5) Air alarm: poor blood flow, loose connection, air leakage in blood pipeline, inadvertent air intake during infusion, etc.

3. Observation during dialysis: changes of blood pressure, pulse, respiration and body temperature; Observe blood flow, blood pressure, dialysate flow, temperature and concentration; Accurately record the dialysis time, dehydration amount and heparin dosage, and pay attention to the alarm and troubleshooting of the machine.

4. Observation and prevention of acute complications:

(1) hypotension

1) reason: ○ 1 effective blood volume decreased; ○2 Decreased vasoconstriction; ○3 Decreased cardiac output; ○4 The dialysis membrane has poor biocompatibility.

2) Clinical manifestations: A small number of patients have asymptomatic hypotension, and most patients may have pallor, chest tightness, cold sweat, nausea and vomiting, and even transient loss of consciousness. Patients with coronary heart disease may induce arrhythmia and angina pectoris.

3) Treatment: supine, head down and feet fast, slow down blood flow and slow down or suspend ultrafiltration. Oxygen inhalation, and normal saline 100-200ml if necessary. If the symptoms are serious, increase fluid replacement until the blood pressure rises and the symptoms are relieved. Hypertonic saline, hypertonic glucose, albumin, etc. Can also be given, but also combined with the cause of symptomatic treatment.

(2) Imbalance syndrome: refers to the syndrome with neuropsychiatric system as the main symptom that appears 65438±0h or several hours after the start of dialysis, and usually disappears after several hours to 24 hours.

1) Cause: After HD, the toxin in blood drops rapidly, and the osmotic pressure of plasma drops, while the blood-brain barrier makes solutes such as urea in cerebrospinal fluid slowly drop, making the osmotic pressure of cerebrospinal fluid greater than that of blood, and water enters cerebrospinal fluid from blood to form brain edema. It is also related to the increase of PH gradient between cerebrospinal fluid and blood after dialysis, that is, the PH value in cerebrospinal fluid is relatively low.

2) Clinical manifestations: mild headache, nausea, vomiting, lethargy, restlessness, muscle spasm, blurred vision and elevated blood pressure. Severe cases are characterized by seizures, convulsions, stupor and even coma.

3) Treatment: Mild patients don't need treatment, and severe patients can be given 40ml 50% 50% glucose or 3% sodium chloride or albumin, and sedatives and other symptomatic treatments if necessary.

(3) Muscle spasm: The main parts are gastrocnemius, feet or upper limbs and abdominal muscles.

1) reasons: low blood pressure, too much and too fast ultrafiltration, which makes the body weight after dialysis lower than the dry weight; Low sodium dialysate.

2) Treatment and prevention: mild cases can be relieved by suspension of ultrafiltration, and severe cases need to be infused with hypertonic glucose solution or hypertonic saline. The ultrafiltration setting should be appropriate and correct, and the sodium concentration of dialysate should be adjusted to145mol/l or higher.

(4) Arrhythmia: Ventricular premature beats are more common.

1) reasons: the main reason is the change of serum potassium and calcium concentration, followed by the decrease of blood pressure during dialysis, the decrease of coronary circulation blood volume and myocardial ischemia and hypoxia.

2) Treatment and prevention: monitor the changes of serum potassium and calcium concentrations before and after HD, correct electrolyte disorder in time, and stop HD if severe arrhythmia occurs.

(5) heart failure:

1) reason: people with hypertension, water and sodium retention or cardiac insufficiency are prone to heart failure during HD. Therefore, simple ultrafiltration should be performed before HD, and the osmotic pressure of dialysate should be close to that of plasma.

2) Causal treatment.

(6) Air embolism:

1) Cause: In HD, air escapes into vein due to transfusion before blood pump, blood pipeline rupture, loose connection of each pipeline, dialysis membrane rupture, inadvertent diffusion of air in dialysate into blood, inadvertent reinfusion of blood, damage or air leakage of air catcher.

2) Clinical manifestations: a small amount of air is a tiny foam, which slowly enters the blood without any symptoms; If the air bubble is large and the air leakage rate is fast, obvious air embolism symptoms may appear when it enters more than 5ml at a time, such as dyspnea, cough, cyanosis, chest tightness, irritability, spasm, loss of consciousness and even death.

3) Treatment: immediately stop the pump and clamp the venous line, and put the patient in the left lateral position with his head low and his feet high to prevent cerebral embolism and take oxygen; In severe cases, percutaneous puncture can be used to extract ventricular air, and hyperbaric oxygen chamber treatment can be carried out if conditions permit.

4) Others: allergic reaction, blood loss, hemolysis, fever, etc.

Third, nursing after dialysis

1. At the end of dialysis, blood should be slowly reinfusion. After measuring blood pressure, if the blood pressure is normal, let the patient lie on his back for a few minutes, and then get up slowly after sitting for a few minutes to prevent postural hypotension.

2. Pay attention to the bleeding situation: after the arteriovenous puncture needle is pulled out, immediately apply moderate pressure to stop bleeding 10 ~ 15 min, and the compression point should be the blood vessel puncture point. If the artery is punctured, the pressing time is more than 30 minutes. If there is bleeding tendency, protamine can be used for neutralization, and the ratio of heparin to protamine is 1 mg: 1 mg.

3. Pay attention to the nursing of puncture and internal fistula after dialysis to prevent blockage and infection.

4. Weigh yourself and make an appointment with the patient for the next dialysis.