Central Venous Pressure (CVP)

Central venous pressure refers to the pressure of the superior vena cava or inferior vena cava. The central vein reflects to some extent the comprehensive status of the patient's effective blood volume, cardiac function and vascular tone at the time of pressure measurement. Therefore, continuous measurement of changes in central venous pressure can dynamically understand changes in blood volume and determine the ability of the heart to tolerate rehydration, which is an important reference for regulating infusion therapy. Basic Information Specialist Category: Cardiovascular Examination Category: Other Examinations Applicable gender: whether men and women apply fasting: not fasting Tips: Actively cooperate with the doctor during the examination. Normal value 0.59 ~ 1.18kPa. Clinical significance Increased indicates a clear heart failure and a risk of pulmonary edema. Reduce the effective reflux blood volume. Low results may be diseases: iliac vein compression syndrome, pediatric shock, sepsis, penetrating cardiac trauma, prerenal renal failure, high anaphylactic shock may be diseases: neonatal shock, heart penetrating injury, Phlebitis, heart failure precautions 1. It must be strictly sterile during operation. 2. The zero point of the pressure measuring tube must be in the same plane as the middle part of the right atrium. After the position change, the zero point should be recalibrated. 3, the catheter should be kept open, otherwise it will affect the pressure measurement results. 4. The length of time the central venous catheter is retained is closely related to the incidence of infection. If the condition allows, the catheter should be removed as soon as possible. Usually the central venous catheter is placed for about 1 week, and if necessary, a new catheter can be replayed elsewhere. 5, when hypotension, such as central venous pressure <0.49kPa (5cmH20), suggesting that the effective blood volume is insufficient, can quickly replenish or replenish plasma, so that the central venous pressure is increased to 0.59 ~ l.l8kPa (6 ~ 12cmH20), hypotension but The central venous pressure is higher than 1.18 kPa (l2cmH2O), and the possibility of cardiac insufficiency should be considered. Drugs that increase myocardial contractility, such as dopamine, dobutamine, etc., can be used to control the amount. The central venous pressure is higher than 1.47 ~ 1.96 kPa (15 ~ 2OcmH2O), suggesting obvious right heart dysfunction, and there may be pulmonary edema. Rapid diuretics and digitalis drugs should be applied. In addition, low central venous pressure can also be seen in the state of vasodilatation caused by sepsis, high fever, and the like. It must be pointed out that the significance of evaluating the venous pressure in the center should be considered in terms of blood volume, cardiac function and vascular status. When the blood volume is insufficient and the heart function is incomplete, the central venous pressure can be normal, so it is necessary to combine clinical and comprehensive judgment. Inspection process 1. Pass the sterile plastic tube through the deep vein puncture, through the peripheral vein (usually using subclavian vein, subclavian vein and internal jugular vein junction or femoral vein, etc.) into the superior vena cava or inferior vena cava near the right atrium . 2. Before the intubation, the three-way valve should be connected in advance, and the infusion set should be continuously infused. 3. The "L" shaped pressure measuring tube is fixed on the wooden board and connected to the three-way valve. When the pressure is measured, the three-way valve is moved, and the water column in the pressure measuring tube is first raised, and then the catheter is connected with the pressure measuring tube to block the connection with the infusion set. The measured central venous pressure value is measured when the water column in the pressure measuring tube stops falling. After the measurement, the pressure measuring tube is closed, and the infusion set is connected to continue the infusion. 4. Regardless of the position of the patient, the pressure is measured at the right atrium level. That is, the pressure tube "0" point must be at the same level as the right atrium. The patient should be on the same level as the midline of the sac. 5. In order to prevent coagulation in the tube, a small amount of anticoagulant should be added to the instilled liquid (2.5 to 5 mg of heparin per 500 ml of liquid), or 3.8% sodium citrate should be injected into the pressure measuring tube. Not suitable for the crowd 1. Skin infection of the puncture site. 2. Patients with severe coagulopathy or anticoagulant therapy. 3. Bacteremia or sepsis. 4. Those who are allergic to local anesthetics or specific materials. 5. Yu Tong right heart catheterization. Adverse reactions and risks May cause an infection.