Measurement of arterial blood pressure by an invasive method represents one of the most exact types of monitoring of a system hemodynamics which the ABP, and a condition of peripheric circulation allows to monitor in real time fluctuations as directly. Thanks to emergence and distribution of modern monitors, measurement of IAD is gradually included into routine clinical practice in the CIS countries, and in countries of Western Europe and the USA is not something outstanding for a long time. Wide use of modern disposable expendables allows to make process of catheterization of an artery and control of monitoring of IAD convenient for the doctor and the patient.
The general scheme of measurement of the invasive ABP looks so: fluctuations of pulse wave are transmitted through an arterial catheter on a transdyyusser who is connected directly to the IAD sensor. The sensor transfers indications to the monitor displaying curve IAD, directly numerical value of this indicator and also pulse rate. Size IAD depends not only on pressure in an artery, as well as on arrangement of the sensor concerning the level of the right auricle of the patient. Similarly in real time it is possible to trace also the central venous pressure; at the same time the system joins the catheter located in the top or lower vena cava.
Indications for use of monitoring of the invasive ABP in clinical practice are rather diverse, but most often include:
Operative measures which are followed by considerable fluctuations of a system hemodynamics (heart surgery, vascular surgery, transplantology, neurosurgery, etc.);
Operative measures at patients with high risk of destabilization of a system hemodynamics (heart diseases, the expressed hypovolemia, patients after an extensive myocardial infarction, etc.);
Separate interventions at which tracking of the ABP is in real time very important (a carotid endarteriektomiya, operations for intracranial aneurysms);
Use long mono - and multicomponent angiotonic and inotropic support in intensive care unit;
Maintaining patients with pre-and an eclampsia in obstetric practice.
As choice point for installation of a catheter for measurement of the invasive ABP, as a rule, serves the beam artery. Use of elbow or femoral arteries involves danger of a necrosis of distal department of an extremity therefore their use is recommended only in extreme cases and for short time. Now routine use of the test of the Allene before artery catheterizations in view of its low predictive value is not recommended. Best of all the special arterial catheters with the lock having optimum rigidity are suitable for catheterization of arteries but also use of standard intravenous catheters is possible. "the catheter on a needle", and Seldinger's technique can be used as a technique. The place of a puncture is carefully processed, the catheter is filled with heparin solution. In a stake it is the best of all to produce at an angle 45 degrees in relation to an artery axis, changing then the direction for more flat after hit in an artery. After catheterization it is necessary to connect immediately a washing system with heparin (2500 PIECES of unfractionated heparin on 500 ml of isotonic solution of sodium of chloride) to exclude catheter thrombosing which occurs very quickly. The washing system usually includes the container with washing solution which can be entered as bolyusno, and in the form of continuous infusion by means of the spray pump. Transdyyusser connect to the sensor of the invasive ABP connected to the monitor.
Further so-called installation of zero — a reference point for registration of indicators is carried out. For this purpose the arterial line is blocked, the sensor-transdyyusser system is placed at the level of the right auricle of the patient and press the corresponding point on the monitor. After that there is an updating of indicators. Then the arterial line is opened and begin registration of arterial blood pressure.
In the course of measurement it is necessary to watch that there was no considerable throwing of blood from an artery in the connecting tube departing from a catheter. In this case it is necessary to wash out a catheter a bolus of washing solution at once. It is also necessary to watch the level of arrangement of a transdyyusser; most often it is fixed on a special rack by means of the tablet.
Considering danger of tromboembolic episodes, the catheter has to be in an artery only that time during which monitoring of IAD is necessary. Upon termination of measurement the arterial catheter is deleted and apply a compressing bandage.