Pulsoksimetriya appeared rather recently and already now this method of clinical monitoring is considered the obligatory standard at observation for patients in intensive care unit or during performing surgeries. Attractiveness of this technique is that it allows to trace three very important indicators (pulse, saturation of an arterial blood oxygen and a peripheral blood stream) in real time by means of rather inexpensive device.
The physical principle of a pulsoksimetriya is based that usual hemoglobin and oxyhemoglobin absorb red color differently. It gives the chance to perform measurement of amount of oxygenic hemoglobin in an arterial blood (saturation) and also pulse rate and quality of a peripheral blood-groove (photoplethysmogram). Measurement is performed by means of the special sensor which is put on a finger, foot, a wing of a nose or a lobe of an ear of the patient.
There is a lot of errors at this method and they are generally connected with quality of a peripheral blood-groove. As a rule, measurement of a saturation in the conditions of the expressed disturbance of a peripheral blood-groove is less informative as the device begins to increase automatically signal power that leads to numerous hindrances. Besides, movements of the patient and also the separate morbid conditions connected with hemoglobin discoloration in blood - a methemoglobinemia and a carboxyhaemoglobinaemia can interfere with normal measurement. Therefore the method is informative only at observance of several conditions: good condition of microcirculation, lack of active movements of that part of a body on which the sensor and absence at the patient of the states which are characterized by hemoglobin discoloration is located.
Pulsoksimetriya diagnoses a hypoxemic hypoxia, that is the hypoxia connected with decrease in content of oxygen in an arterial blood. It should be noted that despite updating of indicators of the device in real time, some period during which blood with the reduced content of oxygen will reach the sensor (especially is required if the last is located on a finger).
Use of a pulsoksimetriya in anesthesiology allowed to lower number of episodes of a hypoxia in the operating room several times and now is the absolute standard. Pulsoksimetr allows to monitor oxygenation of the patient, to indirectly control oxygen concentration on a breath (in combination with data of an oksimetriya), to control pulse rate and a peripheral blood stream. It is necessary to emphasize that use of a pulsoksimetr does not cancel need of other obligatory methods of monitoring, such as oksimetriya, kapnografiya, monitoring of an ECG and so on.
Pulsoksimetriya is effective for additional control of a preoksigenation (in combination with oksimetriya indicators on an exhalation). At achievement of sufficient level of oxygenation of the patient the device shows a saturation of 99-100% that in combination with oxygen concentration indicators on an exhalation speaks about efficiency of a preoksigenation.
In the course of performance to the patient of an intubation of a trachea or other manipulations connected with the termination of external respiration, the pulsoksimetriya allows to control extent of oxygenation of the patient, preventing thereby development of a hypoxia. However it is necessary to remember that data of this research are late a little as blood needs to do a certain way from lungs to the place on which the pulsoksimetrichesky sensor is installed.
In intensive care unit the pulsoksimetriya is the invaluable assistant at treatment of heavy patients. It allows to carry out diagnostics of various states, for example, respiratory a distress syndrome and also to control efficiency of respiratory therapy. Besides, the pulsoksimetriya is often used for observation of respiratory function of the patient in combination with respiratory rate measuring, the analysis of gas composition of blood and other methods of clinical, tool and laboratory monitoring.
When carrying out IVL the pulsoksimetriya allows to control oxygenation of the patient, in combination with other types of monitoring giving an opportunity to the doctor to pick up the IVL necessary parameters.
Registration of the photoplethysmogram allows the doctor to estimate a condition of a peripheral blood-groove and to diagnose the pathology connected with its disturbance. Measurement of pulse rate allows to estimate heart rate and in combination with monitoring of an ECG to diagnose increase or an urezheniye of a warm rhythm.