One of the functions of a machine of hemodialysis is to measure and show arterial pressures as well as to inform the operator when these pressures float outside of an established limit of alarm. It is of, however, the responsibility for the caregiver which supervises and interprets these readings of pressure to determine how effectively or without risk a treatment is carried out and for launching suitable interventions. A comparison of the readings of pressure of the preceding treatments of the patient at the similar speeds of pump of blood should be made each treatment to determine if the currently shown pressures are typical or can be an indication of a problem. It is this comparison and the knowledge of the acceptable limits of arterial pressure which make it possible caregivers to provide the care of quality for patients of hemodialysis. The arterial and venous monitoring of pressure provides information concerning the vascular access and the circuit extracorporeal in which the blood of a patient circulates. The correct interpretation of these pressures can: 1. prevents the hemolysis and the microboules in the piping of blood regulated of the excessive negative pressure;
2. evaluate the vascular access for to proportioned flow of blood or the problems such as the venous stenose;
3. ensure precise blood cross the dialyzer for the optimal therapy of dialysis (Bosch and Ronco, 1993;
Cogan and Schoenfeld, 1991; Francos and others., 1983; Sharp, Lancaster, and Binkley, 1995; Taking away, Sherman, and Nosher, 1992; Base national kidney [NKF], 1997a, 1997b; Polaschegg, 1995; Twardowski, Haynie, and Moore, 1999).To increase the effectiveness of dialysis, high speeds of pump of blood are frequently employed. With the limited diameters of the needles or catheters of dent, gradients with high arterial pressure are created in the lines of blood and high speeds of blood in the narrow segments. This high speed of blood increases the forces of shearing, which can the red globules of hemolyze. If a fold or an occlusion occurs in the circuit extracorporeal, the speed of blood can be increased so much that, without warning (according to the place of the fold or occlusion), the massive hemolysis can occur. The symptoms of the hemolysis include faintness, nausea, the pain of trunk, the brevity of the breath, the abdominal pain, the back pains, cyanosite, the headache, and [or decreased] the increased blood pressure. The gallstones and the pancreatite frequently develop after a haemolytic episode (Twardowski and others., 1999).To determine if the hemolysis occurs, to place a sample of blood in a tube of clot and to turn to separate the serum. If the serum seems pink, the test can be positive for the hemolysis. The pink serum is due to the presence of free haemoglobin, a very high concentration of lactate deshydrogenase of serum, and to the almost complete disappearance of the haptoglobin (Twardowski and others., 1999). To confirm the hemolysis, to repeat this test. If you re-examine the pink serum, to send a specimen of blood to the laboratory to check the hemolysis. Very while waiting for the laboratory results, to inform the doctor of the potential of the hemolysis.
Monitoring of arterial pressure. The blood pressures can be prepump or postpump supervised according to the type of the machine of hemodialysis and the piping of blood being employed. The readings of pressure for the prepump against the arterial monitors of postpump provide information different concerning the treatment from hemodialysis and/or the access of the patient. If the caregiver at the time of choosing that the type of monitoring of blood pressure must be carried out (based on the pressure of the machine supervising of the possibilities and the availability of piping of blood), the choice should be based on the type of necessary information to better address the state of a patient. For example, of the arterial vascular problems of access better are indicated with the arterial monitoring of prepump while problems of coagulation better are indicated with the arterial monitoring of postpump. Monitoring of arterial pressure of Prepump. The blood pressure of supervising Prepump reflects the pressure exerted with the blood of traction of the arterial member of the vascular access of the patient to the pump of blood. Because of this “which draws” the effect or the aspiration, the reading of blood pressure of prepump is a negative number. This reading of arterial pressure describes the quantity of necessary aspiration to construct the whole speed of pump of blood on the machine of hemodialysis and described better the flow of blood of the vascular access of the patient in the circuit extracorporeal.
