monitoring Of Central Venous Pressure(CVP) Essay

Management/monitoring Of Central Venous Pressure(CVP) Essay Management/monitoring Of Central Venous Pressure(CVP) â€" Essay Example > The care management of an adult patient with central venous lineIntroductionManagement of Central venous pressure is essential in treating the patients with septic shock. Doctors find the need of maintaining CVP while adjusting cardiac preload, contractility, after-load to balance systemic oxygen delivery on demand. Maintenance of adequate central venous pressure helps in carrying out hemodynamic adjustments and maximizing mixed or central venous oxygen saturation. In general patient need CVP greater than 8mm Hg in case of one lactate greater than 4mmol/L and initial fluid challenge with 20mL/Kg of crystalloid equivalent. Management of CVP includes maintaining CVP, considering blood products, maintaining pressure in mechanically ventilated patients, in the cases to increase abdominal pressure and in the cases of septic patients having multi-factorial aspects that demand CVP. 2. Literature Review2.1 General View about CVP: CVP is a direct measurement of the blood pressure in the ri ght atrium and vena cava. The system acquires this pressure threading a central venous catheter into any of various large veins in the cavity. A pressure monitoring assembly in distal port of a multilumen central vein catheter helps in monitor the CVP. The CVP catheter is a significant tool to assess the right ventricular function and systemic fluid status. In normal conditions, the CVP is 2-6mm Hg. CVP increases due to over-hydration that increases venous return. The heart failure or PA stenosis also may lead to venous congestion as it limits the venous outflow. CVP decreases below normal due to hypo-volemic shock from haemorrhage. This may be due to fluid shift and dehydration. The mechanical negative pressure used for high spinal cord injuries also can lead to the decrease of CVP. Considering above-mentioned measurements, the CVP catheter is an important tool for treatment. The monitoring is essential in the cases of rapid infusion, infusion of hypertonic solutions and medicati ons that may damage veins and venous blood assessment. 2.2 Definition and Measurement: According to publications of Sepsis Surviving Campaign, there are no definite calculations provided for Central Venous Pressure. Clinicians like to have a not that central venous pressure as an estimate of volume status that is underestimated in patients receiving positive end expiratory pressure. This is due to absence of measurement tool to account for the effects of PEEP on CVP. 2.3During Liver Transplantations: The effect of low central venous pressure is a factor in transfusion requirements of blood products during liver transplantations and has considerable effect. According to Massicotte et al observation in 2006 regarding liver transplantations, maintaining low central venous pressure through restriction of volume replacement corrected the coagulation defects with plasma transfusion. The basis is regarding the observation of the results in 100 liver transplantations during a two-year peri od. They concluded that the avoidance of plasma transfusion and maintenance of low CVP before anhepatic phase finds its association with RBC transfusions during liver transplantations. This study supports practicing of lowering CVP with phlebotomy in order to reduce blood loss during liver dissection without harmful effect. 2.4 Relationship with Arterial Blood Pressure: The Arterial Blood Pressure is dependent on the product of cardiac output and peripheral resistance. Heart rate and stroke volume control cardiac output. The stroke volume is in turn, related with myocardial contractility and blood volume. The central venous filling or central venous pressure depends on the above-mentioned conditions. Due to this, the venous pressure originates from the arterial pressure. This is in turn, transmitted through the capillary pressure into the venous reservoir. The effects of three factors that include circulation then calculate the CVP. Those three effects are Cardiac pump action, Cir culating blood volume and vascular tone. Cardiac pump action contains inflow that accelerates venous flow and outflow that impedes the venous pressure. The circulating blood volume is a determining factor in the maintenance of central venous pressure. This is because the venous side of vascular system accommodates 50 to 55 percent of total blood volume. Vascular tone refers to external pressure exerted on veins. This depends on contractility of veins, as the veins are resistance vessels. The stimulation of alpha-receptor sites can result in vasoconstriction. Other factors that contribute to external and lateral pressure are pressure by skeletal muscles, tone and pump valve effects. The tissue pressure and respiratory movements also result in exerting CVP. However, the CVP is not an index of blood volume per second as it is the analysis of the interrelated effects of the blood volume, cardiac pump action and vascular tone.