Product Detail

Definition of PVI

Pleth variability index (PVI) is a breakthrough measurement technology, which can help clinicians to evaluate the infusion status of patients noninvasive and continuously, effectively conduct fluid management, evaluate the perfusion status of patients to reflect the patient’s volume level, and monitor the trend and effect of liquid therapy. Under the condition of mechanical ventilation or intubation, the PVI value should be between 9 and 14, and under normal conditions, the PVI value should be between 14 and 25.
MAXIME CANNESSON, associate professor of anesthesiology in the Department of Anesthesiology and Perioperative Nursing at the University of California, Irvine, put forward: “It has been proved that PVI has a high accuracy in distinguishing between those who respond to infusion and those who do not, which is the only opportunity to improve the cardiac function and organ blood flow perfusion level by better managing the infusion volume of patients.”

• Infusion management is very important to improve the condition of patients
• The traditional methods to guide infusion management are usually unable to predict infusion reaction
• Newer methods can accurately predict responses, but are invasive or costly
• It has been proved that PVI can help clinicians predict the infusion reaction of patients receiving mechanical oxygen transfusion during surgery, intensive care and general anesthesia
• It has been proved that PVI can help clinicians improve infusion management and reduce lactic acid level compared with standard nursing care

Clinical advantages of PVI

As shown in the figure, PVI has a similar accuracy (0.94) of pulse pressure changes measured during invasive arterial intubation (0.93 area below the curve), which is higher than the heart index (0.56), central vein pressure (0.42) and pulmonary capillary wedge pressure (0.40).
It is confirmed that according to the definition that the cardiac output increases significantly after infusion management, PVI can help clinicians predict the infusion reaction of patients receiving mechanical oxygen infusion under general anesthesia.

• If PVI before capacity expansion> 14%, it can be predicted that the patient will have infusion reaction (81% sensitivity)
• If PVI before capacity expansion< 14%, it can be predicted that the patient will not have infusion reaction (100% specificity)

The higher the PVI value, the more likely the patient is to have infusion reaction. The PVI threshold is 14%. If it is greater than 14%, you can take more active steps to replenish albumin or colloidal solution; If the infusion rate is less than 14%, the infusion rate should be slowed down.

Clinical application of PVI

PVI can effectively assist doctors in fluid management, evaluate patients’ perfusion status to reflect patients’ capacity level, and monitor the trend and effect of fluid therapy through single site monitoring. It can be observed in cooperation with PI.
——Noninvasive monitoring tool for continuous evaluation of local tissue perfusion and systemic circulation perfusion.

• Evaluation of local tissue perfusion:
  PI will change when the local blood flow changes due to the contraction or expansion of skin vessels at the monitoring site. PI can confirm the analgesic effect of epidural anesthesia

• Evaluate systemic perfusion:
  Real time monitoring of physiological conditions is conducted by observing the trend change of PI. The significant decrease of patients’ peripheral circulation indicates clinically important physiological changes, including potential hypothermia, hypovolemia, shock and sepsis.
  For example: evaluation of circulatory function of severed fingers or limbs, limb vascular injury or infarction, vasculitis, vascular stenosis, edema, Raynaud’s disease, regional block, etc

• The greater the PI value, the better the perfusion condition
• PI Normal> 1.0%； Masimo SET can measure 0.02%~20%

PVI measurement technology platform — pulse carbon oxygen blood oxygen detector

Masimo rainbow SET technology is a globally recognized “gold standard” technology for pulse blood oxygen. It has high sensitivity and specificity for antibody movement, anti hypothermia and low perfusion. In addition to providing Masimo SET Plus Oximeter for measurement under the condition of body movement and low blood perfusion, it is also a non-invasive monitoring platform, which can be used to evaluate a variety of blood components and physiological parameters. Previously, invasive or complex processes were required for evaluation.
Masimo SET technology (basic three parameters)

• SpO2
• PR
• PI (blood flow perfusion index)

Rainbow SET technology (Rainbow parameter)

• SpOC
• SpMet
• PVI
• SpHb (non-invasive total hemoglobin)
• SpCO

With the upgradable rainbow SET platform, you can now choose the appropriate rainbow measurement parameters without worrying about the investment in patients.