Evaluation of pleth variability index in the monitoring of noxious stimulus

Abstract

Objective To investigate whether the pleth variability index (PVI),a noninvasive and continuous tool,was to predict the nociceptive stimulus.Methods Patients with ASA status Ⅰ-Ⅱ undergoing gastric operation were randomly divided into two groups:tracheal intubation general anesthesia (group GA) and combined general-epidural anesthesia (group GE) in 30 cases.Heart rate(HR),mean radial artery blood pressure(MBP),perfusion index(PI),PVI were recorded before and after the skin incision.Results The skin incision did not affect the HR and MBP in two groups.The PI in group GA decreased significantly from(2.7 ±0.6)％to (0.77±0.28)％ and (0.7±0.4)％ at 1 min and 5 min after the skin incision.The PVI increased significantly form (10.8±2.6)％ to (23.7 ±3.6)％ and (26.6 ±4.1)％ at 1 min and 5 min after the skin incision.Both the PVI and the PI had no significant change in group GE after the skin incision.There were significant differences of PI and PVI between two groups after the skin incision.A significant negative correlation was observed between the changes in PI and PVI before and after the skin incision.Conclusions The PVI is a noninvasive and effective tool to monitor the patient's noxious stimulation. Key words: Perfusion index; Pleth variability index; Noxious stimulus