Application of Surgical Pleth Index (SPI) in Pain Monitoring
（长按 识别二维码 搜索更多麻醉学知识点） 【Definition】 The Surgical Pleth Index (SPI) is a monitoring tool that measures the photoplethysmographic signal from the fingertip to monitor the nociception-anti-nociception balance during general anesthesia. 【Principle】 Stress stimuli activate the peripheral sympathetic nervous system, inducing distal vascular contraction. By measuring the absorption of red light from the fingertip, the photoplethysmographic pulse … Read more