分娩痛被稱為世界上程度最強的疼痛，劇痛的強應激和對體力的消耗都會對產婦和胎兒（新生兒）產生不利的影響，而無痛分娩在提供有效鎮痛的同時又不影響分娩的程序，因此，國內逐步普及無痛分娩。無痛分娩的實現離不開硬膜外導管的正確放置，那硬膜外導管的位置如何確定呢？
常用氣泡壓縮試驗等方法來確定導管是否位於硬膜外腔，控制導管放置長度和方向來調節導管位置，注射試驗劑量來判斷位置（有無全脊麻），測試麻醉效果判斷位置等，這些方法都是基於臨床經驗，那麼有沒有其他更為客觀的方法呢？
今天分享一篇相關文獻，供參考！
持續硬膜外分娩鎮痛採用硬膜外波形分析確定導管位置
背景：
硬膜外腔壓力具有搏動性，與動脈搏動同步。監測硬膜外波形已被建議作為一種定位硬膜外導管的可靠方法。
目的：
選擇腰硬聯合技術（CSE）用於產婦分娩鎮痛的患者，評價使用連續壓力波形感測技術的計算機控制給藥系統（CCDDS）評估硬膜外導管在硬膜外腔內位置是否正確的敏感性和特異性。
方法：
選擇40例CSE分娩鎮痛成功的健康產婦。所有檢測到與心率同步搏動波形的病例均為真陽性；對所有無搏動波的病例進行隨訪。如果這些病人最終不得不重新放置硬膜外導管，則認為這些病例為真陰性。如果在分娩期間觀察到成功鎮痛時沒有脈搏波，則認為這些病例為假陰性。
結果：
33例患者出現與心率同步的搏動波形，鎮痛效果良好。5例因單側鎮痛或導管阻塞而無搏動波形（真陰性）。2例患者鎮痛有效，但未能觀察到明顯的搏動波形。硬膜外導管壓力波形分析的敏感性為95%，陽性預測值為100%，特異性為100%，陰性預測值為60%。
結論：
CCDDS經硬膜外導管記錄脈搏波具有較高的敏感性和陽性預測價值，有助於正確放置硬膜外導管。
關鍵詞：
腰硬聯合阻滯；硬膜外鎮痛；硬膜外脈搏波。
原文摘要
Analysis of Epidural Waveform to Determine Correct Epidural Catheter Placement After CSE Labor Analgesia
Background： The epidural pressure is pulsatile and synchronized with arterial pulsations。 Monitoring the epidural waveform has been suggested as a technique to reliably confirm the appropriate localization of the epidural catheter。
Objective： The aim of this study was to evaluate the sensitivity and specificity of the Computer Controlled Drug Delivery System with continuous pressure and waveform sensing technology （CCDDS） （CompuFlo® CathCheck™） as an instrument to assess the correct placement of the catheter in the epidural space in parturients who have received combined spinal-epidural technique （CSE） for labor analgesia。
Methods： We enrolled 40 consecutive healthy patients undergoing CSE labor analgesia with successful analgesia。 All the cases in which pulsatile waveforms in synchrony with heart rate were detected were considered to be true positives； all the cases in which there was the absence of pulsatile waves were followed up。 If these patients had to eventually relocate or manipulate the epidural catheter， they were considered to be true negative。 If the absence of pulse waves was observed in the presence of successful analgesia during labor， the patients were considered to be false negatives。
Results： Pulsatile waveforms synchronous with heart rate were observed in 33 cases associated with adequate analgesia。 In 5 cases， the pulsatile waveforms were absent due to unilateral analgesia or catheter occlusion （true negatives）。 In 2 cases， the patients had effective analgesia but we were not able to observe a distinct pulsatile waveform。 The pressure waveform analysis through the epidural catheter had a sensitivity of 95%， a positive predictive value of 100%， a specificity of 100% and a negative predictive value of 60%。
Conclusion： Pulsatile pressure waveform recording with CCDDS through the epidural catheter resulted in high sensitivity and positive predictive value which can help the proper placement of the epidural catheter。
Keywords： combined epidural block； epidural analgesia； epidural pulse waves。