Distinguishing cerebrospinal fluid from mepivacaine using the pH test in patients undergoing elective cesarean section with combined spinal-epidural anesthesia

JA Clinical Reports

Kunihisa Hotta¹  Hiromi Ikegami²  Yoshie Toba² 

[1] Department of Anesthesiology and Critical Care Medicine, Jichi Medical University, Tochigi, Japan;Department of Anesthesiology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu city, 430-8558, Shizuoka, Japan;

关键词: Cerebrospinal fluid;    Acid-base equilibrium;    Epidural anesthesia;    Spinal anesthesia;    Mepivacaine;   

DOI  :  10.1186/s40981-020-00383-y

来源: Springer

【 摘 要 】

IntroductionIn single-space combined spinal-epidural anesthesia (CSEA), it is important to correctly determine if the fluid coming out of the spinal needle is cerebrospinal fluid (CSF) or the liquid used in the loss of resistance (LOR) technique. In this study, we used mepivacaine for LOR and measured the pH values of CSF and mepivacaine to determine whether the pH test is a reliable method to confirm CSF when performing single-space CSEA.MethodsThis clinical trial included 47 full-term pregnant women who underwent cesarean section. Single-space CSEA was administered at the lumbar intervertebral space using a small amount of mepivacaine for LOR. The pH values of CSF and mepivacaine were determined by the color of the test strip immediately after dropping. The area under the curve (AUC) for the pH values was calculated to determine the cutoff value for distinguishing between CSF and mepivacaine.ResultsThe median pH values were 7.7 (7.1–8.0) and 6.2 (5.9–6.8) for CSF and mepivacaine, respectively. When the cutoff value of pH for distinguishing CSF from mepivacaine was 7.1 or greater, the AUC was 1.0 (100% sensitivity and specificity). Our result demonstrated that CSF can be correctly distinguished from mepivacaine in patients undergoing cesarean section under single-space CSEA using a cutoff value of pH 7.1.ConclusionThe pH test is a simple and reliable method to confirm CSF when performing single-space CSEA with mepivacaine for LOR.Trial registrationAccuracy of pH test paper for cerebrospinal fluid during spinal anesthesia: prospective study in healthy pregnant women under scheduled caesarean section; University Hospital Medical Information Network, UMIN000036454. Registered 1 May 2019

【 授权许可】

CC BY