Quantifying and personalizing blood patch risk

Abstract

Editor—Providing consent for neuraxial procedures involves explanation and understanding of risk and benefit, and for the former we have increasing evidence.1Cook TM Counsell D Wildsmith JAW on behalf of the RCOA Third National Audit Project Major complications of central neuraxial block: report on the Third National Audit Project of the Royal College of Anaesthetists.Br J Anaesth. 2009; 102: 179-190Abstract Full Text Full Text PDF PubMed Scopus (574) Google Scholar Consenting guidance from the The Association of Anaesthetists of Great Britain and Ireland mentions particularly disclosing information that would be important to the individual patient.2The Association of Anaesthetists of Great Britain and Ireland. Consent for Anaesthesia. London, revised edition 2006.Google Scholar The frequency of postdural puncture headache (PDPH) may be quoted as a percentage depending on procedure, patient, and clinician factors. But what does this number mean for the patient and can we clarify this particular risk any further? More specifically, what is their chance of requiring intervention for a PDPH? We decided to review data from our institution to reflect the risk of requiring an intervention for PDPH more accurately. We calculated epidural blood patch rates after neuraxial procedures (spinal, epidural, or lumbar puncture) at our district general hospital. We obtained the number of spinal and epidural procedures performed and the number of blood patches between April 2010 and March 2013. The number of diagnostic lumbar punctures was obtained from the cerebrospinal fluid samples sent to the laboratory in the same time period. In total, 7185 spinal and 997 epidural procedures were performed in theatre and 830 lumbar punctures on the wards in this time period. Seventeen epidural blood patches were performed, eight after a spinal procedure, giving around a one in 1000 risk, and six after lumbar puncture, giving around a one in 100 risk. Three patches were performed after epidurals, giving around a one in 300 risk, two of which were documented dural taps. All patches performed were successful, data from one were missing, and three patches were repeated before success. Five of the lumbar puncture cases showed evidence of multiple attempts, though much of the documentation was poor and data were missing. Data collection for this project was simple and easy to do. Through education and review of the equipment used, we are now looking to reduce our patch rate after lumbar puncture. When consenting for neuraxial technique, we quote the risk of PDPH and can now add in the risk of requiring intervention (i.e. a blood patch) for this. We believe this gives more meaningful outcome information to patients to inform them better of the risk and consequences of PDPH in our hospital. None declared.