False Negative Epidural Aspiration – A Benchtop Investigation

Hasnain Moosvi, Kashif Mahmood, Aisling Kelly, Stephane Blouin, Kevin Nolan, Prof. Conan McCaul

Rotunda Hospital, Dublin, Ireland

Introduction

In order to prevent accidental intrathecal injection and consequent high neuraxial blockade epidural catheters should be aspirated prior to injection of medication. There is no standardized technique for this and there are many cases in the literature in which high neuraxial blockade occurred despite the anesthesia provider reporting a prior negative catheter aspiration.1 We sought to examine the return of aspirate in a benchtop model to determine the optimal method of catheter aspiration. In particular we were interested in the relationship between syringe size, removal of the filter and connector type