Confirmation of Epidural Catheter Location by Epidural Pressure Waveform Recordings by the Compuflo&sup&® &/sup& Cath-Checker System

摘要

Background: Pulsatile waveforms originating from the spinal cord and transmitted through the dura in synchrony with heart rate have been used to confirm the epidural location of the catheter. Lumbar epidural space identification using the CompuFlo~(?) instrument has been reported and validated. The aim of this preliminary study was to evaluate the new CompuFlo instrument which allows the identification of pulsatile waveform recordings. Methods: We tested 30 epidural catheters previously successfully used for post cesarean analgesia and about to be removed. All patients were given 5 mL 2% lidocaine to test the catheter before its removal. After priming with 5 mL saline, the catheter was connected to CompuFlo~(?) to record the occurrence of pulsatile waveforms and/or their disappearance during its removal. Results: Pulsatile waveforms were observed in all the catheters properly located in the epidural space and disappeared when the catheter was extracted from the epidural space. No waveforms were recorded in 2 cases in which no sensory block occurred after the test dose (catheter dislodgement). The pressure waveform analysis through the epidural catheter had a sensitivity of 100%, a positive predictive value of 100%, a specificity of 100% and a negative predictive value of 100%. Conclusions: In this preliminary trial pulsatile pressure waveform recording with CompuFlo~(?) CathCheck? System through the epidural catheter resulted in high sensitivity and positive predictive value.