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

Abstract

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.

Analysis of Epidural Waveform to Determine Correct Epidural Catheter Placement After CSE Labor Analgesia

“…This result was similar to that previously obtained in a completely different setting, such as with epidural catheters previously used for post-cesarean analgesia and about to be removed. 6 …”

“…This result was similar to that previously obtained in a completely different setting, such as with epidural catheters previously used for post-cesarean analgesia and about to be removed. 6 Concerning laboring women, using a commercially available transducer for invasive pressure, Sebbag et al 7 observed no epidural pressure waveforms without priming, and they attributed their findings to anatomical and physiological differences in the lumbar epidural space of parturients. On the contrary, Al-Aamri et al 8 who used an invasive blood pressure transducer reported a pulsatile waveform in 96% of cases in laboring women, after priming the epidural space with 5 mL of saline, as suggested by de Medicis et al 9 However, unlike us, these previous studies in laboring women to date observed epidural waveforms through the epidural needle and not through the epidural catheter.…”

“…Most recently, Milestone Scientific has introduced the Computer Controlled Drug Delivery System 4 , 5 with continuous pressure and waveform sensing technology (CCDDS) to detect and display the pulsatile waveform found in the epidural space, utilizing a high-resolution in-line pressure sensor. 6 …”

“…Most recently, Milestone Scientific has introduced the Computer Controlled Drug Delivery System 4,5 with continuous pressure and waveform sensing technology (CCDDS) to detect and display the pulsatile waveform found in the epidural space, utilizing a high-resolution inline pressure sensor. 6 The purpose of this prospective, single arm, open-label study was to evaluate the sensitivity and specificity of CCDDS technology in detecting epidural pulse waveforms to assess the correct placement of the catheter in the epidural space in parturients who have received CSE for labor analgesia.…”