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Completed

NCT Number: NCT03603574

Epidural Waveform Analysis for Thoracic Epidural Blocks

Epidural waveform analysis (EWA) provides a simple confirmatory adjunct for loss-of-resistance (LOR): when the needle/catheter tip is correctly positioned inside the epidural space, pressure measurement results in a pulsatile waveform. Epidural waveform analysis can be carried out through the tip of the needle or the catheter. In this randomized trial, the objective is to compare epidural waveform analysis through the needle (EWA-N) and through the catheter (EWA-C) for thoracic epidural blocks.

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Key information

Conditions

Surgical Procedure, Unspecified

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Hospital Clínico Universidad de Chile, Santiago, RM, Chile

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About this study

The epidural space is most commonly identified with loss-of-resistance (LOR). Though sensitive Epidural waveform analysis (EWA) provides a simple confirmatory adjunct for LOR. When the needle (or catheter) is correctly positioned inside the epidural space, pressure measurement at its tip results in a pulsatile waveform synchronized with arterial pulsations Currently, there exist two different methods for EWA. Since local anesthetic (LA) is administered through the catheter, pressure transduction through its tip ensures that it is properly positioned inside the epidural space prior to LA injection. Alternately, EWA can be performed through the needle prior to blind advancement of the epidural catheter.

Thus, in this randomized trial, the aim is to compare epidural waveform analysis through the needle (EWA-N) and through the catheter (EWA-C) for thoracic epidural blocks. The hypothesis is that, compared to EWA-C, EWA-N will result in a shorter performance time.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • age between 18 and 80 years
  • American Society of Anesthesiologists classification 1-3
  • body mass index between 20 and 35

Exclusion criteria

  • adults who are unable to give their own consent
  • coagulopathy
  • renal failure
  • hepatic failure
  • allergy to local anesthetic
  • pregnancy
  • prior surgery in the thoracic spine

Treatment and study plan

EWA through the needle

Device

In the EWA-N group, 5 mL of normal saline are injected through the epidural needle after the occurrence of loss-of-resistance (LOR). The needle is connected to the pressure transducer. A satisfactory endpoint is defined as the presence of waveforms synchronized with arterial pulsations. In the absence of pulsatile waveforms, the operator injects an additional 2.5 mL-bolus of normal saline through the epidural needle and reconnects the latter to the pressure transducer. If no waveforms are detected after the second injection, the operator removes the needle and reattempts the epidural block at a different intervertebral level. A maximum of 3 levels is permitted: if waveforms are still absent at the third level, the operator simply accepts LOR as the technical endpoint.

EWA through the catheter

Device

In the EWA-C group, the epidural catheter is advanced 5 cm beyond the needle tip after the occurrence of LOR. Subsequently, the operator injects 5 mL of normal saline through the catheter and the latter is connected to the pressure transducer via the sterile, rigid extension tubing. A satisfactory endpoint is defined as the presence of waveforms. In the absence of pulsatile waveforms, the operator injects an additional 2.5 mL-bolus of saline through the catheter and reconnects the latter to the pressure transducer. If no waveforms are detected after the second injection are still absent at the third level, the operator simply accepts this position for catheter placement (intent-to-treat analysis).

Primary outcomes

  1. Performance time of block

    Time frame: From skin infiltration until local anesthetic administration through the needle or catheter, up to 60 minutes

    temporal interval in minutes between skin infiltration and local anesthetic administration through the epidural catheter (after obtaining a satisfactory waveform either through the needle or through the catheter depending on randomized group assignment).

Secondary outcomes

  1. Incidence of successful epidural block

    Time frame: 15 minutes after the administration of local anesthetic through the epidural catheter

    bilateral block to ice in at least 2 dermatomes

  2. Procedural pain during epidural block assessed by the numeric rating scale

    Time frame: From the performance of the epidural block until induction of general anesthesia, up to 2 hours

    pain in the back of the patient, related to the performance of the epidural block, using a numeric rating scale from 0 to 10 points (0=no pain and 10= worst imaginable pain)

  3. Postoperative pain related to surgical incision assessed by the numeric rating scale

    Time frame: twice a day from the arrival at PACU or until catheter removal, up to 5 days

    pain at rest and upon deep breathing/coughing, measured using a numeric rating scale from 0 to 10 points ((0=no pain and 10= worst imaginable pain)

  4. Local anesthetic consumption

    Time frame: once a day from the arrival at PACU or until catheter removal, up to 5 days

    amount of local anesthetic consumed

  5. Breakthrough opioid consumption (if required)

    Time frame: once a day from the arrival at PACU or until catheter removal, up to 5 days

    amount of opioids consumed

  6. Incidence of adverse events

    Time frame: Once a day from catheter insertion until removal, up to 5 days

    side effects related to the performance of the epidural block (eg, dural/vascular puncture, paresthesia) or breakthrough opioids (nausea, vomiting, pruritus, somnolence, respiratory depression)

Sponsors and collaborators

Lead sponsor

McGill University Health Centre/Research Institute of the McGill University Health Centre

Other

Collaborators

  • Ramathibodi Hospital
  • University of Chile

Registry information

Official study title

A Randomized Comparison Between Epidural Waveform Analysis Through the Needle Versus the Catheter for Thoracic Epidural Blocks

Important dates

Study start
2018
Primary completion
2019
Study completion
2019
First posted
Jul 27, 2018
Registry last updated
Feb 6, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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