Epidural Waveform Analysis for Thoracic Epidural Blocks

McGill University

Status: Completed

Conditions: Surgical Procedure, Unspecified

Treatments: Device: EWA through the needle; Device: EWA through the catheter

Study type: Interventional

Funder types: Other

Identifiers

NCT03603574

2019-4669

Details and patient eligibility

About

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.

Full description

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.

Enrollment: 120 patients

Sex: All

Ages: 18 to 80 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

---

120 participants in 2 patient groups

EWA through the needle

Experimental group

Description:

EWA through the needle group, 5 mL of normal saline are injected through the epidural needle after the occurrence of LOR. The needle is subsequently connected to the pressure transducer (leveled with the heart) via the sterile, rigid extension tubing. A satisfactory endpoint is defined as the presence of waveforms synchronized with arterial pulsations.

Treatment:

Device: EWA through the needle

EWA through the catheter

Experimental group

Description:

EWA through the catheter 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 synchronized with arterial pulsations.

Treatment:

Device: EWA through the catheter