Agreement Between Laterality of Tsui Test and Laterality of Color Flow Doppler Signals During Labor Epidural Analgesia

Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Status: Completed

Conditions: Labor Pain

Treatments: Device: Doppler ultrasonography; Device: Tsui test

Study type: Observational

Funder types: Other

Identifiers

NCT05281991

22-01

Details and patient eligibility

About

Epidural analgesia for relief of labor pain is a very common, safe and reliable technique that requires placement of a catheter in the epidural space. About 5% of labor epidural catheters may need to be re-sited due to failure of analgesia. This is often caused by malposition of the epidural catheter. Many factors may influence the position of the tip of the epidural catheter and the resulting spread of local anesthetic solution within the epidural space and consequently the quality of labor pain management. The electrical stimulation of the epidural catheter, commonly known as Tsui test, can reliably confirm its positioning within the epidural space if this stimulus produces a muscular twitch under a certain current amplitude threshold. This muscular response is unilateral in 90% of the cases, not having any relationship between unilaterality and unsatisfactory catheter performance. It is unknown if this unilateral response has any correlation with the actual position of the catheter tip in terms of right or left side of the epidural space. Furthermore, the Tsui test does not give any information on the spread of anesthetic solution into the epidural space. Recent investigation shows that color flow doppler ultrasound during fluid injection through the epidural catheter may be helpful in determining the laterality of the tip of the epidural catheter; furthermore it may be able to inform about the spread the anesthetic solution, which is a limitation of the Tsui test. The investigators will perform an observational study to investigate the response patterns of Tsui test and Color flow Doppler ultrasound in the obstetric population. Women who have delivered under epidural analgesia will be approached for the study before the epidural catheter is removed. The investigators aim to characterize the laterality and current thresholds of Tsui test response and the laterality of the lumbar epidural catheter tip by color doppler ultrasound. The investigators hope to describe the findings and to correlate them with other clinical outcomes.

Enrollment: 25 patients

Sex: Female

Ages: 18 to 55 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Patients who have delivered vaginally under epidural anesthesia

Exclusion criteria

• Patients who refuse, are unable to give or have withdrawn consent
• Patients unable to communicate fluently in English.
• Patients who experience fetal or maternal complications during delivery.

Trial design

25 participants in 1 patient group

Patients who had an epidural placed for labour

Description:

Patients who had an epidural placed for labour may take part. Study procedures will take place after delivery and prior to removal of the epidural catheter.

Treatment:

Device: Tsui test

Device: Doppler ultrasonography