Clinical trial NCT06655675: Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women (PART II)
Official title: Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women (PART I and PART II)
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Labor Pain
Keywords: combined spinal epidural (CSE)
fetal bradycardia
ultrasound
velocimetric index
hypertension
Lead sponsor: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Sponsor class: OTHER
First posted: 2024-10-23
Enrollment: 54
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 50
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: DIAGNOSTIC

Brief summary: Combined spinal-epidural (CSE) for labor analgesia has been used for many years and is practiced commonly at our institution, especially when the patient requests immediate pain relief. CSE is not only beneficial for its faster onset of analgesia, but also it is favorable in relation to the need for rescue analgesia, urinary retention, and rate of instrumental delivery compared to the traditional epidural. Despite its beneficial effects, there is a risk of about 15-30% of developing abnormal fetal heart rate following CSE. This is self-resolving with minimal or no intervention. Although the cause of fetal bradycardia is not fully elucidated, variations in uterine artery blood flow after epidural analgesia are thought to be due to the interaction of numerous events related to blockade of sympathetic innervations, fluid administration, maternal hypotension, uterine vascular effects of sympathetic block, fluctuations in circulating catecholamines, and possibly the effect of opioids. Similar mechanism is thought to be a cause of fetal bradycardia after the CSE with its faster onset and superior block.

Maternal or fetal circulation during labor can be assessed using continuous-wave Doppler ultrasound to monitor maternal uterine artery (UtA) and fetal umbilical artery (UmA) velocity waveforms to detect changes in blood flow. The velocimetry indices mentioned above have been often used to assess the changes in the blood flow before and after the induction of epidural analgesia during labor in several studies. Although there are some studies regarding the effect of labor epidural analgesia using velocimetry indices, but there is currently no published study evaluating velocimetry indices of uterine and umbilical arteries before and after the induction of CSE. Thus, the aim of this study is to investigate the impact of CSE to maternal and fetal blood flow to evaluate the relationships.

The investigators hypothesize that both uterine artery and umbilical artery blood flow are reduced after the induction of CSE, which may be responsible for the occurrence of fetal bradycardia.


Eligibility criteria: Inclusion Criteria:

* Written informed consent
* Term pregnant patients requesting labor analgesia
* Singleton pregnancy
* Term pregnant patients in active labor
* ASA\<4
* No evidence of fetal congenital anomalies, fetal compromise or fetal decelerations prior to CSE
* Patients with and without diagnosed hypertensive disorders of pregnancy

Exclusion Criteria:

* Refusal to consent for the study
* Known spinal deformities
* Previous back instrumentation
* Patients with BMI\>50 kg/㎡ due to anticipated technical challenges in Doppler studies

Primary outcomes:
measure: Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes
timeFrame: 10 minutes
measure: Umbilical artery velocimetric index - pulsatility index (PI) at 10 minutes
timeFrame: 10 minutes
measure: Umbilical artery velocimetric index - resistance index (RI) at 10 minutes
timeFrame: 10 minutes
Secondary outcomes:
measure: Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at baseline
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - pulsatility index (PI) at baseline
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - resistance index (RI) at baseline
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 5 minutes
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - pulsatility index (PI) at 5 minutes
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - resistance index (RI) at 5 minutes
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 20 minutes
timeFrame: 20 minutes
measure: Umbilical artery velocimetric index - pulsatility index (PI) at 20 minutes
timeFrame: 20 minutes
measure: Umbilical artery velocimetric index - resistance index (RI) at 20 minutes
timeFrame: 20 minutes
measure: Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes
timeFrame: 5 minutes
measure: Umbilical artery velocimetric index - pulsatility index (PI) at 30 minutes
timeFrame: 30 minutes
measure: Umbilical artery velocimetric index - resistance index (RI) at 30 minutes
timeFrame: 30 minutes
measure: Pain score at baseline - questionnaire
timeFrame: 1 minute
measure: Pain score at 10 minutes - questionnaire
timeFrame: 10 minutes
measure: Pain score at 30 minutes - questionnaire
timeFrame: 30 minutes
measure: Sensory block level at 10 minutes
timeFrame: 10 minutes
measure: Sensory block level at 30 minutes
timeFrame: 30 minutes
measure: frequency of uterine contractions
timeFrame: 10 minutes
measure: Presence of prolonged hypertonic uterine contractions- questionnaire
timeFrame: 30 minutes
measure: Hypotension: systolic blood pressure less than 80% of baseline
timeFrame: 30 minutes
measure: Hypertension: systolic blood pressure greater than 120% of baseline
timeFrame: 30 minutes
measure: Bradycardia: heart rate less than 70% of baseline
timeFrame: 30 minutes
measure: Desaturation: oxygen level <95%
timeFrame: 30 minutes
measure: fetal heart rate at baseline
timeFrame: 5 minutes
measure: fetal heart rate q5 min up to 30 minutes
timeFrame: 30 minutes
measure: presence of fetal bradycardia - questionnaire
timeFrame: 30 minutes
measure: presence of fetal prolonged deceleration - questionnaire
timeFrame: 30 minutes
measure: presence of fetal persistent late decelerations - questionnaire
timeFrame: 30 minutes
measure: presence of fetal non-reassuring variable deceleration - questionnaire
timeFrame: 30 minutes
measure: presence of fetal salutatory variability - questionnaire
timeFrame: 30 minutes
measure: Neonatal weight
timeFrame: up to 24 hours
measure: Apgar score at 1 minute
timeFrame: 1 minute
measure: Apgar score at 5 minutes
timeFrame: 5 minutes
measure: Mode of delivery - questionnaire
timeFrame: up to 24 hours
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Mount Sinai Hospital
state: Ontario
Study officials:
affiliation: MOUNT SINAI HOSPITAL
name: Mrinalini Balki, MD
role: PRINCIPAL_INVESTIGATOR
References: