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Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women (PART II)

Not Applicable
Recruiting
Conditions
Labor Pain
Registration Number
NCT06655675
Lead Sponsor
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
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.

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
Female
Target Recruitment
54
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Primary Outcome Measures
NameTimeMethod
Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes10 minutes

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 10 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - pulsatility index (PI) at 10 minutes10 minutes

Umbilical artery velocimetric index - pulsatility index (PI) will be measured 10 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - resistance index (RI) at 10 minutes10 minutes

Umbilical artery velocimetric index - resistance index (RI) will be measured 10 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Secondary Outcome Measures
NameTimeMethod
Umbilical artery velocimetric index - pulsatility index (PI) at 20 minutes20 minutes

Umbilical artery velocimetric index - pulsatility index (PI) will be measured 20 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at baseline5 minutes

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured prior to combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - pulsatility index (PI) at baseline5 minutes

Umbilical artery velocimetric index - pulsatility index (PI) will be measured prior to combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - resistance index (RI) at baseline5 minutes

Umbilical artery velocimetric index - resistance index (RI) will be measured prior to combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 5 minutes5 minutes

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 5 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - pulsatility index (PI) at 5 minutes5 minutes

Umbilical artery velocimetric index - pulsatility index (PI)will be measured 5 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - resistance index (RI) at 5 minutes5 minutes

Umbilical artery velocimetric index - resistance index (RI) will be measured 5 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 20 minutes20 minutes

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 20 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - resistance index (RI) at 20 minutes20 minutes

Umbilical artery velocimetric index - resistance index (RI) will be measured 20 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes5 minutes

Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) will be measured 30 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - pulsatility index (PI) at 30 minutes30 minutes

Umbilical artery velocimetric index - pulsatility index (PI) will be measured 30 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Umbilical artery velocimetric index - resistance index (RI) at 30 minutes30 minutes

Umbilical artery velocimetric index - resistance index (RI) will be measured 30 minutes after combined spinal epidural, with the uterus in relaxed and contracted states.

Pain score at baseline - questionnaire1 minute

Pain score - verbal numeric rating scale (0-10) prior to combined spinal epidural

Pain score at 10 minutes - questionnaire10 minutes

Pain score - verbal numeric rating scale (0-10) at 10 minute after combined spinal epidural

Pain score at 30 minutes - questionnaire30 minutes

Pain score - verbal numeric rating scale (0-10) at 30 minute3 after combined spinal epidural

Sensory block level at 10 minutes10 minutes

Sensory block level at 10 minutes following combined spinal epidural

Sensory block level at 30 minutes30 minutes

Sensory block level at 30 minutes following combined spinal epidural

frequency of uterine contractions10 minutes

The number of contractions on the monitor in a 10 minute period.

Presence of prolonged hypertonic uterine contractions- questionnaire30 minutes

Presence of prolonged hypertonic uterine contractions as measured by the monitor

Hypotension: systolic blood pressure less than 80% of baseline30 minutes

Systolic blood pressure \< 80% of baseline, monitored q5 for 30 minutes following combined spinal epidural

Hypertension: systolic blood pressure greater than 120% of baseline30 minutes

Systolic blood pressure \> 120% of baseline, monitored q5 for 30 minutes following combined spinal epidural

Bradycardia: heart rate less than 70% of baseline30 minutes

Heart rate \< 70% of baseline or a heart rate \< 50bpm, monitored q5 for 30 minutes following combined spinal epidural

Desaturation: oxygen level <95%30 minutes

Oxygen level \<95%, monitored q5 for 30 minutes following combined spinal epidural

fetal heart rate at baseline5 minutes

fetal heart rate at baseline, prior to combined spinal epidural

fetal heart rate q5 min up to 30 minutes30 minutes

fetal heart rate q5 min up to 30 minutes following combined spinal epidural

presence of fetal bradycardia - questionnaire30 minutes

presence of fetal bradycardia (fetal heart rate \<110)

presence of fetal prolonged deceleration - questionnaire30 minutes

presence of fetal prolonged deceleration (fetal heart rate \<110/min lasting less than 10 minutes)

presence of fetal persistent late decelerations - questionnaire30 minutes

presence of fetal persistent late decelerations will be recorded

presence of fetal non-reassuring variable deceleration - questionnaire30 minutes

presence of fetal non-reassuring variable deceleration will be recorded

presence of fetal salutatory variability - questionnaire30 minutes

presence of fetal salutatory variability (FHR change\>25beats) will be recorded

Neonatal weightup to 24 hours

Neonatal weight measured after delivery in grams minutes

Apgar score at 1 minute1 minute

Apgar score at 1 minute

Apgar score at 5 minutes5 minutes

Apgar score at 5 minutes

Mode of delivery - questionnaireup to 24 hours

Mode of delivery will be recorded as vaginal, assisted (forceps or vacuum), or cesarean

Trial Locations

Locations (1)

Mount Sinai Hospital

🇨🇦

Toronto, Ontario, Canada

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