Changes in Velocimetric Indices of Uterine and Umbilical Arteries Before and After Combined Spinal-epidural Analgesia in Laboring Women (PART II)
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In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Ultrasound.
- Who it may be relevant to
- Registry conditions: Labor Pain. Basic parameters: 18 years — 50 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Canada
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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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)
Overview
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.
Interventions
- Device Ultrasound
Ultrasound scan of the umbilical artery
Primary outcome measures
- Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 10 minutes [Time frame: 10 minutes]
- Umbilical artery velocimetric index - pulsatility index (PI) at 10 minutes [Time frame: 10 minutes]
- Umbilical artery velocimetric index - resistance index (RI) at 10 minutes [Time frame: 10 minutes]
Secondary outcome measures (12)
- Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at baseline [Time frame: 5 minutes]
- Umbilical artery velocimetric index - pulsatility index (PI) at baseline [Time frame: 5 minutes]
- Umbilical artery velocimetric index - resistance index (RI) at baseline [Time frame: 5 minutes]
- Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 5 minutes [Time frame: 5 minutes]
- Umbilical artery velocimetric index - pulsatility index (PI) at 5 minutes [Time frame: 5 minutes]
- Umbilical artery velocimetric index - resistance index (RI) at 5 minutes [Time frame: 5 minutes]
- Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 20 minutes [Time frame: 20 minutes]
- Umbilical artery velocimetric index - pulsatility index (PI) at 20 minutes [Time frame: 20 minutes]
- Umbilical artery velocimetric index - resistance index (RI) at 20 minutes [Time frame: 20 minutes]
- Umbilical artery velocimetric index - systolic/diastolic ratio (S/D) at 30 minutes [Time frame: 5 minutes]
- Umbilical artery velocimetric index - pulsatility index (PI) at 30 minutes [Time frame: 30 minutes]
- Umbilical artery velocimetric index - resistance index (RI) at 30 minutes [Time frame: 30 minutes]
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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Open label
- Primary purpose
- Diagnostic
Study locations
Canada · 1 center
- Mount Sinai Hospital — Toronto
Identifiers
NCT: NCT06655675 · 24-09