Pupillary Light Reflex to Predict Post-Spinal Hypotension in Elective Cesarean Delivery
For patients and families
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: Not applicable- observational study.
- Who it may be relevant to
- Registry conditions: Hypotension, Spinal Anesthesia, Cesarean Delivery. Basic parameters: 18 years — 45 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
- Center list to be confirmed — check the primary protocol.
- 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
Pupillary Light Reflex for Predicting Hypotension Risk After Spinal Anesthesia for Elective Cesarean Section: A Prospective Observational Cohort Study
Overview
This prospective observational cohort study investigates whether pre-anesthetic pupillary light reflex (PLR) parameters can predict the risk of hypotension following spinal anesthesia in women undergoing elective cesarean section. Spinal anesthesia-induced hypotension is common, with reported incidence rates of 50-90%, and current predictors such as baseline blood pressure and BMI have limited accuracy. PLR, a sensitive marker of autonomic nervous system balance, may offer a simple, objective, and non-invasive tool for identifying patients at higher risk. The study evaluates pupillary reaction latency and other PLR parameters and correlates them with post-spinal blood pressure changes to determine their predictive value.
Detailed description
Spinal anesthesia is the standard technique for elective cesarean delivery, yet it is frequently associated with maternal hypotension due to sympathetic blockade. According to the study protocol, spinal anesthesia-induced hypotension (SAIH) occurs in 50-90% of cases, and currently available predictors-including baseline blood pressure, BMI, and block height-demonstrate limited accuracy (AUC \<0.65). The pupillary light reflex (PLR) is a sensitive indicator of autonomic nervous system balance, and pupillary reaction latency may reflect parasympathetic conduction efficiency. As noted in the protocol, no published studies have evaluated PLR as a predictor of hypotension after spinal anesthesia in obstetric patients.
This prospective observational cohort study aims to determine whether pre-anesthetic PLR parameters, particularly pupillary reaction latency, can predict the occurrence and severity of hypotension following spinal anesthesia for elective cesarean section. Additional pupillometry parameters-including baseline diameter, constriction velocity, and minimum diameter-will also be assessed. Measurements are obtained using a handheld pupillometer after 5 minutes of dark adaptation, with three readings taken at 60-second intervals.
Following spinal anesthesia with hyperbaric bupivacaine and fentanyl, maternal blood pressure is monitored every 5 minutes for the first 20 minutes. The primary outcome is hypotension, defined as a \>20% decrease in systolic blood pressure. Secondary outcomes include severe hypotension, vasopressor requirements, maternal symptoms, and neonatal Apgar scores and umbilical artery pH.
Statistical analysis includes ROC curve evaluation, Youden's index for cutoff determination, and multivariate logistic regression. The study involves no interventions beyond routine care, and pupillometry is non-invasive and safe. Findings may support the development of a novel, objective, and clinically useful predictor for SAIH in obstetric anesthesia.
Interventions
- Other Not applicable- observational study
This study does not involve any investigational drugs, devices, or therapeutic interventions. Pupillometry is a non-invasive measurement performed as part of the observational assessment and is not considered an intervention.
Primary outcome measures
- Incidence of Hypotension After Spinal Anesthesia [Time frame: 0-20 minutes after spinal anesthesia]
Secondary outcome measures (5)
- Incidence of Severe Hypotension [Time frame: 0-20 minutes after spinal anesthesia]
- Total Vasopressor Dose Administered [Time frame: Intraoperative period (first 20 minutes post-spinal)]
- Maternal Symptoms Associated With Hypotension [Time frame: Intraoperative period]
- Neonatal Apgar Scores [Time frame: 1 minute and 5 minutes postpartum]
- Umbilical Artery pH [Time frame: Immediately after delivery]
Eligibility criteria
Inclusion criteria
ASA II Term pregnancy ≥37 weeks Singleton pregnancy Elective cesarean section Age 18-45 years Written informed consent
Exclusion criteria
Emergency cesarean section Hypertensive disorders Diabetes mellitus Cardiovascular disease Neurological or autonomic disorders Ophthalmic disease Medications affecting autonomic function BMI >40 kg/m² Failed spinal anesthesia
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Observational model
- Cohort
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07678723 · DFM-IRB 00012367- 26-06-005