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Variability of Perfusion Index to Predict Hypotension

Not Applicable
Not yet recruiting
Conditions
Post-spinal Hypotension
Registration Number
NCT06769750
Lead Sponsor
Assistance Publique - Hôpitaux de Paris
Brief Summary

About one-third of deliveries are performed by cesarean section, and this rate is increasing. The standard anesthetic technique for this procedure is spinal anesthesia (SA), which is associated with hypotension in nearly 70% of cases . The mechanism is a sympatholysis leading to a drop in systemic vascular resistance and cardiac output, which can be aggravated by relative hypovolemia. This hypotension is responsible for maternal dizziness, nausea, and vomiting, as well as fetal acidosis, and in extreme cases, fetal circulatory insufficiency.

Currently, it is recommended to prevent post-spinal hypotension through a strategy combining co-loading with fluids and the administration of vasopressors in all patients. However, this non-individualized strategy is not always effective in preventing hypotension and may even be harmful to the mother in cases of excessive fluid administration.

Current guidelines for perioperative fluid management in elective surgery advocate for an individualized approach based on preoperative assessment of preload dependence through cardiac output monitoring. Correcting this relative hypovolemia helps maintain an appropriate blood pressure for the patient's needs.

In parturients, we have shown that evaluating preload dependence by measuring the variation in the time-velocity integral under the aorta (ΔTVI) using cardiac ultrasound before and after a passive leg raising test (PLR) can predict post-spinal hypotension with good sensitivity and specificity. We obtained comparable results using monitoring of the variation in stroke volume by the Clearsight™ system (Edwards Lifesciences, Irvine, California, US), before and after PLR .

However, these technologies have limitations: availability of equipment, cost, operator expertise, and patient echogenicity in the case of ultrasound. Using a non-invasive, simple, and accessible method for monitoring preload dependence that can be used by an untrained operator would help easily identify patients at higher risk for post-spinal hypotension, enabling individualized management.

The main objective of our study is to evaluate the ability of ΔIPELJP to predict post-rachianesthesia hypotension in parturients scheduled for a cesarean section.

Detailed Description

This is a prospective, monocentric study carried out at the level 3 maternity unit of Marseille's Hôpital Nord Patients will be monitored as usual using an SpO2 sensor placed on the index finger of the limb contralateral to the blood pressure cuff, giving the PI value, a blood pressure monitor taking blood pressure (systolic, diastolic and mean) every 2 minutes, and an ECG.

A transthoracic cardiac echocardiogram will be performed with measurement of the sub-aortic time-velocity integral, and the same measurement will be taken 1 min after a passive leg-lift to see whether this maneuver significantly increases systolic ejection volume. The PI value and arterial pressure will be measured at each of these manoeuvres. The same data will be collected one minute after return to the initial position. Thereafter, PI and arterial pressure will be recorded every two minutes until the newborn is delivered.

The pH of the newborn's cord blood is systematically recorded.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
Female
Target Recruitment
45
Inclusion Criteria
  • Parturient women
  • With a term of more than 34 weeks' amenorrhea (SA)
  • Requiring a scheduled caesarean section under spinal anaesthesia at the maternity ward of the Hôpital Nord de Marseille (AP-HM).
  • Patients affiliated to a Social Security System
Exclusion Criteria
  • Urgent caesarean section
  • Contraindication to perimedullary anesthesia
  • Clinical features likely to distort the plethysmographic signal: scleroderma, Raynaud's syndrome, nail pathology, etc.
  • Presence of anti-hypertensive treatment
  • Cardiac arrhythmia
  • Anesthetist not trained in transthoracic cardiac echography
  • Refusal to participate in the study
  • Guardianship or curatorship, safeguard of justice
  • Instable Perfusion Index Signal

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Primary Outcome Measures
NameTimeMethod
ΔIPELJPat the time of cesarean section

This value will be calculated by subtracting the PI one minute after the passive leg lift from the resting value measured one minute before he passive leg lift was performed.

Secondary Outcome Measures
NameTimeMethod
Incidence of hypotension after rachianesthesiaAt the time of cesarean delivery

Defined as a fall in systolic blood pressure of more than 20% between the resting value before lifting the passive leg and the performance of rachi anesthesia, until delivery of the newborn.

- The delta of PI between PI before spinal anaesthesia and minimum and maximum PI values after spinal anaesthesia and until delivery of the newborn,At the time of cesarean delivery

PI will be recorded every minute.

The correlation between ΔIPELJP and ΔITVELJPBefore spinal anaesthesia
Relationship between basal PI and ΔIPELJP to individualize groups at risk of developing hypotensionAt the time of cesarean delivery
Correlation between fetal pH value at cord and relationship with initial PI value, PI variation and ΔITVELJPAt delivery
Maximum doses of norepinephrine in mg/h from the time of rachi anesthesia to delivery of the neonateAt delivery
-Cumulative doses of noradrenaline in mg from rachi anesthesia to neonatal deliveryAt delivery

Trial Locations

Locations (1)

Department of Anesthesia and Intensive Care, Perioperative Medicine, Hôpital Nord,

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Marseille, Marseilles, France

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