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NCT Number: NCT06813989

Carotid Flow Measurements in Pregnant Women

The goal of this observational study is to reveal the relation between carotid flow changes and post-spinal hypotension in pregnant women between the ages of 20-40. The main question it aims to answer is:

Do the carotid flow blood flow measurements and corrected flow time change before and after spinal anaesthesia related to postspinal hypotension? Participants are already receiving spinal anaesthesia to receive a caesarean section. As part of their regular anaesthesia management protocol, they will answer questions about anaesthesia management. The participants will only examined by ultrasound twice.

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Key information

Age range

20 year–40 year

Sex eligibility

Female

Study type

Observational

Primary location

About this study

In this study, Doppler ultrasound measurements will be taken to evaluate the diameter and flow velocity of the left carotid artery in pregnant women aged 20-40 years, classified as ASA 1-2 term and uncomplicated, upon their arrival at the operating room in the supine position. Measurements will be performed three times at the cricoid level, before the carotid bifurcation, and directly from the arch to mitigate any errors due to the measurer. These measurements will be conducted by the same individual (B.C) and repeated three minutes after returning to the supine position post-spinal anaesthesia, with changes between the two measurements recorded.

The spinal anaesthesia dose will be standardized with 10 mg of heavy bupivacaine and 10 mcg of fentanyl. Hemodynamic data from the time patients enter the operating room until baby delivery will be recorded.

Hypotension during this period will be defined as (1) a decrease in systolic blood pressure >30% or a decrease in mean arterial pressure (MAP) >20% from baseline, or (2) systolic blood pressure <90 mmHg or MAP <65 mmHg. Carotid flow measurements and the amount of crystalloid administered during spinal anaesthesia will be noted in hypotensive and non-hypotensive patients.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • "Uncomplicated term pregnant women aged 20-40 years classified as ASA 1-2.

Exclusion criteria

  • Those diagnosed with preeclampsia or eclampsia or with systolic blood pressure above 160

Individuals with arrhythmia

Individuals with contraindications for spinal anesthesia

Individuals with Ba MI over 40

Those with a gestational age under 36 weeks or over 41 weeks

Individuals with chronic kidney insufficiency (GRF under 60)

Those with carotid stenosis or a history of previous cerebrovascular events

Patients with placental anomalies

Those initially planned for expected delivery but later switched to cesarean after being taken to trauma.

Patients were taken to the operating room with an emergency cesarean decision

In case of failed spinal anaesthesia, those who switched to general anaesthesia before delivery

Treatment and study plan

Carotid Ultrasound

Other

The investigator will perform a carotid ultrasound just 2 cm before the carotid bulb and measure the corrected flow time and flow using Doppler and pulse wave analysis. The corrected carotid flow time will be calculated according to Bazett's equation.

Primary outcomes

  1. postspinal hypotension

    Time frame: from spinal anaesthesia till surgical delivery

    Hypotension is defined as (1) a decrease in systolic blood pressure >30% or a decrease in mean arterial pressure (MAP) >20% from baseline, or (2) systolic blood pressure <90 mmHg or MAP <65 mmHg.

Secondary outcomes

  1. fluid resuscitation

    Time frame: from spinal anaesthesia till surgical delivery

    amount of fluid given for co loading during anaesthesia application

Study contacts

Contact information is provided by the study sponsor or research team.

Berna Caliskan

CONTACT

[email protected]

Berna Caliskan, MD

CONTACT

[email protected]

05067108770

Sponsors and collaborators

Lead sponsor

Haseki Training and Research Hospital

Other

Registry information

Official study title

Evaluation of the Effectiveness of Carotid Flow Measurements in Predicting Post-Spinal Hypotension in Pregnant Women

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Feb 7, 2025
Registry last updated
Mar 18, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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