Predictability of Preoperative Carotid Artery Corrected Flow Time for Hypotension After Spinal Anesthesia in Patients Undergoing Cesarean Section

The purpose of this study was to investigate the incidence of hypotension after spinal anesthesia in patients undergoing cesarean section as predicted by preoperative carotid artery corrected flow time measured by Doppler ultrasound. Before entering the operation room, Two inspectors perform two measurements of carotid artery corrected blood flow time respectively, and an average of the four measurements is calculated and analyzed. At this time, the patient's posture is supine, and the head is turned about 30 degrees to the left. Corrected blood flow time (FTc) is measured using carotid ultrasound as previously described by Blehar and colleagues. Corrected blood flow time is calculated by Bazett's formular and Wodey's formular by evaluating a single cycle after several successive cycles have reached a stable and acceptable quality level.

The occurrence of hypotension is recorded from the spinal anesthetic injection until the fetus is delivered.

The definition of hypotension after spinal anesthesia is that the systolic blood pressure drops to 80 mmHg, less than 75% of the baseline value, or even if it does not meet the former criteria, symptoms that are consistent with hypotension (dizziness, dizziness, dyspnea, nausea or vomiting).

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Key information

Conditions

Cesarean Section

Age range

20 year–40 year

Sex eligibility

Female

Study type

Observational

Primary location

Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institue, Yonsei Universiy College of Medicine

Seoul, 03722, South Korea

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

Uncomplicated singleton full-term parturients undergoing cesarean delivery
age 20~40
ASA class 1~3

Exclusion criteria

Emergency surgery
Placenta previa
Preeclampsia or Preeclampsia
Cardiovascular or cerebrovascular disease
Morbid obesity with a body mass index (BMI) of 40 kg / m2 or higher
Gestational age <36 or ≥ 41 weeks
Contraindications to spinal anesthesia
Carotid stenosis> 50% (angiography, CT angiography, MR angiography, or duplex ultrasonography)
Basal systolic blood pressure> 160 mmHg
The preoperative examination revealed that the electrocardiogram was not normal sinus rhythm
Chronic kidney disease (eGFR <60 mL / min / 1.73 m2)
If the subject includes a person who can not read the written consent (eg, illiterate, foreigner, etc.)

Treatment and study plan

Doppler sonographic measurement

Diagnostic Test

First, place a 4.5-12.0 MHz linear array transducer vertically on the neck with the probe marker facing the patient's head. A long axis B-mode image of the right common carotid artery is obtained at the lower border of the thyroid cartilage. The sample volume is then placed in the center of the lumen located approximately 2 cm proximal to the carotid bifurcation. Next, pulsed wave Doppler tracing is performed in the arterial blood flow. The cycle time using the calliper function in an ultrasonic machine is obtained by measuring the interval between heartbeats at the beginning of the Doppler blood flow upstroke and the Flow time is measured as the time from the beginning of the systolic upstroke to the dicrotic notch.

Primary outcomes

Occurrence of Hypotension

Time frame: from the spinal anesthetic injection until the fetus is delivered.

The definition of hypotension after spinal anesthesia is that the systolic blood pressure drops to 80 mmHg, less than 75% of the baseline value , or even if it does not meet the former criteria, symptoms that are consistent with hypotension (dizziness, dizziness, dyspnea, nausea or vomiting) .

Secondary outcomes

The systolic blood pressure difference

Time frame: from the spinal anesthetic injection until the fetus is delivered.

The most significant difference in systolic blood pressure dropped

Sponsors and collaborators

Lead sponsor

Yonsei University

Other

Registry information

Important dates

Study start: 2018
Primary completion: 2019
Study completion: 2019
First posted: Aug 15, 2018
Registry last updated: Jan 7, 2020

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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