Carotid Artery Corrected Flow Time Measured by Ultrasonography as a Predictor of Hypotension After Induction of General Anesthesia

NCT ID: NCT02891772

Last Updated: 2019-01-16

Basic Information

• Recruitment Status: WITHDRAWN
• Study Classification: OBSERVATIONAL
• Study Start Date: 2016-08-31
• Study Completion Date: 2017-08-31

Brief Summary

Hypotension often happens immediately after anesthetic induction. Particularly in 5-10 minutes after anesthetic induction it is reported to happen more frequently. Patients may have preexisting hypovolemia resulting from dehydration and impaired compensatory responses, which increase the risk. However, it is still challenging to assess intravascular volume status in spontaneously breathing patients before anesthetic induction. Recently, the measurement of corrected flow time in carotid artery was introduced as quite useful, simple and noninvasive for the evaluation of circulating blood volume. The aim of this study is to evaluate whether corrected carotid artery flow time as determined by ultrasonography in spontaneously breathing patients before general anesthesia can predict hypotension after induction.

Conditions

General Anesthesia Induction for Elective Surgery

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: PROSPECTIVE

Study Groups

Hypotension after anesthetic induction group

Patients with hypotension after anesthetic induction

ultrasonographic measurement of corrected flow time(FTc) in carotid artery

Intervention Type: PROCEDURE

Corrected carotid artery flow time is measured using 10-5 MHz linear probe on a portable ultrasound machine. On the two-dimensional image, the optimal image of the long-axis view is obtained at the left common carotid artery. The sample volume is placed on the center of the lumen, 2 cm proximal to the bulb, and a pulsed wave Doppler examination was performed. Then, cardiac cycle time and carotid flow time is measured. Carotid flow time is measured between the upstroke of the flow tracing and the dicrotic notch, and it is corrected for pulse rate by dividing flow time by the square root of the cardiac cycle time to calculate corrected carotid artery flow time (flow time/√cycle time). The blood pressure was taken before anesthetic induction and every two minutes after anesthetic induction till ten minutes after endotracheal intubation.

Interventions

ultrasonographic measurement of corrected flow time(FTc) in carotid artery

Corrected carotid artery flow time is measured using 10-5 MHz linear probe on a portable ultrasound machine. On the two-dimensional image, the optimal image of the long-axis view is obtained at the left common carotid artery. The sample volume is placed on the center of the lumen, 2 cm proximal to the bulb, and a pulsed wave Doppler examination was performed. Then, cardiac cycle time and carotid flow time is measured. Carotid flow time is measured between the upstroke of the flow tracing and the dicrotic notch, and it is corrected for pulse rate by dividing flow time by the square root of the cardiac cycle time to calculate corrected carotid artery flow time (flow time/√cycle time). The blood pressure was taken before anesthetic induction and every two minutes after anesthetic induction till ten minutes after endotracheal intubation.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

• adult patients (19-80 years of age) who were scheduled to undergo elective surgery under general anesthesia

Exclusion Criteria

• mean blood pressure < 70 mmHg before induction of general anesthesia
• Patients who have currently taken angiotensin-converting enzyme inhibitor
• Patients who have currently taken angiotensin receptor blocker
• the presence of carotid artery stenosis > 50%
• cardiac rhythm other than sinus
• unstable angina
• a left ventricular ejection fraction of < 40%
• severe vascular disease
• implanted pacemaker/cardioverter
• autonomic nervous system disorders
• anticipated difficult airway
• pregnancy

• Minimum Eligible Age: 19 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Yonsei University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

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

Seoul, , South Korea

Countries

South Korea

Other Identifiers

4-2016-0606

Identifier Type: -

Identifier Source: org_study_id