Patient Position and Phase of Respiration Affect the Doppler Waveform in the Celiac Artery

Abstract

Introduction.-Multiple factors might affect the velocity recording in the celiac artery (CA), causing a compression syndrome. Reports that focused on the phase of respiration found that the CA is highly compressed during the phase of expiration. Few reports in the literature have focused on body position during Doppler scanning of the CA. The aim of this study was to evaluate the effect of patient position as well as the phase of respiration on velocity recording in the CA.Methods.-Thirty male subjects were entered prospectively into the study. Peak systolic velocity and vessel diameter at the origin of the CA at different body position and different phases of respiration were recorded by the use of duplex ultrasound while the subject was fasting.Results.-There were 30 healthy men; their average age was 25.5 ± 5.30 (±SD, years), and their average body mass index was 24.8 ± 3.1 (±SD, kg/m 2 ). The average diameter of CA in supine position and expiration was 0.70 ± 0.10 (±SD, cm), and the average peak systolic velocity was 111.2 ± 29.7 (±SD, cm/s). Moreover, the average diameter of CA in standing position in expiration was 0.75 ± 0.10 (±SD, cm), and the average peak systolic velocity was 96.8 ± 25.2 (±SD, cm/s). Paired Student t test for the effect of body position and phase of respiration in the peak systolic velocities and the diameter of the CA was performed and demonstrated statistical signifi cance (p < 0.05).Conclusion.-The CA peak systolic velocity varies between 2 positions in healthy young men, which may have implications for disease detection and needs further study.

Subject Body Mass Index Affects Doppler Waveform in Celiac Artery by Duplex Ultrasound

“…[25] concluded that among patients with elevated velocities in the CA and SMA, repeated Doppler examination with the patient standing may demonstrate normalized velocities, consistent with CACS. Depending on Downing results [25] and our previous results [26] which showed that the best subject position to examine the CA is supine position and the best phase of respiration is during inspiration, we concluded that the CA should be examined in both phases of respiration and supine and upright body positions in subjects with possible CACS. In our present study we did not repeat the scanning during inspiration and with the subject in upright position as performed in our previous study [26] because we believe that the velocities in group A to be normalized.…”

“…The extent of CA compression varies with varying position of the diaphragm. It is most pronounced in expiration phase of respiration while the patient in supine position [26] because of the abrupt change in direction of the CA that occurs during expiration. …”

“…Reports focus on the effect of phase of respiration, especially expiration [20-23], and body position [23-26] as an essential factor affecting the flow velocity in the CA during duplex ultrasound scanning, whereas no reports in the literature put into consideration other factors affecting Doppler signal in the CA such as BMI. The aim of the present study is to determine the effect of BMI in Doppler velocity.…”

“…Duplex ultrasound is used in our present study because of its availability, accuracy, reproducibility, ease, costs, and avoidance of radiation [26]. Due to this one experienced sonographer who was trained in Australia performed the examination.…”

“…These factors include phase of respiration [20-23] and body position during ultrasound scanning [23-26], transducer pressure over the vessel, and body mass index (BMI). In literature, there are no reports about the effect of BMI in the CA Doppler waveform especially in normal subjects.…”