Related Experiment Video
Updated: Aug 26, 2026
Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
Published on: January 20, 2023
Monitoring of respiratory variations of aortic blood flow velocity using esophageal Doppler
Michel Slama1, Henri Masson, Jean-Louis Teboul
1Laboratoire de Physiopathologie et de Pharmacologie Cardiovasculaire, Faculté de Médecine, Université de Picardie Jules Verne, 80054 Amiens cedex 1, France. MSlama0508@aol.com
Objective:
The purpose of this study was to determine whether monitoring of respiratory changes in aortic blood flow velocity, recorded by esophageal Doppler, could be used to detect changes in volume depletion.
Design:
Animal study.
Animals And Interventions:
After general anesthesia and tracheotomy, ten New Zealand female rabbits, weighing 4-4.5 kg were studied under mechanical ventilation at a fixed tidal volume; during this time 5-ml blood samples were withdrawn (in increments up to a total of 30 ml) and then retransfused.
Measurements And Results:
At each step, systolic (SBP), diastolic (DBP), pulse (PP) pressures and maximum descending aortic blood flow (V) were recorded. Respiratory changes of V (DeltaV), SBP (DeltaSBP) and PP (DeltaPP) were calculated as the difference of maximal and minimal values divided by their respective means and expressed as a percentage. The amount of blood withdrawn correlated negatively with SBP, DBP, PP and V and positively with DeltaSBP, DeltaPP and DeltaV. Among these parameters, DeltaV correlated best with the amount of blood withdrawn ( r=0.89, p<0.001) and it was the most accurate index of volume depletion.
Conclusion:
Monitoring of the respiratory variation in V, calculated by esophageal Doppler technique, seems to be a highly accurate index of blood volume depletion and restitution.
Related Concept Videos
01:30Equipments Used To Measure Blood Pressure
This invasive approach involves cannulating a peripheral artery. During each cardiac contraction, pressure generates mechanical motion within the catheter, transmitted through rigid, fluid-filled tubing to a transducer. This transducer converts mechanical motion into electrical signals displayed as waveforms on a monitor. An automatic flushing system prevents blood backflow. Due to the potential risk of unexpected arterial blood loss, this method is primarily used in intensive...
01:19Assessing Blood pressure using a doppler ultrasound
Pre-Procedural Guidelines for Doppler Ultrasound Blood Pressure Assessment:
Preparation of Equipment:
01:22Aortic Regurgitation II: Clinical Features and Diagnostic Tests
01:17Assessment of Diffusion and Perfusion
The Role of Diffusion in Respiration
Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. In the respiratory system, this principle...
01:28Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
01:17Measurement of Blood Pressure