Monitoring of respiratory variations of aortic blood flow velocity using esophageal Doppler.
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.


METHODS
Animal study.


METHODS
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4-4.5 kg were studied under mechanical ventilation at a fixed tidal volume; during this time 5-ml blood samples were withdrawn (in increments up to a total of 30 ml) and then retransfused.


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 The amount of blood withdrawn correlated negatively with SBP, DBP, PP and V and positively with DeltaSBP, DeltaPP and DeltaV. Among these parameters, DeltaV correlated best with the amount of blood withdrawn ( r=0.89, p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.


CONCLUSIONS
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.
Slama
Michel
M
Laboratoire de Physiopathologie et de Pharmacologie Cardiovasculaire, Faculté de Médecine, Université de Picardie Jules Verne, 80054 Amiens cedex 1, France. MSlama0508@aol.com
Masson
Henri
H
Teboul
Jean-Louis
JL
Arnould
Marie-Luce
ML
Nait-Kaoudjt
Rachida
R
Colas
Bouchra
B
Peltier
Marcel
M
Tribouilloy
Christophe
C
Susic
Dinko
D
Frohlich
Edward
E
Andréjak
Michel
M
D000704:Analysis of Variance; D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging*; D001783:Blood Flow Velocity; D017548:Echocardiography, Transesophageal; D005260:Female; D006439:Hemodynamics; D020896:Hypovolemia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008991:Monitoring, Physiologic / Q000379:methods; D011175:Positive-Pressure Respiration; D011817:Rabbits; D015203:Reproducibility of Results; D013318:Stroke Volume