Clinical evaluation of an ensemble-averaging impedance cardiograph for monitoring stroke volume during spontaneous breathing.
Simultaneous determination of stroke volume (SV) with an ensemble-averaging impedance cardiograph (AIGG) and the thermodilution technique (TD) was compared in 10 patients scheduled for major vascular surgery. A small, successive increase in SV was achieved by a step-wise infusion of dextran-70 and elevation of the patient's legs. The patients were allowed to breathe normally during the measurement procedures. There was no difference between the ability of AICG and TD to monitor changes in SV and the correlation coefficient for the measurement of changes in SV by the two methods was 0.88. There was no difference between the reproducibility of AICG- (4.6 ml) and TD- (9.2 ml) determined SV or between the coefficient of variation for AICG (4.8%) and TD (9.9%). The mean difference between AICG- and TD-determined SV at the different measurement points (range 1.3-4.2 ml) was well within acceptable limits. In conclusion, the ensemble-averaging impedance cardiograph described in this study was found to be reliable for monitoring changes in SV during uninterrupted, spontaneous breathing.
Ekman
L G
LG
Department of Surgery, East Hospital, University of Göteborg, Sweden.
Milsom
I
I
Arvidsson
S
S
Biber
B
B
Martinell
S
S
Sjöqvist
B A
BA
D000368:Aged; D002307:Cardiography, Impedance / Q000295:instrumentation / Q000379:methods*; D003911:Dextrans / Q000494:pharmacology; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D010992:Plethysmography, Impedance / Q000379:methods*; D011187:Posture; D012119:Respiration; D013318:Stroke Volume / Q000502:physiology*; D013815:Thermodilution; D014655:Vascular Resistance / Q000502:physiology; D014656:Vascular Surgical Procedures
D003911:Dextrans