[Evaluation by bioelectric impedance of body fluid compartments and body mass in cardiosurgical patients before and after total cardiopulmonary bypass].
BACKGROUND
To evaluate the influence of extracorporeal circulation (ECC) on fluid compartments and body mass using impedance measurements.


METHODS
A prospective study was performed in 20 consecutive patients undergoing ECC during heart surgery at the Department of Heart Surgery of Verona Hospital. Resistance or reactance measurements at 1-5-10-50-100 KHz were performed in 20 patients undergoing heart surgery for valvular or coronary pathologies in class NYHA I or II, preoperatively and on day 1, 3 and 6 in order to evaluate total body water (TBW), intracellular water (ICW), extracellular water (ECW), thin and fat body mass. Weight, fluid-electrolytic balance and hematochemical parameters relating to electrochemical phenomena and the distribution of volumes in the various compartments, namely sodium, potassium and plasmatic osmolarity, were measured at the same times. Comparisons were made both between the data and during ECC.


RESULTS
It was found that there was a mean postoperative weight gain of 2 kg in terms of total body water. Subsequently, this finding tended to decrease to basal values by day 6. Immediately after ECC, the water gain appeared to be predominantly extracellular, whereas the intracellular increase peaked on day 1. The change in total body water was correlated with the weight and fluid balance, but electrical measurements showed values above the corresponding weight gain. The duration of ECC was significantly correlated with bioelectric parameters, but not with absolute weight values.


CONCLUSIONS
The method proved useful for the purpose, especially with regard to the overall population examined rather than individual patients. The dual-compartment electric model appears to be more suitable than the single-compartment model for exploring the different compartments. The trend of weight and total body water, which were correlated in pattern but not in absolute values, may be interpreted as a redistribution of fluids, also suggested by changes in electric parameters relating to compartmental distribution.
Franchi
G
G
II Servizio Autonomo di Anestesia e Rianimazione, Azienda Ospedaliera, Verona.
Girardini
F
F
Rossi
L
L
Luzzani
A
A
D000368:Aged; D001825:Body Fluid Compartments / Q000502:physiology*; D001835:Body Weight; D002315:Cardiopulmonary Bypass; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period
Valutazione impedenziometrica dei compartimenti idrici e di massa corporea in pazienti cardiochirurgici prima e dopo bypass cardiopolmonare totale.