Jd. Obenar et al., HEMODYNAMIC AND METABOLIC RESPONSES TO REPEATED HEMORRHAGE AND RESUSCITATION WITH HYPERTONIC SALINE DEXTRAN IN CONSCIOUS SWINE, Shock, 10(3), 1998, pp. 223-228
Citations number
33
Categorie Soggetti
Peripheal Vascular Diseas","Emergency Medicine & Critical Care",Hematology,Surgery
Previous work in our laboratory has demonstrated that HSD is an effect
ive small-volume resuscitation fluid for the treatment of hemorrhagic
hypotension, but limitations to its usefulness in severe hemorrhage ha
ve not been explored. In the present study, animals (N = 12) were bled
from an arterial line at a rate of 1 mL/kg/min until continuously mon
itored aortic blood flow was reduced to one-half its baseline value, a
nd then they were immediately resuscitated with 7.5% NaCl/6% dextran 7
0 (hypertonic saline dextran, 4 mL/kg) administered intravenously over
3 min. After recording the maximum improvement in blood pressure, blo
od samples were obtained and the hemorrhage-resuscitation sequence was
repeated until no further measurable increase in cardiac index or blo
od pressure could be elicited by resuscitation. In the majority of the
animals, cardiac index and right and left ventricular stroke work cou
ld be improved at least through two bleedings and resuscitation. These
improvements sufficed to increase oxygen delivery and consumption, de
spite the decreases in hematocrit induced by bleeding, transcapillary
refill, and asanguineous fluid administration. Under these severe hemo
rrhage conditions, the acid-base imbalance was not improved by hyperto
nic saline dextran, and the rate of increase in acidosis was not affec
ted by its administration. We observed a progressive decrease in base
excess from +1.35 +/- 3.19 (mean +/- standard error) to -12.9 +/- 2.1
mEq/L even when resuscitation improved oxygen consumption significantl
y by 95 +/- 20%. In animals that survived as many as three bleedings a
nd resuscitation, the depletion of buffering capacity of the blood was
most predominant, and bicarbonate reached a nadir of 7.62 mEq/L with
a base excess of -22.4 mEq/L. It is evident that restoration of perfus
ion in shock treats only a portion of the physiologic dysfunction, lea
ving major metabolic derangements uncorrected.