Changes of the hemodynamics and extravascular lung water after different-volume fluid resuscitation in a piglet model of endotoxic shock

Abstract

Practice recommendations have evolved, and consensus now exists among leading organizations such as the American College of Critical Care Medicine (ACCM) and Surviving Sepsis Campaign that fluid infusion is best initiated with boluses of 20 ml/kg, commonly requires 40-60 ml/kg but can be as much as 200 ml/kg if the liver is not enlarged and/or rales are not heard. The present study aimed to investigate and compare the changes of the hemodynamics and extravascular lung water after higher volume fluid resuscitation in a piglet model of endotoxic shock. Twenty piglets were used for establishing animal models of endotoxic shock by intravenous infusing lipopolysaccharide (LPS). The experimental animals were divided into three groups according to the volume infused during the resuscitation. The three groups received different volume of saline in less than an hour after endotoxic shock. By the PiCCO plus system, we investigated the changes of hemodynamics and extravascular lung water. After fluid resuscitation, global end diastolic volume inder, (GEDI) and intrathoracic blood volume index, (ITBI) markedly increased in the group of 80 ml/kg and 120 ml/kg, but there was no change in the group of 40 ml/kg. GEDI: Fifteen min after fluid resuscitation R1 was (261 ± 64) ml/m(2), R2 (457 ± 124) ml/m(2), R3 (413 ± 148) ml/m(2), 4 h R1 (251 ± 68) ml/m(2), R2 (422 ± 70) ml/m(2), R3 (470 ± 160) ml/m(2); ITBI: Fifteen min after fluid resuscitation R1 was (335 ± 69) ml/m(2), R2 (550 ± 179) ml/m(2), R3 (520 ± 183) ml/m(2), 4 h R1 (314 ± 84) ml/m(2), R2 (534 ± 96) ml/m(2), R3 (594 ± 200) ml/m(2) (R1 vs. R2 vs. R3, F = 26.373, P < 0.05; R1 vs. R2, R1 vs. R3, P < 0.05; R2 vs. R3, P > 0.05). CI of all three groups significantly decreased when the models were established. After fluid resuscitation, the base level was maintained in the group of 80 ml/kg and 120 ml/kg, but it was under the basic level in the group of 40 ml/kg.Fifteen min after fluid resuscitation R1 was (4.5 ± 0.7) L/(min·m(2)), R2 (6.4 ± 2.2) L/(min·m(2)), R3 (5.5 ± 0.7) L/(min·m(2)), 4 h R1 (4.1 ± 1.0) L/(min·m(2)), R2 (5.2 ± 0.9) L/(min·m(2)), R3 (5.1 ± 0.8) L/(min·m(2)). There was no significant difference in CI between these two groups (P > 0.05).ELWI of the group of 80 ml/kg and 120 ml/kg were still higher than that of the group of 40 ml/kg, 15 min after fluid resuscitation R1 was (19.2 ± 8.6) ml/kg, R2 (29.2 ± 5.5) ml/kg, R3 (23.4 ± 8.2) ml/kg, 4 h R1 (18.3 ± 6.5) ml/kg, R2 (23.8 ± 2.6) ml/kg, R3 (21.4 ± 3.9) ml/kg, but there was no significant difference in ELWI among the groups (P > 0.05). Resuscitation with higher volume of fluid infusion in the early stage of endotoxic shock was more efficient to increase the preload and maintain the cardiac output at the baseline level, and might reduce the need for vasoactive agents. Meanwhile, resuscitation with higher volume of fluid in the early stage of endotoxic shock did not sharply increase the extravascular lung water.