[Intraoperative fluid therapy during experimental laparotomy of long duration]

Intraoperative fluid therapy was studied using 18 adult mongrel dogs in which laparotomy of long duration was performed. The 18 mongrel dogs were divided into three groups (Group I: lactated Ringer solution (LR) infused at the rate of 10 ml.kg-1.h-1, Group II: LR infused at the rate of 20 ml.kg-1.h-1, Group III: LR infused at the rate of 5 ml.kg-1.h-1 and Salinhes infused at the rate of 5 ml.kg-1.h-1). The differences in hemodynamic status, plasma colloid osmotic pressure, O2 delivery, O2 consumption et al were investigated in the three groups. Mean arterial pressure, cardiac output and renal blood flow were maintained in all groups. In group I, skin blood flow decreased and O2 extraction ratio started to increase four hours later suggesting that there is trouble in the balance of O2 delivery and consumption. In group II, skin blood flow and urine volume were maintained, but plasma colloid osmotic pressure was lowest in this group. In group III, skin blood flow volume decreased as it did in group I, but plasma colloid osmotic pressure was maintained at a higher level than that in the two other groups, and O2 extraction ratio showed no significant changes. These findings indicate that colloid solution is useful for laparotomy of long duration. In conclusion, colloid solution should be added to the fluid used in laparotomy of long duration.