Comparison of the hemodynamics and dynamics of fluid shift of Ringer's solution before surgery in children and adults

Abstract

Abstract. The present study investigated the hemodynamics, vascular and extravascular volume expansion induced by infusion of lactated Ringer's solution in children and adults before surgery. This was a prospective randomized double-blind study. A total of 28 patients (14 children and 14 adult patients; American Society of Anesthesiology status I) scheduled for similar minor pelvic, anal rectal or lower limb surgery were recruited for the present study. All patients were administered with 10 ml/kg of lactated Ringer's solution at a constant rate over 20 min. After fluid infusion, plasma dilutions were calculated based on the concentration of hemoglobin. Heart rate (HR), mean arterial pressure (MAP) and urine output were measured before anesthesia was administered for surgery. Results demonstrated that the plasma dilution within 90 min of infusion initiation of lactated Ringer's solution was less pronounced in children compared with adult patients (0.07 vs. 0.16; P<0.001). Children also excreted more of the infused fluid through the kidney within 90 min of infusion initiation than the adults (55% vs. 24%; P=0.01). Following completion of fluid infusion, the volume expansion efficiency was higher in adults [0.82 (0.52-1.00)] than in children [0.46 (0.26-0.68)]. The relative changes in HR were significantly greater in children than in adults 15-60 min after infusion initiation (P<0.01). After 60 min, HRs were comparable between the groups; however, MAP declined significantly from 25-90 min after infusion initiation in children (P<0.05), yet remained nearly constant in adults (P>0.05). Simple regression analysis revealed a positive relationship between the relative changes in MAP and the plasma dilution, and the reduction in MAP in children was able to explain 47% of the variation in plasma dilution (R 2 =0.47; P=0.007). In conclusion, different hemodynamics and dynamics of fluid shift of Ringer's solution prior to surgery in children and adults may provide anesthesiologists with new information of how to administer fluid treatment for each patient.

The Effects of Acute and Chronic Inflammation on the Dynamics of Fluid Shift of Ringer’s Solution and Hemodynamics during Surgery

“…In this study, even at 120 min post-infusion, the VEE was still more than 20%, indicating that the distribution balance of crystalloid (1:4 distribution rule) was not reached. In another our previous study, 18) VEE was less than 100% after RL infusion and before anesthesia induction for minor surgery in both adults and children. VEE reached a distribution balance of 1:4 at 30 mins post-infusion in children and at 90 mins post-infusion in adults.…”

“…Our previous studies 3,4) indicated that the volume expansion of infused crystalloid was more than 1:1 on some certain occasions, such as during anesthesia, at early times of infusion and with low blood volume. Multi-factor regression found that hypotension was an independent factor for increased volume expansion.…”

“…[1][2][3] During the induction of anesthesia, due to the vasodilatation effect of general or local anesthetics, there exists a relative blood volume deficiency. 4) Therefore, all surgical patients require fluid therapy before anesthesia induction. A variety of methods have been used to detect the volume expansion effect of fluid therapy.…”

“…A variety of methods have been used to detect the volume expansion effect of fluid therapy. In previous studies, 3,4) we used hemoglobin (Hb) dilution to reflect the volume expansion of the infused fluid. Lactated Ringer's solution (RL) is preoperative main infusion fluid, and a period of time after infusion, in accordance with the principle of 4:1 allocation of crystalloid, only 20% of fluid remains in the intra-vascular space, resulting in volume expansion.…”

“…One of our studies 3) showed that, compared with epidural anesthesia, the volume expansion of infusion crystalloid was higher during the induction of general anesthesia. Another clinical study 4) showed that the volume expansion of infused crystalloid was stronger in adults than in children. Additionally, the hemodynamic changes of patients in the two age groups showed different trends post-infusion.…”