Fluid distribution kinetics during cardiopulmonary bypass

Abstract

OBJECTIVE:The purpose of this study was to examine the isovolumetric distribution kinetics of crystalloid fluid during cardiopulmonary bypass.METHODS:Ten patients undergoing coronary artery bypass grafting participated in this prospective observational study. The blood hemoglobin and the serum albumin and sodium concentrations were measured repeatedly during the distribution of priming solution (Ringer's acetate 1470 ml and mannitol 15% 200 ml) and initial cardioplegia. The rate of crystalloid fluid distribution was calculated based on 3-min Hb changes. The preoperative blood volume was extrapolated from the marked hemodilution occurring during the onset of cardiopulmonary bypass. Clinicaltrials.gov: NCT01115166.RESULTS:The distribution half-time of Ringer's acetate averaged 8 minutes, corresponding to a transcapillary escape rate of 0.38 ml/kg/min. The intravascular albumin mass increased by 5.4% according to mass balance calculations. The preoperative blood volume, as extrapolated from the drop in hemoglobin concentration by 32% (mean) at the beginning of cardiopulmonary bypass, was 0.6-1.2 L less than that estimated by anthropometric methods (p<0.02). The mass balance of sodium indicated a translocation from the intracellular to the extracellular fluid space in 8 of the 10 patients, with a median volume of 236 ml.CONCLUSIONS:The distribution half-time of Ringer's solution during isovolumetric cardiopulmonary bypass was 8 minutes, which is the same as for crystalloid fluid infusions in healthy subjects. The intravascular albumin mass increased. Most patients were hypovolemic prior to the start of anesthesia. Intracellular edema did not occur.

Recruitment of extravascular fluid by hyperoncotic albumin

“…Because Na is evenly distributed throughout the ECF space, the serum sodium (S‐Na) concentration at a certain time either during or after an IV infusion of fluid equals the amount of Na in the ECF volume divided by the current ECF volume. There is a change in intracellular fluid volume (∆ICF) if the measured S‐Na (S‐Na t ) differs from the theoretical S‐Na, based on losses and additions of Na and water, where,…”

Extracellular-to-Intracellular Fluid Volume Ratio as a Prognostic Factor for Survival in Patients With Metastatic Cancer

“…E/I ratio has already shown a relationship with overall condition and prognostic possibility in patients with chronic disease. 12,13,20 The E/I ratio in patients with cancer may be imbalanced due to several reasons. Patients with cancer experience a higher incidence of hyponatremia, which is mainly related to the syndrome of inappropriate secretion of antidiuretic hormone secretion.…”

The effect of ultrafiltration on end-cardiopulmonary bypass hematocrit during cardiac surgery

“…One most important focus today during CPB is the desire for keeping the patient Hct level >(21%), ideally (24-26%), since delivery of oxygen (DO 2 ) is diminished as the Hct decreases. 3,15,16 According to Ranucci et al, the pump flow should be increased when the Hct falls on CPB to increase oxygen delivery. 15 Oxygen delivery should be higher than 270 to 280 mL/min/m 2 and not just the measurement of Hct alone.…”