Population-based volume kinetics of Ringer's lactate solution in patients undergoing open gastrectomy.

In order to maintain stable blood pressure and heart rate during surgery, anesthesiologists need to administer the appropriate amount of fluid with appropriate fluid type to the patient, then quantifying how fluid is distributed and eliminated from the body is useful for establishing a fluid administration strategy. In this study we characterized the volume kinetics of Ringer's lactate solution in patients undergoing open gastrectomy. When propofol and remifentanil reached a pseudosteady state at the target concentration and blood pressure was stabilized following surgical stimulation, enrolled patients were administered 1000 mL of Ringer's lactate solution for 20 min, followed by continuous infusion at a rate of 6 mL/kg/h until the time of the last blood collection for volume kinetic analysis.

Estimation of indocyanine green elimination rate constant k and retention rate at 15 min using patient age, weight, bilirubin, and albumin.

Background: We sought to estimate the indocyanine green (ICG) clearance (Cl), the elimination rate constant (k), and the retention rate at 15 min (R (15)) using patient-specific covariates only.

Methods: We analyzed plasma ICG concentration data at 5, 10, and 15 min after intravenous injection of 0.5 mg/kg of ICG and 17 kinds of patient-specific covariates in 1,276 patients using NONMEM (GloboMax LLC, Ellicott City, MD) for population pharmacokinetic modeling.