Propofol pharmacodynamics in a pregnant patient with portal hypertension: a case report

This case report describes target-controlled propofol anesthesia using the Eleveld pharmacokinetic-pharmacodynamic model in a third-trimester pregnant woman with significant comorbidity undergoing elective non-obstetric surgery. A 31-year-old woman, 35 weeks pregnant with portal hypertension secondary to portal vein thrombosis after gastric bypass, underwent endoscopic esophageal variceal ligation under total intravenous anesthesia with remifentanil and propofol, guided by Bispectral Index monitoring. Propofol was administered via effect-site target-controlled infusion using the Eleveld model, with an initial stepwise increase in target concentration followed by adjustments guided by the Bispectral Index. All infusion and monitor data were recorded and compared with model-predicted values using a simulator. During induction, the observed Bispectral Index decreased more rapidly and profoundly than predicted, whereas during maintenance there was good agreement between observed and predicted values, with fluctuations of approximately 20%. The divergence observed during induction likely reflects the complex hemodynamic interaction between pregnancy and portal hypertension and remifentanil administration, where increased cardiac output and expanded blood volume alter the initial drug distribution, with a net effect of these competing physiological changes difficult to quantify. Clinically, anesthesia and recovery were uneventful, with timely emergence and tracheal extubation. This case suggests that the Eleveld model is feasible in this setting despite the presence of physiological confounders; nonetheless, continuous electroencephalogram-based titration is necessary to ensure safe anesthesia care.