Evaluation of dynamic cerebrovascular autoregulation during liver transplantation.

Abstract

Cerebrovascular autoregulation in patients with acute and chronic liver failure is often impaired, yet an intact autoregulation is essential for the demand-driven supply of oxygenated blood to the brain. It is unclear, whether there is a connection between cerebrovascular autoregulation during liver transplantation (LTX) and the underlying disease, and if perioperative anesthesiologic consequences can result from this. In this prospective observational pilot study, data of twenty patients (35% female) undergoing LTX were analyzed. Cerebral blood velocity was measured using transcranial doppler sonography and was correlated with arterial blood pressure. The integrity of dynamic cerebrovascular autoregulation (dCA) was evaluated in the frequency domain through transfer function analysis (TFA). Standard clinical parameters were recorded. Mixed one-way ANOVA and generalized estimating equations were fitted to data involving repeated measurements on the same patient. For all other correlation analyses, Spearman's rank correlation coefficient (Spearman's-Rho) was used. Indications of impaired dCA are seen in frequency domain during different phases of LTX. No correlation was found between various parameter of dCA and primary disease, delirium, laboratory values, length of ICU or hospital stay, mortality or surgical technique. Although in most cases the dCA has been impaired during LTX, the heterogeneity of the underlying diseases seems to be too diverse to draw valid conclusions from this observational pilot study.