A Randomized Controlled Trial Comparison of NeuroSENSE and Bispectral Brain Monitors During Propofol-Based Versus Sevoflurane-Based General Anesthesia.

BACKGROUND: NeuroSENSE is a depth of anesthesia monitor that uses automated electroencephalogram quantification. The Wavelet-based Anesthetic Value for Central Nervous System (WAVCNS) index calculated by this monitor is based on wavelet analysis of a normalized electroencephalogram signal in the γ-frequency band. The aim of this study was to determine the extent of disagreement between the Bispectral Index (BIS) and the WAVCNS index during propofol-based and sevoflurane-based maintenance of general anesthesia in a routine surgical population. METHODS: Patients undergoing elective surgery were enrolled in the study and randomly assigned to receive either propofol or sevoflurane for the maintenance of anesthesia and remifentanil in both groups. Anesthesiologists were blinded to monitors in both groups. Discordance between the 2 monitors was assessed by the count of discrepancy in recommendation (DR) (type 1 defined as one parameter <40 and the other >60, or type 2 defined as BIS and WAVCNS values on different sides of a threshold [40 or 60]) and also by the proportion of agreement (P0) between WAVCNS and BIS, obtained every 5 seconds, in 3 categories of index (<40, 40-60, and >60). RESULTS: The analyzed data set consisted of 22 patients (36,872 data pairs) in the propofol group and 24 patients (32,826 data pairs) in the sevoflurane group. The type 1 DR rarely occurred in both the groups (<1%); however, the median (interquartile range) type 2 DR was significantly more frequent in the propofol group (20.6% [7.0-36.9] vs 4.5% [2.3-12.4]; P = 0.0005). The median difference in P0 was 11.53% (95% confidence interval, 0.57-21.32). Major disagreement between WAVCNS index and BIS was related to the weight of burst suppression pattern for the index calculation. CONCLUSIONS: Disagreement between BIS and NeuroSENSE during the maintenance of general anesthesia was worse in the propofol group than that in the sevoflurane groups. The disagreement increases during deep anesthesia or in the occurrence of burst suppression.

Abnormal plasma microparticles impair vasoconstrictor responses in patients with cirrhosis.

BACKGROUND & AIMS: Circulating membrane-shed microparticles (MPs) participate in regulation of vascular tone. We investigated the cellular origins of MPs in plasma from patients with cirrhosis and assessed the contribution of MPs to arterial vasodilation, a mechanism that contributes to portal hypertension. METHODS: We analyzed MPs from blood samples of 91 patients with cirrhosis and 30 healthy individuals (controls) using flow cytometry; their effects on the vascular response to vasoconstrictors were examined in vitro and in vivo. RESULTS: Circulating levels of leuko-endothelial (CD31(+)/41(-)), pan-leukocyte (CD11a(+)), lymphocyte (CD4(+)), and erythrocyte (CD235a(+)) MPs were higher in patients with cirrhosis than in controls. Plasma of patients with cirrhosis contained hepatocyte-derived MPs (cytokeratin-18(+)), whereas plasma from controls did not. The severity of cirrhosis and systemic inflammation were major determinants of the levels of leuko-endothelial and hepatocyte MPs. MPs from patients with advanced cirrhosis significantly impaired contraction of vessels in response to phenylephrine, whereas MPs from healthy controls or from patients of Child-Pugh class A did not. This effect depended on cyclooxygenase type 1 and required phosphatidylserine on the surface of MPs. Intravenous injection of MPs from patients with cirrhosis into BALB/C mice decreased mean arterial blood pressure. CONCLUSIONS: Cirrhosis is associated with increases in circulating subpopulations of MPs, likely resulting from systemic inflammation and liver cell damage. The overall pool of circulating MPs from patients with advanced cirrhosis impairs vasoconstrictor responses and decreases blood pressure, contributing to the arterial vasodilation associated with portal hypertension.