Myocardial oxidative stress protection with sevoflurane versus propofol

Real-time Monitoring of Contrast-enhanced Ultrasound for Radio Frequency Ablation

Background

This study compared the realtime monitoring effects of conventional ultrasound and contrast-enhanced ultrasound (CEUS) on evaluating radio frequency ablation (RFA) in a living swine liver model.

Methodology

Liver RFA was performed on 10 young swine. Conventional ultrasound and CEUS were performed immediately. After the animals were sacrificed, ablation lesions were removed to histopathologically examine the range of the lesions. Ablation completeness based on three methods were compared using histopathology as the gold standard.

Results

Forty-three ablation lesions were produced in the animals. The horizontal diameter, vertical diameter and ablation lesion area based on conventional ultrasound were all significantly smaller than those based on the gross sample, but no significant differences existed between the results of the CEUS and the gross sample. Histopathology showed that 30 lesions were incompletely ablated and 13 were completely ablated, while CEUS showed that 28 lesions were incompletely ablated and 15 were completely ablated. Compared with histopathology, CEUS had an accuracy of 81.4%, a sensitivity of 83.3%, and a specificity of 76.9%. No significant difference in ablation completeness judgment between CEUS and histopathology was observed.

Conclusion

CEUS provides a real-time radiological foundation for evaluating RFA lesion ranges and completeness in a living swine liver model.

Xenon triggers pro-inflammatory effects and suppresses the anti-inflammatory response compared to sevoflurane in patients undergoing cardiac surgery

Introduction

Cardiac surgery encompasses various stimuli that trigger pro-inflammatory mediators, reactive oxygen species and mobilization of leucocytes. The aim of this study was to evaluate the effect of xenon on the inflammatory response during cardiac surgery.

Methods

This randomized trial enrolled 30 patients who underwent elective on-pump coronary-artery bypass grafting in balanced anaesthesia of either xenon or sevoflurane. For this secondary analysis, blood samples were drawn prior to the operation, intra-operatively and on the first post-operative day to measure the pro- and anti-inflammatory cytokines interleukin-6 (IL-6), interleukin-8/C-X-C motif ligand 8 (IL-8/CXCL8), and interleukin-10 (IL-10). Chemokines such as C-X-C motif ligand 12/ stromal cell-derived factor-1α (CXCL12/SDF-1α) and macrophage migration inhibitory factor (MIF) were measured to characterize xenon’s perioperative inflammatory profile and its impact on migration of peripheral blood mononuclear cells (PBMC).

Results

Xenon enhanced the postoperative increase of IL-6 compared to sevoflurane (Xenon: 90.7 versus sevoflurane: 33.7 pg/ml; p = 0.035) and attenuated the increase of IL-10 (Xenon: 127.9 versus sevoflurane: 548.3 pg/ml; p = 0.028). Both groups demonstrated a comparable intraoperative increase of oxidative stress (intra-OP: p = 0.29; post-OP: p = 0.65). While both groups showed an intraoperative increase of the cardioprotective mediators MIF and CXCL12/SDF-1α, only MIF levels decreased in the xenon group on the first postoperative day (50.0 ng/ml compared to 23.3 ng/ml; p = 0.012), whereas it remained elevated after sevoflurane anaesthesia (58.3 ng/ml to 53.6 ng/ml). Effects of patients’ serum on chemotactic migration of peripheral mononuclear blood cells taken from healthy volunteers indicated a tendency towards enhanced migration after sevoflurane anaesthesia (p = 0.07).

Conclusions

Compared to sevoflurane, balanced xenon anaesthesia triggers pro-inflammatory effects and suppresses the anti-inflammatory response in cardiac surgery patients even though the clinical significance remains unknown.

Trial registration

This clinical trial was approved by the European Medicines Agency (EudraCT-number: 2010-023942-63) and at ClinicalTrials.gov (NCT01285271; first received: January 24, 2011).

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1082-7) contains supplementary material, which is available to authorized users.