Stanford Advisors


All Publications

  • Impact of Regional Block Failure in Ambulatory Hand Surgery on Patient Management: A Cohort Study. Journal of clinical medicine Picard, L., Belnou, P., Debes, C., Lapidus, N., Sung Tsai, E., Gaillard, J., Sautet, A., Bonnet, F., Lescot, T., Verdonk, F. 2020; 9 (8)


    Regional anesthesia (RA) is an anesthetic technique essential for the performance of ambulatory surgery. Failure rates range from 6% to 20%, and the consequences of these failures have been poorly investigated. We determined the incidence and the impact of regional block failure on patient management in the ambulatory setting. This retrospective cohort study includes all adult patients who were admitted to a French University Hospital (Hopital Saint-Antoine, AP-HP) between 1 January 2016 and 31 December 2017 for unplanned ambulatory distal upper limb surgery. Univariate and stepwise multivariate analyses were performed to determine factors associated with block failure. Among the 562 patients included, 48 (8.5%) had a block failure. RA failure was associated with a longer surgery duration (p = 0.02), more frequent intraoperative analgesics administration (p < 0.01), increased incidence of unplanned hospitalizations (p < 0.001), and a 39% prolongation of Post-Anesthesia Care Unit (PACU) length of stay (p < 0.0001). In the multivariate analysis, the risk factors associated with block failure were female sex (p = 0.04), an American Society of Anesthesiologists (ASA) score > 2 (p = 0.03), history of substance abuse (p = 0.01), and performance of the surgery outside of the specific ambulatory surgical unit (p = 0.01). Here, we have documented a significant incidence of block failure in ambulatory hand surgery, with impairment in the organization of care. Identifying patients at risk of failure could help improve their management, especially by focusing on providing care in a dedicated ambulatory circuit.

    View details for DOI 10.3390/jcm9082453

    View details for PubMedID 32751880

  • How machine learning could be used in clinical practice during an epidemic. Critical care (London, England) Verdonk, C., Verdonk, F., Dreyfus, G. 2020; 24 (1): 265

    View details for DOI 10.1186/s13054-020-02962-y

    View details for PubMedID 32456690

  • VoPo leverages cellular heterogeneity for predictive modeling of single-cell data. Nature communications Stanley, N., Stelzer, I. A., Tsai, A. S., Fallahzadeh, R., Ganio, E., Becker, M., Phongpreecha, T., Nassar, H., Ghaemi, S., Maric, I., Culos, A., Chang, A. L., Xenochristou, M., Han, X., Espinosa, C., Rumer, K., Peterson, L., Verdonk, F., Gaudilliere, D., Tsai, E., Feyaerts, D., Einhaus, J., Ando, K., Wong, R. J., Obermoser, G., Shaw, G. M., Stevenson, D. K., Angst, M. S., Gaudilliere, B., Aghaeepour, N. 2020; 11 (1): 3738


    High-throughput single-cell analysis technologies produce an abundance of data that is critical for profiling the heterogeneity of cellular systems. We introduce VoPo (, a machine learning algorithm for predictive modeling and comprehensive visualization of the heterogeneity captured in large single-cell datasets. In three mass cytometry datasets, with the largest measuring hundreds of millions of cells over hundreds of samples, VoPo defines phenotypically and functionally homogeneous cell populations. VoPo further outperforms state-of-the-art machine learning algorithms in classification tasks, and identified immune-correlates of clinically-relevant parameters.

    View details for DOI 10.1038/s41467-020-17569-8

    View details for PubMedID 32719375

  • Preferential inhibition of adaptive immune system dynamics by glucocorticoids in patients after acute surgical trauma. Nature communications Ganio, E. A., Stanley, N., Lindberg-Larsen, V., Einhaus, J., Tsai, A. S., Verdonk, F., Culos, A., Gahemi, S., Rumer, K. K., Stelzer, I. A., Gaudilliere, D., Tsai, E., Fallahzadeh, R., Choisy, B., Kehlet, H., Aghaeepour, N., Angst, M. S., Gaudilliere, B. 2020; 11 (1): 3737


    Glucocorticoids (GC) are a controversial yet commonly used intervention in the clinical management of acute inflammatory conditions, including sepsis or traumatic injury. In the context of major trauma such as surgery, concerns have been raised regarding adverse effects from GC, thereby necessitating a better understanding of how GCs modulate the immune response. Here we report the results of a randomized controlled trial (NCT02542592) in which we employ a high-dimensional mass cytometry approach to characterize innate and adaptive cell signaling dynamics after a major surgery (primary outcome) in patients treated with placebo or methylprednisolone (MP). A robust, unsupervised bootstrap clustering of immune cell subsets coupled with random forest analysis shows profound (AUC = 0.92, p-value = 3.16E-8) MP-induced alterations of immune cell signaling trajectories, particularly in the adaptive compartments. By contrast, key innate signaling responses previously associated with pain and functional recovery after surgery, including STAT3 and CREB phosphorylation, are not affected by MP. These results imply cell-specific and pathway-specific effects of GCs, and also prompt future studies to examine GCs' effects on clinical outcomes likely dependent on functional adaptive immune responses.

    View details for DOI 10.1038/s41467-020-17565-y

    View details for PubMedID 32719355

  • Virtual Reality for PEripheral Regional Anesthesia (VR-PERLA Study). Journal of clinical medicine Alaterre, C., Duceau, B., Sung Tsai, E., Zriouel, S., Bonnet, F., Lescot, T., Verdonk, F. 2020; 9 (1)


    When used as an add-on to regional anesthesia, virtual reality (VR) has been reported to provide anxiety-reducing benefits and sedation-sparing effects. However, its impact on patient satisfaction is still a matter of controversy. We investigated the feasibility and benefits of implementing intraoperative VR distraction in a French University Hospital (Hôpital Saint-Antoine, AP-HP). This monocentric observational before-after study included 100 patients who underwent ambulatory upper limb surgery under peripheral nerve block in January 2019, 50 before and 50 after implementation of an intraoperative VR distraction protocol. Primary outcome was patient self-rated satisfaction score evaluated right after surgery. Secondary outcomes included 2-month patient-reported satisfaction score, perioperative self-rated anxiety and intraoperative hemodynamic changes. Compared to former standard care, VR distraction was associated with significantly higher postoperative satisfaction scores (10 [IQR 9; 10] vs. 9 [8; 10], p < 0.001) still reported two months after surgery (10 [10;10] vs. 10 [8.5;10], p = 0.06). Patient median intraoperative anxiety score was lower in the VR group, compared to Standard Care group (0 [0; 2] vs. 3 [0.25; 7], p < 0.001), and occurrence of intraoperative hemodynamic changes was also lessened in the VR group (2% vs. 16%, 0R = 0.11[95% CI 0.002-0.87], p = 0.031). The present findings suggest that VR distraction program in the operating room could effectively improve patient satisfaction with anxiety-reduction and hemodynamic benefits.

    View details for DOI 10.3390/jcm9010215

    View details for PubMedID 31941129

  • Ketamine/xylazine and barbiturates modulate microglial morphology and motility differently in a mouse model. PloS one Hristovska, I., Verdonk, F., Comte, J. C., Tsai, E. S., Desestret, V., Honnorat, J., Chrétien, F., Pascual, O. 2020; 15 (8): e0236594


    Microglia, the resident immune cells of the brain, are highly ramified and motile and their morphology is strongly linked to their function. Microglia constantly monitor the brain parenchyma and are crucial for maintaining brain homeostasis and fine-tuning neuronal networks. Besides affecting neurons, anesthetics may have wide-ranging effects mediated by non-neuronal cells and in particular microglia. We thus examined the effect of two commonly used anesthetic agents, ketamine/xylazine and barbiturates, on microglial motility and morphology. A combination of two-photon in vivo imaging and electroencephalography (EEG) recordings in unanesthetized and anesthetized mice as well as automated analysis of ex vivo sections were used to assess morphology and dynamics of microglia. We found that administration of ketamine/xylazine and pentobarbital anesthesia resulted in quite distinct EEG profiles. Both anesthetics reduced microglial motility, but only ketamine/xylazine administration led to reduction of microglial complexity in vivo. The change of cellular dynamics in vivo was associated with a region-dependent reduction of several features of microglial cells ex vivo, such as the complexity index and the ramification length, whereas thiopental altered the size of the cytoplasm. Our results show that anesthetics have considerable effects on neuronal activity and microglial morphodynamics and that barbiturates may be a preferred anesthetic agent for the study of microglial morphology. These findings will undoubtedly raise compelling questions about the functional relevance of anesthetics on microglial cells in neuronal physiology and anesthesia-induced neurotoxicity.

    View details for DOI 10.1371/journal.pone.0236594

    View details for PubMedID 32760073

Latest information on COVID-19