Cerebral Hemodynamics and Levosimendan Use in Patients with Cerebral Vasospasm and Subarachnoid Hemorrhage: An Observational Perfusion CT-Based Imaging Study.

BACKGROUND: Delayed cerebral ischemia associated with cerebral vasospasm (CVS) in aneurysmal subarachnoid hemorrhage significantly affects patient prognosis. Levosimendan has emerged as a potential treatment, but clinical data are lacking. The aim of this study is to decipher levosimendan's effect on cerebral hemodynamics by automated quantitative measurements of brain computed tomography perfusion (CTP). METHODS: We conducted a retrospective analysis of a database of a neurosurgical intensive care unit. All patients admitted from January 2018 to July 2022 for aneurysmal subarachnoid hemorrhage and treated with levosimendan for CVS who did not respond to other therapies were included. Quantitative measurements of time to maximum (Tmax), relative cerebral blood volume (rCBV), and relative cerebral blood flow (rCBF) were automatically compared with coregistered CTP before and after levosimendan administration in oligemic regions. RESULTS: Of 21 patients included, CTP analysis could be performed in 16. Levosimendan improved Tmax from 14.4 s (interquartile range [IQR] 9.1-21) before treatment to 7.1 s (IQR 5.5-8.1) after treatment (p < 0.001). rCBV (94% [IQR 79-103] before treatment and 89% [IQR 72-103] after treatment, p = 0.63) and rCBF (85% [IQR 77-90] before treatment and 87% [IQR 73-98] after treatment, p = 0.98) remained stable. The subgroup of six patients who did not develop cerebral infarction attributed to delayed cerebral ischemia showed an approximately 10% increase (rCBV 85% [IQR 79-99] before treatment vs. 95% [IQR 88-112] after treatment, p = 0.21; rCBF 81% [IQR 76-87] before treatment vs. 89% [IQR 84-99] after treatment, p = 0.4). CONCLUSIONS: In refractory CVS, levosimendan use was associated with a significant reduction in Tmax in oligemic regions. However, this value remained at an abnormal level, indicating the presence of a persistent CVS. Further analysis raised the hypothesis that levosimendan causes cerebral vasodilation, but other studies are needed because our design does not allow us to quantify the effect of levosimendan from that of the natural evolution of CVS.

Myocardial dysfunction assessed by speckle-tracking in good-grade subarachnoid hemorrhage patients (WFNS 1-2): a prospective observational study.

BACKGROUND: Cardiac complications due to non-traumatic subarachnoid hemorrhage (SAH) are usually described using classical echocardiographic evaluation. Strain imaging appears to have better sensitivity than standard echocardiographic markers for the diagnosis of left ventricular dysfunction. The aim of this study was to determine the prevalence of cardiac dysfunction defined as a Global Longitudinal Strain (GLS) ≥ - 20% in patients with good-grade SAH (WFNS 1 or 2). METHODS: Seventy-six patients with good-grade SAH were prospectively enrolled and analyzed at admission for neurocritical care. Transthoracic echocardiography was performed on days 1, 3, and 7 after hemorrhage. Routine measurements, including left ventricular ejection fraction (LVEF), were performed, and off-line analysis was performed by a blinded examiner, to determine 2-, 3-, and 4-cavity longitudinal strain and left ventricular GLS. GLS was considered altered if it was ≥ - 20%, we also interested the value of ≥ - 17%. LVEF was considered altered if it was < 50%. RESULTS: On day 1, 60.6% of patients had GLS ≥ - 20% and 21.2% of patient had GLS ≥ - 17%. In comparison, alteration of LVEF was present in only 1.7% of patients. The concordance rate between LVEF < 50% and GLS ≥ - 20% and LVEF ≥ 50% and GLS < - 20% was 46%. CONCLUSION: Strain imaging showed a higher prevalence (60.6%) of left ventricular dysfunction during the acute phase of good-grade SAH (WFNS 1 or 2) than previously described.

Ability of the Analgesia Nociception Index variations to identify a response to a volume expansion of 250 mL of crystalloids in the operating room (REVANI): a prospective observational study.

BACKGROUND: Analgesia Nociception Index (ANI) is a device based on analysis of the R-R interval and respiratory sinus arrhythmia to assess the balance between sympathetic and parasympathetic activity. The autonomic system is directly affected by load changes. Therefore, monitoring sympathetic tone and its change could theoretically allow tracking of load changes during volume expansion. The aim of the present study was to determine whether changes in ANI are able to track the increase in stroke volume caused by volume expansion (SV). METHODS: This prospective observational study included mechanically ventilated patients undergoing neurosurgery and benefiting from SV monitoring. Exclusion criteria were cardiac dysfunction, arrhythmias, beta-blockade therapy, and dysautonomia. SV was optimized by fluid administration of 250 ml of crystalloid fluid. A positive fluid increase was defined as a SV increase of 10% or more from baseline. Changes in SV and medium ANI (ANIm) were recorded before and 4 to 5 min after volume expansion. RESULTS: Sixty-nine patients had 104 fluid challenges (36 positive and 68 negative). Volume expansion resulted in a greater ANI increase in responders than in nonresponders. The change in ANIm > 5 predicted fluid responsiveness with a sensitivity of 68.4% (95% CI: 67.4% to 69.5%) and a specificity of 51.2% (95% CI: 50.1% to 52.3%). The area under the receiver operating characteristic curve was 0.546 (95% CI: 0.544 to 0.549) and appeared to be affected by remifentanil dose and baseline ANI. CONCLUSION: Changes in ANIm induced by fluid challenge is not able to predict fluid responsiveness in mechanically ventilated patients undergoing neurosurgery. TRIAL REGISTRATION: Clinical trial registration: NCT04223414.

When to discharge patients following a neuronavigation-assisted brain biopsy for supratentorial lesion? A single-center experience.

OBJECTIVE: Most brain biopsies are performed using the frame-based stereotactic technique and several studies describe the time taken and rate of complications, often allowing an early discharge. In comparison, neuronavigation-assisted biopsies are performed under general anesthesia and their complications have been poorly described. We examined the complication rate and determined which patients will worsen clinically. METHODS: All adults who underwent a neuronavigation-assisted brain biopsy for a supratentorial lesion from Jan, 2015, to Jan, 2021, in the Neurosurgical Department of the University Hospital Center of Bordeaux, France, were analyzed retrospectively in accordance with the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) statement. The primary outcome of interest was short-term (7 days) clinical deterioration. The secondary outcome of interest was the complication rate. RESULTS: The study included 240 patients. The median postoperative Glasgow score was 15. Thirty patients (12.6 %) showed acute postoperative clinical worsening, including 14 (5.8 %) with permanent neurological worsening. The median delay was 22 h after the intervention. We examined several clinical combinations that allowed early postoperative discharge. A preoperative Glasgow prognostic score of 15, Charlson Comorbidity Index ≤ 3, preoperative World Health Organization Performance Status ≤ 1, and no preoperative anticoagulation or antiplatelet treatment predicted postoperative worsening (negative predictive value, 96.3 %). CONCLUSION: Optical neuronavigation-assisted brain biopsies might require longer postoperative observation than frame-based biopsies. Based on strict preoperative clinical criteria, we consider to plan postoperative observation for 24 h a sufficient hospital stay for patients who undergo these brain biopsies.

Anaesthetic and peri-operative management for thrombectomy procedures in stroke patients.

PURPOSE: To provide recommendations for the anaesthetic and peri-operative management for thrombectomy procedure in stroke patients DESIGN: A consensus committee of 15 experts issued from the French Society of Anaesthesia and Intensive Care Medicine (Société Française d'Anesthésie et Réanimation, SFAR), the Association of French-language Neuro-Anaesthetists (Association des Neuro-Anesthésistes Réanimateurs de Langue Francaise, ANARLF), the French Neuro-Vascular Society (Société Francaise de Neuro-Vasculaire, SFNV), the French Neuro-Radiology Society (Société Francaise de Neuro-Radiologie, SFNR) and the French Study Group on Haemostasis and Thrombosis (Groupe Français d'Études sur l'Hémostase et la Thrombose, GFHT) was convened, under the supervision of two expert coordinators from the SFAR and the ANARLF. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guideline elaboration process was conducted independently of any industry funding. The authors were required to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide their assessment of quality of evidence. METHODS: Four fields were defined prior to the literature search: (1) Peri-procedural management, (2) Prevention and management of secondary brain injuries, (3) Management of antiplatelet and anticoagulant treatments, (4) Post-procedural management and orientation of the patient. Questions were formulated using the PICO format (Population, Intervention, Comparison, and Outcomes) and updated as needed. Analysis of the literature was then conducted and the recommendations were formulated according to the GRADE methodology. RESULTS: The SFAR/ANARLF/SFNV/SFNR/GFHT guideline panel drew up 18 recommendations regarding anaesthetic management of mechanical thrombectomy procedures. Due to a lack of data in the literature allowing to conclude with high certainty on relevant clinical outcomes, the experts decided to formulate these guidelines as "Professional Practice Recommendations" (PPR) rather than "Formalized Expert Recommendations". After two rounds of rating and several amendments, a strong agreement was reached on 100% of the recommendations. No recommendation could be formulated for two questions. CONCLUSIONS: Strong agreement among experts was reached to provide a sizable number of recommendations aimed at optimising anaesthetic management for thrombectomy in patients suffering from stroke.

Relationship Between Brain Tissue Oxygen and Near-Infrared Spectroscopy in Patients with Nontraumatic Subarachnoid Hemorrhage.

BACKGROUND: Continuous monitoring of cerebral oxygenation is one of the diagnostic tools used in patients with brain injury. Direct and invasive measurement of cerebral oxygenation with a partial brain oxygen pressure (PbtO2) probe is promising but invasive. Noninvasive assessment of regional transcranial oxygen saturation using near-infrared spectroscopy (NIRS) may be feasible. The aim of this study was to evaluate the interchangeability between PbtO2 and NIRS over time in patients with nontraumatic subarachnoid hemorrhage. METHODS: This retrospective study was performed in a neurocritical care unit. Study participants underwent hourly PbtO2 and NIRS measurements over 72 h. Temporal agreement between markers was described by their pointwise correlation. A secondary analysis assessed the structure of covariation between marker trajectories using a bivariate linear mixed model. RESULTS: Fifty-one patients with subarachnoid hemorrhage were included. A total of 3362 simultaneous NIRS and PbtO2 measurements were obtained. The correlation at each measurement time ranged from - 0.25 to 0.25. The global correlation over time was - 0.026 (p = 0.130). The bivariate linear mixed model confirmed the lack of significant correlation between the PbtO2 and NIRS measurements at follow-up. NIRS was unable to detect PbtO2 values below 20 mm Hg (area under the receiver operating characteristic curve 0.539 [95% confidence interval 0.536-0.542]; p = 0.928), and percentage changes in NIRS were unable to detect a decrease in PbtO2 ≥ 10% (area under the receiver operating characteristic curve 0.615 [95% confidence interval 0.614-0.616]; p < 0.001). CONCLUSIONS: PbtO2 and NIRS measurements were not correlated. There is no evidence that NIRS could be a substitute for PbtO2 monitoring in patients with nontraumatic subarachnoid hemorrhage.

The ability of Oxygen Reserve Index® to detect hyperoxia in critically ill patients.

BACKGROUND: Hyperoxia is associated with increased morbidity and mortality in the intensive care unit. Classical noninvasive measurements of oxygen saturation with pulse oximeters are unable to detect hyperoxia. The Oxygen Reserve Index (ORI) is a continuous noninvasive parameter provided by a multi-wave pulse oximeter that can detect hyperoxia. Primary objective was to evaluate the diagnostic accuracy of the ORI for detecting arterial oxygen tension (PaO2) > 100 mmHg in neurocritical care patients. Secondary objectives were to test the ability of ORI to detect PaO2 > 120 mmHg and the ability of pulse oximetry (SpO2) to detect PaO2 > 100 mmHg and PaO2 > 120 mmHg. METHODS: In this single-center study, we collected ORI and arterial blood samples every 6 h for 3 consecutive days. Diagnostic performance was estimated using the area under the receiver operating characteristic curve (AUROC). RESULTS: There were 696 simultaneous measurements of ORI and PaO2 in 62 patients. Considering the repeated measurements, the correlation between ORI and PaO2 was r = 0.13. The area under the receiver operating characteristic curve (AUROC), obtained to test the ability of ORI to detect PaO2 > 100 mmHg, was 0.567 (95% confidence interval = 0.566-0.569) with a sensitivity of 0.233 (95%CI = 0.230-0.235) and a specificity of 0.909 (95%CI = 0.907-0.910). The AUROC value obtained to test the ability of SpO2 to detect a PaO2 > 100 mmHg was 0.771 (95%CI = 0.770-0.773) with a sensitivity of 0.715 (95%CI = 0.712-0.718) and a specificity of 0.700 (95%CI = 0.697-0.703). The diagnostic performance of ORI and SpO2 for detecting PaO2 > 120 mmHg was AUROC = 0.584 (95%CI = 0.582-0.586) and 0.764 (95%CI = 0.762-0.766), respectively. The AUROC obtained for SpO2 was significantly higher than that for ORI (p < 0.01). Diagnostic performance was not affected by sedation, norepinephrine infusion, arterial partial pressure of carbon dioxide, hemoglobin level and perfusion index. CONCLUSION: In a specific population of brain-injured patients hospitalized in a neurointensive care unit, our results suggest that the ability of ORI to diagnose hyperoxia is relatively low and that SpO2 provides better detection.

Impact of Model Choice When Studying the Relationship Between Blood Pressure Variability and Risk of Stroke Recurrence.

[Figure: see text].

Implementation of French Recommendations for the Prevention and the Treatment of Hospital-acquired Pneumonia: A Cluster-randomized Trial.

BACKGROUND: We determined whether an audit on the adherence to guidelines for hospital-acquired pneumonia (HAP) can improve the outcomes of patients in intensive care units (ICUs). METHODS: This study was conducted at 35 ICUs in 30 hospitals. We included consecutive, adult patients hospitalized in ICUs for 3 days or more. After a 3-month baseline period followed by the dissemination of recommendations, an audit on the compliance to recommendations (audit period) was followed by a 3-month cluster-randomized trial. We randomly assigned ICUs to either receive audit and feedback (intervention group) or participate in a national registry (control group). The primary outcome was the duration of ICU stay. RESULTS: Among 1856 patients enrolled, 602, 669, and 585 were recruited in the baseline, audit, and intervention periods, respectively. The composite measures of compliance were 47% (interquartile range [IQR], 38-56%) in the intervention group and 42% (IQR, 25-53%) in the control group (P = .001). As compared to the baseline period, the ICU lengths of stay were reduced by 3.2 days in the intervention period (P = .07) and by 2.8 days in the control period (P = .02). The durations of ICU stay were 7 days (IQR, 5-14 days) in the control group and 9 days (IQR, 5-20 days) in the intervention group (P = .10). After adjustment for unbalanced baseline characteristics, the hazard ratio for being discharged alive from the ICU in the control group was 1.17 (95% confidence interval, .69-2.01; P = .10). CONCLUSIONS: The publication of French guidelines for HAP was associated with a reduction of the ICU length of stay. However, the realization of an audit to improve their application did not further improve outcomes. CLINICAL TRIALS REGISTRATION: NCT03348579.

Utility of changes in end-tidal carbon dioxide after volume expansion to assess fluid responsiveness in the operating room: a prospective observational study.

BACKGROUND: From a physiological viewpoint, changes in end-tidal carbon dioxide (EtCO2) could be a simple, noninvasive, and inexpensive way to monitor changes in cardiac index. This study aimed to assess the utility of changes in EtCO2 as a marker of fluid responsiveness after volume expansion in the operating room. METHODS: A prospective observational study was conducted in a tertiary university teaching hospital, from August 2018 to February 2019. A total of 109 non-consecutive, mechanically ventilated adults undergoing neurosurgery in the supine position with cardiac output monitors were included. Patients with major respiratory disease, arrhythmia, or heart failure were excluded. Volume expansion with 250 ml of saline 0.9% was performed over 10 min to maximise cardiac output during surgery, according to current guidelines. A positive fluid challenge was defined as an increase in stroke volume index of more than 10% from baseline. Changes in stroke volume index (monitored using pulse contour analysis) and EtCO2 were recorded before and after infusion. RESULTS: A total of 242 fluid challenges in 114 patients were performed, of which 26.9% were positive. Changes in EtCO2 > 1.1% induced by infusions had utility for identifying fluid responsiveness, with a sensitivity of 62.9% (95% confidence interval [CI], 62.5-63.3%) and a specificity of 77.8% (95% CI, 77.6-78.1%). The area under the receiver operating characteristic curve for changes in EtCO2 after volume expansion was 0.683 (95% CI, 0.680-0.686). CONCLUSIONS: Changes in EtCO2 induced by rapid infusion of 250 ml saline 0.9% lacked accuracy for identifying fluid responsiveness in mechanically ventilated patients in the operating room. CLINICAL TRIAL REGISTRATION: NCT03635307.

EQSAR: A national survey of sleep duration among French Anaesthesiologists and Intensivists.

INTRODUCTION: The US National Sleep Foundation recommends more than 7 hours of sleep per night for adults. Anaesthesiologists and intensivists (AI) are at high risk of short sleep time. The aim of this present survey was to assess the sleep duration of French AI and to identify independent factors related to a sleep time less than the recommended 7 hours. METHODS: This prospective observational study was conducted between April and June 2018 and included 6,210 French AI with night-work obligations. The primary outcome variable was sleep duration strictly inferior to 7 hours per night. The covariables included in the multivariable model were selected after the univariate analysis, with those with a p < 0.05 included in the final model. RESULTS: Of the 6,210 AI, 3,699 responded to the survey, and 2,483 were included in the analysis. Of the 2,483 responders, 1,533 (61.7%) reported sleep duration strictly less than 7 hours per night. After the multivariate analysis, the following risk factors were independently associated with sleep duration strictly under 7 hours: age (OR: 1.28 ; IC [1.19 - 1.37]), more than 5 on-call shifts per month, (OR: 1.41 ; IC [1.30 - 1.50]), active smoking (OR: 1.37 ; IC [1.07 - 1.75]), and screen consultation at bedtime (OR: 1.85 ; IC [1.31 - 2.62]). CONCLUSION: This study gives a recent overview of sleep time and quality of French AI. It could be a useful tool for monitoring sleep disorders among the practitioners and their impact on quality of life.

Do changes in perfusion index reflect changes in stroke volume during preload-modifying manoeuvres?

Changes in stroke volume (deltaSV) induced by a lung recruitment manoeuvre (LRM) have been shown to accurately predict fluid responsiveness during protective mechanical ventilation. Cardiac output monitors are used in a limited number of surgical patients. In contrast, all patients are monitored with a pulse oximeter, that may enable the continuous monitoring of a peripheral perfusion index (PI). We postulated that changes in PI (deltaPI) may reflect deltaSV during brief modifications of cardiac preload. We studied 47 patients undergoing neurosurgery and ventilated with a tidal volume of 6-8 ml/kg. All patients were monitored with a pulse contour system enabling the continuous monitoring of SV and with a pulse oximeter enabling the continuous monitoring of PI. LRMs were performed by increasing airway pressure up to 30 cmH20 for 30 s. Fluid loads (250 ml of saline 0.9% in 10 min) were performed only in patients who experienced a deltaSV > 30% during LRMs (potential fluid responders). LRMs induced a 26% decrease in SV (p < 0.05) and a 27% decrease in PI (p < 0.05). We observed a fair relationship between deltaPI and deltaSV (r2 = 0.34). A deltaPI ≥ 26% predicted a deltaSV > 30% with a sensitivity of 83% and a specificity of 78%  (AUC  =  0.84, 95%CI 0.71-0.93). 24 patients experienced a deltaSV > 30% and subsequently received fluid. Fluid loads induced a 16% increase in SV and a 17% increase in PI, but fluid-induced deltaPI and deltaSV were weakly correlated (r2 = 0.19). In neurosurgical patients, we conclude that deltaPI may be used as a surrogate for deltaSV during LRMs but not during fluid loading.

Increased ß-Lactams dosing regimens improve clinical outcome in critically ill patients with augmented renal clearance treated for a first episode of hospital or ventilator-acquired pneumonia: a before and after study.

BACKGROUND: Augmented renal clearance (ARC) is recognized as a leading cause of ß-lactam subexposure when conventional dosing regimens are used. The main objective was to compare the clinical outcome of ARC patients treated by conventional or increased ß-lactam dosing regimens for a first episode of hospital or ventilator-acquired pneumonia (HAP-VAP). METHODS: In this single-center, retrospective study, every ARC patient treated by ß-lactam for a first episode of HAP-VAP was included during two 15-month periods, before (Control period) and after (Treatment period) the modification of a local antibiotic therapy protocol. ARC was defined by a 24-h measured creatinine clearance ≥ 150 ml/min. The primary endpoint was defined as a therapeutic failure of the antimicrobial therapy or a HAP-VAP relapse within 28 days. Inverse probability of treatment weight (IPTW) was derived from a propensity score model. Cox proportional hazard models were used to evaluate the association between treatment period and clinical outcome. RESULTS: During the study period, 177 patients were included (control period, N = 88; treatment period, N = 89). Therapeutic failure or HAP-VAP relapse was significantly lower in the treatment period (10 vs. 23%, p = 0.019). The IPTW-adjusted hazard ratio of poor clinical outcome in the treatment period was 0.35 (95% CI 0.15-0.81), p = 0.014. No antibiotic side effect was reported during the treatment period. CONCLUSIONS: Higher than licensed dosing regimens of ß-lactams may be safe and effective in reducing the rate of therapeutic failure and HAP-VAP recurrence in critically ill augmented renal clearance (ARC) patients.

Evaluation of least significant changes of pulse contour analysis-derived parameters.

BACKGROUND: Many maneuvers assessing fluid responsiveness (minifluid challenge, lung recruitment maneuver, end-expiratory occlusion test, passive leg raising) are considered as positive when small variations in cardiac index, stroke volume index, stroke volume variation or pulse pressure variation occur. Pulse contour analysis allows continuous and real-time cardiac index, stroke volume, stroke volume variation and pulse pressure variation estimations. To use these maneuvers with pulse contour analysis, the knowledge of the minimal change that needs to be measured by a device to recognize a real change (least significant change) has to be studied. The aim of this study was to evaluate the least significant change of cardiac index, stroke volume index, stroke volume variation and pulse pressure variation obtained using pulse contour analysis (ProAQT®, Pulsion Medical System, Germany). METHODS: In this observational study, we included 50 mechanically ventilated patients undergoing neurosurgery in the operating room. Cardiac index, stroke volume index, pulse pressure variation and stroke volume variation obtained using ProAQT® (Pulsion Medical System, Germany) were recorded every 12 s during 15-min steady-state periods. Least significant changes were calculated every minute. RESULTS: Least significant changes statistically differed over time for cardiac index, stroke volume index, pulse pressure variation and stroke volume variation (p < 0.001). Least significant changes ranged from 1.3 to 0.7% for cardiac index, from 1.3 to 0.8% for stroke volume index, from 10 to 4.9% for pulse pressure variation and from 10.8 to 4.3% for stroke volume variation. CONCLUSION: To conclude, the present study suggests that pulse contour analysis is able to detect rapid and small changes in cardiac index and stroke volume index, but the interpretation of rapid and small changes of pulse pressure variation and stroke volume variation must be done with caution.

Changes in dynamic arterial elastance induced by volume expansion and vasopressor in the operating room: a prospective bicentre study.

BACKGROUND: Dynamic arterial elastance (Eadyn), defined as the ratio between pulse pressure variations and stroke volume variations, has been proposed to assess functional arterial load. We evaluated the evolution of Eadyn during volume expansion and the effects of neosynephrine infusion in hypotensive and preload-responsive patients. METHODS: In this prospective bicentre study, we included 56 mechanically ventilated patients in the operating room. Each patient had volume expansion and neosynephrine infusion. Stroke volume and stroke volume variations were obtained using esophageal Doppler, and pulse pressure variations were measured through the arterial line. Pressure response to volume expansion was defined as an increase in mean arterial pressure (MAP) ≥ 10%. RESULTS: Twenty-one patients were pressure responders to volume expansion. Volume expansion induced a decrease in Eadyn (from 0.69 [0.58-0.85] to 0.59 [0.42-0.77]) related to a decrease in pulse pressure variations more pronounced than the decrease in stroke volume variations. Baseline and changes in Eadyn after volume expansion were related to age, history of arterial hypertension, net arterial compliance and effective arterial elastance. Eadyn value before volume expansion > 0.65 predicted a MAP increase ≥ 10% with a sensitivity of 76% (95% CI 53-92%) and a specificity of 60% (95% CI 42-76%). Neosynephrine infusion induced a decrease in Eadyn (from 0.67 [0.48-0.80] to 0.54 [0.37-0.68]) related to a decrease in pulse pressure variations more pronounced than the decrease in stroke volume variations. Baseline and changes in Eadyn after neosynephrine infusion were only related to heart rate. CONCLUSION: Eadyn is a potential sensitive marker of arterial tone changes following vasopressor infusion.