Early hyperoxia and 28-day mortality in patients on venoarterial ECMO support for refractory cardiogenic shock: a bicenter retrospective propensity score-weighted analysis.

BACKGROUND: The mortality rate for a patient with a refractory cardiogenic shock on venoarterial (VA) extracorporeal membrane oxygenation (ECMO) remains high, and hyperoxia might worsen this prognosis. The objective of the present study was to evaluate the association between hyperoxia and 28-day mortality in this setting. METHODS: We conducted a retrospective bicenter study in two French academic centers. The study population comprised adult patients admitted for refractory cardiogenic shock. The following arterial partial pressure of oxygen (PaO2) variables were recorded for 48 h following admission: the absolute peak PaO2 (the single highest value measured during the 48 h), the mean daily peak PaO2 (the mean of each day's peak values), the overall mean PaO2 (the mean of all values over 48 h), and the severity of hyperoxia (mild: PaO2 < 200 mmHg, moderate: PaO2 = 200-299 mmHg, severe: PaO2 ≥ 300 mmHg). The main outcome was the 28-day all-cause mortality. Inverse probability weighting (IPW) derived from propensity scores was used to reduce imbalances in baseline characteristics. RESULTS: From January 2013 to January 2020, 430 patients were included and assessed. The 28-day mortality rate was 43%. The mean daily peak, absolute peak, and overall mean PaO2 values were significantly higher in non-survivors than in survivors. In a multivariate logistic regression analysis, the mean daily peak PaO2, absolute peak PaO2, and overall mean PaO2 were independent predictors of 28-day mortality (adjusted odds ratio [95% confidence interval per 10 mmHg increment: 2.65 [1.79-6.07], 2.36 [1.67-4.82], and 2.85 [1.12-7.37], respectively). After IPW, high level of oxygen remained significantly associated with 28-day mortality (OR = 1.41 [1.01-2.08]; P = 0.041). CONCLUSIONS: High oxygen levels were associated with 28-day mortality in patients on VA-ECMO support for refractory cardiogenic shock. Our results confirm the need for large randomized controlled trials on this topic.

Individualised or liberal red blood cell transfusion after cardiac surgery: a randomised controlled trial.

BACKGROUND: Current practice guidelines for red blood cell (RBC) transfusion in ICUs are based on haemoglobin threshold, without consideration of oxygen delivery or consumption. We aimed to evaluate an individual physiological threshold-guided by central venous oxygen saturation ScvO2. METHODS: In a randomised study in two French academic hospitals, 164 patients who were admitted to ICU after cardiac surgery with postoperative haemoglobin <9 g dl-1 were randomised to receive a transfusion with one unit of RBCs (haemoglobin group) or transfusion only if the ScvO2 was <70% (individualised group). The primary outcome was the number of subjects receiving at least one unit of RBCs. The secondary composite outcome was acute kidney injury, stroke, myocardial infarction, acute heart failure, mesenteric ischaemia, or in-hospital mortality. One- and 6-month mortality were evaluated during follow-up. RESULTS: The primary outcome was observed for 80 of 80 subjects (100%) in the haemoglobin group and in 61 of 77 patients (79%) in the individualised group (absolute risk -21% [-32.0; -14.0]; P<0.001). There was no significant difference in the secondary outcome between the two groups. Follow-up showed a non-significant difference in mortality at 1 and 6 months. CONCLUSIONS: An individualised strategy based on an central venous oxygen saturation threshold of 70% allows for a more restrictive red blood cell transfusion strategy with no incidence on postoperative morbidity or 6-month mortality. CLINICAL TRIAL REGISTRATION: NCT02963883.

Central venous-to-arterial CO2 difference is a poor tool to predict adverse outcomes after cardiac surgery: a retrospective study.

PURPOSE: The venous-to-arterial carbon dioxide partial pressure difference (CO2 gap) has been reported to be a sensitive indicator of cardiac output adequacy. We aimed to assess whether the CO2 gap can predict postoperative adverse outcomes after cardiac surgery. METHODS: A retrospective study was conducted of 5,151 patients from our departmental database who underwent cardiac surgery from 1 January 2008 to 31 December 2018. Lactate level (mmol·L-1), central venous oxygen saturation (ScVO2) (%), and the venous-to-arterial carbon dioxide difference (CO2 gap) were measured at intensive care unit (ICU) admission and on days 1 and 2 after cardiac surgery. The following postoperative adverse outcomes were collected: ICU mortality, hemopericardium or tamponade, resuscitated cardiac arrest, acute kidney injury, major bleeding, acute hepatic failure, mesenteric ischemia, and pneumonia. The primary outcome was the presence of at least one postoperative adverse outcome. Logistic regression was used to assess the association between ScVO2, lactate, and the CO2 gap with adverse outcomes. Their diagnostic performance was compared using a receiver operating characteristic (ROC) curve. RESULTS: There were 1,933 patients (38%) with an adverse outcome. Cardiopulmonary bypass (CPB) parameters were similar between groups. The CO2 gap was slightly higher for the "adverse outcomes" group than for the "no adverse outcomes" group. Arterial lactate at admission, day 1, and day 2 was also slightly higher in patients with adverse outcomes. Central venous oxygen saturation was not significantly different between patients with and without adverse outcomes. The area under the ROC curve to predict outcomes after CPB for the CO2 gap at admission, day 1, and day 2 were 0.52, 0.55, and 0.53, respectively. CONCLUSION: After cardiac surgery with CPB, the CO2 gap at ICU admission, day 1, and day 2 was associated with postoperative adverse outcomes but showed poor diagnostic performance.

RéSUMé: OBJECTIF: La différence de pression partielle de dioxyde de carbone veineux versus artériel (gradient de CO2) a été rapportée comme étant un indicateur sensible d'un débit cardiaque adéquat. Nous avons tenté d'évaluer si le gradient de CO2 pouvait prédire les devenirs postopératoires défavorables après une chirurgie cardiaque. MéTHODE: Une étude rétrospective a été réalisée en se basant sur les dossiers de 5151 patients issus de notre base de données départementale ayant subi une chirurgie cardiaque entre le 1er janvier 2008 et le 31 décembre 2018. Les taux de lactate (mmol·L−1), la saturation en oxygène veineux central (ScVO2) (%), et la différence de dioxyde de carbone veineux versus artériel (gradient de CO2) ont été mesurés lors de l'admission en réanimation (ICU) et aux jours 1 et 2 après la chirurgie cardiaque. Les complications postopératoires suivantes ont été colligées : mortalité en réanimation, hémopéricarde ou tamponnade, arrêt cardiaque récupéré, insuffisance rénale aiguë, saignements majeurs, insuffisance hépatique aiguë, ischémie mésentérique et pneumonie. Le critère d'évaluation principal était la présence d'au moins une complication postopératoire. La régression logistique a été utilisée pour évaluer l'association entre ScVO2, taux de lactate et gradient de CO2 et les complications. Leur performance diagnostique a été comparée à l'aide d'une courbe ROC (receiver operating characteristic). RéSULTATS: Des complications sont survenues chez 1933 patients (38 %). Les paramètres de circulation extracorporelle (CEC) étaient semblables entre les groupes. Le gradient de CO2 était légèrement plus élevé dans le groupe « complications ¼ que dans le groupe « pas de complication ¼. Les taux de lactate artériels à l'admission, au jour 1 et au jour 2 étaient également légèrement plus élevés chez les patients ayant subi des complications. La différence de saturation en oxygène veineux central n'était pas significative entre les patients avec ou sans complications. L'aire sous la courbe ROC pour prédire les devenirs après la CEC pour le gradient de CO2 à l'admission, au jour 1 et au jour 2 était de 0,52, 0,55 et 0,53, respectivement. CONCLUSION: Après une chirurgie cardiaque avec CEC, le gradient de CO2 à l'admission en réanimation, au jour 1 et au jour 2 était associé aux complications postopératoires, mais sa performance diagnostique était médiocre.

Usefulness of Right Ventricular Longitudinal Shortening Fraction to Detect Right Ventricular Dysfunction in Acute Cor Pulmonale Related to COVID-19.

OBJECTIVE: To compare two-dimensional-speckle tracking echocardiographic parameters (2D-STE) and classic echocardiographic parameters of right ventricular (RV) systolic function in patients with coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (CARDS) complicated or not by acute cor pulmonale (ACP). DESIGN: Prospective, between March 1, 2020 and April 15, 2020. SETTING: Intensive care unit of Amiens University Hospital (France). PARTICIPANTS: Adult patients with moderate-to-severe CARDS under mechanical ventilation for fewer than 24 hours. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Tricuspid annular displacement (TAD) parameters (TAD-septal, TAD-lateral, and RV longitudinal shortening fraction [RV-LSF]), RV global longitudinal strain (RV-GLS), and RV free wall longitudinal strain (RVFWLS) were measured using transesophageal echocardiography with a dedicated software and compared with classic RV systolic parameters (RV-FAC, S' wave, and tricuspid annular plane systolic excursion [TAPSE]). RV systolic dysfunction was defined as RV-FAC <35%. Twenty-nine consecutive patients with moderate-to-severe CARDS were included. ACP was diagnosed in 12 patients (41%). 2D-STE parameters were markedly altered in the ACP group, and no significant difference was found between patients with and without ACP for classic RV parameters (RV-FAC, S' wave, and TAPSE). In the ACP group, RV-LSF (17% [14%-22%]) had the best correlation with RV-FAC (r = 0.79, p < 0.001 v r = 0.27, p = 0.39 for RVGLS and r = 0.28, p = 0.39 for RVFWLS). A RV-LSF cut-off value of 17% had a sensitivity of 80% and a specificity of 86% to identify RV systolic dysfunction. CONCLUSIONS: Classic RV function parameters were not altered by ACP in patients with CARDS, contrary to 2D-STE parameters. RV-LSF seems to be a valuable parameter to detect early RV systolic dysfunction in CARDS patients with ACP.

Changes in Plasma Angiopoietin Levels After Transcatheter Aortic Valve Replacement and Surgical Aortic Valve Replacement: A Prospective Cohort Study.

OBJECTIVE: Angiopoietins (Angs) regulate endothelial permeability. Ang-1 and 2 (Ang-1 and Ang-2) are implied in endothelial stability through an antagonism effect. The objectives of the present study were to describe and compare changes in Ang levels after transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR). DESIGN: A prospective, single-center study. PARTICIPANTS: Adult patients with aortic stenosis scheduled for SAVR or TAVR. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Ang-1 and Ang-2 were measured using an enzyme-linked immunosorbent assay right before surgery (T0), at the end of surgery (T1), and at day one (T2). Sixty consecutive patients (SAVR group [n = 30] and TAVR group [n = 30]) were included between January and June 2017. Ang-1 decreased significantly after both TAVR (T0: 3,663 [2,602-4,262]; T1: 1,611 [981-2,409]; T2: 1,082 [652-1,589] ng/mL; p < 0.0001) and SAVR (T0: 1,603 [975-2,849]; T1: 783 [547-1,024]; T2: 828 [460-1,227] ng/mL; p = 0.0001). Ang-2 increased significantly after SAVR (T0: 2,472 [1,502-3,622]; T1: 2,997 [1,759-3,839]; T2: 5,421 [3,557-7,087] ng/mL; p < 0.0001) but did not change markedly after TAVR (T0: 3,343 [2,661-6,272]; T1: 3,788 [2,574-5,016]; T2: 3,446 [3,029-6,313] ng/mL; p = 0.066). Among patients with paravalvular leakage, the changes in the plasma Ang-2 level and the Ang-2/Ang-1 ratio were greater. CONCLUSION: SAVR induces greater alterations of Ang homeostasis than TAVR, confirming a role for the use of cardiopulmonary bypass. Paravalvular leakage after TAVR is associated with Ang changes similar to those observed with SAVR.

Fluid expansion improve ventriculo-arterial coupling in preload-dependent patients: a prospective observational study.

BACKGROUND: The objectives of the present study was to evaluate the effect of fluid challenge (FC) on ventriculo-arterial (V-A) coupling, its determinants: arterial elastance and ventricular elastance, and ability to predict fluid responsiveness. METHODS: Thirty patients admitted to cardio-thoracic ICU in whom the physician decided to perform FC were included. Arterial pressure, cardiac output, arterial elastance, and ventricular elastance, were measured before and after FC with 500 ml of lactated Ringer's solution. Fluid responders were defined as patients with more than a 15% increase in stroke volume. V-A coupling was evaluated by the arterial elastance to ventricular elastance ratio. RESULTS: Twenty-three (77%) of the 30 patients included in the study were fluid responders. Before FC, responders had higher arterial elastance and arterial elastance to ventricular elastance ratio. FC significantly increased mean arterial pressure, stroke volume and cardiac output, and significantly decreased systemic vascular resistance, arterial elastance and consequently the arterial elastance to ventricular elastance ratio. Changes in arterial elastance were correlated with changes in stroke volume, systemic vascular resistance, and arterial compliance. Baseline arterial elastance to ventricular elastance ratio over 1.4 predicted fluid responsiveness (area under the curve [95% confidence interval]: 0.84 [0.66-1]; p < 0.0001). CONCLUSIONS: Fluid responsiveness patients had V-A coupling characterized by increase arterial elastance to ventricular elastance ratio, in relation to an increase arterial elastance. Fc improved the V-A coupling ratio by decreasing arterial elastance without altering ventricular elastance. Arterial elastance changes were related to those of systemic vascular resistance (continue component) and of arterial compliance (pulsatile component).

Vasoplegia After Cardiac Surgery Is Associated With Endothelial Glycocalyx Alterations.

OBJECTIVE: To assess endothelial glycocalyx (EG) alteration in vasoplegic syndrome after cardiac surgery with cardiopulmonary bypass. DESIGN: Prospective analysis SETTING: Single university hospitals. PARTICIPANTS: Patients undergoing elective cardiac surgery under cardiopulmonary bypass. INTERVENTIONS: Observational study METHODS: Heparan sulfate and syndecan-1 levels were assessed in plasma before surgery, on intensive care unit admission, and on the first postoperative day. The primary outcome was comparisons of heparan sulfate and syndecan-1 levels in patients with and without vasoplegic syndrome. RESULTS: A total of 46 patients were analyzed. Only syndecan-1 was modified by cardiac surgery (p < 0.05). Plasma syndecan-1 levels were lower in patients with vasoplegic syndrome at the 3 time-points and were associated with the cumulative norepinephrine dose. Baseline plasma syndecan-1 predicted the development of vasoplegic syndrome with an area under the curve of 0.7 (confidence interval 95%: 0.51-0.85, p = 0.045). Heparan sulfate levels were not modified by cardiac surgery. CONCLUSION: Patients with vasoplegic syndrome after cardiac surgery present a different pattern of EG components. Lower syndecan-1 levels were associated with vasoplegic syndrome. These preliminary results suggest a specific phenotype that may reflect endothelial activation leading to alteration of the EG.

An urgent open surgical approach for left ventricle venting during peripheral veno-arterial extracorporeal membrane oxygenation for refractory cardiac arrest: case report.

The objective of the study is to describe an emergency procedure for left ventricle venting during veno-arterial extracorporeal life support for refractory cardiac arrest. Veno-arterial extracorporeal membrane oxygenation is widely used in refractory cardiac arrest but is characterized by an increase in left ventricle afterload, which may impair cardiac contractility improvement. Different left ventricle venting techniques are available. We report the use of a surgical approach with sternotomy for left ventricle venting in a 21-year-old patient who was placed under veno-arterial extracorporeal membrane oxygenation for refractory cardiac arrest with severe pulmonary edema, respiratory failure, and left ventricle stasis. A 21-year-old woman was admitted for laparoscopic sleeve gastrectomy. In the recovery room, she developed a refractory circulatory shock. Transthoracic echocardiography revealed a dilated cardiomyopathy with severe left ventricle systolic dysfunction (left ventricle ejection fraction at 20%). Coronary angiogram was normal. On day 2, she underwent laparotomy for sepsis and she presented cardiac arrest secondary to ventricular tachycardia. We proceeded to peripheral veno-arterial extracorporeal membrane oxygenation as the cardiac arrest was refractory. A miniaturized veno-arterial extracorporeal membrane oxygenation system was implanted into the right femoral vessels onsite .The low flow duration was 40 minutes. Veno-arterial extracorporeal membrane oxygenation blood flow was set to 3 L min-1, resulting in a closed aortic valve and a massive pulmonary edema. Transesophageal echocardiography showed left ventricular ejection fraction at 5% without aortic valve opening. We first implanted an intra-aortic balloon pump without clinical improvement. Transesophageal echocardiography revealed massive thrombus formation into the aortic root. We decided to perform an open surgical approach for left ventricle unload using a transmitral cannula (22 Fr) via the right superior pulmonary vein connected to the inflow tube of the veno-arterial extracorporeal membrane oxygenation with Y connection. Transesophageal echocardiography showed a full opening of aortic valve and elimination of valve aortic thrombus. Chest radiography showed a significant decrease of pulmonary congestion. We were able to withdraw extracorporeal life support organization on day 10 and discharged on day 54. Clinical explorations reveal a fulminant rocuronium-related hypersensitivity myocarditis. This salvage surgical technique using a modified central veno-arterial extracorporeal membrane oxygenation cannulation technique has efficiently decreased blood stasis and permitted rapid recovery.

Postoperative Vasoplegic Syndrome Is Associated With Impaired Endothelial Vasomotor Response in Cardiac Surgery: A Prospective, Observational Study.

OBJECTIVES: Vasoplegic syndrome (VS) affects up to 30% of cardiac surgery patients. Onset of VS may be associated with overproduction of nitric oxide (NO). The response of the brachial artery to NO can be assessed using flow-mediated vasodilation (FMD). The aim of this study was to assess brachial artery diameter and FMD response immediately after cardiac surgery. DESIGN: Prospective, observational study. SETTING: Single-center study in a tertiary teaching hospital. PATIENTS: Patients older than 18 years undergoing elective cardiac surgery with cardiopulmonary bypass who provided informed consent. INTERVENTIONS: Brachial artery diameter and FMD response were measured before cardiac surgery and just after surgery on admission to the intensive care unit. Patients were screened for VS for the following 48 hours. RESULTS: Eleven (39%) of the 28 patients included in the study developed VS. Brachial artery diameter and FMD differed between VS and non-VS patients. On intensive care unit admission, mean (± standard deviation) brachial artery diameter was greater in VS patients than in non-VS patients (3.9 ± 0.7 mm v 3.0 ± 0.8 mm, respectively; p = 0.002). Similarly, the FMD response after surgery was greater in VS patients than in non-VS patients (42% ± 8% v 31% ± 1%, respectively; p = 0.014). Brachial artery diameter and FMD response after surgery were both predictive of VS, with an area under the curve (95% confidence interval) of 0.850 (0.705-0.995) (p = 0.002) and 0.755 (0.56-0.95) (p = 0.047), respectively. CONCLUSION: Cardiac surgery with cardiopulmonary bypass appears to alter the NO-mediated endothelial vasomotor response.

A norepinephrine weaning strategy using dynamic arterial elastance is associated with reduction of acute kidney injury in patients with vasoplegia after cardiac surgery: A post-hoc analysis of the randomized SNEAD study.

STUDY OBJECTIVE: To evaluate the impact of a dynamic arterial elastance guided norepinephrine weaning strategy on the occurrence of acute kidney injury (AKI) in patients with vasoplegia after cardiac surgery. DESIGN: A post-hoc analysis of a monocentric randomized controlled trial. SETTING: A tertiary care hospital in France. PARTICIPANTS: Vasoplegic cardiac surgical patients treated with norepinephrine. INTERVENTION: Patients were randomized to an algorithm-based norepinephrine weaning intervention (dynamic arterial elastance) group or a control group. MEASUREMENTS: The primary endpoint was the number of patients with AKI defined according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. The secondary endpoint were major adverse cardiac post-operative events (new onset of atrial fibrillation or flutter, low cardiac output syndrome, and in-hospital death). End points were evaluated during the first seven post-operative days. RESULTS: 118 patients were analyzed. In the overall study population, the mean age was 70 (62-76) years, 65% were male and the median EuroSCORE was 7 (5-10). Overall, 46 (39%) patients developed AKI (30 KDIGO 1, 8 KDIGO 2, 8 KDIGO 3), and 6 patients required renal replacement therapy. The incidence of AKI was significantly lower in the intervention group than in the control group (16 patients (27%) vs 30 patients (51%), p = 0.12). Higher dose and longer duration of norepinephrine were associated with AKI severity. CONCLUSION: Decreasing norepinephrine exposure by using a dynamic arterial elastance guided norepinephrine weaning strategy was associated with a reduced incidence of acute kidney injury in patients with vasoplegia after cardiac surgery. Further prospective multicentric studies are needed to confirm these results.