Central Versus Peripheral Arterial Pressure Monitoring in Patients Undergoing Cardiac Surgery: A Prospective Observational Study.

OBJECTIVE: The aortic-to-radial arterial pressure gradient is described during and after cardiopulmonary bypass (CPB), and can lead to underestimating arterial blood pressure. The authors hypothesized that central arterial pressure monitoring would be associated with lower norepinephrine requirements than radial arterial pressure monitoring during cardiac surgery. DESIGN: An observational prospective cohort with propensity score analysis. SETTING: At a tertiary academic hospital's operating room and intensive care unit (ICU). PARTICIPANTS: A total of 286 consecutive adult patients undergoing cardiac surgery with CPB (central group: 109; radial group: 177) were enrolled and analyzed. INTERVENTIONS: To explore the hemodynamic effect of the measurement site, the authors divided the cohort into 2 groups according to a femoral/axillary (central group) or radial (radial group) site of arterial pressure monitoring. MEASUREMENT AND MAIN RESULTS: The primary outcome was the intraoperative amount of norepinephrine administered. Secondary outcomes included norepinephrine-free hours and ICU-free hours at postoperative day 2 (POD2). A logistic model with propensity score analysis was built to predict central arterial pressure monitoring use. The authors compared demographic, hemodynamic, and outcomes data before and after adjustment. Central group patients had a higher European System for Cardiac Operative Risk Evaluation. (EuroSCORE) compared to the radial group-7.9 ± 14.0 versus 3.8 ± 7.0, p < 0.001. After adjustment, both groups had similar patient EuroSCORE and arterial blood pressure levels. Intraoperative norepinephrine dose regimens were 0.10 ± 0.10 µg/kg/min in the central group and 0.11 ± 0.11 µg/kg/min in the radial group (p = 0.519). Norepinephrine-free hours at POD2 were 38 ± 17 hours versus 33 ± 19 hours in central and radial groups, respectively (p = 0.034). The ICU-free hours at POD2 were greater in the central group: 18 ± 13 hours versus 13 ± 13 hours, p = 0.008. Adverse events were less frequent in the central group than in the radial group-67% versus 50%, p = 0.007. CONCLUSIONS: No differences in the norepinephrine dose regimen were found according to the arterial measurement site during cardiac surgery. However, norepinephrine use and length of stay in the ICU were shorter, and adverse events were decreased when central arterial pressure monitoring was used.

Lower Limb Ischemia in Surgical Femoral Veno-Arterial Extracorporeal Membrane Oxygenation.

OBJECTIVES: To analyze the incidence, clinical impact on survival, and risk factors of lower limb ischemia (LLI) of surgical peripheral femoral venoarterial extracorporeal membrane oxygenation (VA ECMO) in the current era. DESIGN: A retrospective analysis of the authors' institutional database of VA ECMO was performed. Patients were divided into 2 groups according to the occurrence of LLI. The primary endpoint was survival to hospital discharge. Risk factors of LLI were searched with multivariate analyses. SETTING: University hospital. PARTICIPANTS: Adult patients receiving peripheral VA ECMO for refractory cardiogenic shock and cardiac arrest. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: From January 2018 to December 2021, 188 patients (mean age: 52.0 ± 14.1 years; 63.8% male, 36.2% female) received peripheral VA ECMO. Male sex was more prevalent in the group without LLI (65.9% v 33.3%; p = 0.031). Twelve (6.4%) patients developed LLI during VA ECMO support (n = 6) or after VA ECMO removal (n = 6). Survival to hospital discharge was not statistically different between patients with and without LLI (50.0% v 48.3%; p = 0.571). Female sex patients were at increased risk for LLI (odds ratio 4.38, 95% CI 1.21-15.81; p = 0.024). CONCLUSIONS: Peripheral femoral VA ECMO through a surgical approach is associated with a low LLI rate, which does not increase the risk of in-hospital mortality. The female sex is an independent risk factor for LLI.

Preload Dependence Fails to Predict Hemodynamic Instability During a Fluid Removal Challenge in Children.

OBJECTIVES: Fluid overload increases morbidity and mortality in PICU patients. Active fluid removal improves the prognosis but may worsen organ dysfunction. Preload dependence in adults does predict hemodynamic instability induced by a fluid removal challenge (FRC). We sought to investigate the diagnostic accuracy of dynamic and static markers of preload in predicting hemodynamic instability and reduction of stroke volume during an FRC in children. We followed the Standards for Reporting of Diagnostic Accuracy statement to design conduct and report this study. DESIGN: Prospective noninterventional cohort study. SETTINGS: From June 2017 to April 2019 in a pediatric cardiac ICU in a tertiary hospital. PATIENTS: Patients 8 years old or younger, with symptoms of fluid overload after cardiac surgery, were studied. INTERVENTIONS: We confirmed preload dependence by echocardiography before and during a calibrated abdominal compression test. We then performed a challenge to remove 10-mL/kg fluid in less than 120 minutes with an infusion of diuretics. Hemodynamic instability was defined as a decrease of 10% of mean arterial pressure. MEASUREMENT AND MAIN RESULTS: We compared patients showing hemodynamic instability with patients remaining stable, and we built receiver operative characteristic (ROC) curves. Among 58 patients studied, 10 showed hemodynamic instability. The area under the ROC curve was 0.55 for the preload dependence test (95% CI, 0.34-0.75). Using a threshold of 10% increase in stroke volume index (SVi) during calibrated abdominal compression, the specificity was 0.30 (95% CI, 0.00-0.60) and the sensitivity was 0.77 (95% CI, 0.65-0.88). Mean arterial pressure variation and SVi variation were not correlated during fluid removal; r = 0.19; 95% CI -0.07 to 0.43; p = 0.139. CONCLUSIONS: Preload dependence is not accurate to predict hemodynamic instability during an FRC. Our data do not support a reduction in intravascular volume being mainly responsible for the reduction in arterial pressure during an FRC in children.

Veno-arterial extracorporeal membrane oxygenation for drug intoxications: A single center, 14-year experience.

BACKGROUND AND AIM OF THE STUDY: Acute cardiovascular failure remains a leading cause of death in severe poisonings. Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has been increasingly used as a rescue therapeutic option for those cases refractory to optimal conventional treatment. We sought to evaluate the outcomes after VA-ECMO used for drug intoxications in a single-center experience. METHODS: We performed an observational analysis of our prospective institutional database. The primary endpoint was survival to hospital discharge. RESULTS: Between January 2007 and December 2020, 32 patients (mean age: 45.4 ± 15.8 years; 62.5% female) received VA-ECMO for drug intoxication-induced refractory cardiogenic shock (n = 25) or cardiac arrest (n = 7). Seven (21.8%) patients developed lower limb ischemia during VA-ECMO support. Twenty-six (81.2%) patients were successfully weaned after a mean VA-ECMO support of 2.9 ± 1.3 days. One (3.1%) patient died after VA-ECMO weaning for multiorgan failure and survival to hospital discharge was 78.1% (n = 25). In-hospital survivors were discharged from hospital with a good neurological status. Survival to hospital discharge was not statistically different according to sex (male = 75.0% vs. female = 80.0%; p = .535), type of intoxication (single drug = 81.8% vs. multiple drugs = 76.1%; p = .544) and location of VA-ECMO implantation (within our center = 75% vs. peripheral hospital using our Mobile Unit of Mechanical Circulatory Support = 100%; p = .352). Survival to hospital discharge was significantly lower in patients receiving VA-ECMO during on-going cardiopulmonary resuscitation (42.8% vs. 88.0%; p = .026). CONCLUSIONS: VA-ECMO appears to be a feasible therapeutic option with a satisfactory survival rate and acceptable complications rate in poisonings complicated by refractory cardiogenic shock or cardiac arrest.

Effects of methylene blue on microcirculatory alterations following cardiac surgery: A prospective cohort study.

BACKGROUND: Methylene blue is used as rescue therapy to treat catecholamine-refractory vasoplegic syndrome after cardiac surgery. However, its microcirculatory effects remain poorly documented. OBJECTIVE: We aimed to study microcirculatory abnormalities in refractory vasoplegic syndrome following cardiac surgery with cardiopulmonary bypass and assess the effects of methylene blue. DESIGN: A prospective open-label cohort study. SETTING: 20-Bed ICU of a tertiary care hospital. PATIENTS: 25 Adult patients receiving 1.5 mg kg-1 of methylene blue intravenously for refractory vasoplegic syndrome (defined as norepinephrine requirement more than 0.5 µg kg-1 min-1) to maintain mean arterial pressure (MAP) more than 65 mmHg and cardiac index (CI) more than 2.0 l min-1 m-2. MAIN OUTCOME MEASURES: Complete haemodynamic set of measurements at baseline and 1 h after the administration of methylene blue. Sublingual microcirculation was investigated by sidestream dark field imaging to obtain microvascular flow index (MFI), total vessel density, perfused vessel density and heterogeneity index. Microvascular reactivity was assessed by peripheral near-infrared (IR) spectroscopy combined with a vascular occlusion test. We also performed a standardised measurement of capillary refill time. RESULTS: Despite normalised CI (2.6 [2.0 to 3.8] l min-1 m-2) and MAP (66 [55 to 76] mmHg), patients with refractory vasoplegic syndrome showed severe microcirculatory alterations (MFI < 2.6). After methylene blue infusion, MFI significantly increased from 2.0 [0.1 to 2.5] to 2.2 [0.2 to 2.8] (P = 0.008), as did total vessel density from 13.5 [8.3 to 18.5] to 14.9 [10.1 to 14.7] mm mm-2 (P = 0.02) and perfused vessel density density from 7.4 [0.1 to 11.5] to 9.1 [0 to 20.1] mm mm-2 (P = 0.02), but with wide individual variation. Microvascular reactivity assessed by tissue oxygen resaturation speed also increased from 0.5 [0.1 to 1.8] to 0.7 [0.1 to 2.7]% s-1 (P = 0.002). Capillary refill time remained unchanged throughout the study. CONCLUSION: In refractory vasoplegic syndrome following cardiac surgery, we found microcirculatory alterations despite normalised CI and MAP. The administration of methylene blue could improve microvascular perfusion and reactivity, and partially restore the loss of haemodynamic coherence. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT04250389.

Prediction of intraoperative hypotension from the linear extrapolation of mean arterial pressure.

BACKGROUND: Hypotension prediction index (HPI) software is a proprietary machine learning-based algorithm used to predict intraoperative hypotension (IOH). HPI has shown superiority in predicting IOH when compared to the predictive value of changes in mean arterial pressure (ΔMAP) alone. However, the predictive value of ΔMAP alone, with no reference to the absolute level of MAP, is counterintuitive and poor at predicting IOH. A simple linear extrapolation of mean arterial pressure (LepMAP) is closer to the clinical approach. OBJECTIVES: Our primary objective was to investigate whether LepMAP better predicts IOH than ΔMAP alone. DESIGN: Retrospective diagnostic accuracy study. SETTING: Two tertiary University Hospitals between May 2019 and December 2019. PATIENTS: A total of 83 adult patients undergoing high risk non-cardiac surgery. DATA SOURCES: Arterial pressure data were automatically extracted from the anaesthesia data collection software (one value per minute). IOH was defined as MAP < 65 mmHg. ANALYSIS: Correlations for repeated measurements and the area under the curve (AUC) from receiver operating characteristics (ROC) were determined for the ability of LepMAP and ΔMAP to predict IOH at 1, 2 and 5 min before its occurrence (A-analysis, using the whole dataset). Data were also analysed after exclusion of MAP values between 65 and 75 mmHg (B-analysis). RESULTS: A total of 24 318 segments of ten minutes duration were analysed. In the A-analysis, ROC AUCs to predict IOH at 1, 2 and 5 min before its occurrence by LepMAP were 0.87 (95% confidence interval, CI, 0.86 to 0.88), 0.81 (95% CI, 0.79 to 0.83) and 0.69 (95% CI, 0.66 to 0.71) and for ΔMAP alone 0.59 (95% CI, 0.57 to 0.62), 0.61 (95% CI, 0.59 to 0.64), 0.57 (95% CI, 0.54 to 0.69), respectively. In the B analysis for LepMAP these were 0.97 (95% CI, 0.9 to 0.98), 0.93 (95% CI, 0.92 to 0.95) and 0.86 (95% CI, 0.84 to 0.88), respectively, and for ΔMAP alone 0.59 (95% CI, 0.53 to 0.58), 0.56 (95% CI, 0.54 to 0.59), 0.54 (95% CI, 0.51 to 0.57), respectively. LepMAP ROC AUCs were significantly higher than ΔMAP ROC AUCs in all cases. CONCLUSIONS: LepMAP provides reliable real-time and continuous prediction of IOH 1 and 2 min before its occurrence. LepMAP offers better discrimination than ΔMAP at 1, 2 and 5 min before its occurrence. Future studies evaluating machine learning algorithms to predict IOH should be compared with LepMAP rather than ΔMAP.

Improving the prognostic value of ∆PCO2 following cardiac surgery: a prospective pilot study.

Conflicting results have been published on prognostic significance of central venous to arterial PCO2 difference (∆PCO2) after cardiac surgery. We compared the prognostic value of ∆PCO2 on intensive care unit (ICU) admission to an original algorithm combining ∆PCO2, ERO2 and lactate to identify different risk profiles. Additionally, we described the evolution of ∆PCO2 and its correlations with ERO2 and lactate during the first postoperative day (POD1). In this monocentre, prospective, and pilot study, 25 patients undergoing conventional cardiac surgery were included. Central venous and arterial blood gases were collected on ICU admission and at 6, 12 and 24 h postoperatively. High ∆PCO2 (≥ 6 mmHg) on ICU admission was found to be very frequent (64% of patients). Correlations between ∆PCO2 and ERO2 or lactate for POD1 values and variations were weak or non-existent. On ICU admission, a high ∆PCO2 did not predict a prolonged ICU length of stay (LOS). Conversely, a significant increase in both ICU and hospital LOS was observed in high-risk patients identified by the algorithm: 3.5 (3.0-6.3) days versus 7.0 (6.0-8.0) days (p = 0.01) and 12.0 (8.0-15.0) versus 8.0 (8.0-9.0) days (p < 0.01), respectively. An algorithm incorporating ICU admission values of ∆PCO2, ERO2 and lactate defined a high-risk profile that predicted prolonged ICU and hospital stays better than ∆PCO2 alone.

Capillary refill time variation induced by passive leg raising predicts capillary refill time response to volume expansion.

BACKGROUND: A peripheral perfusion-targeted resuscitation during early septic shock has shown encouraging results. Capillary refill time, which has a prognostic value, was used. Adding accuracy and predictability on capillary refill time (CRT) measurement, if feasible, would benefit to peripheral perfusion-targeted resuscitation. We assessed whether a reduction of capillary refill time during passive leg raising (ΔCRT-PLR) predicted volume-induced peripheral perfusion improvement defined as a significant decrease of capillary refill time following volume expansion. METHODS: Thirty-four patients with acute circulatory failure were selected. Haemodynamic variables, metabolic variables (PCO2gap), and four capillary refill time measurements were recorded before and during a passive leg raising test and after a 500-mL volume expansion over 20 min. Receiver operating characteristic curves were built, and areas under the curves were calculated (ROCAUC). Confidence intervals (CI) were performed using a bootstrap analysis. We recorded mortality at day 90. RESULTS: The least significant change in the capillary refill time was 25% [95% CI, 18-30]. We defined CRT responders as patients showing a reduction of at least 25% of capillary refill time after volume expansion. A decrease of 27% in ΔCRT-PLR predicted peripheral perfusion improvement with a sensitivity of 87% [95% CI, 73-100] and a specificity of 100% [95% CI, 74-100]. The ROCAUC of ΔCRT-PLR was 0.94 [95% CI, 0.87-1.0]. The ROCAUC of baseline capillary refill time was 0.73 [95% CI, 0.54-0.90] and of baseline PCO2gap was 0.79 [0.61-0.93]. Capillary refill time was significantly longer in non-survivors than in survivors at day 90. CONCLUSION: ΔCRT-PLR predicted peripheral perfusion response following volume expansion. This simple low-cost and non-invasive diagnostic method could be used in peripheral perfusion-targeted resuscitation protocols. TRIAL REGISTRATION: CPP Lyon Sud-Est II ANSM: 2014-A01034-43 Clinicaltrial.gov, NCT02248025 , registered 13th of September 2014.

Outcomes after extracorporeal life support for postcardiotomy cardiogenic shock.

BACKGROUND AND AIM OF THE STUDY: Extracorporeal life support (ECLS) may be necessary in refractory postcardiotomy cardiogenic shock (PCS) unresponsive to optimal medical treatment. We sought to analyze the results and temporal outcomes of ECLS for PCS. METHODS: We performed an observational analysis of our prospective database. In order to analyze the temporal trends of ECLS for PCS, patients were divided into two groups according to the period of ECLS implantation: Group I from January 2007-June 2012, Group II from July 2012-December 2017. The primary endpoint was survival to hospital discharge. RESULTS: During the study period, 90 patients required ECLS for PCS (Group I n = 29, 32%; Group II n = 61, 68%). Mean age was 57.5 ± 15.0 years with 62% of males. Preoperative characteristics were comparable over the two periods. A high proportion of patients were in NYHA class III/IV (61%) or cardiogenic shock (22%). Group II showed a significantly higher proportion of miscellaneous cardiac surgery operations (23 vs 3%, P = 0.031). Crossclamp and cardiopulmonary bypass times were significantly shorter in Group II (85.4 vs 114.2 min, P = 0.023 and 135.2 vs 184.2 min, P = 0.022, respectively). The complication rate during ECLS support was comparable between both groups. Successful weaning from ECLS could be accomplished in 45 (50%) patients (Group I = 52% vs Group II = 49%, P = 0.822) after a mean support of 6.4 days. Thirty-five (39%) patients survived to hospital discharge (Group I = 41% vs Group II = 38%, P = 0.738). CONCLUSIONS: Outcomes following ECLS remained stable over an 11-year period. ECLS may be limited in patients with severe preoperative cardiac dysfunction. Our data suggest that these patients may be better served with less invasive, percutaneous procedures.

Inferior vena cava stenosis after heart transplant: a rare cause of venoarterial extracorporeal membrane oxygenation weaning failure.

INTRODUCTION: The discontinuation of venoarterial extracorporeal membrane oxygenation (VA ECMO) is a critical step in patient recovery. To reduce risks, weaning trials must be performed to buttress this important decision. However, a successful weaning trial does not preclude the possibility of complications. CASE REPORT: Here, we report a case of sudden multiple organ failure in a heart transplant patient, occurring after a successful ECMO weaning trial. We finally diagnosed a rare post-surgical complication of bicaval orthotopic heart transplantation, a severe stenosis of the inferior vena cava (IVC) that had been masked by the post-operative ECMO. DISCUSSION AND CONCLUSION: Our case report should serve as a cautionary tale: it may be of interest to add a search for complications at the vascular anastomoses to the weaning trial procedure and to keep an eye out for them in the following days.

Microvascular effects of intravenous esmolol in patients with normal cardiac function undergoing postoperative atrial fibrillation: a prospective pilot study in cardiothoracic surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) is commonplace after cardiothoracic surgery. A rate control strategy using short-acting beta blockers is recommended as a first-line therapy in patients without hemodynamic instability. Microcirculatory effects of POAF and esmolol have not yet been investigated. We hypothesized that POAF without hemodynamic instability would induce microvascular dysfunction which could be reversed by intravenous esmolol. METHODS: Twenty-five cardiothoracic surgical patients with POAF were included in the study. Microcirculation was assessed by peripheral near-infrared spectroscopy (NIRS) in association with a vascular occlusion test (VOT) before esmolol infusion, during incremental doses of esmolol (25, 50, 100, and 200 µg/kg/min), and after a return to sinus rhythm. Esmolol was given to control heart rate to between 60 and 90 beats/min. Regional tissue oxygen saturation variables (StO2, StO2 min, StO2 max, and ∆StO2) and desaturation/resaturation speeds during VOT were recorded to evaluate the microcirculation. RESULTS: StO2 and resaturation speed were significantly improved when POAF returned to sinus rhythm (StO2 64% ± 6 versus 67% ± 6, P < 0.01; resaturation speed 0.53%/s (0.42-0.97) versus 0.66%/s (0.51-1.04), P = 0.020). ∆StO2 was significantly decreased after a return to sinus rhythm (7.9% ± 4.8 versus 6.1% ± 4.7, P = 0.026). During esmolol infusion, we found a significant decrease in both heart rate (P < 0.001) and blood pressure (P < 0.001), and a non-significant dose-dependent increase in StO2 (P = 0.081) and resaturation speed (P = 0.087). CONCLUSION: POAF without hemodynamic instability is associated with significant impairment in the microcirculation which could be partially reversed by intravenous esmolol.

Protocol for venoarterial ExtraCorporeal Membrane Oxygenation to reduce morbidity and mortality following bilateral lung TransPlantation: the ECMOToP randomised controlled trial.

INTRODUCTION: Lung transplantation (LTx) aims at improving survival and quality of life for patients with end-stage lung diseases. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is used as intraoperative support for LTx, despite no precise guidelines for its initiation. We aim to evaluate two strategies of VA-ECMO initiation in the perioperative period in patients with obstructive or restrictive lung disease requiring bilateral LTx. In the control 'on-demand' arm, high haemodynamic and respiratory needs will dictate VA-ECMO initiation; in the experimental 'systematic' arm, VA-ECMO will be pre-emptively initiated. We hypothesise a 'systematic' strategy will increase the number of ventilatory-free days at day 28. METHODS AND ANALYSIS: We designed a multicentre randomised controlled trial in parallel groups. Adult patients with obstructive or restrictive lung disease requiring bilateral LTx, without a formal indication for pre-emptive VA-ECMO before LTx, will be included. Patients with preoperative pulmonary hypertension with haemodynamic collapse, ECMO as a bridge to transplantation, severe hypoxaemia or hypercarbia will be secondarily excluded. In the systematic group, VA-ECMO will be systematically implanted before the first pulmonary artery cross-clamp. In the on-demand group, VA-ECMO will be implanted intraoperatively if haemodynamic or respiratory indices meet preplanned criteria. Non-inclusion, secondary exclusion and VA-ECMO initiation criteria were validated by a Delphi process among investigators. Postoperative weaning of ECMO and mechanical ventilation will be managed according to best practice guidelines. The number of ventilator-free days at 28 days (primary endpoint) will be compared between the two groups in the intention-to-treat population. Secondary endpoints encompass organ failure occurrence, day 28, day 90 and year 1 vital status, and adverse events. ETHICS AND DISSEMINATION: The sponsor is the Assistance Publique-Hôpitaux de Paris. The ECMOToP protocol version 2.1 was approved by Comité de Protection des Personnes Ile de France VIII. Results will be published in international peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: NCT05664204.

Elaboration of a French version of the Duke Activity Status Index questionnaire and performance to predict functional capacity.

BACKGROUND: Guidelines recommend detecting poor functional capacity (VO2max < 14 ml.kg-1.min-1) to assess preoperative cardiac risk. This screening is performed via a cardiopulmonary exercise test (CPET), the self-reported inability to climb two flights of stairs, or the use of the Duke Activity Status Index (DASI) questionnaire, which has shown a significant correlation with VO2max and postoperative outcomes. The objectives of the present study were: 1) to create a French version of the DASI questionnaire (FDASI); 2) to assess its diagnostic performance in predicting functional capacity. METHODS: Consecutive adult patients undergoing CPET for medical or preoperative evaluation were prospectively included between May 2020 and March 2021. All patients were asked to complete FDASI as a self-questionnaire and report their inability to climb two flights of stairs. RESULTS: 122 patients were included. Test-retest reliability was 0.88 and 23 (19%) patients experienced a VO2max < 14 ml.kg-1.min-1. There was a significant positive relationship between FDASI and VO2max: r2 = 0.32; p < 0.001. ROCAUC was 0.81 [95%CI: 0.73-0.89]. The best FDASI score threshold was 36 points, leading to sensitivity and specificity values of 87% [74-100] and 68% [56-79], respectively. Besides, sensitivity and specificity were 35% [17-56] and 92% [86-97] for the self-reported inability to climb two flights of stairs. CONCLUSION: A FDASI score of 36 represents a reliable threshold the clinicians could routinely use to identify patients with a VO2max < 14 ml.kg-1.min-1. FDASI could advantageously replace the self-reported inability to climb two flights of stairs.

Hemodynamic Effects of Awake Prone Positioning With COVID-19 Acute Respiratory Failure.

INTRODUCTION: Awake prone positioning (PP) reduces need for intubation for patients with COVID-19 with acute respiratory failure. We investigated the hemodynamic effects of awake PP in non-ventilated subjects with COVID-19 acute respiratory failure. METHODS: We conducted a single-center prospective cohort study. Adult hypoxemic subjects with COVID-19 not requiring invasive mechanical ventilation receiving at least one PP session were included. Hemodynamic assessment was done with transthoracic echocardiography before, during, and after a PP session. RESULTS: Twenty-six subjects were included. We observed a significant and reversible increase in cardiac index (CI) during PP compared to supine position (SP): 3.0 ± 0.8 L/min/m2 in PP, 2.5 ± 0.6 L/min/m2 before PP (SP1), and 2.6 ± 0.5 L/min/m2 after PP (SP2, P < .001). A significant improvement in right ventricular (RV) systolic function was also evidenced during PP: The RV fractional area change was 36 ± 10% in SP1, 46 ± 10% during PP, and 35 ± 8% in SP2 (P < .001). There was no significant difference in PaO2 /FIO2 and breathing frequency. CONCLUSION: CI and RV systolic function are improved by awake PP in non-ventilated subjects with COVID-19 with acute respiratory failure.

Outcome of primary graft dysfunction rescued by venoarterial extracorporeal membrane oxygenation after heart transplantation.

BACKGROUND: Primary graft dysfunction remains the leading cause of 30-day mortality after heart transplantation. Few data have been published about the clinical outcome of severe primary graft dysfunction treated with venoarterial extracorporeal membrane oxygenation (VA-ECMO). AIM: To evaluate the prevalence and outcome of severe primary graft dysfunction requiring VA-ECMO, and to identify factors associated with hospital mortality. METHODS: We performed an observational analysis of our institutional database of VA-ECMO for primary graft dysfunction after heart transplantation. Patients with severe primary graft dysfunction, according to the International Society for Heart and Lung Transplantation classification, were included. The primary outcome was survival to hospital discharge. Risk factors for in-hospital mortality were searched with multiple logistic regression analysis using backward stepwise variable elimination. RESULTS: Of the 397 patients who had heart transplantation between January 2007 and December 2018, 60 (15.1%) developed severe primary graft dysfunction requiring VA-ECMO. The median age was 52 (interquartile range 39-59) years, and 73.3% were male. Thirty-nine (65.0%) patients were weaned after a mean duration of VA-ECMO support of 7.2±6.0 days. Thirty-two (53.3%) patients were alive at hospital discharge. Inotropic support in the recipient before heart transplantation (odds ratio [OR] 3.88, 95% confidence interval [CI] 1.04-14.44; P=0.04), total ischaemic time (OR 0.99, 95% CI 0.99-1.00; P=0.01) and 48-hour total blood transfusion (OR 1.14, 95% CI 1.04-1.26; P=0.01) were independent predictors of in-hospital mortality. CONCLUSIONS: Severe primary graft dysfunction requiring VA-ECMO is frequent after heart transplantation. Survival to hospital discharge after VA-ECMO for severe primary graft dysfunction is satisfactory in such a critically ill population.

De Novo Complement-Binding Anti-HLA Antibodies in Heart Transplanted Patients Is Associated with Severe Cardiac Allograft Vasculopathy and Poor Long-Term Survival.

Introduction: De novo anti-HLA donor specific antibodies (DSA) have been inconsistently associated with cardiac allograft vasculopathy (CAV) and long-term mortality. We tested whether C3d-binding de novo DSA were associated with CAV or long-term-survival. Methods: We included 282 consecutive patients without preformed DSA on coronary angiography between 2010 and 2012. Angiographies were classified according to CAV ISHLT grading. The primary outcome was a composite criterion of severe CAV or mortality. As the impact of de novo antibodies should be assessed only after appearance, we used a Cox regression with time-dependent covariables. Results: Of the 282 patients, 51(18%) developed de novo DSA during follow-up, 29 patients had DSA with C3d-binding ability (DSA+C3d+), and 22 were without C3d-binding ability (DSA+C3d-). Compared with patients without DSA, DSA+C3d+ patients had an increased risk for the primary outcome of severe CAV or mortality (adjusted HR = 4.31 (2.40−7.74) p < 0.001) and long-term mortality (adjusted HR = 3.48 (1.97−6.15) p < 0.001) whereas DSA+C3d- did not (adjusted HR = 1.04 (0.43−2.47) p = 0.937 for primary outcome and HR = 1.08 (0.45−2.61) p = 0.866 for mortality). Conclusion: According to this large monocentric study in heart transplant patients, donor specific antibodies were associated with worse clinical outcome when binding complement. DSA and their complement-binding ability should thus be screened for to optimize heart transplant patient follow-up.