Definitions of major bleeding for predicting mortality in critically ill adult patients who survived 24 hours while supported with peripheral veno-arterial extracorporeal membrane oxygenation for cardiogenic shock: a comparative historical cohort study.

PURPOSE: The severity of bleeding events is heterogeneously defined during peripheral veno-arterial extracorporeal membrane oxygenation (pVA-ECMO). We studied three bleeding definitions in pVA-ECMO: the Extracorporeal Life Support Organization (ELSO)-serious bleeding, the Bleeding Academic Research Consortium (BARC), and the universal definition of postoperative bleeding (UPDB) classifications. METHODS: We included consecutive adult patients supported by pVA-ECMO for refractory cardiogenic shock admitted to Lille academic hospitals between January 2013 and December 2019. We assessed the association of bleeding definitions with the primary endpoint of 28-day all-cause mortality with the use of multivariate models accounting for time-dependent and competing variables. We compared models' performances using the Harrell's C-Index and the Akaike information criteria. RESULTS: Twenty-eight-day mortality occurred in 128/308 (42%) 308 patients. The ELSO-serious bleeding (hazard ratio [HR], 1.67; 95% confidence interval [CI], 1.09 to 2.56) and BARC ≥ type 2 (HR, 1.55; 95% CI, 1.01 to 2.37) were associated with 28-day mortality (Harrell's C-index, 0.69; 95% CI, 0.63 to 0.74 for both). Predictors of ELSO-serious bleeding were postcardiotomy, body mass index, baseline platelets count, fibrinogen, and hemoglobin levels. CONCLUSION: Extracorporeal Life Support Organization-serious bleeding and BARC ≥ type 2 are relevant definitions of major bleeding regarding their association with mortality in critically ill patients who survived the first 24 hr while supported with pVA-ECMO for cardiogenic shock. STUDY REGISTRATION: CERAR (IRB 00010254-2022-050, Paris, France); first submitted on 18 April 2022.

RéSUMé: OBJECTIF: La gravité des événements hémorragiques est définie de manière hétérogène pendant une oxygénation par membrane extracorporelle veino-artérielle périphérique (ECMO-VA périphérique). Nous avons étudié trois définitions du saignement sous ECMO-VA périphérique : les classifications des saignements graves selon l'Extracorporeal Life Support Organization (ELSO), celles du Bleeding Academic Research Consortium (BARC) et la définition universelle du saignement postopératoire (UPDB). MéTHODE: Nous avons inclus des patient·es adultes pris·es en charge de manière consécutive par ECMO-VA périphérique à la suite d'un choc cardiogénique réfractaire et admis·es dans les centres hospitaliers universitaires de Lille entre janvier 2013 et décembre 2019. Nous avons évalué l'association des définitions du saignement avec le critère d'évaluation principal de mortalité toutes causes confondues à 28 jours à l'aide de modèles multivariés tenant compte des variables dépendantes du temps et concurrentes. Nous avons comparé les performances des modèles à l'aide de l'indice C de Harrell et du critère d'information d'Akaike. RéSULTATS: La mortalité à 28 jours est survenue chez 128/308 (42 %) patient·es. Le saignement grave selon l'ELSO (rapport de risque [RR], 1,67; intervalle de confiance [IC] à 95 %, 1,09 à 2,56) et une classification BARC ≥ type 2 (RR, 1,55; IC 95 %, 1,01 à 2,37) étaient associés à une mortalité à 28 jours (indice C de Harrell, 0,69; IC 95 %, 0,63 à 0,74 pour les deux). Les prédicteurs d'hémorragie grave selon l'ELSO étaient la postcardiotomie, l'indice de masse corporelle, la numération plaquettaire initiale, le taux de fibrinogène et les taux d'hémoglobine. CONCLUSION: Les définitions du saignement grave de l'Extracorporeal Life Support Organization et une classification BARC ≥ type 2 sont des définitions pertinentes des saignements majeurs en ce qui touche à leur association avec la mortalité chez les personnes gravement malades qui ont survécu aux premières 24 heures alors qu'elles étaient prises en charge par ECMO-VA périphérique à la suite d'un choc cardiogénique. ENREGISTREMENT DE L'éTUDE: CERAR (IRB 00010254-2022-050, Paris, France); soumis pour la première fois le 18 avril 2022.

V stenting technique with covered stents for the management of ostial circumflex perforation: Good or bad idea?

We report the case of a redo Ross surgery complicated by an ostial left circumflex occlusion requiring emergent percutaneous coronary intervention. The latter was complicated by coronary perforation treated by two covered stents with V-stenting technique. After immediate success, the clinical course was marked by acute stent thrombosis requiring emergent coronary bypass. Learning objectives: Ostial left circumflex perforation is a rare and potentially fatal complication that is challenging to manage. V stenting technique with two covered stents could be used as a life-saving procedure, but is associated with a high thrombotic risk.

Shear Forces Induced Platelet Clearance Is a New Mechanism of Thrombocytopenia.

BACKGROUND: Thrombocytopenia has been consistently described in patients with extracorporeal membrane oxygenation (ECMO) and associated with poor outcome. However, the prevalence and underlying mechanisms remain largely unknown, and a device-related role of ECMO in thrombocytopenia has been hypothesized. This study aims to investigate the mechanisms underlying thrombocytopenia in ECMO patients. METHODS: In a prospective cohort of 107 ECMO patients, we investigated platelet count, functions, and glycoprotein shedding. In an ex vivo mock circulatory ECMO loop, we assessed platelet responses and VWF (von Willebrand factor)-GP Ibα (glycoprotein Ibα) interactions at low- and high-flow rates, in the presence or absence of red blood cells. The clearance of human platelets subjected or not to ex vivo perfusion was studied using an in vivo transfusion model in NOD/SCID (nonobese diabetic/severe combined Immunodeficient) mice. RESULTS: In ECMO patients, we observed a time-dependent decrease in platelet count starting 1 hour after device onset, with a mean drop of 7%, 35%, and 41% at 1, 24, and 48 hours post-ECMO initiation (P=0.00013, P<0.0001, and P<0.0001, respectively), regardless of the type of ECMO. This drop in platelet count was associated with a decrease in platelet GP Ibα expression (before: 47.8±9.1 versus 24 hours post-ECMO: 42.3±8.9 mean fluorescence intensity; P=0.002) and an increase in soluble GP Ibα plasma levels (before: 5.6±3.3 versus 24 hours post-ECMO: 10.8±4.1 µg/mL; P<0.0001). GP Ibα shedding was also observed ex vivo and was unaffected by (1) red blood cells, (2) the coagulation potential, (3) an antibody blocking VWF-GP Ibα interaction, (4) an antibody limiting VWF degradation, and (5) supraphysiological VWF plasma concentrations. In contrast, GP Ibα shedding was dependent on rheological conditions, with a 2.8-fold increase at high- versus low-flow rates. Platelets perfused at high-flow rates before being transfused to immunodeficient mice were eliminated faster in vivo with an accelerated clearance of GP Ibα-negative versus GP Ibα-positive platelets. CONCLUSIONS: ECMO-associated shear forces induce GP Ibα shedding and thrombocytopenia due to faster clearance of GP Ibα-negative platelets. Inhibiting GP Ibα shedding could represent an approach to reduce thrombocytopenia during ECMO.

Thrombus formation during ECMO: Insights from a detailed histological analysis of thrombus composition.

OBJECTIVES: Intra-device thrombosis remains one of the most common complications during extracorporeal membrane oxygenation (ECMO). Despite anticoagulation, approximately 35% of patients develop thrombi in the membrane oxygenator, pump heads, or tubing. The aim of this study was to describe the molecular and cellular features of ECMO thrombi and to study the main drivers of thrombus formation at different sites in the ECMO circuits. APPROACH AND RESULTS: Thrombi (n = 85) were collected immediately after veno-arterial-(VA)-ECMO circuit removal from 25 patients: 23 thrombi from the pump, 25 from the oxygenator, and 37 from the tubing. Quantitative histological analysis was performed for the amount of red blood cells (RBCs), platelets, fibrin, von Willebrand factor (VWF), leukocytes, and citrullinated histone H3 (H3Cit). ECMO thrombi consist of a heterogenous composition with fibrin and VWF being the major thrombus components. A clustering analysis of the four major histological parameters identified two typical thrombus types: RBC-rich and RBC-poor/fibrin-rich thrombi with no significant differences in VWF and platelet content. Thrombus composition was not associated with the thrombus location, except for higher amounts of H3Cit that were found in pump and oxygenator thrombi compared to tubing samples. We observed higher blood leukocyte count and lactate dehydrogenase levels in patients with fibrin-rich thrombi. CONCLUSION: We found that thrombus composition is heterogenous, independent of their location, consisting of two types: RBC-rich and a fibrin-rich types. We also found that NETs play a minor role. These findings are important to improve current anticoagulation strategies in ECMO.

End-tidal Carbon Dioxide for Diagnosing Anaphylaxis in Patients with Severe Postinduction Hypotension.

BACKGROUND: Perioperative hypersensitivity reactions may be difficult to diagnose during general anesthesia. Postinduction hypotension is the most common sign but is not specific. It was recently suggested that low end-tidal carbon dioxide (ETco2) might be a marker of anaphylaxis (Ring and Messmer grades III to IV immediate hypersensitivity reactions) in hypotensive patients under mechanical ventilation. To test this hypothesis, the authors compared ETco2 in patients with a diagnosis of anaphylaxis and in patients with severe hypotension from any other cause after the induction of anesthesia. METHODS: This was a retrospective single-center case-control study in which two groups were formed from an anesthesia data warehouse. The anaphylaxis group was formed on the basis of tryptase/histamine assay data and allergy workup data recorded over the period 2010 to 2018. The control (hypotension) group consisted of all patients having experienced severe hypotension (mean arterial pressure less than 50 mmHg for 5 min or longer) with a cause other than anaphylaxis after anesthesia induction in 2017. RESULTS: The anaphylaxis and hypotension groups comprised 49 patients (grade III: n = 38; grade IV: n = 11) and 555 patients, respectively. The minimum ETco2 value was significantly lower in the anaphylaxis group (median [interquartile range]: 17 [12 to 23] mmHg) than in the hypotension group (32 [29 to 34] mmHg; P < 0.001). The area under the receiver operating characteristic curve (95% CI) for ETco2 was 0.95 (0.91 to 0.99). The sensitivity and specificity (95% CI) for the optimal cutoff value were 0.92 (0.82 to 0.98) and 0.94 (0.92 to 0.99), respectively. In multivariable analysis, minimum ETco2 was associated with anaphylaxis after adjusting for confounders and competing predictors, including arterial pressure, heart rate, and peak airway pressure (odds ratio [95% CI] for ETco2: 0.51 [0.38 to 0.68]; P < 0.001). CONCLUSIONS: In case of severe hypotension after anesthesia induction, a low ETco2 contributes to the diagnosis of anaphylaxis, in addition to the classical signs of perioperative immediate hypersensitivity.

Venoarterial Extracorporeal Membrane Oxygenation in Severe Drug Intoxication: A Retrospective Comparison of Survivors and Nonsurvivors.

Selecting patients most likely to benefit from venoarterial extracorporeal membrane oxygenation (V-A ECMO) to treat refractory drug-induced cardiovascular shock remains a difficult challenge for physicians. This study reported short-term survival outcomes and factors associated with mortality in V-A ECMO-treated patients for poisoning. Twenty-two patients placed on V-A ECMO after drug intoxication from January 2014 to December 2020 were retrospectively analyzed. The primary endpoint of this study was survival at hospital discharge. Univariate descriptive analysis was performed to compare survivors and nonsurvivors during hospitalization. The overall survival at hospital discharge was 45.4% (n = 10/22). Survival rate tended to be higher in patients treated for refractory shock (n = 7/10) compared with those treated for refractory cardiac arrest (n = 3/12, p = 0.08). Low-flow duration and time from admission to ECMO cannulation were shorter in survivors ( p = 0.02 and p = 0.03, respectively). Baseline characteristics before ECMO, including the class of drugs involved in the poisoning, between survivors and nonsurvivors were not statistically different except pH, bicarbonate, serum lactate, Sequential Organ Failure Assessment, and Survival After Veno-arterial-ECMO (SAVE) score. All patients with SAVE-score risk classes II/III survived whereas 85.7% (n = 12/14) of those with SAVE-score risk classes IV/V died. A lactic acid >9 mmol/L predicts mortality with a sensitivity/specificity ratio of 83.3%/100%. V-A ECMO for severe drug intoxication should be reserved for highly selected poisoned patients who do not respond to conventional therapies. Shortening the timing of V-A ECMO initiation should be a key priority in improving outcomes. Low-flow time >60min, lactic acid >9mmol/L, and SAVE-score may be good indicators of a worse prognosis.

Mid-Term Survival and Risk Factors Associated With Myocardial Injury After Fenestrated and/or Branched Endovascular Aortic Aneurysm Repair.

OBJECTIVE: Myocardial injury after non-cardiac surgery (MINS) is an independent predictor of post-operative mortality in non-cardiac surgery patients and may increase health costs. Few data are available for MINS in vascular surgery patients, in general, and those undergoing fenestrated/branched endovascular aortic repairs (F/BEVAR), in particular. The incidence of MINS after F/BEVAR, the associated risk factors, and prognosis have not been determined. The aim of the present study was to help fill these knowledge gaps. METHODS: A single centre, retrospective study was carried out at a high volume F/BEVAR centre in a university hospital. Adult patients who underwent F/BEVAR between October 2010 and December 2018 were included. A high sensitivity troponin T (HsTnT) assay was performed daily in the first few post-operative days. MINS was defined as a HsTnT level ≥ 14 ng/L (MINS14) or ≥ 20 ng/L (MINS20). After assessment of the incidence of MINS, survival up to two years was estimated in a Kaplan-Meier analysis and the groups were compared according to MINS status. A secondary aim was to identify predictors of MINS. RESULTS: Of the 387 included patients, 240 (62.0%) had MINS14 and 166 (42.9%) had MINS20. In multivariable Cox models, both conditions were significantly associated with poor two year survival (MINS14: adjusted hazard ratio [aHR] 2.15, 95% confidence interval [CI] 1.10 - 4.19; MINS20: aHR 2.43, 95% CI 1.36 - 4.34). In a multivariable logistic regression, age, revised cardiac risk index, duration of surgery, pre-operative estimated glomerular filtration rate (eGFR), and haemoglobin level were independent predictors of MINS. CONCLUSION: After F/BEVAR surgery, the incidence of MINS was particularly high, regardless of the definition considered (MINS14 or MINS20). MINS was significantly associated with poor two year survival. The modifiable predictors identified were duration of surgery, eGFR, and haemoglobin level.

Anti-Xa activity and hemorrhagic events under extracorporeal membrane oxygenation (ECMO): a multicenter cohort study.

BACKGROUND: Hemorrhagic events remain a major concern in patients under extracorporeal membrane oxygenation (ECMO) support. We tested the association between anticoagulation levels and hemorrhagic events under ECMO using anti-Xa activity monitoring. METHODS: We performed a retrospective multicenter cohort study in three ECMO centers. All adult patients treated with veno-venous (VV)- or veno-arterial (VA)-ECMO in 6 intensive care units between September 2017 and August 2019 were included. Anti-Xa activities were collected until a hemorrhagic event in the bleeding group and for the duration of ECMO in the non-bleeding group. All dosages were averaged to obtain means of anti-Xa activity for each patient, and patients were compared according to the occurrence or not of bleeding. RESULTS: Among 367 patients assessed for eligibility, 121 were included. Thirty-five (29%) presented a hemorrhagic complication. In univariate analysis, anti-Xa activities were significantly higher in the bleeding group than in the non-bleeding group, both for the mean anti-Xa activity (0.38 [0.29-0.67] vs 0.33 [0.22-0.42] IU/mL; p = 0.01) and the maximal anti-Xa activity (0.83 [0.47-1.46] vs 0.66 [0.36-0.91] IU/mL; p = 0.05). In the Cox proportional hazard model, mean anti-Xa activity was associated with bleeding (p = 0.0001). By Kaplan-Meier analysis with the cutoff value at 0.46 IU/mL obtained by ROC curve analysis, the probability of survival under ECMO without bleeding was significantly lower when mean anti-Xa was > 0.46 IU/mL (p = 0.0006). CONCLUSION: In critically ill patients under ECMO, mean anti-Xa activity was an independent risk factor for hemorrhagic complications. Anticoagulation targets could be revised downward in both VV- and VA-ECMO.

SARS-CoV-2 Versus Influenza-associated Acute Respiratory Distress Syndrome Requiring Veno-venous Extracorporeal Membrane Oxygenation Support.

No study has compared patients with COVID-19-related refractory ARDS requiring veno-venous extracorporeal membrane oxygenation (V-V ECMO) to a relevant and homogenous control population. We aimed to compare the outcomes, the clinical characteristics, and the adverse effects of COVID-19 patients to a retrospective cohort of influenza patients. This retrospective case-control study was conducted in the ICUs of Lille and Rouen University Hospitals between January 2014 and May 2020. Two independent cohorts of patients with ARDS requiring V-V ECMO infected with either COVID-19 (n = 30) or influenza (n = 22) were compared. A 3-month follow-up was completed for all patients. Median age of COVID-19 and influenza patients was similar (57 vs. 55 years; p = 0.62). The 28-day mortality rate did not significantly differ between COVID-19 (43.3%) and influenza patients (50%, p = 0.63). There was no significant difference considering the cumulative incidence of ECMO weaning, hospital discharge, and 3-month survival. COVID-19 patients had a lower SAPS II score (58 [37-64] vs. 68 [52-83]; p = 0.039), a higher body mass index (33 [29-38] vs. 30 [26-34] kg/m2; p = 0.05), and were cannulated later (median delay between mechanical support and V-V ECMO 6 vs. 3 days, p = 0.004) compared with influenza patients. No difference in overall adverse events was observed between COVID-19 and influenza patients (70% vs. 95.5% respectively; p = 0.23). Despite differences in clinical presentation before V-V ECMO implantation, 28-day and 3-month mortality rate did not differ between COVID-19 and influenza patients. Considering the lack of specific treatment for COVID-19, V-V ECMO should be considered as a relevant rescue organ support.

Development, implementation and preliminary evaluation of clinical dashboards in a department of anesthesia.

Clinical dashboards summarize indicators of high-volume patient data in a concise, user-friendly visual format. There are few studies of the use of dashboards to improve professional practice in anesthesiology. The objective of the present study was to describe the user-centered development, implementation and preliminary evaluation of clinical dashboards dealing with anesthesia unit management and quality assessment in a French university medical center. User needs and technical requirements were identified in end user interviews and then synthesized. Several representations were then developed (according to good visualization practice) and submitted to end users for appraisal. Lastly, dashboards were implemented and made accessible for everyday use via the medical center's network. After a period of use, end user feedback on the dashboard platform was collected as a system usability score (range 0 to 100). Seventeen themes (corresponding to 29 questions and 42 indicators) were identified. After prioritization and feasibility assessment, 10 dashboards were ultimately implemented and deployed. The dashboards variously addressed the unit's overall activity, compliance with guidelines on intraoperative hemodynamics, ventilation and monitoring, and documentation of the anesthesia procedure. The mean (standard deviation) system usability score was 82.6 (11.5), which corresponded to excellent usability. We developed clinical dashboards for a university medical center's anesthesia units. The dashboards' deployment was well received by the center's anesthesiologists. The dashboards' impact on activity and practice after several months of use will now have to be assessed.

Central venous-to-arterial PCO2 difference, arteriovenous oxygen content and outcome after adult cardiac surgery with cardiopulmonary bypass: A prospective observational study.

BACKGROUND: Rapid identification and treatment of tissue hypoxia reaching anaerobiosis (dysoxia) may reduce organ failure and the occurrence of major postoperative complications (MPC) after cardiac surgery. The predictive ability of PCO2-based dysoxia biomarkers, central venous-to-arterial PCO2 difference (ΔPCO2) and ΔPCO2 to arteriovenous oxygen content difference ratio, is poorly studied in this setting. OBJECTIVES: We evaluated the ability of PCO2-based tissue dysoxia biomarkers, blood lactate concentration and central venous oxygen saturation measured 2 h after admission to the ICU as predictors of MPC. DESIGN: A prospective, observational cohort study. SETTING: Single-centre, academic hospital cardiovascular ICU. PATIENTS: We included adult patients undergoing cardiac surgery with cardiopulmonary bypass and measured dysoxia biomarkers at ICU admission, and after 2, 6 and 24 h. MAIN OUTCOME MEASURES: The primary endpoint was MPC, a composite of cardiac and noncardiac MPC evaluated in the 48 h following surgery. After univariate analysis of MPC covariates including dysoxia biomarkers measured at 2 h, multivariate logistic regression analyses were performed to identify the association of these biomarkers with MPC for confounders. Areas under the receiver operating characteristic curves were determined for biomarkers which remained independently associated with MPC. RESULTS: MPC occurred in 56.5% of the 308 patients analysed. ΔPCO2, blood lactate concentration and central venous oxygen saturation measured at 2 h, but not ΔPCO2 to arteriovenous oxygen content difference ratio, were significantly associated with MPC. However, only ΔPCO2 was independently associated with MPC after multivariate analysis. The areas under the receiver operating characteristic curves of ΔPCO2 measured at 2 h for MPC prediction was 0.64 (95% CI 0.57 to 0.70, P < 0.001). CONCLUSION: After cardiac surgery with cardiopulmonary bypass, ΔPCO2 measured 2 h after ICU admission was the only dysoxia biomarker independently associated with MPC, but with limited performance. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03107572.

C-reactive protein kinetics after major surgery.

BACKGROUND: Diagnosis of sepsis in the postoperative period is a challenge. Measurements of inflammatory markers, such as C-reactive protein (CRP), have been proposed in medical patients, but the interpretation of these values in surgical patients is more difficult. We evaluated the changes in blood CRP levels and white blood cell count in postoperative patients with and without infection. METHODS: All patients admitted to our 34-bed Department of Intensive Care after major (elective or emergency) cardiac, neuro-, vascular, thoracic, or abdominal surgery during a 4-month period were prospectively included. Patients were screened daily and characterized as infected or noninfected. CRP levels and white blood cell counts were recorded daily in all patients for up to 7 days after the surgical intervention. RESULTS: Of the 151 patients enrolled, 115 underwent elective surgery and 36 emergency surgery; cardiac surgery was performed in 49 patients, neurosurgery in 65, abdominal surgery in 25, vascular surgery in 7, and thoracic surgery in 5. In noninfected patients (n = 117), mean CRP values increased from baseline to postoperative day (POD) 3 (P < 0.0001, estimated mean difference [EMD] = 99.7 mg/L [95% confidence interval, 85.6-113.8]) and then decreased until POD 7 but remained higher than the level at baseline (P < 0.0001, EMD = 49.2 mg/L [95% confidence interval, 27.1-71.2]). Postoperative infection occurred in 20 patients (13.2%). In these patients, CRP values were already higher on POD 1 than in noninfected patients (P = 0.0054). CONCLUSIONS: CRP levels increase in the first week after major surgery but to a much larger extent in infected than in noninfected patients. Persistently high CRP levels after POD 4, especially when >100 mg/L, suggest the presence of a postoperative infection.