Peripheral-to-central extracorporeal corporeal membrane oxygenation switch in refractory cardiogenic shock patients: outcomes and bridging strategies.

BACKGROUND: Peripheral veno-arterial extracorporeal membrane oxygenation (pECMO) has become the first-line device in refractory cardiogenic shock (rCS). Some pECMO complications can preclude any bridging strategies and a peripheral-to-central ECMO (cECMO) switch can be considered as a bridge-to-decision. We conducted this study to appraise the in-hospital survival and the bridging strategies in patients undergoing peripheral-to-central ECMO switch. METHODS: This retrospective monocenter study included patients admitted to a ECMO-dedicated intensive care unit from February 2006 to January 2023. Patients with rCS requiring pECMO switched to cECMO were included. Patients were not included when the cECMO was the first mechanical circulatory support. RESULTS: Eighty patients, with a median [IQR25-75] age of 44 [29-53] years at admission and a female-to-male sex ratio of 0.6 were included in the study. Refractory pulmonary edema was the main switching reason. Thirty patients (38%) were successfully bridged to: heart transplantation (n = 16/80, 20%), recovery (n = 10/80, 12%) and ventricle assist device (VAD, n = 4/30, 5%) while the others died on cECMO (n = 50/80, 62%). The most frequent complications were the need for renal replacement therapy (76%), hemothorax or tamponade (48%), need for surgical revision (34%), mediastinitis (28%), and stroke (28%). The in-hospital and one-year survival rates were 31% and 27% respectively. Myocardial infarction as the cause of the rCS was the only variable independently associated with in-hospital mortality (HR 2.5 [1.3-4.9], p = 0.009). CONCLUSIONS: The switch from a failing pECMO support to a cECMO as a bridge-to-decision is a possible strategy for a very selected population of young patients with a realistic chance of heart function recovery or heart transplantation. In this setting, cECMO allows patients triage preventing from wasting expensive and limited resources.

Extracorporeal membrane oxygenation for tuberculosis-related acute respiratory distress syndrome: An international multicentre retrospective cohort study.

OBJECTIVE: To report the outcomes of patients with severe tuberculosis (TB)-related acute respiratory distress syndrome (ARDS) on extracorporeal membrane oxygenation (ECMO), including predictors of 90-day mortality and associated complications. METHODS: An international multicenter retrospective study was conducted in 20 ECMO centers across 13 countries between 2002 and 2022. RESULTS: We collected demographic data, clinical details, ECMO-related complications, and 90-day survival status for 79 patients (median APACHE II score of 20 [25th to 75th percentile, 16 to 28], median age 39 [28 to 48] years, PaO2/FiO2 ratio of 69 [55 to 82] mmHg before ECMO) who met the inclusion criteria. Thoracic computed tomography showed that 61 patients (77%) had cavitary TB, while 18 patients (23%) had miliary TB. ECMO-related complications included major bleeding (23%), ventilator-associated pneumonia (41%), and bloodstream infections (32%). The overall 90-day survival rate was 51%, with a median ECMO duration of 20 days [10 to 34] and a median ICU stay of 42 days [24 to 65]. Among patients on VV ECMO, those with miliary TB had a higher 90-day survival rate than those with cavitary TB (90-day survival rates of 81% vs. 46%, respectively; log-rank P = 0.02). Multivariable analyses identified older age, drug-resistant TB, and pre-ECMO SOFA scores as independent predictors of 90-day mortality. CONCLUSION: The use of ECMO for TB-related ARDS appears to be justifiable. Patients with miliary TB have a much better prognosis compared to those with cavitary TB on VV ECMO.

Impact of the transpulmonary pressure on right ventricle impairment incidence during acute respiratory distress syndrome: a pilot study in adults and children.

BACKGROUND: Right ventricle impairment (RVI) is common during acute respiratory distress syndrome (ARDS) in adults and children, possibly mediated by the level of transpulmonary pressure (PL). We sought to investigate the impact of the level of PL on ARDS-associated right ventricle impairment (RVI). METHODS: Adults and children (> 72 h of life) were included in this two centers prospective study if they were ventilated for a new-onset ARDS or pediatric ARDS, without spontaneous breathing and contra-indication to esophageal catheter. Serial measures of static lung, chest wall, and respiratory mechanics were coupled to critical care echocardiography (CCE) for 3 days. Mixed-effect logistic regression models tested the impact of lung stress (ΔPL) along with age, lung injury severity, and carbon dioxide partial pressure, on RVI using two definitions: acute cor pulmonale (ACP), and RV dysfunction (RVD). ACP was defined as a dilated RV with septal dyskinesia; RVD was defined as a composite criterion using tricuspid annular plane systolic excursion, S wave velocity, and fractional area change. RESULTS: 46 patients were included (16 children, 30 adults) with 106 CCE (median of 2 CCE/patient). At day one, 19% of adults and 4/7 children > 1 year exhibited ACP, while 59% of adults and 44% of children exhibited RVD. In the entire population, ACP was present on 17/75 (23%) CCE. ACP was associated with an increased lung stress (mean ΔPL of 16.2 ± 6.6 cmH2O in ACP vs 11.3 ± 3.6 cmH2O, adjusted OR of 1.33, CI95% [1.11-1.59], p = 0.002) and being a child. RVD was present in 59/102 (58%) CCE and associated with lung stress. In children > 1 year, PEEP was significantly lower in case of ACP (9.3 [8.6; 10.0] cmH2O in ACP vs 15.0 [11.9; 16.3] cmH2O, p = 0.03). CONCLUSION: Lung stress was associated with RVI in adults and children with ARDS, children being particularly susceptible to RVI. Trial registration Clinical trials identifier: NCT0418467.

Fluid responsiveness in acute respiratory distress syndrome patients: a post hoc analysis of the HEMOPRED study.

PURPOSE: Optimal fluid management in patients with acute respiratory distress syndrome (ARDS) is challenging due to risks associated with both circulatory failure and fluid overload. The performance of dynamic indices to predict fluid responsiveness (FR) in ARDS patients is uncertain. METHODS: This post hoc analysis of the HEMOPRED study compared the performance of dynamic indices in mechanically ventilated patients with shock, with and without ARDS, to predict FR, defined as an increase in aortic velocity time integral (VTI) > 10% after passive leg raising (PLR). RESULTS: Among 540 patients, 117 (22%) had ARDS and were ventilated with a median tidal volume of 7.6 mL/kg [6.9-8.4] and a median positive end-expiratory pressure of 7 cmH2O [5-9]. FR was observed in 45 ARDS patients (39% vs 44% in non-ARDS patients, p = 0.384). Reliability of dynamic indices to predict FR remained consistent in ARDS patients, though with different thresholds. Collapsibility index of the superior vena cava (ΔSVC) showed the best predictive performance in both ARDS (area under the curve [AUC] = 0.763 [0.659-0.868]) and non-ARDS (AUC = 0.750 [0.698-0.802]) patients. A right to left ventricle end-diastolic area ratio > 0.8 or paradoxical septal motion were strongly linked to the absence of FR (> 80% specificity). FR was not associated with intensive care unit (ICU) mortality (47% vs. 46%, p = 1). However, hypovolemia, defined as an aortic VTI increase > 32% during PLR (median increase in patients with a partial SVC collapse) was independently associated with ICU mortality (odds ratio [OR] = 1.355 [1.077-1.705], p = 0.011), as well as pulse pressure variation (OR = 1.014 [1.001-1.026], p = 0.034). CONCLUSION: Performance of dynamic indices to predict FR appears preserved in ARDS patients, albeit with distinct thresholds. Hypovolemia, indicated by a > 32% increase in aortic VTI during PLR, rather than FR, was associated with ICU mortality in this population.

Mechanical ventilation settings during weaning from venovenous extracorporeal membrane oxygenation.

BACKGROUND: The optimal timing of weaning from venovenous extracorporeal membrane oxygenation (VV ECMO) and its modalities have been rarely studied. METHODS: Retrospective, multicenter cohort study over 7 years in two tertiary ICUs, high-volume ECMO centers in France and Italy. Patients with ARDS on ECMO and successfully weaned from VV ECMO were classified based on their mechanical ventilation modality during the sweep gas-off trial (SGOT) with either controlled mechanical ventilation or spontaneous breathing (i.e. pressure support ventilation). The primary endpoint was the time to successful weaning from mechanical ventilation within 90 days post-ECMO weaning. RESULTS: 292 adult patients with severe ARDS were weaned from controlled ventilation, and 101 were on spontaneous breathing during SGOT. The 90-day probability of successful weaning from mechanical ventilation was not significantly different between the two groups (sHR [95% CI], 1.23 [0.84-1.82]). ECMO-related complications were not statistically different between patients receiving these two mechanical ventilation strategies. After adjusting for covariates, older age, higher pre-ECMO sequential organ failure assessment score, pneumothorax, ventilator-associated pneumonia, and renal replacement therapy, but not mechanical ventilation modalities during SGOT, were independently associated with a lower probability of successful weaning from mechanical ventilation after ECMO weaning. CONCLUSIONS: Time to successful weaning from mechanical ventilation within 90 days post-ECMO was not associated with the mechanical ventilation strategy used during SGOT. Further research is needed to assess the optimal ventilation strategy during weaning off VV ECMO and its impact on short- and long-term outcomes.

Thrombolysis before venoarterial ECMO for high-risk pulmonary embolism: a retrospective cohort study.

PURPOSE: Despite systemic thrombolysis, a few patients with high-risk pulmonary embolism (PE) remain hemodynamically unstable. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a considerable lifesaving therapy but systemic thrombolysis before cannulation could carry a high risk of hemorrhage and alter the prognosis. METHODS: Between June 2012 and June 2023, we retrospectively analyzed from three intensive care units in Sorbonne University, ECMO-related complications and 90-day mortality for high-risk PE patients who received ECMO without previous systemic thrombolysis compared to those cannulated after systemic thrombolysis failure. Hospital discharge survivors were assessed for long-term health-related quality of life and echocardiographic evaluations. RESULTS: 72 high-risk PE patients [median age 48 (37-61) years, Simplified Acute Physiology Score II (SAPS II) 74 (60-85)] were placed on VA-ECMO for 5 (5-7) days. 31 (43%) patients underwent pre-ECMO thrombolysis (thrombolysis ECMO group, T +) compared to 41 patients (57%, no thrombolysis ECMO group, T-). There was more pre-ECMO cardiac arrest in the thrombolysis ECMO group (94% vs. 67%, p = 0.02). Ninety-day survival was not different between groups (39% vs 46%, log-rank test, p = 0.31). There was no difference in severe hemorrhages (61% vs 59%, p = 1). Twenty-five over 28 patients attended follow-up at a median time of 69 (52-95) months. Long-term quality of life was acceptable and none of them experienced chronic thromboembolic pulmonary hypertension. CONCLUSIONS: Ninety-day survival and bleeding events rates did not differ in patients treated with VA-ECMO after systemic thrombolysis compared to those who were not. Recent systemic thrombolysis, as a single parameter, should not be considered as a contraindication for VA-ECMO in high-risk PE.

Isoproterenol improves hemodynamics and right ventricle-pulmonary artery coupling after heart transplantation.

Right ventricular failure (RVF) is a major cause of early mortality after heart transplantation (HT). Isoproterenol (Iso) has chronotropic, inotropic, and vasodilatory properties, which might improve right ventricle function in this setting. We aimed to investigate the hemodynamic effects of isoproterenol on patients with post-HT RVF. We conducted a 1-yr retrospective observational study including patients receiving isoproterenol (Iso) and dobutamine for early RVF after HT. A comprehensive multiparametric hemodynamic evaluation was performed successively three times: no isoproterenol, low doses: 0.025 µg/kg/min, and high doses: 0.05 µg/kg/min (henceforth, respectively, called no Iso, low Iso, and high Iso). From June 2022 to June 2023, 25 patients, median [interquartile range (IQR) 25-75] age 54 [38-61] yr, were included. Before isoproterenol was introduced, all patients received dobutamine, and 15 (60%) were on venoarterial extracorporeal membrane oxygenation (VA-ECMO). Isoproterenol significantly increased heart rate from 84 [77-99] (no Iso) to 91 [88-106] (low Iso) and 102 [90-122] beats/min (high Iso, P < 0.001). Similarly, cardiac index rose from 2.3 [1.4-3.1] to 2.7 [1.8-3.4] and 3 [1.9-3.7] L/min/m2 (P < 0.001) with a concomitant increase in indexed stroke volume (28 [17-34] to 31 [20-34] and 33 [23-35] mL/m2, P < 0.05). Effective pulmonary arterial elastance and pressures were not modified by isoproterenol. Pulmonary vascular resistance (PVR) tended to decrease from 2.9 [1.4-3.6] to 2.3 [1.3-3.5] wood units (WU), P = 0.06. Right ventricular ejection fraction/systolic pulmonary artery pressure (sPAP) evaluating right ventricle-pulmonary artery (RV-PA) coupling increased after isoproterenol from 0.8 to 0.9 and 1%·mmHg-1 (P = 0.001). In conclusion, in post-HT RVF, isoproterenol exhibits chronotropic and inotropic effects, thereby improving RV-PA coupling and resulting in a clinically relevant increase in the cardiac index.NEW & NOTEWORTHY This study offers a detailed and comprehensive hemodynamic investigation at the bedside, illustrating the favorable impact of isoproterenol on right ventricular-pulmonary arterial coupling and global hemodynamics. It elucidates the physiological effects of an underused inotropic strategy in a critical clinical scenario. By enhancing cardiac hemodynamics, isoproterenol has the potential to expedite right ventricular recovery and mitigate primary graft dysfunction, thereby reducing the duration of mechanical support and intensive care unit stay posttransplantation.

Ceftazidime/avibactam serum concentration in patients on ECMO.

OBJECTIVES: The use of extracorporeal membrane oxygenation (ECMO) may alter blood levels of several drugs, including antibiotics, leading to under dosing of these drugs and thus to potential treatment failure. No data exist on pharmacokinetics of new antimicrobial, in particular ceftazidime/avibactam. We therefore perform this study to evaluate ceftazidime/avibactam blood levels in ECMO patients and find factors associated with underdosing. METHODS: Retrospective observational study of patients on ECMO having received ceftazidime/avibactam and in whom trough blood levels of ceftazidime and avibactam were available. Main outcome measurement was the number of patients with ceftazidime and avibactam blood levels above predefined cut-off values, derived from the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints for Enterobacteriaceae and Pseudomonas aeruginosa, namely 8 mg/L for ceftazidime and 4 mg/L for avibactam, and explored factors associated with underdosing. RESULTS: Twenty-three ceftazidime/avibactam trough levels were available in 14 ECMO patients, all of them having received veno-venous ECMO for SARS-CoV-2-associated pneumonia. Although ceftazidime levels were above 8 mg/L in all except one patient, nine (39%) of the avibactam dosages were below 4 mg/L. Increased renal clearance (creatinine clearance > 130 mL/min) was the main factor associated with under dosing, since 7 out of the 10 dosages below the predefined cut-offs were measured in patients with this condition. CONCLUSIONS: In ECMO patients receiving ceftazidime/avibactam, ceftazidime and avibactam serum levels are above EUCAST breakpoints in most cases, justifying the use of normal dosing in ECMO patients. Increased renal clearance may lead to ceftazidime and avibactam under dosing.

Right ventricular injury in patients with COVID-19-related ARDS eligible for ECMO support: a multicenter retrospective study.

BACKGROUND: Coronavirus disease 2019 (COVID-19)-related acute respiratory distress syndrome (ARDS) is associated with high mortality. Extracorporeal membrane oxygenation (ECMO) has been proposed in this setting, but optimal criteria to select target patients remain unknown. Our hypothesis is that evaluation of right ventricular (RV) function could be helpful. The aims of our study were to report the incidence and outcomes of patients eligible for ECMO according to EOLIA criteria, and to identify a subgroup of patients with RV injury, which could be a target for ECMO. METHODS: Retrospective observational study involving 3 French intensive care units (ICUs) of teaching hospitals. Patients with confirmed SARS-CoV-2 infection between March 2020 and March 2021, presenting ARDS and with available echocardiography, were included. Patients were classified in three groups according to whether or not they met the EOLIA criteria and the presence of RV injury (RVI) ("EOLIA -", "EOLIA + RVI -" and "EOLIA + RVI + "). RVI was defined by the association of RV to left ventricular end-diastolic area ratio > 0.8 and paradoxical septal motion. Kaplan-Meier survival curves were used to analyze outcome as well as a Cox model for 90 day mortality. RESULTS: 915 patients were hospitalized for COVID-19, 418 of them with ARDS. A total of 283 patients with available echocardiography were included. Eighteen (6.3%) patients received ECMO. After exclusion of these patients, 107 (40.5%) were classified as EOLIA -, 126 (47.5%) as EOLIA + RVI -, and 32 (12%) as EOLIA + RVI + . Ninety-day mortality was 21% in the EOLIA-group, 44% in the EOLIA + RVI-group, and 66% in the EOLIA + RVI + group (p < 0.001). After adjustment, RVI was statistically associated with 90-day mortality (HR = 1.92 [1.10-3.37]). CONCLUSIONS: Among COVID-19-associated ARDS patients who met the EOLIA criteria, those with significant RV pressure overload had a particularly poor outcome. This subgroup may be a more specific target for ECMO. This represented 12% of our cohort compared to 60% of patients who met the EOLIA criteria only. How the identification of this high-risk subset of patients translates into patient-centered outcomes remains to be evaluated.

Antibiotic definitive treatment in ventilator associated pneumonia caused by AmpC-producing Enterobacterales in critically ill patients: a prospective multicenter observational study.

BACKGROUND: Ventilator associated pneumonia (VAP) due to wild-type AmpC-producing Enterobacterales (wtAE) is frequent in intensive care unit (ICU) patients. Despite a low level of evidence, definitive antimicrobial therapy (AMT) with third generation cephalosporins (3GCs) or piperacillin is discouraged. METHODS: Observational prospective study including consecutive wtAE VAP patients in 20 French ICUs. The primary objective was to assess the association of the choice of definitive AMT, i.e. piperacillin ± tazobactam (PTZ), 3GCs or other molecule (4GCs, carbapenems, quinolones, cotrimoxazole; control group), with treatment success at day-7. Recurrence of infection was collected as a secondary outcome, and analyzed accounting for the competing risk of death. RESULTS: From February 2021 to June 2022, 274 patients were included. Enterobacter cloacae was the most prevalent specie (31%). Seventy-eight patients (28%) had PTZ as definitive AMT while 44 (16%) had 3GCs and 152 (56%) were classified in the control group. Day-7 success rate was similar between the 3 groups (74% vs. 73% vs. 68% respectively, p = 0.814). Recurrence probability at day-28 was 31% (95% CI 21-42), 40% (95% CI 26-55) and 21% (95% CI 15-28) for PTZ, 3GCs and control groups (p = 0.020). In multivariable analysis, choice of definitive AMT was not associated with clinical success, but definitive AMT with 3GCs was associated with recurrence at day-28 [csHR(95%CI) 10.9 (1.92-61.91)]. CONCLUSION: Choice of definitive antimicrobial therapy was not associated with treatment success at day 7. However, recurrence of pneumonia at day-28 was higher in patients treated with third generation cephalosporins with no differences in mortality or mechanical ventilation duration.

Hemodynamic effects of positive end-expiratory pressure.

PURPOSE OF REVIEW: Positive end-expiratory pressure (PEEP) is required in the Berlin definition of acute respiratory distress syndrome and is a cornerstone of its treatment. Application of PEEP increases airway pressure and modifies pleural and transpulmonary pressures according to respiratory mechanics, resulting in blood volume alteration into the pulmonary circulation. This can in turn affect right ventricular preload, afterload and function. At the opposite, PEEP may improve left ventricular function, providing no deleterious effect occurs on the right ventricle. RECENT FINDINGS: This review examines the impact of PEEP on cardiac function with regards to heart-lung interactions, and describes its consequences on organs perfusion and function, including the kidney, gut, liver and the brain. PEEP in itself is not beneficious nor detrimental on end-organ hemodynamics, but its hemodynamic effects vary according to both respiratory mechanics and association with other hemodynamic variables such as central venous or mean arterial pressure. There are parallels in the means of preventing deleterious impact of PEEP on the lungs, heart, kidney, liver and central nervous system. SUMMARY: The quest for optimal PEEP settings has been a prominent goal in ARDS research for the last decades. Intensive care physician must maintain a high degree of vigilance towards hemodynamic effects of PEEP on cardiac function and end-organs circulation.

Ventricular interdependence in critically ill patients: from physiology to bedside.

The review focuses on the mechanism of ventricular interdependence, a frequently encountered phenomena, especially in critically ill patients. It is explained by the anatomy of the heart, with two ventricles sharing a common wall, the septum, and nested in an acutely inextensible envelope, the pericardium. In pathological situation, it results in abnormal movements of the interventricular septum driven by respiration, leading to abnormal filling of one or the other ventricle. Ventricular interdependence has several clinical applications and explains some situations of hemodynamic impairment, especially in situations of cardiac tamponade, severe acute asthma, right ventricular (RV) overload, or more simply, in case of positive pressure ventilation with underlying acute pulmonary hypertension. Ventricular interdependence can be monitored with pulmonary arterial catheter or echocardiography. Knowledge of this phenomena has very concrete clinical applications in the management of filling or in the prevention or treatment of RV overload.

Diagnostic yield, safety and therapeutic consequences of myocardial biopsy in clinically suspected fulminant myocarditis unweanable from mechanical circulatory support.

BACKGROUND: Fulminant myocarditis is a rare and severe disease whose definite and etiological diagnoses rely on pathological examination. Albeit, myocardial biopsy can be associated with significant morbidity and mortality, its therapeutic consequences are unclear. We conducted a study to determine the diagnostic yield, the safety and the therapeutic consequences of myocardial biopsy in patients with fulminant clinically suspected myocarditis unweanable from mechanical circulatory support (MCS). METHODS: Monocenter, retrospective, observational cohort study in a 26-bed French tertiary ICU between January 2002 and February 2019. Inclusion of all fulminant clinically suspected myocarditis patients undergoing in-ICU myocardial biopsy while being on MCS. The primary endpoint was the proportion of patients classified as definite myocarditis using Bonaca criteria before and after including myocardial biopsy results. RESULTS: Forty-seven patients (median age 41 [30-47], female 53%) were included: 55% died before hospital discharge, 34% could be bridged-to-recovery and 15% bridged-to-transplant. Myocardial biopsy was endomyocardial or surgical in 36% and 64% cases respectively. Tamponade requiring emergency pericardiocentesis occurred in 29% patients after endomyocardial biopsy. After adding the biopsy results in the Bonaca classification algorithm the percentage of definite myocarditis raised from 13 to 55% (p < 0.0001). The rate of biopsy-related treatments modifications was 13%, leading to patients' recovery in only 4% patients. CONCLUSIONS: In clinically suspected myocarditis unweanable from MCS, myocardial biopsy increased the rate of definite myocarditis but was associated with a low rate of treatment modification and a significant proportion of adverse events. We believe the benefit/risk ratio of myocardial biopsy should be more carefully weighted in these frail and selected patients than suggested by actual guidelines. Further prospective studies are now needed to determine its value in patients under MCS.

Agreement between pulse oximetry and arterial oxygen saturation measurement in critical care patients during COVID-19: a cross-sectional study.

Some publications suggest that pulse oximetry measurement (SpO2) might overestimate arterial oxygen saturation (SaO2) measurement in COVID-19 patients. This study aims to evaluate the agreement between SpO2 and SaO2 among COVID-19 and non-COVID-19 patients. We conducted a multicenter, prospective study including consecutive intensive care patients from October 15, 2020, to March 4, 2021, and compared for each measurement the difference between SpO2 and SaO2, also called the systematic bias. The primary endpoint was the agreement between SpO2 and SaO2 measured with the Lin concordance coefficient and illustrated using the Bland and Altman method. Factors associated with systematic bias were then identified using a generalised estimating equation. The study included 105 patients, 66 COVID-19 positive and 39 COVID-19 negative, allowing for 1539 measurements. The median age was 66 [57; 72] years with median SOFA and SAPSII scores of, respectively, 4 [3; 6] and 37 [31; 47]. The median SpO2 and SaO2 among all measurements was respectively 97 [96-99] and 94 [92-96] with a systematic bias of 0.80 [- 0.6; 2.4]. This difference was, respectively, 0.80 [- 0.7; 2.5] and 0.90 [- 0.3; 2.0] among COVID-19 positive and negative patients. Overall agreement measured with the Lin correlation coefficient was 0.65 [0.63; 0.68] with 0.61 [0.57; 0.64] and 0.53 [0.45; 0.60] among the COVID-19 positive and negative groups, respectively. Factors independently associated with the variation of the SpO2-SaO2 difference were the PaO2/FiO2 ratio and need for mechanical ventilation. In our population, agreement between SpO2 and SaO2 is acceptable. During the COVID-19 pandemic, SaO2 remains an efficient monitoring tool to characterise the level of hypoxemia and follow therapeutic interventions. As is already known about general intensive care unit patients, the greater hypoxemia, the weaker the correlation between SpO2 and SaO2.

Timing of Prone Positioning During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome.

OBJECTIVES: To assess the association of timing to prone positioning (PP) during venovenous extracorporeal membrane oxygenation (V-V ECMO) with the probability of being discharged alive from the ICU at 90 days (primary endpoint) and the improvement of the respiratory system compliance (Cpl,rs). DESIGN: Pooled individual data analysis from five original observational cohort studies. SETTING: European extracorporeal membrane oxygenation (ECMO) centers. PATIENTS: Acute respiratory distress syndrome (ARDS) patients who underwent PP during ECMO. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Time to PP during V-V ECMO was explored both as a continuous and a categorical variable with Cox proportional hazard models. Three hundred patients were included in the analysis. The longer the time to PP during V-V ECMO, the lower the adjusted probability of alive ICU discharge (adjusted hazard ratio [HR] 0.90 for each day increase; 95% CI, 0.87-0.93). Two hundred twenty-three and 77 patients were included in the early PP (≤ 5 d) and late PP (> 5 d) groups, respectively. The cumulative 90-day probability of being discharged alive from the ICU was 61% in the early PP group vs 36% in the late PP group (log-rank test, p <0.001). This benefit was maintained after adjustment for confounders (adjusted HR, 2.52; 95% CI, 1.66-3.81; p <0.001). In the early PP group, PP was associated with a significant improvement of Cpl,rs (4 ± 9 mL/cm H2O vs 0 ± 12 in the late PP group, p=0.038). CONCLUSIONS: In a large cohort of ARDS patients on ECMO, early PP during ECMO was associated with a higher probability of being discharged alive from the ICU at 90 days and a greater improvement of Cpl,rs.

Hemodynamics and vasopressor support during targeted temperature management after cardiac arrest with non-shockable rhythm: A post hoc analysis of a randomized controlled trial.

Background: Patients admitted after cardiac arrest with non-shockable rhythm frequently experience hemodynamic instability. This study assessed the hemodynamic consequences of TTM in this sub population. Methods: This is a post hoc analysis of the HYPERION trial (NCT01994772), that randomized patients to either hypothermia or normothermia after non-shockable rhythm related cardiac arrest. Patients with no, moderate or severe circulatory failure were identified with cardiovascular Sequential Organ Failure Assessment at randomization. Primary outcome was the number of patients at day 7 with resolution of shock, accounting for the risk of death (competing risk analysis). Secondary endpoint included neurological outcome and death at day-90. Results: 584 patients were included in the analysis: 195 (34%), 46 (8%) and 340 (59%) had no, moderate and severe circulatory failure, respectively. Resolution of circulatory failure at day 7 was more frequently observed in the normothermia group than in the TTM group (60% [95 %CI 54-66] versus 53% [95 %CI 46-60], Gray-test: p = 0.016). The severity of circulatory failure at randomization was associated with its less frequent resolution at day 7 accounting for the risk of death (76 % [62-86] versus 54% [49-59] for patients with moderate versus severe circulatory failure, Gray test, p < 0.001, respectively). At day 90, the proportion of patients with Cerebral Performance Category score of 1 or 2 was lower in patients presenting severe circulatory failure (p = 0.038). Conclusion: Circulatory failure is frequent after CA with non-shockable rhythm. Its severity at admission and TTM were associated with delayed resolution of circulatory failure.

Effect of prone positioning on survival in adult patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review and meta-analysis.

PURPOSE: Previous studies support the potential efficacy of venovenous extracorporeal membrane oxygenation (vvECMO) for improving survival in severe acute respiratory distress syndrome (ARDS) cases. Prone positioning (PP) has been shown to improve the outcomes of moderate-to-severe ARDS patients. Few studies and no randomized controlled trials have evaluated the effect of PP performed in ECMO patients. METHODS: We performed a systematic review and meta-analysis examining the effect of prone positioning for ARDS patients receiving vvECMO on survival. All authors were contacted to obtain complementary information not mentioned in the original articles. The main objective was to compare 28-day survival in vvECMO patients with PP to vvECMO patients without PP (controls). RESULTS: Thirteen studies with a combined population of 1836 patients satisfied the inclusion criteria. PP was associated with a significant improvement in 28-day survival (503 survivors among 681 patients in the PP group [74%; 95% CI 71-77] vs. 450 survivors among 770 patients in the control group [58%, 95% CI 55-62]; RR 1.31 [95% CI 1.21-1.41]; I2 22% [95% CI 0-62%]; P < 0.0001). Survival was also improved in terms of other endpoints (60-day survival, 90-day survival, ICU survival, and hospital survival). In contrast, the duration of mechanical ventilation was increased in vvECMO patients with PP (mean difference 11.4 days [95% CI 9.2-13.5]; 0.64 [95% CI 0.50-0.78]; I2 8%; P < 0.0001). CONCLUSION: According to this meta-analysis, survival was improved when prone positioning was used in ARDS patients receiving vvECMO. The impact of this combination on survival should be investigated in prospective randomized controlled trials.

Prone positioning during venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a pooled individual patient data analysis.

BACKGROUND: Prone positioning (PP) reduces mortality of patients with acute respiratory distress syndrome (ARDS). The potential benefit of prone positioning maneuvers during venovenous extracorporeal membrane oxygenation (ECMO) is unknown. The aim of this study was to evaluate the association between the use of prone positioning during extracorporeal support and ICU mortality in a pooled population of patients from previous European cohort studies. METHODS: We performed a pooled individual patient data analysis of European cohort studies which compared patients treated with prone positioning during ECMO (Prone group) to "conventional" ECMO management (Supine group) in patients with severe ARDS. RESULTS: 889 patients from five studies were included. Unadjusted ICU mortality was 52.8% in the Supine Group and 40.8% in the Prone group. At a Cox multiple regression analysis PP during ECMO was not significantly associated with a reduction of ICU mortality (HR 0.67 95% CI: 0.42-1.06). Propensity score matching identified 227 patients in each group. ICU mortality of the matched samples was 48.0% and 39.6% for patients in the Supine and Prone group, respectively (p = 0.072). CONCLUSIONS: In a large population of ARDS patients receiving venovenous extracorporeal support, the use of prone positioning during ECMO was not significantly associated with reduced ICU mortality. The impact of this procedure will have to be definitively assessed by prospective randomized controlled trials.