Initiation Of Venovenous Extracorporeal Membrane Oxygenation Research Articles

Age and associated outcomes among patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory failure: analysis of the Extracorporeal Life Support Organization registry.

Venovenous extracorporeal membrane oxygenation (VV-ECMO) can be used to support patients with refractory acute respiratory failure, though guidance on patient selection is lacking. While age is commonly utilized as a factor in establishing the potential VV-ECMO candidacy of these patients, little is known regarding its association with outcome. We studied the association between increasing patient age and outcomes among patients with acute respiratory failure receiving VV-ECMO. In this registry-based cohort study, we used individual patient data from 144 centres. We included adult patients (≥ 18years of age) receiving VV-ECMO from 2017 to 2022. The primary outcome was hospital mortality. Secondary outcomes included a composite of complications following initiation of VV-ECMO. We conducted Bayesian analyses to estimate the association between chronological age and outcomes. We included 27,811 patients receiving VV-ECMO. Of these, 11,533 (41.5%) died in hospital. For the analysis conducted using weakly informed priors, and as compared to the reference category of age 18-29, the age brackets of 30-39 (odds ratio [OR] 1.17, 95% credible interval [CrI] 1.06-1.31), 40-49 (OR 1.65, 95% CrI 1.49-1.82), 50-59 (OR 2.39, 95% CrI 2.16-2.61), 60-69 (OR 3.29, 95% CrI 2.97-3.67), 70-79 (OR 4.57, 95% CrI 3.90-5.37), and ≥ 80 (OR 8.08, 95% CrI 4.85-13.74) were independently associated with increasing hospital mortality. Similar results were found between increasing age and post-ECMO complications. Among patients receiving VV-ECMO for acute respiratory failure, increasing age is significantly associated with poorer outcomes, and this association emerges as early as 30years of age.

Characterizing the Relationship Between Arterial Carbon Dioxide Trajectory and Serial Brain Biomarkers with Central Nervous System Injury During Veno-Venous Extracorporeal Membrane Oxygenation: A Prospective Cohort Study.

Central nervous system (CNS) injury following initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) is common. An acute decrease in partial pressure of arterial carbon dioxide (PaCO2) following VV-ECMO initiation has been suggested as an etiological factor, but the challenges of diagnosing CNS injuries has made discerning a relationship between PaCO2 and CNS injury difficult. We conducted a prospective cohort study of adult patients undergoing VV-ECMO for acute respiratory failure. Arterial blood gas measurements were obtained prior to initiation of VV-ECMO, and at every 2-4h for the first 24h. Neuroimaging was conducted within the first 7-14days in patients who were suspected of having neurological injury or unable to be examined because of sedation. We collected blood biospecimens to measure brain biomarkers [neurofilament light (NF-L); glial fibrillary acidic protein (GFAP); and phosphorylated-tau 181] in the first 7days following initiation of VV-ECMO. We assessed the relationship between both PaCO2 over the first 24h and brain biomarkers with CNS injury using mixed methods linear regression. Finally, we explored the effects of absolute change of PaCO2 on serum levels of neurological biomarkers by separate mixed methods linear regression for each biomarker using three PaCO2 exposures hypothesized to result in CNS injury. In our cohort, 12 of 59 (20%) patients had overt CNS injury identified on head computed tomography. The PaCO2 decrease with VV-ECMO initiation was steeper in patients who developed a CNS injury (- 0.32%, 95% confidence interval - 0.25 to - 0.39) compared with those without (- 0.18%, 95% confidence interval - 0.14 to - 0.21, P interaction < 0.001). The mean concentration of NF-L increased over time and was higher in those with a CNS injury (464 [739]) compared with those without (127 [257]; P = 0.001). GFAP was higher in those with a CNS injury (4278 [11,653] pg/ml) compared with those without (116 [108] pg/ml; P < 0.001). The mean NF-L, GFAP, and tau over time in patients stratified by the three thresholds of absolute change of PaCO2 showed no differences and had no significant interaction for time. Although rapid decreases in PaCO2 following initiation of VV-ECMO were slightly greater in patients who had CNS injuries versus those without, data overlap and absence of relationships between PaCO2 and brain biomarkers suggests other pathophysiologic variables are likely at play.

Days spent on non-invasive ventilation support: can it determine when to initiate VV- ECMO? Observational study in a cohort of Covid-19 patients

BackgroundThe study evaluates the impact of the time between commencing non-invasive ventilation (NIV) support and initiation of venovenous extracorporeal membrane oxygenation (VV-ECMO) in a cohort of critically ill patients with coronavirus disease 2019 (COVID-19) associated acute respiratory distress syndrome (ARDS).MethodsProspective observational study design in an intensive Care Unit (ICU) of a tertiary hospital in Barcelona (Spain). All patients requiring VV-ECMO support due to COVID-19 associated ARDS between March 2020 and January 2022 were analysed. Survival outcome was determined at 90 days after VV-ECMO initiation. Demographic data, comorbidities at ICU admission, RESP (respiratory ECMO survival prediction) score, antiviral and immunomodulatory treatments received, inflammatory biomarkers, the need for vasopressors, the thromboprophylaxis regimen received, and respiratory parameters including the length of intubation previous to ECMO and the length of each NIV support (high-flow nasal cannula, continuous positive airway pressure and bi-level positive airway pressure), were also collated in order to assess risk factors for day-90 mortality. The effect of the time lapse between NIV support and VV-ECMO on survival was evaluated using logistic regression and adjusting the association with all factors that were significant in the univariate analysis.ResultsSeventy-two patients finally received VV-ECMO support. At 90 days after commencing VV-ECMO 35 patients (48%) had died and 37 patients (52%) were alive. Multivariable analysis showed that at VV-ECMO initiation, age (p = 0.02), lactate (p = 0.001), and days from initiation of NIV support to starting VV-ECMO (p = 0.04) were all associated with day-90 mortality.ConclusionsIn our small cohort of VV-ECMO patients with COVID-19 associated ARDS, the time spent between initiation of NIV support and VV-ECMO (together with age and lactate) appeared to be a better predictor of mortality than the time between intubation and VV-ECMO.

Venovenous Extracorporeal Membrane Oxygenation Initiation for Pediatric Acute Respiratory Distress Syndrome With Cardiovascular Instability is Associated With an Immediate and Sustained Decrease in Vasoactive-Inotropic Scores.

To determine the association of venovenous extracorporeal membrane oxygenation (VV-ECMO) initiation with changes in vasoactive-inotropic scores (VISs) in children with pediatric acute respiratory distress syndrome (PARDS) and cardiovascular instability. Retrospective cohort study. Single academic pediatric ECMO center. Children (1 mo to 18 yr) treated with VV-ECMO (2009-2019) for PARDS with need for vasopressor or inotropic support at ECMO initiation. Arterial blood gas values, VIS, mean airway pressure (mPaw), and oxygen saturation (Sp o2 ) values were recorded hourly relative to the start of ECMO flow for 24 hours pre-VV-ECMO and post-VV-ECMO cannulation. A sharp kink discontinuity regression analysis clustered by patient tested the difference in VISs and regression line slopes immediately surrounding cannulation. Thirty-two patients met inclusion criteria: median age 6.6 years (interquartile range [IQR] 1.5-11.7), 22% immunocompromised, and 75% had pneumonia or sepsis as the cause of PARDS. Pre-ECMO characteristics included: median oxygenation index 45 (IQR 35-58), mPaw 32 cm H 2o (IQR 30-34), 97% on inhaled nitric oxide, and 81% on an advanced mode of ventilation. Median VIS immediately before VV-ECMO cannulation was 13 (IQR 8-25) with an overall increasing VIS trajectory over the hours before cannulation. VISs decreased and the slope of the regression line reversed immediately surrounding the time of cannulation (robust p < 0.0001). There were pre-ECMO to post-ECMO cannulation decreases in mPaw (32 vs 20 cm H 2o , p < 0.001) and arterial P co2 (64.1 vs 50.1 mm Hg, p = 0.007) and increases in arterial pH (7.26 vs 7.38, p = 0.001), arterial base excess (2.5 vs 5.2, p = 0.013), and SpO 2 (91% vs 95%, p = 0.013). Initiation of VV-ECMO was associated with an immediate and sustained reduction in VIS in PARDS patients with cardiovascular instability. This VIS reduction was associated with decreased mPaw and reduced respiratory and/or metabolic acidosis as well as improved oxygenation.

VV-ECMO in severe COVID-19: multidimensional perspectives on the use of a complex treatment

VV-ECMO in severe COVID-19: multidimensional perspectives on the use of a complex treatment

The impact of reduction in intensity of mechanical ventilation upon venovenous ECMO initiation on radiographically assessed lung edema scores: A retrospective observational study.

BackgroundPatients with severe acute respiratory distress syndrome (ARDS) typically receive ultra-protective ventilation after extracorporeal membrane oxygenation (ECMO) is initiated. While the benefit of ECMO appears to derive from supporting “lung rest”, reductions in the intensity of mechanical ventilation, principally tidal volume limitation, may manifest radiologically. This study evaluated the relative changes in radiographic assessment of lung edema (RALE) score upon venovenous ECMO initiation in patients with severe ARDS.MethodsDigital chest x-rays (CXR) performed at baseline immediately before initiation of ECMO, and at intervals post (median 1.1, 2.1, and 9.6 days) were reviewed in 39 Adult ARDS patients. One hundred fifty-six digital images were scored by two independent, blinded radiologists according to the RALE (Radiographic Assessment of Lung Edema) scoring criteria. Ventilatory data, ECMO parameters and fluid balance were recorded at corresponding time points. Multivariable analysis was performed analyzing the change in RALE score over time relative to baseline.ResultsThe RALE score demonstrated excellent inter-rater agreement in this novel application in an ECMO cohort. Mean RALE scores increased from 28 (22–37) at baseline to 35 (26–42) (p < 0.001) on D1 of ECMO; increasing RALE was associated with higher baseline APACHE III scores [ß value +0.19 (0.08, 0.30) p = 0.001], and greater reductions in tidal volume [ß value −2.08 (−3.07, −1.10) p < 0.001] after ECMO initiation. Duration of mechanical ventilation, and ECMO support did not differ between survivors and non-survivors.ConclusionsThe magnitude of reductions in delivered tidal volumes correlated with increasing RALE scores (radiographic worsening) in ARDS patients receiving ECMO. Implications for patient centered outcomes remain unclear. There is a need to define appropriate ventilator settings on venovenous ECMO, counterbalancing the risks vs. benefits of optimal “lung rest” against potential atelectrauma.

Use of two parallel oxygenators during veno-venous extracorporeal membrane oxygenation in a patient with severe obesity and COVID-19 pneumonia.

Background: Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO) is one effective treatment for COVID-19 pneumonia, but controversy regarding VV-ECMO management in obese patients still exists. In this report, we described a case in which two oxygenators were used in parallel in a severely obese patient (Body mass index: 60 kg/m2, body surface area: 2.8 m2).Case: The case was of a 27-year-old man diagnosed with COVID-19 pneumonia and admitted to our hospital. VV-ECMO was required on the fifth day after admission due to gradually worsening respiratory conditions and partial pressure of arterial oxygen (PaO2)/FiO2 ratio of 77. Immediately after the initiation of VV-ECMO, post-oxygenator in circuit, PaO2 was low at 134 mmHg. Even though the VV-ECMO circuit was replaced on the same day, the PaO2 still was low at 261 mmHg. Thus, we decided to use two oxygenators in parallel, after which the PaO2 stabilized at 400–500 mmHg.Conclusions: In this case, VV-ECMO oxygenation could be stabilized by utilizing two oxygenators in parallel. Using two membrane oxygenators may be a treatment option in severely obese patients with respiratory failure.

Impact of major bleeding and thrombosis on 180-day survival in patients with severe COVID-19 supported with veno-venous extracorporeal membrane oxygenation in the United Kingdom: a multicentre observational study.

SummaryBleeding and thrombosis are major complications in patients supported with extracorporeal membrane oxygenation (ECMO). In this multicentre observational study of 152 consecutive patients (≥18 years) with severe COVID‐19 supported by veno‐venous (VV) ECMO in four UK commissioned centres during the first wave of the COVID‐19 pandemic (1 March to 31 May 2020), we assessed the incidence of major bleeding and thrombosis and their association with 180‐day mortality. Median age (range) was 47 years (23–65) and 75% were male. Overall, the 180‐day survival was 70·4% (107/152). The rate of major bleeding was 30·9% (47/152), of which intracranial bleeding (ICH) was 34% (16/47). There were 96 thrombotic events (63·1%) consisting of venous 44·7% [68/152 of which 66·2% were pulmonary embolism (PE)], arterial 18·6% (13/152) and ECMO circuit thrombosis 9·9% (15/152). In multivariate analysis, only raised lactate dehydrogenase (LDH) at the initiation of VV ECMO was associated with an increased risk of thrombosis [hazard ratio (HR) 1·92, 95% CI 1·21‐3·03]. Major bleeding and ICH were associated with 3·87‐fold (95% CI 2·10–7·23) and 5·97‐fold [95% confidence interval (CI) 2·36–15·04] increased risk of mortality and PE with a 2·00‐fold (95% CI1·09–3·56) risk of mortality. This highlights the difficult balancing act often encountered when managing coagulopathy in COVID‐19 patients supported with ECMO.

A new anticoagulation strategy using recombinant human thrombomodulin in patients on veno-venous extracorporeal membrane oxygenation: a retrospective study.

During veno-venous extracorporeal membrane oxygenation (VV-ECMO), systemic anticoagulation is required to prevent thrombotic complications within the circuit and oxygenator. The unfractionated heparin (UFH) is commonly administered as a standard anticoagulant, but in our institute recombinant human thrombomodulin (rhTM), instead of UFH, is used as an anticoagulant for VV-ECMO. In the present study, we reviewed whether rhTM could be applied effectively and safely as an anticoagulant agent during VV-ECMO. All 15 patients with severe respiratory failure on VV-ECMO were analyzed retrospectively. The following data were collected: age, gender, underlying disease, APACHE-II score, SOFA score, Japanese association for acute medicine (JAAM) DIC score, the usage of anticoagulants, time course of coagulationrelated parameters during ECMO, hemorrhagic and thrombotic complications. The median age of the patients was 73 years. The median JAAM DIC score at day 0 was 5 points, indicating that 13 patients were diagnosed with DIC at the initiation of VV-ECMO. The total number of days of VV-ECMO runs combined was 193 days, with a median duration of VV-ECMO of 9 days. Among the 15 VV-ECMO runs, rhTM was used as monotherapy in 5 runs, and a combination of rhTM and (antithrombin) AT was used in 8 runs. UFH was used in combination with rhTM in only 2 runs. Median ACT and aPTT remained a little longer than normal range over the course of the 14 days of a VV-ECMO run. Bleeding events were observed in 6 cases (40%) and no major thromboses were observed in all patients. In this retrospective study, we analyzed 15 patients with severe respiratory failure who were administered rhTM as an anticoagulant during VV-ECMO and found that anticoagulation therapy with rhTM is maybe a feasible option which allows for effective and safe VV-ECMO.

Mechanical Power during Veno-Venous Extracorporeal Membrane Oxygenation Initiation: A Pilot-Study.

Mechanical power (MP) represents a useful parameter to describe and quantify the forces applied to the lungs during mechanical ventilation (MV). In this multi-center, prospective, observational study, we analyzed MP variations following MV adjustments after veno-venous extra-corporeal membrane oxygenation (VV ECMO) initiation. We also investigated whether the MV parameters (including MP) in the early phases of VV ECMO run may be related to the intensive care unit (ICU) mortality. Thirty-five patients with severe acute respiratory distress syndrome were prospectively enrolled and analyzed. After VV ECMO initiation, we observed a significant decrease in median MP (32.4 vs. 8.2 J/min, p < 0.001), plateau pressure (27 vs. 21 cmH2O, p = 0.012), driving pressure (11 vs. 8 cmH2O, p = 0.014), respiratory rate (RR, 22 vs. 14 breaths/min, p < 0.001), and tidal volume adjusted to patient ideal body weight (VT/IBW, 5.5 vs. 4.0 mL/kg, p = 0.001) values. During the early phase of ECMO run, RR (17 vs. 13 breaths/min, p = 0.003) was significantly higher, while positive end-expiratory pressure (10 vs. 14 cmH2O, p = 0.048) and VT/IBW (3.0 vs. 4.0 mL/kg, p = 0.028) were lower in ICU non-survivors, when compared to the survivors. The observed decrease in MP after ECMO initiation did not influence ICU outcome. Waiting for large studies assessing the role of these parameters in VV ECMO patients, RR and MP monitoring should not be underrated during ECMO.

Timing, Outcome, and Risk Factors of Intracranial Hemorrhage in Acute Respiratory Distress Syndrome Patients During Venovenous Extracorporeal Membrane Oxygenation.

Intracranial hemorrhage is a serious complication in patients receiving venovenous extracorporeal membrane oxygenation during treatment of the acute respiratory distress syndrome. We analyzed timing, outcome, and risk factors of intracranial hemorrhage in patients on venovenous extracorporeal membrane oxygenation. Retrospective cohort study. Single acute respiratory distress syndrome referral center. Patients receiving venovenous extracorporeal membrane oxygenation were identified from a cohort of 1,044 patients with acute respiratory distress syndrome. Patients developing an intracranial hemorrhage during venovenous extracorporeal membrane oxygenation therapy were compared with patients without evidence for intracranial hemorrhage. The primary objective was to assess the association of intracranial hemorrhage with 60-day mortality. Further objectives included the identification of risk factors for intracranial hemorrhage and the evaluation of clinical cutoff values. None. Among 444 patients treated with venovenous extracorporeal membrane oxygenation, 49 patients (11.0% [95% CI, 8.3-14.4%]) developed an intracranial hemorrhage. The median time to intracranial hemorrhage occurrence was 4 days (95% CI, 2-7 d). Patients who developed an intracranial hemorrhage had a higher 60-day mortality compared with patients without intracranial hemorrhage (69.4% [54.4-81.3%] vs 44.6% [39.6-49.6%]; odds ratio 3.05 [95% CI, 1.54-6.32%]; p = 0.001). A low platelet count, a high positive end expiratory pressure, and a major initial decrease of Paco2 were identified as independent risk factors for the occurrence of intracranial hemorrhage. A platelet count greater than 100/nL and a positive end expiratory pressure less than or equal to 14 cm H2O during the first 7 days of venovenous extracorporeal membrane oxygenation therapy as well as a decrease of Paco2 less than 24 mm Hg during venovenous extracorporeal membrane oxygenation initiation were identified as clinical cutoff values to prevent intracranial hemorrhage (sensitivity 91% [95% CI, 82-99%], 94% [85-99%], and 67% [48-81%], respectively). Intracranial hemorrhage occurs early during venovenous extracorporeal membrane oxygenation and is a determinant for 60-day mortality. Appropriate adjustment of identified modifiable risk factors might lower the prevalence of intracranial hemorrhage during venovenous extracorporeal membrane oxygenation therapy.

Does Earlier Cannulation With Veno-Venous Extracorporeal Membrane Oxygenation in Adult Patients With Acute Respiratory Distress Syndrome Decrease Duration of Artificial Mechanical Ventilation?

Acute respiratory distress syndrome (ARDS) is characterized by an acute, diffuse, inflammatory lung injury, leading to increased alveolar capillary permeability, increased lung weight, and loss of aerated lung tissue (Fan, Brodie, & Slutsky, 2018). Primary treatment for ARDS is artificial mechanical ventilation (AMV) (Wu, Huang, Wu, Wang, & Lin, 2016). Given recent advances in technology, the use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) to treat severe ARDS is growing rapidly (Combes et al., 2014). This 49-month quantitative, retrospective inpatient EMR chart review compared if cannulation with VV-ECMO up to and including 48 hours of admission and diagnosis in adult patients 30 to 65 years of age diagnosed with ARDS, decreased duration on AMV, as compared to participants who were cannulated after 48 hours of admission and diagnosis with ARDS. A total of 110 participants were identified as receiving VV-ECMO during the study timeframe. Of the 58 participants who met all inclusion criteria, 39 participants were cannulated for VV-ECMO within 48 hours of admission and diagnosis with ARDS, and 19 participants were cannulated with VV-ECMO after 48 hours of admission and diagnosis with ARDS. Data collected identified no statistically significant (p < 0.579) difference in length of days on AMV between participant groups. Further studies are needed to determine if earlier initiation of VV-ECMO in adult patients with ARDS decrease time on AMV. Although the results related to length of time on AMV did not produce statistical significance, the decreased duration of AMV in the participants who were cannulated within 48 hours (21 days vs. 27 days) may support several benefits associated with this participant population including increased knowledge of healthcare providers, decreased lung injury, earlier discharge which decreases hospital and patient cost, ability for patients to communicate sooner, decreased risk of pulmonary infection, decreased length of stay, decreased cost, and improved patient and family satisfaction.

Feasibility of Venovenous Extracorporeal Membrane Oxygenation Without Systemic Anticoagulation

Venovenous extracorporeal membrane oxygenation (ECMO) is increasingly being used for acute respiratory distress syndrome and as a bridge to lung transplantation. After initiation of venovenous ECMO, systemic anticoagulation therapy is traditionally administered and can cause bleeding diathesis. Here, we investigated whether venovenous ECMO can be administered without continuous systemic anticoagulation administration for patients with acute respiratory distress syndrome. This is a retrospective review of an institutional ECMO database. We included consecutive patients from January 2015 through February 2019. Overall, 38 patients received low levels of continuous systemic anticoagulation (AC+) whereas the subsequent 36 patients received standard venous thromboprophylaxis (AC-). Published Extracorporeal Life Support Organization guidelines were used for the definition of outcomes and complications. Overall, survival was not different between the two groups (P= .58). However, patients in the AC+ group had higher rates of gastrointestinal bleeding (28.9%, vs AC- group 5.6%; P < .001). The events per patient-day of gastrointestinal bleeding was 0.00025 in the AC- group and 0.00064 in the AC+ group (P < .001). In addition, oxygenator dysfunction was increased in the AC+ group (28.9% and 0.00067 events per patient-day, vs AC- 11.1% and 0.00062 events per patient-day; P= .02). Furthermore, the AC+ group received more transfusions: packed red blood cells, AC+ group 94.7% vs AC- group 55.5% (P < .001); fresh frozen plasma, AC+ 60.5% vs AC- 16.6% (P= .001); and platelets, AC+ 84.2% vs AC- 27.7% (P < .001). There was no circuit thrombosis in either groups throughout the duration of ECMO support. Our results suggest that venovenous ECMO can be safely administered without continuous systemic anticoagulation therapy. This approach may be associated with reduced bleeding diathesis and need for blood transfusions.

Pre-Intubation Veno-Venous Extracorporeal Membrane Oxygenation in Patients at Risk for Respiratory Decompensation

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has emerged as a potential life-saving treatment for patients with acute respiratory failure. Given the accumulating literature supporting the use of VV-ECMO without therapeutic levels of anticoagulation, it might be feasible to use it for planned intubation before surgical procedures. Here, we report consecutive series of patients who underwent planned initiation of VV-ECMO, without anticoagulation, before induction of general anesthesia for anticipated difficult airways or respiratory decompensation. We describe the approach to safely initiate VV-ECMO in an awake patient. We retrospectively identified patients in a prospectively maintained database who underwent planned initiation of VV-ECMO before intubation. Standard statistical methods were used to determine post-procedure outcomes. Patients included were three men and one woman, with a mean age of 34.3 ± 10.4 years. Indications included mediastinal lymphoma, foreign body obstruction, hemoptysis, and tracheo-esophageal fistula. VV-ECMO was initiated electively for all patients, and no anticoagulation was used. The median duration of VV-ECMO support was 2.5 days (1–11 days), the median length of ventilator dependence and intensive care unit stay was 1 day (1–23 days) and 5 days (4–31 days), respectively. The median length of stay was 18.5 days (8–39 days). There were no thrombotic complications and no mortality at 30 days. Initiation of awake VV-ECMO is feasible and is safe before intubation and induction of anesthesia in patients at high risk for respiratory decompensation.

Pre-Intubation Veno-Venous Extracorporeal Membrane Oxygenation in Patients at Risk for Respiratory Decompensation.

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) has emerged as a potential life-saving treatment for patients with acute respiratory failure. Given the accumulating literature supporting the use of VV-ECMO without therapeutic levels of anticoagulation, it might be feasible to use it for planned intubation before surgical procedures. Here, we report consecutive series of patients who underwent planned initiation of VV-ECMO, without anticoagulation, before induction of general anesthesia for anticipated difficult airways or respiratory decompensation. We describe the approach to safely initiate VV-ECMO in an awake patient. We retrospectively identified patients in a prospectively maintained database who underwent planned initiation of VV-ECMO before intubation. Standard statistical methods were used to determine post-procedure outcomes. Patients included were three men and one woman, with a mean age of 34.3 ± 10.4 years. Indications included mediastinal lymphoma, foreign body obstruction, hemoptysis, and tracheo-esophageal fistula. VV-ECMO was initiated electively for all patients, and no anticoagulation was used. The median duration of VV-ECMO support was 2.5 days (1-11 days), the median length of ventilator dependence and intensive care unit stay was 1 day (1-23 days) and 5 days (4-31 days), respectively. The median length of stay was 18.5 days (8-39 days). There were no thrombotic complications and no mortality at 30 days. Initiation of awake VV-ECMO is feasible and is safe before intubation and induction of anesthesia in patients at high risk for respiratory decompensation.

Sedation Practice in Extracorporeal Membrane Oxygenation–Treated Patients with Acute Respiratory Distress Syndrome: A Retrospective Study

Our objective was to characterize sedation management in adult patients with severe respiratory distress syndrome (ARDS) treated with venovenous extracorporeal membrane oxygenation (VV-ECMO). We conducted a retrospective chart review of these patients treated at Toronto General Hospital between January 2012 and October 2015. Medications administered (sedative, analgesic, paralytic, and antipsychotic), sedation depth (Sedation Agitation Scale [SAS] score) delirium assessments, and mobilization were recorded daily. Forty-five adults (33 males, median age 47 years; interquartile range [IQR], 35-56]) with ARDS (median PaO2/FiO2 71; IQR 59-83) because of respiratory infection (91%) were treated with VV-ECMO for a median of 11 days (IQR, 7-17). After ECMO initiation, 96% patients were deeply sedated (SAS score < 3) with continuous infusions of midazolam (49%), propofol (18%), or both (29%) and 98% were receiving opioid infusions (93% fentanyl). Patients were deeply sedated for a median of 6 days (IQR, 3-10) after cannulation before transitioning to intermediate or light sedation (SAS score ≥ 3). Before ECMO discontinuation, 77% of surviving patients were intermediately or lightly sedated, 20% were receiving no sedatives, and 9% were receiving no opioids. During ECMO, 58% had positive delirium assessment and 24% experienced agitation (SAS ≥ 6). During ECMO support, 71% received physical therapy that occurred after a median of 7 days (IQR, 4-12) after cannulation. In conclusion, we found that although patients were deeply sedated for a prolonged duration after VV-ECMO initiation, many were able to safely achieve light sedation and active mobilization.

Intracranial Hemorrhage and Early Mortality in Patients Receiving Extracorporeal Membrane Oxygenation for Severe Respiratory Failure.

Intracranial hemorrhage (ICH) is a serious complication in patients receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) and is associated with high mortality. It is unknown whether ICH may be a consequence of the ECMO or of an underlying disease. The authors first aimed to assess the incidence of ICH at initiation and during the course of VV-ECMO and its associated mortality. The second aim was to identify clinical and laboratory measures that could predict the development of ICH in severe respiratory failure. Data were collected from a total number of 165 patients receiving VV-ECMO from January, 2012 to December, 2016 in a single tertiary center and treated according to a single protocol. Only patients who had a brain computed tomography within 24 hours of initiation of ECMO (n = 149) were included for analysis. The prevalence and incidence of ICH at initiation and during the course of VV-ECMO (at median 9 days) were 10.7% (16/149) and 5.2% (7/133), respectively. Thrombocytopenia and reduced creatinine clearance (CrCL) were independently associated with increased risk of ICH on admission; odds ratio (95% confidence interval): 22.6 (2.6-99.5), and 10.8 (5.6-16.2). Only 30-day (not 180-day) mortality was significantly higher in patients with ICH on admission versus those without (37.5% [6/16] vs 16.4% [22/133]; p = 0.03 and 43.7% [7/16] vs 26.3% [35/133]; p = 0.15, respectively). Reduced CrCL and thrombocytopenia were associated with ICH at initiation of VV-ECMO. The higher incidence of ICH at initiation suggests it is more closely related to the severity of the underlying lung injury than to the VV-ECMO itself. ICH at VV-ECMO initiation was associated with early mortality.

Sedation and Mobilization During Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Failure: An International Survey.

To characterize sedation, analgesia, delirium, and mobilization practices in patients supported with venovenous extracorporeal membrane oxygenation for severe acute respiratory failure. Cross-sectional electronic survey administered January 2016 to March 2016. Three-hundred ninety-four extracorporeal membrane oxygenation centers registered with the Extracorporeal Life Support Organization. Extracorporeal membrane oxygenation medical directors and program coordinators. None. We analyzed responses from 209 respondents (53%), mostly from academic centers (63%); 41% respondents provide venovenous extracorporeal membrane oxygenation to adults exclusively. Following venovenous extracorporeal membrane oxygenation initiation, 97% respondents administer sedative/analgesic infusions, and the sedation target was "sedated" or "very sedated" for 59%, "calm and cooperative" for 25%, and "unarousable" for 16%. Use of daily sedation interruption and a sedation/analgesia protocol was reported by 51% and 39%, respectively. Midazolam (48%) and propofol (19%) were reported as the most frequently used sedatives; fentanyl (44%) and morphine (20%) the most frequent opioids. Use of a delirium scale was reported by 55% respondents. Physical therapy was reported by 84% respondents, with 41% initiating it within 72 hours after cannulation. Mobilization goals varied from range of motion exercises (81%) to ambulation (22%). The most frequently perceived barriers to mobilization were hemodynamic instability, hypoxemia, and dependency on venovenous extracorporeal membrane oxygenation support. The majority of respondents reported targeting moderate to deep sedation following cannulation, with the use of sedative and opioid infusions. There is considerable variability surrounding early physical therapy and mobilization goals for patients with acute respiratory failure supported by venovenous extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation: beyond rescue therapy for acute respiratory distress syndrome?

This article summarizes the results of past and more recent series on venovenous extracorporeal membrane oxygenation (VV-ECMO) and discusses its potential indications beyond the rescue of patients with lung failure refractory to conventional mechanical ventilation. Successful VV-ECMO treatment in patients with extremely severe influenza A(H1N1)-associated acute respiratory distress syndrome (ARDS) and positive results of the CESAR trial have led to an exponential use of the technology in recent years. Beyond its currently accepted indication as a salvage therapy in ARDS patients with refractory hypoxemia or unable to tolerate volume-limited strategies, VV-ECMO may improve the outcomes of less severe ARDS patients by facilitating lung-protective ventilation. As initiation of VV-ECMO allows significant decrease in tidal volume, plateau and driving pressures, which has been associated with improved survival in ARDS patients, new trials should evaluate the impact of its early initiation in patients with severe but not refractory ARDS.

Venovenous Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome in Adults: Prognostic Factors for Outcomes.

Despite a therapeutic option for severe acute respiratory distress syndrome (ARDS), the survival benefit of venovenous extracorporeal membrane oxygenation (VV-ECMO) is still controversial in adults. This study was aimed at investigating the prognostic factors for ECMO-treated ARDS in adult patients.From 2012 to 2015, 49 patients (median age: 57 years) received VV-ECMO in our institution and were included in this retrospective study. The indication of VV-ECMO was a severe hypoxemia (PaO2/FiO2 ratio <70 mmHg) under mechanical ventilation (MV) with a peak inspiratory pressure (PIP) >35 cmH2O and a FiO2 >0.8. To decrease the impact of pulmonary injuries associated with the high-pressure ventilation, the settings of MV on VV-ECMO were downgraded according to our protocol. Outcomes of this study were death on VV-ECMO and death in hospital. Important demographic and clinical data during the treatment were collected for outcome analyses.All patients experienced significant improvements in arterial oxygenation on VV-ECMO. Twenty-four hours after initiation of VV-ECMO, the median PaO2/FiO2 ratio increased from 58 to 172 mmHg (P < 0.001) and the median SaO2 increased from 86% to 97% (P < 0.001). In the meantime, the MV settings were also effectively downgraded. The median PIP decreased from 35 to 29 cmH2O (P < 0.001) and the median tidal volume decreased from 7 to 5 ml/kg/min (P < 0.001). Twelve patients died during the treatment of VV-ECMO and 21 patients died before hospital discharge. Among all of the pre-ECMO variables, the pre-ECMO pulmonary dynamic compliance (PCdyn) <20 mL/cmH2O was identified to be the prognostic factor of death on VV-ECMO (odds ratio [OR]: 6, 95% confidence interval [CI]: 1–35, P = 0.03), and the pre-ECMO duration of MV >90 hours was the prognostic factor of death before hospital discharge (OR: 7, 95% CI: 1–29, P = 0.01).VV-ECMO was a useful salvage therapy for severe ARDS in adults. However, the value of PCdyn and the duration of MV before intervention with VV-ECMO may significantly affect the patients’ outcomes.