VV ECMO cannulation in infants and children under 10kg: Evolving strategies, outcomes, and innovations.

Currently, there is scarcity of data on whether differences exist in clinical characteristics and outcomes of bloodstream infection (BSI) between venoarterial (VA) and venovenous (VV) extracorporeal membrane oxygenation (ECMO) and whether they differ between Candida BSI and bacteremia in adult ECMO patients. We retrospectively reviewed data of patients who required ECMO for > 48 h and had BSIs while receiving ECMO between January 2015 and June 2020. Cases with a positive blood culture result within 24 h of ECMO implantation were excluded. We identified 94 (from 64 of 194 patients) and 38 (from 17 of 56 patients) BSI episodes under VA and VV ECMO, respectively. Fifty nine BSIs of VA ECMO (59/94, 62.8%) occurred in the first 2 weeks after ECMO implantation, whereas 24 BSIs of VV ECMO (24/38, 63.2%) occurred after 3 weeks of ECMO implantation. Gram-negative bacteremia (39/59, 66.1%) and gram-positive bacteremia (10/24, 41.7%) were the most commonly identified BSI types in the first 2 weeks after VA ECMO implantation and after 3 weeks of VV implantation, respectively. Timing of Candida BSI was early (6/11, 54.5% during the first 2 weeks) in VA ECMO and late (6/9, 66.7% after 3 weeks of initiation) in VV ECMO. Compared with bacteremia, Candida BSI showed no differences in clinical characteristics and outcomes during VA and VV ECMO, except the significant association with prior exposure to carbapenem in VA ECMO (vs. gram-negative bacteremia [P = 0.006], vs. gram-positive bacteremia [P = 0.03]). Our results suggest that ECMO modes may affect BSI clinical features and timing. In particular, Candida BSI occurrence during the early course of VA ECMO is not uncommon, especially in patients with prior carbapenem exposure; however, it usually occurs during the prolonged course of VV ECMO. Consequently, routine blood culture surveillance and empiric antifungal therapy might be warranted in targeted populations of adult ECMO patients, regardless of levels of inflammatory markers and severity scores.

Parallel Venovenous Extracorporeal Membrane Oxygenation Circuits for Refractory Hypoxemia in a Super-Super-Obese Patient

Background/Aim: The use of extracorporeal life support (ECLS) in children has notably increased over the last two decades, the indications for its use are expanding. According to the Extracorporeal Life Support Organization (ELSO) 2016 report, the rate of pediatric extracorporeal membrane oxygenation (ECMO) runs was 24% among all ECMO patients. A relationship between higher ECMO volume and mortality for neonates and adult patients supported with ECLS was reported. Different mortality rates were reported for different diagnostic and age groups for ECMO patients. The objective of this study was to describe our experience with pediatric ECMO. Methods: A retrospective cohort study was conducted on patients between 1 month and 18 years who underwent ECMO treatment in a pediatric intensive care unit from January 2015 to June 2022. Patients’ characteristics, outcomes, and complications were recorded. Results: A total of 22 children underwent ECMO during the study period. The median age of the patients was 4.5 years (ranging from 2 months to 18 years). Eight (36.4%) patients required venoarterial (VA) ECMO, and 14 patients (63.6%) required venovenous (VV) ECMO. Among the eight children who underwent VA ECMO, central cannulation was performed in 62.5% of cases. Seven children who required VV ECMO were cannulated with a double lumen catheter (42.8%). Thirteen (59.1%) patients were successfully weaned from ECMO. Weaning rates were 25% and 78.5% for VA and VV ECMO, respectively. Among 22 patients, overall hospital mortality was 72.7%. Mortality rates were 87.5% and 64.2% for VA and VV ECMO. Five patients (22.7%) survived to hospital discharge. Conclusion: Extracorporeal life support is one of the life-saving treatment modalities. This study found that the children requiring VA ECMO had a higher mortality rate than children requiring VV ECMO, a result that is consistent with the ELSO registry report. In our study, children requiring VV ECMO had a higher weaning rate than the ELSO registry data. However, they had a lower survival to discharge rate than the ELSO registry data. We feel that by describing this case series, the spread of ECMO practice may be supported in Turkey.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) has become an important support modality for patients with acute respiratory failure refractory to optimal medical therapy, such as low tidal volume mechanical ventilator support, early paralytic infusion, and early prone positioning. The objective of this cohort study was to investigate the causes and timing of in-hospital mortality in patients on VV ECMO. All patients, excluding trauma and bridge to lung transplant, admitted 8/2014-6/2019 to a specialty ICU for VV ECMO were reviewed. Two hundred twenty-five patients were included. In-hospital mortality was 24.4% (n = 55). Most non-survivors (46/55, 84%) died prior to lung recovery and decannulation from VV ECMO. Most common cause of death (COD) for patients who died on VV ECMO was removal of life sustaining therapy (LST) in setting of multisystem organ failure (MSOF) (n = 24). Nine patients died a median of 9 days [6, 11] after decannulation. Most common COD in these patients was palliative withdrawal of LST due to poor prognosis (n = 3). Non-survivors were older and had worse predictive mortality scores than survivors. We found that death in patients supported with VV ECMO in our study most often occurs prior to decannulation and lung recovery. This study demonstrated that the most common cause of death in patients supported with VV ECMO was removal of LST due MSOF. Acute hemorrhage (systemic or intracranial) was not found to be a common cause of death in our patient population.

Background: Adjusting drug therapy under veno-venous extracorporeal membrane oxygenation (VV ECMO) is challenging. Although impaired pharmacokinetics (PK) under VV ECMO have been reported for sedative drugs and antibiotics, data about amiodarone are lacking. We evaluated the pharmacokinetics of amiodarone under VV ECMO both in vitro and in vivo. Methods: In vitro: Amiodarone concentration decays were compared between closed-loop ECMO and control stirring containers over a 24 h period. In vivo: Potassium-induced cardiac arrest in 10 pigs with ARDS, assigned to either control or VV ECMO groups, was treated with 300 mg amiodarone injection under continuous cardiopulmonary resuscitation. Pharmacokinetic parameters Cmax, Tmax AUC and F were determined from both direct amiodarone plasma concentrations observation and non-linear mixed effects modeling estimation. Results: An in vitro study revealed a rapid and significant decrease in amiodarone concentrations in the closed-loop ECMO circuitry whereas it remained stable in control experiment. In vivo study revealed a 32% decrease in the AUC and a significant 42% drop of Cmax in the VV ECMO group as compared to controls. No difference in Tmax was observed. VV ECMO significantly modified both central distribution volume and amiodarone clearance. Monte Carlo simulations predicted that a 600 mg bolus of amiodarone under VV ECMO would achieve the amiodarone bioavailability observed in the control group. Conclusions: This is the first study to report decreased amiodarone bioavailability under VV ECMO. Higher doses of amiodarone should be considered for effective amiodarone exposure under VV ECMO.

BackgroundExtracorporeal membrane oxygenation (ECMO) has been increasingly used as rescue therapy for severe pediatric acute respiratory distress syndrome (PARDS) over the past decade. However, a contemporary comparison of venovenous (VV) and venoarterial (VA) ECMO in PARDS has yet to be well described. Therefore, the objective of our study was to assess the difference between VV and VA ECMO in efficacy and safety for infection-associated severe PARDS patients.MethodsThis prospective multicenter cohort study included patients with infection-associated severe PARDS who received VV or VA ECMO in pediatric intensive care units (PICUs) of eight university hospitals in China between December 2018 to June 2021. The primary outcome was in-hospital mortality. Secondary outcomes included ECMO weaning rate, duration of ECMO and mechanical ventilation (MV), ECMO-related complications, and hospitalization costs.ResultsA total of 94 patients with 26 (27.66%) VV ECMO and 68 (72.34%) VA ECMO were enrolled. Compared to the VA ECMO patients, VV ECMO patients displayed a significantly lower in-hospital mortality (50 vs. 26.92%, p = 0.044) and proportion of neurologic complications, shorter duration of ECMO and MV, but the rate of successfully weaned from ECMO, bleeding, bloodstream infection complications and pump failure were similar. By contrast, oxygenator failure was more frequent in patients receiving VV ECMO. No significant intergroup difference was observed for the hospitalization costs.ConclusionThese positive findings showed the conferred survival advantage and safety of VV ECMO compared with VA ECMO, suggesting that VV ECMO may be an effective initial treatment for patients with infection-associated severe PARDS.

Most patients on extracorporeal membrane oxygenation (ECMO) decease during therapy on the system. However, the actual causes of death have not been studied sufficiently. This study analyses the etiology, prevalence, and risk factors for the outcome variable death during ongoing ECMO for all patients and divided according to venoarterial (VA) or venovenous (VV) support. We retrospectively analysed all patients receiving ECMO support at our institution between March 2006 to January 2021. Only the patients deceased during ongoing support were included. 2016 patients were placed on VA (n = 1168; 58%) or VV (n = 848; 42%) ECMO; 759 patients (37.7%) deceased on support. The causes of death differed between the support types: VA ECMO patients mostly died from cerebral ischemia (34%), low-cardiac output (LCO; 24.1%) and multi-organ failure (MOF; 21.6%), whereas in VV ECMO cases, refractory respiratory failure (28.2%), and sepsis (20.4%) dominated. Multivariate regression analysis revealed cardiopulmonary resuscitation (CPR) and acidosis prior to ECMO as risk factors for dying on VA ECMO, while high inotropic doses pre-ECMO, a high fraction of inspired oxygen on day 1, elevated lactate dehydrogenase, and international normalized ratio levels lead to an unfavourable outcome in VV ECMO patients. Even in highly experienced centers, ECMO mortality remains high and occurs mainly on support or 24h after its termination. The causes of death differ between VV and VA ECMO, depending on the underlying diseases responsible for the need of extracorporeal support.

Lung Transplant for Patients with COVID-19 Bridged with VV ECMO: Initial Experience

Multiple prognostic scores have been developed for both veno-arterial (VA) and veno-venous (VV) extracorporeal membrane oxygenation (ECMO), mostly in single-center cohorts. The aim of this study was to compare and validate different prediction scores in a large multicenter ECMO-population. Methods: Data from five ECMO centers included 300 patients on VA and 329 on VV ECMO support (March 2008 to November 2016). Different prognostic scores were compared between survivors and non-survivors: APACHE II, SOFA, SAPS II in all patients; SAVE, modified SAVE and MELD-XI in VA ECMO; RESP, PRESET, ROCH and PRESERVE in VV ECMO. Model performance was compared using receiver-operating-curve analysis and assessment of model calibration. Survival was assessed at intensive care unit discharge. Results: The main indication for VA ECMO was cardiogenic shock; overall survival was 51%. ICU survivors had higher Glasgow Coma Scale scores and pH, required cardiopulmonary resuscitation (CPR) less frequently, had lower lactate levels and shorter ventilation time pre-ECMO at baseline. The best discrimination between survivors and non-survivors was observed with the SAPS II score (area under the curve [AUC] of 0.73 (95% CI 0.67–0.78)). The main indication for VV ECMO was pneumonia; overall survival was 60%. Lower PaCO2, higher pH, lower lactate and lesser need for CPR were observed among survivors. The best discrimination between survivors and non-survivors was observed with the PRESET score (AUC 0.66 (95% CI 0.60–0.72)). Conclusion: The prognostic performance of most scores was moderate in ECMO patients. The use of such scores to decide about ECMO implementation in potential candidates should be discouraged.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) offers the last resort in the treatment of acute respiratory distress syndrome (ARDS). Various scoring systems have been established, yet external validation of these scoring systems in the Asian population remains scarce. We aim to identify factors associated with hospital mortality and to validate various scoring systems in the prediction of hospital mortality. A retrospective analysis of adults admitted to Pamela Youde Nethersole Eastern Hospital intensive care unit who received VV ECMO from January 1, 2010 to June 30, 2019 was performed. Demographics, ventilation strategies, rescue therapies, and clinical outcomes were compared. The primary outcome was hospital mortality and secondary outcomes were intensive care unit (ICU) mortality, ICU, and hospital length of stay. There were 122 VV ECMO performed for ARDS, of which 78 survived and 44 died. VV ECMO performed for viral pneumonitis was significantly associated with better survival (55.1% vs. 25%, p = 0.001) compared with other causes. As for prediction scores, the PREdiction of Survival on ECMO Therapy-Score had the highest area under receiver operator curve of 0.733 (95% confidence interval [CI]: 0.643-0.823), whereas that of PRedicting dEath for SEvere ARDS on VV ECMO score was 0.662 (95% CI: 0.561-0.764), Respiratory Extracorporeal Membrane Oxygenation Survival Prediction score was 0.657 (95% CI: 0.553-0.761), Sequential Organ Failure Assessment score was 0.652 (95% CI: 0.547-0.757), and VV ECMO mortality score was 0.637 (95% CI: 0.532-0.742). In our cohort, VV ECMO performed for viral pneumonitis was associated with a higher hospital survival. Prediction scores are helpful in our population and provide a useful reference to hospital mortality.

High-frequency oscillatory ventilation (HFOV) may assist in the prevention of volutrauma for high-risk patients with acute respiratory distress syndrome (ARDS) during venovenous extracorporeal membrane oxygenation (VV ECMO). In combined VV ECMO and HFOV, we noted that increased intrathoracic pressure contributed to shunt formation in the dual-lumen Avalon® cannula (Maquet, Rastatt, Germany).A 51-year-old female with ARDS secondary to aspiration pneumonia was placed on VV ECMO using a single Avalon cannula. By ECMO Day 16, she became unable to ventilate due to elevated peak airway pressures, even with low tidal volume ventilation and an otherwise stable VV ECMO course. HFOV was introduced to minimize ventilator-induced lung injury. Shortly after HFOV started, the patient desaturated, and consequently, the fraction of inspired oxygen (FiO2) was increased to 100%. We noted that a flash of bright red, oxygenated blood was flowing retrograde in the Avalon cannula at the same rate as the beat of the oscillator, while the patient's ECMO flow rate, arterial blood gas, and blood pressure all remained stable. The ECMO flow was increased above 5.5 L/min and the resolution of the retrograde shunt through the Avalon cannula was immediately observed. Concurrent use of HFOV with VV ECMO using an Avalon cannula may result in a shunt that becomes visible with arterial O2 saturations nearing 100%. Due to pressure differences between the venous and arterial lumens of the Avalon cannula, increasing the ECMO flow rate appeared to decrease this shunting effect caused by elevated intrathoracic pressure.

During veno-venous extracorporeal membrane oxygenation (vv ECMO) therapy, antimicrobial drugs are frequently used, and appropriate dosing is challenging due to there being limited data to support the dosage. Linezolid is effective against multidrug-resistant Gram-positive pathogens frequently isolated in ECMO patients. In total, 53 steady-state linezolid levels were obtained following 600 mg intravenous (IV) injections every 8 h, and these were used to develop a population pharmacokinetic (PopPK) model in patients with COVID-19-associated acute respiratory distress syndrome (CARDS) on vv ECMO. The data were analyzed using a nonlinear mixed-effects modelling approach. Monte Carlo simulation generated 5000 patients' individual PK parameters and corresponding concentration-time profiles using the PopPK model, following the administration of 600 mg/8 h (a higher-than-standard dosing) and 600 mg/12 h (standard). The probabilities of pharmacokinetic/pharmacodynamic (PK/PD) target attainment (PTA) and the cumulative fraction of responses (CFR) for three pathogens were calculated and compared between the two dosing scenarios. Linezolid 600 mg/8 h was predicted to achieve greater than or equal to 85%Tf>MIC in at least 90% of the patients with CARDS on vv ECMO compared to only approximately two thirds of the patients after dosing every 12 h at a minimal inhibitory concentration (MIC) of 2 mg/L. In addition, for the same MIC, fAUC24/MIC ≥ 80 was achieved in almost three times the number of patients following an 8-h versus a 12-h interval. PopPK simulation predicted that a significantly higher proportion of the patients with CARDS on vv ECMO would achieve the PK/PD targets following the 8-h dosing interval compared to standard linezolid dosing. Nevertheless, the safety concern, in particular, for thrombocytopenia, with higher-than-standard linezolid dosage is reasonable, and consequently, monitoring is essential.

IntroductionPatients on extracorporeal membrane oxygenator (ECMO) therapy are critically ill and often develop acute kidney injury (AKI) during hospitalisation. Little is known about the association of exposure to and the effect of the type of ECMO and extent of renal recovery after AKI development.Aim of the study In patients who developed AKI, renal recovery was characterised as complete, partial or dialysis-dependent at the time of hospital discharge in both the Veno-Arterial (VA) and Veno-Venous (VV) ECMO treatment groups.Material and methods The study consisted of a single-centre retrospective cohort that includes all adult patients (n=125) who received ECMO treatment at a tertiary academic medical centre between 2015 to 2019. Data on demographics, type of ECMO circuit, comorbidities, exposure to nephrotoxic factors and receipt of renal replacement therapy (RRT) were collected as a part of the analysis. Acute Kidney Injury Network (AKIN) criteria were used for the diagnosis and classification of AKI. Group differences were assessed using Fisher’s exact tests for categorical data and independent t-tests for continuous outcomes.Results Sixty-four patients received VA ECMO, and 58 received VV ECMO. AKI developed in 58(91%) in the VA ECMO group and 51 (88%) in the VV ECMO group (p=0.77). RRT was prescribed in significantly higher numbers in the VV group 38 (75%) compared to the VA group 27 (47%) (p=0.0035). At the time of discharge, AKI recovery rate in the VA group consisted of 15 (26%) complete recovery and 5 (9%) partial recovery; 1 (2%) remained dialysis-dependent. In the VV group, 22 (43%) had complete recovery (p=0.07), 3(6%) had partial recovery (p=0.72), and 1 (2%) was dialysis-dependent (p>0.99). In-hospital mortality was 64% in the VA group and 49% in the VV group (p=0.13).Conclusions Renal outcomes in critically ill patients who develop AKI are not associated with the type of ECMO used. This serves as preliminary data for future studies in the area.

(907) - Safety of Trans Esophageal Echocardiogram Guided Percutaneous Insertion of Bi-Caval Dual Lumen Cannula (AVALON ELITE®) for Veno-Venous Extracorporeal Membrane Oxygenation

Venoarterial (VA) ECMO is a treatment modality for newborn cardiorespiratory failure refractory to conventional, intensive medical management. Because VA ECMO requires ligation of the right common carotid artery (RCCA), lately venovenous (VV) ECMO has been introduced (ASAIO Transactions 1989;35:650-53) and is being used with increased frequency because it does not require ligation of the RCCA. 153 neonates were treated with VV ECMO from October, 1990 to July, 1995; seven infants (4.6%) were converted to VA ECMO (86% survival). This report describes the mortality and morbidity of our first 146 infants (mean BW = 3400g; GA=40 weeks; oxygenation index (OI) prior to ECMO = 68; mean airway pressure (MAP) = 19.7 cmH20) who completed treatment with VV ECMO. 135/146 patients were outborn. All infants had a 14 Fr double lumen catheter placed for VV ECMO; 132/146 infants(90.4%) survived. The number of infants (% survival) by diagnosis is: meconium aspiration = 94 (94% survival), sepsis = 15 (87%), diaphragmatic hernia= 15(73%), PPHN = 13(92%), RDS = 4(100%), congenital heart disease = 3(100%), other = 2(50%). Deaths occurred from: respiratory failure = 4, brain death = 1, cardiac failure = 3, recurrent PPHN = 3, NEC = 1, after transfer back to referring hospital = 2. Prior to ECMO, survivors had a significantly higher PaO2 when compared to nonsurvivors (35 vs 25 torr, p<0.01). Mean OI was 63 in survivors vs 118 in non-survivors (p<0.01). Complications include: intracranial hemorrhage 11/146 (7.5%), seizures 7/146 (4.8%), hypertension 8/146 (5.5%), myocardial stun 1/146 (0.7%). 75 newborns were treated during the same period of time with VA ECMO (mean OI = 75, 83% survival). Our findings indicate: 1) VV ECMO provides adequate support for critically ill neonates with severe cardiorespiratory failure and preserves the RCCA, 2) the success rate of VV ECMO is high and the morbidity is low given the severity of illness of these infants. We speculate that VV ECMO by preserving the RCCA may minimize ECMO related morbidity in these infants.