Impact of preexisting organ dysfunction on extracorporeal life support for non-postcardiotomy cardiopulmonary failure

Outcomes of continuous renal replacement therapy versus peritoneal dialysis as a renal replacement therapy modality in patients undergoing Venoarterial extracorporeal membrane oxygenation

INTRODUCTION

The optimal modality for renal replacement therapy (RRT) in patients venoarterial extracorporeal membrane oxygenation (VA-ECMO) remains unclear. This study aimed to compare outcomes between continuous renal replacement therapy (CRRT) and peritoneal dialysis (PD) in VA-ECMO patients.

METHODS

This single-center retrospective study included VA-ECMO patients who developed AKI and subsequently required CRRT or PD. Data on patient demographics, comorbidities, clinical characteristics, RRT modality, and outcomes were collected. The primary outcome was in-hospital mortality, with secondary outcomes including length of stays, RRT durations, and complications associated with RRT.

RESULTS

A total of 43 patients were included (72.1% male, mean age 58.2 ± 15.7 years). Of these, 21 received CRRT and 22 received PD during ECMO therapy. In-hospital mortality rates did not significantly differ between CRRT and PD groups (80.9% vs 90.9%, p = 0.35). However, PD was associated with a higher incidence of catheter-related complications, including malposition (31.8% vs 4.7%, p = 0.046), infection (22.7% vs 4.7%, p = 0.19), and bleeding (18.2% vs 9.5%, p = 0.66), respectively.

CONCLUSION

Among patients receiving VA-ECMO-supported RRT, our study revealed comparable in-hospital mortality rates between CRRT and PD, although PD was associated with a higher incidence of catheter-related complications.

Acute Kidney Injury in Patients Undergoing Extracorporeal Membrane Oxygenation: A Retrospective Cohort Study

Aims and background

Extracorporeal membrane oxygenation (ECMO) is a mode of extracorporeal therapy to support oxygenation of patients with severe cardiac or respiratory failure. Studies have shown that acute kidney injury (AKI) can worsen the outcome in these patients. This study aims to assess the incidence and outcome of AKI in patients on ECMO support.

Materials and methods

This retrospective study included 64 patients who underwent ECMO for more than 24 hours. Patients who died within 48 hours of initiation of ECMO and patients with end-stage renal disease (ESRD) on maintenance hemodialysis were excluded. Acute kidney injury was diagnosed and categorized according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria.

Results

Of the 64 patients studied, 38 patients (59.38%) developed AKI and 17 patients (44.73%) among them developed AKI within 24 hours of initiation of ECMO. Age, Acute Physiology and Chronic Health Evaluation (APACHE-II) score, hypertension, use of nephrotoxic agents, inotropic support, and poor cardiac function were the risk factors associated with the development of AKI. Diabetes mellitus, type of ECMO used, and duration of ECMO were not found to be risk factors for AKI. Renal replacement therapy was initiated in 31 patients (81.58%). The overall mortality in the whole group was 67.19%, while it was 81.58% among the patients with AKI.

Conclusion

Acute kidney injury was found to be an independent risk factor for mortality in patients on ECMO. Early identification of the risk factors for AKI and management may help to improve the survival rate.

Clinical significance

The occurrence of AKI among patients on ECMO support increases the risk of mortality significantly. Hence, measures to prevent AKI, as well as early detection and appropriate management of AKI, would improve patient outcomes.

How to cite this article

Surjit A, Prasannan B, Abraham J, Balagopal A, Unni VA. Acute Kidney Injury in Patients Undergoing Extracorporeal Membrane Oxygenation: A Retrospective Cohort Study. Indian J Crit Care Med 2024;28(1):26-29.

Acute kidney injury during extracorporeal life support in cardiogenic shock: Does flow matter?

BACKGROUND

This study examines the role of extracorporeal life support flow in the development of acute kidney injury in cardiogenic shock.

METHODS

We performed a retrospective analysis of 465 patients placed on extracorporeal life support at our institution between January 2015 and December 2020 for cardiogenic shock. Flow index was calculated by dividing mean flow by body surface. Stages of acute kidney injury were determined according to Kidney Disease: Improving Global Outcomes (KDIGO) organization guidelines.

RESULTS

There were 179 (38.5%) patients who developed acute kidney injury, 63.1% of which were classified as Stage 3--the only subgroup associated with 1-year mortality (hazard ratio = 2.03, p < .001). Risk of kidney injury increased up to a flow index of 1.6 L/min/m2, and kidney injury was more common among patients with flow index greater than 1.6 L/min/m2 (p = .034). Those with kidney injury had higher baseline lactate levels (4.4 vs 3.1, p = .04), and Stage 3 was associated wit higher baseline creatinine (p < .001).

CONCLUSIONS

In our cohort, kidney injury was common and Stage 3 kidney injury was associated with worse outcomes compared to other stages. Low flow was not associated with increased risk of kidney injury. Elevated baseline lactate and creatinine among patients with acute kidney injury suggest underlying illness severity, rather than flow, may influence kidney injury risk.

Continuous renal replacement therapy and extracorporeal membrane oxygenation: implications in the COVID-19 era

The novel severe acute respiratory syndrome coronavirus 2, SARS-CoV-2 (coronavirus Disease 19 (COVID-19)) was identified as the causative agent of viral pneumonias in Wuhan, China in December 2019, and has emerged as a pandemic causing acute respiratory distress syndrome (ARDS) and multiple organ dysfunction. Interim guidance by the World Health Organization states that extracorporeal membrane oxygenation (ECMO) should be considered as a rescue therapy in COVID-19-related ARDS. International registries tracking ECMO in COVID-19 patients reveal a 21%-70% incidence of acute renal injury requiring renal replacement therapy (RRT) during ECMO support. The indications for initiating RRT in patients on ECMO are similar to those for patients not requiring ECMO. RRT can be administered during ECMO via a temporary dialysis catheter, placement of a circuit in-line hemofilter, or direct connection of continuous RRT in-line with the ECMO circuit. Here we review methods for RRT during ECMO, RRT initiation and timing during ECMO, anticoagulation strategies, and novel cytokine filtration approaches to minimize COVID-19's pathophysiological impact.

Outcomes of Transferred Adult Venovenous and Venoarterial Extracorporeal Membrane Oxygenation Patients: A Single Center Experience

Objectives

Extracorporeal membrane oxygenation (ECMO) patients with or without transport both have high hospital mortality rate and there are few data on adult VA-ECMO transport patients. Hence, this study was designed to analyze factors that affect the outcomes of patients with ECMO transport.

Methods

This study retrospectively enrolled 126 ECMO patients transferred from regional hospital to the First Affiliated Hospital of Zhengzhou University by our ECMO team during June 2012 to Sept 2020. Data were calculated and analyzed.

Results

The median distance of transportation was 141 (76–228) km, the median transport time consuming was 3 (1.3–4) h, the percentage of complications during transport was 40.5% (except for bleeding on cannula site, and no one death during transport), and the survival rate in hospital was 38.9%. Compared with survivors, the non-survivors were older and showed higher SOFA score, longer time with ECMO assisted, longer time in ICU and in hospital. However, after divided into VA-ECMO and VV-ECMO groups, the older age showed no significant difference between survivors and non-survivors groups of VA-ECMO patients. Moreover, the Cox regression survival analysis showed that higher SOFA score and lactate level indicated higher ICU mortality of VA-ECMO patients while higher SOFA score, higher lactate level, older age and lower MAP after transportation (<70mmHg) indicated higher ICU mortality of VV-ECMO patients. However, there was no significant difference of comorbidities and complications in survivors and non-survivors groups of ECMO patients.

Conclusions

The transportation for ECMO patients can be feasible performed although life-threatening complications might occur. The SOFA score and the lactate level could be used to evaluate the risk of ICU mortality of transportation ECMO patients. Besides, lower MAP after transportation (<70mmHg) had potential predictive value for short-term outcome of VV-ECMO patients.

Support with extracorporeal membrane oxygenation for over 1 year duration as a bridge to cardiac transplantation: a case report and review of the literature

We present the case of a 13-year-old male with a complex congenital cardiac history who was supported with extracorporeal membrane oxygenation for 394 days while awaiting cardiac transplantation. The patient underwent successful cardiac transplantation after 394 days of support with veno-arterial extracorporeal membrane oxygenation and is currently alive 2 years after cardiac transplantation. We believe that this case represents the longest period of time that a patient has been supported with extracorporeal membrane oxygenation as a bridge to cardiac transplantation.We also review the literature associated with prolonged support with extracorporeal membrane oxygenation. This case report documents many of the challenges associated with prolonged support with extracorporeal membrane oxygenation, including polymicrobial bacterial and fungal infections, as well as renal dysfunction. It is possible to successfully bridge a patient to cardiac transplantation with prolonged support with extracorporeal membrane oxygenation of over 1 year; however, multidisciplinary collaboration is critical.

Acute Kidney Injury and Extracorporeal Membrane Oxygenation: Review on Multiple Organ Support Options

Extracorporeal membrane oxygenation (ECMO) is a temporary life support system used to assist patients with life-threatening severe cardiac and/or respiratory insufficiency. Patients requiring ECMO can be considered the sickest patients admitted to the intensive care unit (ICU). Acute kidney injury (AKI) represents a frequent complication during ECMO, affecting up to 70% of patients, with multifactorial pathophysiology and an independent risk factor for mortality. Severe AKI requiring Continuous Renal Replacement Therapy (CRRT) occurs in 20% of ECMO patients, but multiple indications and different timing may imply a significantly higher application rate in different centers. CRRT can be run in parallel to ECMO through different vascular access, or it can be conducted in series by connecting the circuits. Anticoagulation of ECMO is typically managed with systemic heparin, but several approaches can be applied for the CRRT circuit, from no anticoagulation to the addition of intra-filter heparin or regional citrate anticoagulation. The combination of CRRT and ECMO can be considered a form of multiple organ support therapy, but this approach still requires optimization in timing, set-up, anticoagulation, prescription and delivery. The aim of this report is to review the pathophysiology of AKI, the CRRT delivery, anticoagulation strategies and outcomes of patients with AKI treated with ECMO.

Use of SOFA score in cardiac arrest research: A scoping review

Background

The Sequential Organ Failure Assessment (SOFA) score is a commonly used severity-of-illness score in cardiac arrest research. Due to its nature, the SOFA score often has missing data. How much data is missing and how that missing data is handled is unknown.

Objectives

We conducted a scoping review on cardiac arrest studies using SOFA, focusing on missing data.

Data sources

PubMed, Embase, and Web of Science.

Study selection

All English-language peer-reviewed studies of cardiac arrest with SOFA as an outcome or exposure were included.

Data extraction

For each study, quantity of missing SOFA data, analytic strategy to handle missing SOFA variables, whether/to what degree mortality influenced the amount of missing SOFA scores), SOFA score modifications, and number of SOFA measurements was extracted.

Data synthesis

We included 66 studies published between 2006–2019. Five studies were randomized controlled trials, 26 were prospective cohort studies, and 25 were retrospective cohort studies. SOFA was used as an outcome in 36 (55%) and a primary outcome in 10 (15%). Nine studies (14%) mentioned the quantity of missing SOFA data, which ranged from 0 to 76% (median: 10% [IQR: 6%, 42%]). Twenty-seven (41%) studies reported a method to handle missing SOFA. The most common method used excluded subjects with missing data (81%). In the 50 studies using serial SOFA scores, 11 (22%) documented mortality prior to SOFA measurement; which ranged from 3% to 76% (median: 12% [IQR: 6%–35%]).

Conclusions

Missing data is common in cardiac arrest research using SOFA scores. Variability exists in reporting and handling missing SOFA variables.

Renal replacement therapy during extracorporeal membrane oxygenation

The use of extracorporeal membrane oxygenator (ECMO) has significantly increased in the past 20 years. There is a high incidence of acute kidney injury (AKI) in the group of patients on ECMO, with need for continuous renal replacement therapy (CRRT) in most of them. This article will review the basics of CRRT, its indications, the technical aspects of incorporating CRRT with ECMO circuit, data on clinical aspects, and outcomes.

Predictors for acute and chronic renal failure and survival in patients supported with veno-arterial extracorporeal membrane oxygenation

BACKGROUND

Renal failure is a common occurrence in patients with refractory cardiogenic shock including those supported with veno-arterial extracorporeal membrane oxygenation. Prevalence and outcome of acute and chronic kidney failure in extracorporeal membrane oxygenation patients have not been well documented. In this study, we investigated the occurrence of acute and chronic kidney failure in veno-arterial extracorporeal membrane oxygenation patients as well as predictors for survival.

METHODS

This is a single center retrospective clinical study. We included adult patients with refractory cardiogenic shock who were supported by veno-arterial extracorporeal membrane oxygenation between 2008 and 2015. The primary endpoint of the study was acute kidney injury (KDIGO Stage 3) during extracorporeal membrane oxygenation and chronic kidney failure requiring renal replacement therapy, 30 and 90 days after extracorporeal membrane oxygenation. The secondary endpoint was in-hospital survival and 90-day survival.

RESULTS

A total of 196 veno-arterial extracorporeal membrane oxygenation patients were investigated. In total, 41.8% (82/196) patients had acute renal failure requiring continuous renal replacement therapy during extracorporeal membrane oxygenation. The 30- and 90-day survival was 55.1% (108/196) and 48.5% (95/196), respectively; 21.3% (23/108) and 11.6% (11/95) patients needed renal replacement therapy after 30 and 90 days, respectively. Predictors for KDIGO Stage 3 renal failure during extracorporeal membrane oxygenation were lactate (p = 0.026) and the number of blood units transfused during extracorporeal membrane oxygenation support (p = 0.000). A predictor for renal replacement therapy after 30 and 90 days was an elevated plasma-free hemoglobin level. The in-hospital survival was 54.6% (107/196). Serum lactate of less than 4.3 mmol/L, lower age, plasma-free hemoglobin of ⩽62 mg/dL, low number of blood units transfused during extracorporeal membrane oxygenation, and the use of an intra-aortic balloon pump were predictors for in-hospital and 90-day survival.

Acute Kidney Injury in Pediatric Patients on Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-analysis

Background: Acute kidney injury (AKI) is a well-established complication of extra-corporal membrane oxygenation (ECMO) in the adult population. The data in the pediatric and neonatal population is still limited. Moreover, the mortality risk of AKI among pediatric patients requiring ECMO remains unclear. Thus, this meta-analysis aims to assess the incidence of AKI, AKI requiring renal replacement therapy and AKI associated mortality in pediatric/neonatal patients requiring ECMO. Methods: A literature search was performed utilizing MEDLINE, EMBASE, and the Cochrane Database from inception through June 2019. We included studies that evaluated the incidence of AKI, severe AKI requiring renal replacement therapy (RRT) and the risk of mortality among pediatric patients on ECMO with AKI. Random-effects meta-analysis was used to calculate the pooled incidence of AKI and the odds ratios (OR) for mortality. Results: 13 studies with 3523 pediatric patients on ECMO were identified. Pooled incidence of AKI and AKI requiring RRT were 61.9% (95% confidence interval (CI): 39.0-80.4%) and 40.9% (95%CI: 31.2-51.4%), respectively. A meta-analysis limited to studies with standard AKI definitions showed a pooled estimated AKI incidence of 69.2% (95%CI: 59.7-77.3%). Compared with patients without AKI, those with AKI and AKI requiring RRT while on ECMO were associated with increased hospital mortality ORs of 1.70 (95% CI, 1.38-2.10) and 3.64 (95% CI: 2.02-6.55), respectively. Conclusions: The estimated incidence of AKI and severe AKI requiring RRT in pediatric patients receiving ECMO are high at 61.9% and 40.9%, respectively. AKI among pediatric patients on ECMO is significantly associated with reduced patient survival.

Clinical implications of the initial SAPS II in veno-arterial extracorporeal oxygenation

Background

Prediction of survival and weaning probability in VA ECMO (veno-arterial extracorporeal membrane oxygenation) patients could be of great benefit for real-time decision making on VA ECMO initiation in critical ill patients. We investigated whether the SAPS II score would be a real-time determinant for VA ECMO initiation and could be a predictor of survival and weaning probability in patients on VA ECMO.

Methods

Between January 1, 2010 and December 31, 2014, VA ECMO was carried out on 135 adult patients suffering from primary cardiogenic shock. To avoid selection bias, we excluded respiratory failure patients treated with VV or other types of ECMO. Successful VA ECMO weaning was defined as weaning, followed by stable survival for more than 48 hours. Survival after VA ECMO was defined as successful weaning and treatment of the underlying medical condition, followed by discharge without any further events.

Results

A total of 135 patients consisted of 41 women and 94 men, with a mean age of 59.4±16.5 years. Fifty-three patients had successful weaning, and 35 survived and were discharged uneventfully. Compared to the non-survivors, the survivors showed a lower SAPS II (67.77±20.79 vs. 90.29±13.31, P<0.001), a lower SOFA score (12.63±3.49 vs. 15.33±2.28, P<0.001), a lower predicted death rate (71.12±30.51 vs. 94.00±9.36, P<0.001), a higher initial ipH (7.14±0.22 vs. 6.98±0.15, P<0.001), and a lower initial lactate level (7.09±4.93 vs. 12.11±4.84, P<0.001). The average duration of hospital stay in the successful vs. failed weaning groups was 33.43±27.41 vs. 6.35±8.71 days, and the average duration of ICU stay in the successful vs. failed weaning groups was 20.60±16.88 vs. 5.39±5.95 days. By multivariate logistic regression analysis of initial parameters for VA ECMO assistance, the simplified acute physiology score II (SAPS II) (OR =1.1019, P=0.0389), ipH (OR =0.0010, P=0.0452), and hospital stay (OR =0.8140, P=0.001) had an association with in-hospital mortality on VA ECMO. The initial SAPS II score [area under the curve (AUC) =0.821] demonstrated significantly superior prediction of VA ECMO mortality than age (AUC =0.697), SOFA score (AUC =0.701), ipH (AUC =0.551), and the other parameters. By multivariable CoX regression analysis of survival, only the SAPS II score proved to have statistical significance (hazard ratio, 1.0423; 95% CI, 1.0083-1.0775; P=0.01).

Conclusions

Although the precise predictive scoring systems for VA ECMO still remains one of the most difficult challenges to ECMO physicians, the SAPS II score could provide valuable information on prognosis to patient himself, family members and caretakers, and might help physicians increase the survival rate and might avoid a waste of healthcare resources.

Retrospective study on the effects of the prognosis of patients treated with extracorporeal membrane oxygenation combined with continuous renal replacement therapy

Background

Patients undergoing extracorporeal membrane oxygenation (ECMO) treatment often have severe fluid overload and electrolyte imbalances and may even suffer acute kidney injury (AKI). It is often necessary to use continuous renal replacement therapy (CRRT). In this study, we aimed to retrospectively analyze the prognosis of patients treated with ECMO combined with CRRT and to find the independent factors that affect the survival rate.

Methods

There were 32 patients who were treated with ECMO combined with CRRT in our hospital from January 2007 to December 2017 who were analyzed. All of the patients were divided into a survival group and death group. The clinical indicators and biochemical indexes of the two groups were observed, and their differences were compared. Multivariate logistic regression analysis was carried out to determine the independent risk factors.

Results

The fluid balance at ECMO day 3, SOFA score and lactate at CRRT initiation, sequential organ failure assessment (SOFA) score at ECMO weaning, CRRT duration, ECMO to CRRT interval, mechanical ventilation (MV) duration, length of ICU, and overall hospital length of stay were statistically significant (P<0.05). The clinical biochemical indexes at CRRT initiation and ECMO weaning [serum creatinine, pH, white blood cell (WBC), hemoglobin (Hb), bilirubin]; patient's age, gender and BMI; and the fluid balance at ECMO days 1 and 7 were not statistically significance (P>0.05). The fluid balance at ECMO day 3 and lactate at CRRT initiation by multivariable logistic regression analysis were independent risk factors affecting patient prognosis.

Conclusions

The fluid balance at ECMO day 3 and lactate at CRRT initiation are the prognosis independent risk factors for ECMO + CRRT patients.

Impact of dynamic changes of elevated bilirubin on survival in patients on veno-arterial extracorporeal life support for acute circulatory failure

Aims

Veno-arterial extracorporeal life support (ECLS) is an established method to stabilize acute circulatory failure. Parameters and data on when to ideally wean circulatory support are limited. Bilirubin is a marker of end-organ damage. Therefore, the purpose of this large study was to evaluate the impact of dynamic changes of elevated bilirubin levels on survival in patients on ECLS.

Methods and results

We reviewed 502 consecutive cases of ECLS from 2007 to 2015. Bilirubin levels were recorded before implantation and until six days after explantation. Dynamic bilirubin changes, and hemodynamic and laboratory outcome parameters were compared in survivors and nonsurvivors. Reason for ECLS implantation was cardiac arrest with ongoing resuscitation in 230 (45.8%), low cardiac output in 174 (34.7%) and inability to wean off cardiopulmonary bypass in 98 (19.5%) patients. 307 (61.2%) patients were weaned off ECLS, however, 206 (41.0%) survived. Mean duration of ECLS was 3 (2–6) days, and survivors received significantly longer ECLS (5 vs 3 days, p < 0.001). Survivors had significantly lower baseline bilirubin levels (p = 0.003). Bilirubin started to rise from day 2 in all patients. In survivors, bilirubin levels had trended down on the day of ECLS explantation and stayed at an acceptable level. However, in weaned patients who did not survive and patients who died on ECLS bilirubin levels continued to rise during the recorded period.

Conclusion

ECLS support improves survival in patients with acute circulatory failure. Down trending bilirubin levels on veno-arterial ECLS indicate improved chances of successful weaning and survival in hemodynamically stable patients.

Advanced Age as a Predictor of Survival and Weaning in Venoarterial Extracorporeal Oxygenation: A Retrospective Observational Study

Background. In most reports on ECMO treatment, advanced age is classified as a contraindication to VA ECMO. We attempted to investigate whether advanced age would be a main risk factor deciding VA ECMO application and performing VA ECMO support. We determined whether advanced age should be regarded as an absolute or relative contraindication to VA ECMO and could affect weaning and survival rates of VA ECMO patients. Methods. VA ECMO was performed on 135 adult patients with primary cardiogenic shock between January 2010 and December 2014. Successful weaning was defined as weaning from ECMO followed by survival for more than 48 hours. Results. Among the 135 patients, 35 survived and were discharged uneventfully, and the remaining 100 did not survive. There were significant differences in survival between age groups, and older age showed a lower survival rate with statistical significance (P = .01). By multivariate logistic regression analysis, age was not significantly associated with in-hospital mortality (P = .83) and was not significantly associated with VA ECMO weaning (P = .11). Conclusions. Advanced age is an undeniable risk factor for VA ECMO; however, patients of advanced age should not be excluded from the chance of recovery after VA ECMO treatment.

Extracorporeal Membrane Oxygenation Outcomes in Acute Respiratory Distress Treatment: Case Study in a Chinese Referral Center

Background

No definitive conclusions have been drawn from the available data about the utilization of extracorporeal membrane oxygenation (ECMO) to treat severe acute respiratory distress syndrome (ARDS). The aim of this study was to review our center’s experience with ECMO and determine predictors of outcome from our Chinese center.

Material/Methods

We retrospectively analyzed a total of 23 consecutive candidates who fulfilled the study entry criteria between January 2009 and December 2015. Detailed clinical data, ECMO flow, and respiratory parameters before and after the introduction of ECMO were compared among in-hospital survivors and nonsurvivors; factors associated with mortality were investigated.

Results

Hemodynamics and oxygenation parameters were significantly improved after ECMO initiation. Thirteen patients survived to hospital discharge. Univariate correlation analysis demonstrated that APACHE II score (r=−0.463, p=0.03), acute kidney injury (r=−0.574, p=0.005), membrane oxygenator replacement (r=−0.516, p=0.014) and total length of hospital stay (r=0.526, p=0.012) were significantly correlated with survival to hospital discharge, and that the evolution of the levels of urea nitrogen, platelet, and fibrinogen may help to determine patient prognosis. Sixteen patients referred for ECMO from an outside hospital were successfully transported to our institution by ambulance, including seven transported under ECMO support. The survival rate of the ECMO-transport group was comparable to the conventional transport or the non-transport group (both p=1.000).

Conclusions

ECMO is an effective alternative option for severe ARDS. APACHE II score on admission, onset of acute kidney injury, and membrane oxygenator replacement, and the evolution of levels of urea nitrogen, platelet, and fibrinogen during hospitalization may help to determine the in-hospital patient prognosis. By establishing a well-trained mobile ECMO team, a long-distance, inter-hospital transport can be administered safely.

Outcomes and survival prediction models for severe adult acute respiratory distress syndrome treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) for severe acute respiratory distress syndrome (ARDS) has known a growing interest over the last decades with promising results during the 2009 A(H1N1) influenza epidemic. Targeting populations that can most benefit from this therapy is now of major importance.

Survival has steadily improved for a decade, reaching up to 65% at hospital discharge in the most recent cohorts. However, ECMO is still marred by frequent and significant complications such as bleeding and nosocomial infections. In addition, physiological and psychological symptoms are commonly described in long-term follow-up of ECMO-treated ARDS survivors. Because this therapy is costly and exposes patients to significant complications, seven prediction models have been developed recently to help clinicians identify patients most likely to survive once ECMO has been initiated and to facilitate appropriate comparison of risk-adjusted outcomes between centres and over time. Higher age, immunocompromised status, associated extra-pulmonary organ dysfunction, low respiratory compliance and non-influenzae diagnosis seem to be the main determinants of poorer outcome.

Developing a simple preinterventional score to predict hospital mortality in adult venovenous extracorporeal membrane oxygenation: A pilot study

Despite gaining popularity, venovenous extracorporeal membrane oxygenation (VV-ECMO) remains a controversial therapy for acute respiratory failure (ARF) in adult patients due to its equivocal survival benefits. The study was aimed at identifying the preinterventional prognostic predictors of hospital mortality in adult VV-ECMO patients and developing a practical mortality prediction score to facilitate clinical decision-making.This retrospective study included 116 adult patients who received VV-ECMO for severe ARF in a tertiary referral center, from 2007 to 2015. The definition of severe ARF was PaO2/ FiO2 ratio < 70 mm Hg under advanced mechanical ventilation (MV). Preinterventional variables including demographic characteristics, ventilatory parameters, and severity of organ dysfunction were collected for analysis. The prognostic predictors of hospital mortality were generated with multivariate logistic regression and transformed into a scoring system. The discriminative power on hospital mortality of the scoring system was presented as the area under receiver operating characteristic curve (AUROC).The overall hospital mortality rate was 47% (n = 54). Pre-ECMO MV day > 4 (OR: 4.71; 95% CI: 1.98-11.23; P < 0.001), pre-ECMO sequential organ failure assessment (SOFA) score >9 (OR: 3.16; 95% CI: 1.36-7.36; P = 0.01), and immunocompromised status (OR: 2.91; 95% CI: 1.07-7.89; P = 0.04) were independent predictors of hospital mortality of adult VV-ECMO. A mortality prediction score comprising of the 3 binary predictors was developed and named VV-ECMO mortality score. The total score was estimated as follows: VV-ECMO mortality score = 2 × (Pre-ECMO MV day > 4) + 1 × (Pre-ECMO SOFA score >9) + 1 × (immunocompromised status). The AUROC of VV-ECMO mortality score was 0.76 (95% CI: 0.67-0.85; P < 0.001). The corresponding hospital mortality rates to VV-ECMO mortality scores were 18% (Score 0), 35% (Score 1), 56% (Score 2), 75% (Score 3), and 88% (Score 4), respectively.Duration of MV, severity of organ dysfunction, and immunocompromised status were important preinterventional prognostic predictors for adult VV-ECMO. The 3 prognostic predictors could also constitute a practical prognosticating tool in patients requiring this advanced respiratory support. Physicians in ECMO institutions are encouraged to perform external validations of this prognosticating tool and make contributions to score optimization.

Venovenous extracorporeal membrane oxygenation in adult respiratory failure: Scores for mortality prediction

Despite a potentially effective therapy for adult respiratory failure, a general agreement on venovenous extracorporeal membrane oxygenation (VV-ECMO) has not been reached among institutions due to its invasiveness and high resource usage. To establish consensus on the timing of intervention, large ECMO organizations have published the respiratory extracorporeal membrane oxygenation survival prediction (RESP) score and the ECMOnet score, which allow users to predict hospital mortality for candidates with their pre-ECMO presentations. This study was aimed to test the predictive powers of these published scores in a medium-sized cohort enrolling adults treated with VV-ECMO for acute respiratory failure, and develop an institutional prediction model under the framework of the 3 scores if a superior predictive power could be achieved. This retrospective study included 107 adults who received VV-ECMO for severe acute respiratory failure (a PaO2/FiO2 ratio <70 mm Hg) in a tertiary referral center from 2007 to 2015. Essential demographic and clinical data were collected to calculate the RESP score, the ECMOnet score, and the sequential organ failure assessment (SOFA) score before VV-ECMO. The predictive power of hospital mortality of each score was presented as the area under receiver-operating characteristic curve (AUROC). The multivariate logistic regression was used to develop an institutional prediction model. The surviving to discharge rate was 55% (n = 59). All of the 3 published scores had a real but poor predictive power of hospital mortality in this study. The AUROCs of RESP score, ECMOnet score, and SOFA score were 0.662 (P = 0.004), 0.616 (P = 0.04), and 0.667 (P = 0.003), respectively. An institutional prediction model was established from these score parameters and presented as follows: hospital mortality (Y) = -3.173 + 0.208 × (pre-ECMO SOFA score) + 0.148 × (pre-ECMO mechanical ventilation day) + 1.021 × (immunocompromised status). Compared with the 3 scores, the institutional model had a significantly higher AUROC (0.779; P < 0.001). The 3 published scores provide valuable information about the poor prognostic factors for adult respiratory ECMO. Among the score parameters, duration of mechanical ventilation, immunocompromised status, and severity of organ dysfunction may be the most important prognostic factors of VV-ECMO used for adult respiratory failure.

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.

Extracorporeal Membrane Oxygenation and the Kidney

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is an effective therapy for patients with reversible cardiac and/or respiratory failure. Acute kidney injury (AKI) often occurs in patients supported with ECMO; it frequently evolves into chronic kidney damage or end-stage renal disease and is associated with a reported 4-fold increase in mortality rate. Although AKI is generally due to the hemodynamic alterations associated with the baseline disease, ECMO itself may contribute to maintaining kidney dysfunction through several mechanisms.

SUMMARY

AKI may be related to conditions derived from or associated with extracorporeal therapy, leading to a reduction in renal oxygen delivery and/or to inflammatory damage. In particular, during pathological conditions requiring ECMO, the biological defense mechanisms maintaining central perfusion by a reduction of perfusion to peripheral organs (such as the kidney) have been identified as pretreatment and patient-related risk factors for AKI. Hormonal pathways are also impaired in patients supported with ECMO, leading to failures in mechanisms of renal homeostasis and worsening fluid overload. Finally, inflammatory damage, due to the primary disease, heart and lung crosstalk with the kidney or associated with extracorporeal therapy itself, may further increase the susceptibility to AKI. Renal replacement therapy can be integrated into the main extracorporeal circuit during ECMO to provide for optimal fluid management and removal of inflammatory mediators.

KEY MESSAGES

AKI is frequently observed in patients supported with ECMO. The pathophysiology of the associated AKI is chiefly related to a reduction in renal oxygen delivery and/or to inflammatory damage. Risk factors for AKI are associated with a patient's underlying disease and ECMO-related conditions.

Effects of Renal Replacement Therapy in Patients Receiving Extracorporeal Membrane Oxygenation: A Meta-Analysis

The use of renal replacement therapy (RRT) in patients receiving extracorporeal membrane oxygenation (ECMO) is increasing, but the effect of RRT on ECMO is controversial. We performed a meta-analysis to determine whether RRT is related to higher mortality in patients receiving ECMO. We searched MEDLINE, EMBASE, the Cochrane Library, and KoreaMed and found 43 observational studies with 21,624 patients receiving ECMO and then compared inpatient mortality rates of patients receiving ECMO both with and without RRT. The risk ratio (RR) of mortality between patients receiving RRT and those not receiving RRT tended to decrease as the mortality of the group not receiving RRT increased. Among patients with RRT use rates of 30% and higher, the overall mortality rates for all patients receiving ECMO tended to decrease. We found that the increase in the RR for RRT tended to be greater the longer the initiation of RRT was delayed. We suggest that in patients receiving ECMO who have high RRT use rates, RRT may decrease mortality rates.

The feasibility of venovenous extracorporeal life support to treat acute respiratory failure in adult cancer patients

Venovenous extracorporeal life support (VV-ECLS) is a lifesaving but invasive treatment for acute respiratory failure (ARF) that is not improved with conventional therapy. However, using VV-ECLS to treat ARF in adult cancer patients is controversial. This retrospective study included 14 cancer patients (median age: 58 years [interquartile range: 51-66]; solid malignancies in 13 patients and hematological malignancy in 1 patient) who received VV-ECLS for ARF that developed within 3 months after anticancer therapies. VV-ECLS would be considered in selected patients with a P(a)O2/F(i)O2 ratio ≤70 mmHg under advanced mechanical ventilation. Before ECLS, the medians of intubation day, P(a)O2/F(i)O2 ratio, and Sequential Organ Failure Assessment (SOFA) score were 8 (2-12), 62 mmHg (53-76), and 10 (9-14), respectively. The case numbers of bacteremia, thrombocytopenia (platelet count <50000 cells/μL), and neutropenia (actual neutrophil count <1000 cells/μL) detected before ECLS were 3 (21%), 2 (14%), and 1 (7%), respectively. After 24 hours of ECLS, a significant improvement was seen in P(a)O2/F(i)O2 ratio but not in SOFA score. Six patients experienced major hemorrhages during ECLS. The median ECLS day, ECLS weaning rate, and hospital survival were 11 (7-16), 50% (n = 7), and 29% (n = 4). The development of dialysis-dependent nephropathy predicted death on ECLS (odds ratio: 36; 95% confidence interval: 1.8-718.7; P = 0.01). With a median follow-up of 11 (6-43) months, half of the survivors died of cancer recurrence and the others were in partial remission. The most prominent benefit of VV-ECLS is to improve the arterial oxygenation and rest the lungs. This may increase the chance of recovery from ARF in selected cancer patients.

Plasma Free Hemoglobin Is an Independent Predictor of Mortality among Patients on Extracorporeal Membrane Oxygenation Support

Background

Hemolysis is common in all extracorporeal circuits as evident by the elevated plasma free hemoglobin (PFHb) level. We investigated whether increased hemolysis during extracorporeal membrane oxygenation (ECMO) is an independent mortality predictor.

Methods

We performed a retrospective observational study of consecutive subjects who received ECMO at a tertiary care facility from 2007-2013 to investigate independent predictors of in-hospital mortality. We examined variables related to patient demographics, comorbidities, markers of hemolysis, ECMO characteristics, transfusion requirements, and complications. 24-hour PFHb> 50 mg/dL was used as a marker of severe hemolysis.

Results

154 patients received ECMO for cardiac (n= 115) or pulmonary (n=39) indications. Patients’ mean age was 51 years and 75.3% were males. Compared to nonsurvivors, survivors had lower pre-ECMO lactic acid (p=0.026), lower 24-hour lactic acid (p=0.023), shorter ECMO duration (P=0.01), fewer RBC transfusions on ECMO (p=0.008) and lower level of PFHb 24-hours post ECMO implantation (p=0.029). 24-hour PFHb> 50 mg/dL occurred in 3.9 % versus 15.5% of survivors and nonsurvivors, respectively, p=0.002. A Cox proportional hazard analysis identified PFHb> 50 mg/dL 24-hours post ECMO as an independent predictor of mortality (OR= 3.4, 95% confidence interval: 1.3 – 8.8, p= 0.011).

Conclusion

PFHb> 50 mg/dL checked 24-hour post ECMO implantation is a useful tool to predict mortality. We propose the routine checking of PFHb 24-hours after ECMO initiation for early identification and treatment of the cause of hemolysis.

Outcome of patients on combined extracorporeal membrane oxygenation and continuous renal replacement therapy: a retrospective study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is a lifesaving therapy used in the management of cardiopulmonary failure. Continuous renal replacement therapy (CRRT) is often added to the treatment for the correction of fluid and electrolyte imbalance in patients with acute kidney injury. Most of the literature on the use of combined ECMO and CRRT has been on pediatric patients. There are limited outcome data on the use of these combined modalities in adult patients.

METHODS

This is a retrospective analysis of all the patients above the age of 18 years who underwent combined ECMO and CRRT at a tertiary care medical center during the period January 2007 to January 2012. The primary outcomes measured were mortality at one year and renal recovery or dialysis dependence at one month.

RESULTS

A total of 40 patients who were treated concurrently with ECMO and CRRT were identified. The mean age was 47.01 ± 18.29 years. The most common indications for initiation of CRRT were combined fluid overload and electrolyte imbalance. Mortality at one month was (32/40) 80%. Among the 8 survivors (20%), 3 patients required continuation of hemodialysis and 5 patients were independent of dialysis at 30 days.

CONCLUSIONS

Mortality of patients treated with combined ECMO and CRRT is high. Initiation of CRRT in these patients is simply an indicator of severity of illness and fatality. Younger age, higher arterial pH, left ventricular dysfunction and use of VA ECMO are associated with improved survival in these patients.

Venovenous extracorporeal life support for posttraumatic respiratory distress syndrome in adults: the risk of major hemorrhages

Background

The aim of this retrospective study is to investigate the therapeutic benefits and the bleeding risks of venovenous extracorporeal life support (VV-ECLS) when used for adult posttraumatic respiratory distress syndrome (posttraumatic ARDS).

Materials and methods

Twenty adult trauma patients (median age: 38 years, median injury severity score: 35) treated with VV-ECLS in a level I trauma center between January 2004 and June 2013 were enrolled in this study. The indication of VV-ECLS for posttraumatic ARDS was refractory hypoxemia (P_aO₂/F_iO₂ ratio ≤ 70 mmHg) under advanced mechanical ventilation. To minimize potential complications, a protocol-guided VV-ECLS was adopted.

Results

Sixteen patients were weaned off VV-ECLS, and of these patients fourteen survived. Medians of the trauma-to-ECLS time, the pre-ECLS mechanical ventilation, and the ECLS duration in all patients were 64, 45, and 144 hours respectively. The median P_aO₂/F_iO₂ ratio was improved significantly soon after VV-ECLS, from 56 to 106 mmHg (p < 0.001). However, seven major hemorrhages occurred during VV-ECLS, of which three were lethal. The multivariate analysis revealed that the occurrence of major hemorrhages during VV-ECLS was independently related to the trauma-to-ECLS time < 24 hours (OR: 20; p = 0.02; 95% CI: 2–239; c-index: 0.81).

Conclusions

Despite an effective respiratory support, VV-ECLS should be cautiously administered to patients who develop advanced ARDS soon after major trauma.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-014-0056-0) contains supplementary material, which is available to authorized users.

Percutaneous extracorporeal life support for patients in therapy refractory cardiogenic shock: initial results of an interdisciplinary team

OBJECTIVES

Therapy refractory cardiogenic shock is associated with dismal outcome. Percutaneous implantation of an extracorporeal life support (ECLS) system achieves immediate cardiopulmonary stabilization, sufficient end-organ perfusion and reduction of subsequent multiorgan failure (MOF).

METHODS

Forty-one patients undergoing percutaneous ECLS implantation for cardiogenic shock from February 2012 until August 2013 were retrospectively analysed. Mean age was 52 ± 13 years, 6 (15%) were female. Mean pH values obtained before ECLS implantation were 7.15 ± 0.24, mean lactate concentration was 11.7 ± 6.4 mmol/l. Levels obtained 6 h after ECLS implantation were 7.30 ± 0.14 and 8.7 ± 5.0 mmol/l, respectively. In 23 patients (56%) cardiogenic shock resulted from an acute coronary syndrome in 13 (32%) from cardiomyopathy, in 5 (12%) from other causes. Twenty-seven (66%) had been resuscitated, in 14 (34%) implantation was performed under ongoing cardiopulmonary resuscitation (CPR). Of note, 97% of the acute coronary syndrome patients underwent percutaneous coronary intervention (PCI) either before ECLS implantation or under ECLS support. Extracorporeal life support implantation was performed on scene (Emergency Department, Cath Lab, Intensive Care Unit) by a senior cardiac surgeon and a trained perfusionist, in 8 cases (20%) in the referring hospital.

RESULTS

Thirty-day mortality was 51% [21 patients, due to MOF (n = 14), cerebral complications (n = 6) and heart failure (n = 1)]. Logistic regression analysis identified 6-h pH values as an independent risk factor of 30-day mortality (P < 0.001, OR = 0.000, 95% CI 0.000-0.042). Neither CPR nor implantation under ongoing CPR resulted in significant differences. In 26 cases (63%), the ECLS system could be explanted, after mean support of 169 ± 67 h. Seven of these patients received cardiac surgery [ventricular assist device implantation (n = 4), heart transplantation (n = 1), other procedures (n = 2)].

CONCLUSIONS

Due to the evolution of transportable ECLS systems and percutaneous techniques implantation on scene is feasible. Extracorporeal life support may serve as a bridge-to-decision and bridge-to-treatment device. Neurological evaluation before ventricular assist device implantation and PCI under stable conditions are possible. Despite substantial mortality, ECLS implantation in selected patients by an experienced team offers additional support to conventional therapy as well as CPR and allows survival in patients that otherwise most likely would have died. This concept has to be implemented in cardiac survival networks in the future.

Outcome of acute respiratory distress syndrome patients treated with extracorporeal membrane oxygenation and brought to a referral center

Purpose

Patients with severe acute respiratory distress syndrome (ARDS) are candidates for extracorporeal membrane oxygenation (ECMO) therapy. The evaluation of organ severity is difficult in patients considered for cannulation in a distant hospital. This study was designed to identify early factors associated with hospital mortality in ARDS patients treated with ECMO and retrieved from referring hospitals.

Methods

Data from 85 consecutive ARDS patients equipped with ECMO by our mobile team and consequently admitted to our ICU were prospectively collected and analyzed.

Results

The main ARDS etiologies were community-acquired bacterial pneumonia (35 %), influenza pneumonia (23 %) (with 12 patients having been treated during the first half of the study period), and nosocomial pneumonia (14 %). The median (interquartile range) time between contact from the referring hospital and patient cannulation was 3 (1–4) h. ECMO was venovenous in 77 (91 %) patients. No complications occurred during transport by our mobile unit. Forty-eight patients died at the hospital (56 %). Based on a multivariate logistic regression, a score including age, SOFA score, and a diagnosis of influenza pneumonia was constructed. The probability of hospital mortality following ECMO initiation was 40 % in the 0–2 score class (n = 58) and 93 % in the 3–4 score class (n = 27). Patients with an influenza pneumonia diagnosis and a SOFA score before ECMO of less than 12 had a mortality rate of 22 %.

Conclusions

Age, SOFA score, and a diagnosis of influenza may be used to accurately evaluate the risk of death in ARDS patients considered for retrieval under ECMO from distant hospitals.

Renal function and survival in 200 patients undergoing ECMO therapy

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is increasingly used in the intensive care unit (ICU) setting to improve gas exchange in patients with acute respiratory distress syndrome as well as in patients pre- and post-heart and lung transplantation. In this clinical setting, acute kidney injury (AKI) is frequently observed. So far, it is unknown how AKI affects the survival of critically ill patients receiving ECMO support and whether veno-veno and veno-arterial ECMO have different effects on kidney function.

METHODS

This is a retrospective analysis of patients undergoing ECMO treatment in medical and surgical ICUs in a tertiary care centre. We evaluated all patients undergoing ECMO treatment at our centre between 1 January 2005 and 31 December 2010. Data from all 200 patients (83F/117M), median age 45 (17-83) years, were obtained by chart review. Follow-up data were obtained for up to 3 months.

RESULTS

Three-month survival of all patients was 31%. Of the 200 patients undergoing ECMO treatment, 60% (120/200) required renal replacement therapy (RRT) for AKI. While patients without RRT showed a 3-month survival of 53%, the survival of patients with AKI requiring RRT was 17% (P = 0.001). Longer duration of RRT was associated with a higher mortality.

CONCLUSIONS

AKI requiring RRT therapy in patients undergoing ECMO treatment increases mortality in ICU patients. Future studies have to clarify whether it is possible to identify patients who benefit from the combination of ECMO and RRT.

Predictors of mortality in patients successfully weaned from extracorporeal membrane oxygenation

Purpose

Extracorporeal membrane oxygenation (ECMO) has been utilized for critically ill patients, such as those with life-threatening respiratory failure or post-cardiotomy cardiogenic shock. This study compares the predictive value of Acute Physiology, Age, and Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), and Organ System Failure (OSF) obtained on the first day of ECMO removal, and the Acute Kidney Injury Network (AKIN) stages obtained at 48 hours post-ECMO removal (AKIN_48-hour) in terms of hospital mortality for critically ill patients.

Methods

This study reviewed the medical records of 119 critically ill patients successfully weaned from ECMO at the specialized intensive care unit of a tertiary-care university hospital between July 2006 and October 2010. Demographic, clinical, and laboratory data were collected retrospectively as survival predictors.

Results

Overall mortality rate was 26%. The most common condition requiring ECMO support was cardiogenic shock. By using the areas under the receiver operating characteristic (AUROC) curve, the Sequential Organ Failure Assessment (SOFA) score displayed good discriminative power (AUROC 0.805±0.055, p<0.001). Furthermore, multiple logistic regression analysis indicated that daily urine output on the second day of ECMO removal (UO_{24–48 hour}), mean arterial pressure (MAP), and SOFA score on the day of ECMO removal were independent predictors of hospital mortality. Finally, cumulative survival rates at 6-month follow-up differed significantly (p<0.001) for a SOFA score≤13 relative to those for a SOFA score>13.

Conclusions

Following successful ECMO weaning, the SOFA score proved a reproducible evaluation tool with good prognostic abilities.

Short-term Mechanical Circulatory Support with a Centrifugal Pump - Results of Peripheral Extracorporeal Membrane Oxygenator According to Clinical Situation

Background

A peripheral extracorporeal membrane oxygenator (p-ECMO) has been developed to support patients who are dying due to a serious cardiopulmonary condition. This analysis was planned to define the clinical situation in which the patient benefits most from a p-ECMO.

Material and Methods

Between June 2007 and Aug 2009, a total of 41 adult patients used the p-ECMO. There were 23 males and 18 females (mean age 54.4±15.1 years). All patients had very unstable vital signs with hypoxia and complex cardiac problems. We divided the patients into 4 groups. In the first group, a p-ECMO was used as a bridge to cardiac operation. In the second group, patients did not have the opportunity to undergo any cardiac procedures; nevertheless, they were treated with a p-ECMO. In the third group, patients mostly had difficulty in weaning from CPB (cardiopulmonary bypass) after cardiac operation. The fourth group suffered from many complications, such as pneumonia, bleeding, infections, and LV dysfunction with underlying cardiac problems. All cannulations were performed by the Seldinger technique or cutting down the femoral vessel. A long venous cannula of DLP® (Medtronic Inc, Minneapolis, MN) or RMI® (Edwards Lifesciences LLC, Irvine, CA) was used together with a 17~21 Fr arterial cannula and a 21 Fr venous cannula. As a bypass pump, a Capiox emergency bypass system (EBS®; Terumo, Tokyo, Japan) was used. We attempted to maintain a flow rate of 2.4~3.0 L/min/m² and an activated clotting time (ACT) of around 180 seconds.

Results

Nine patients survived by the use of the p-ECMO. Ten patients were weaned from a p-ECMO but they did not survive, and the remainder had no chance to be weaned from the p-ECMO. The best clinical situation to apply the p-ECMO was to use it as a bridge to cardiac operation and for weaning from CPB after cardiac operation.

Conclusion

Various clinical results were derived by p-ECMO according to the clinical situation. For the best results, early adoption of the p-ECMO for anatomical correction appears important.

Using extracorporeal life support to resuscitate adult postcardiotomy cardiogenic shock: treatment strategies and predictors of short-term and midterm survival

BACKGROUND

Postcardiotomy extracorporeal life support (ECLS) is a resource-demanding therapy with varied results among institutions. An organized protocol was necessary to improve the effectiveness of this therapy.

METHODS AND RESULTS

A total of 110 patients received ECLS due to refractory postcardiotomy cardiogenic shock between January 2003 and June 2009, and were eligible for inclusion in this retrospective study. Preoperative, perioperative, and postoperative variables were collected, including the European system for cardiac operative risk evaluation (EuroSCORE) and markers of ECLS-related organ injuries. All variables were analyzed for possible associations with mortality in hospital, and after hospital discharge. The mean age, additive EuroSCORE, and left ventricular ejection fraction (LVEF) for all patients was 60 (+/-14) years, 9 (+/-6), and 43% (+/-20%) respectively. Sixty-seven patients were weaned from ECLS and 46 survived to hospital discharge. The mean duration of ECLS support was 143 h (+/-112 h). Multivariate analysis revealed that an age of >60 years, a necessity for postoperative continuous arteriovenous hemofiltration, a maximal serum total bilirubin >6 mg/dL, and a need for ECLS support for >110 h were independent predictors of in-hospital mortality. In addition, persistent heart failure with LVEF <30% was an independent predictor of mortality after hospital discharge. A risk-predicting score for in-hospital mortality associated with postcardiotomy ECLS was developed for clinical application.

CONCLUSION

Based on the abovementioned findings, a comprehensive protocol for postcardiotomy ECLS was designed. The primary objective was to achieve adequate hemodynamics within the first 24h of initiating ECLS. Other objectives of the protocol included a consistent approach to safe anticoagulation while on ECLS, a process to make decisions within 7 days of initiating ECLS, and patient follow-up after hospital discharge.