CRRT Connected to ECMO: Managing High Pressures

A novel configuration for providing continuous renal replacement therapy via the ECMO circuit in VV ECMO without alarm adjustment

BACKGROUND

It is common for patients on venovenous extracorporeal membrane oxygenation (VV ECMO) to require continuous renal replacement therapy (CRRT). This can be done using separate vascular access for the CRRT circuit, by placing the CRRT hemofilter within the ECMO circuit, or through a separate CRRT circuit connected to the ECMO circuit. When a CRRT circuit is connected to the ECMO circuit, the inflow and outflow CRRT limbs can both be placed pre-ECMO pump or the CRRT circuit can span the ECMO pump, with the CRRT inflow post-ECMO pump and the outflow pre-ECMO pump. Both configurations require the CRRT alarms to be inactivated due to high positive pressure experienced post-pump and low negative pressure pre-pump. We describe a novel technique that does not require separate venous access and still allows the CRRT alarms to be activated.

TECHNIQUE

The CRRT inflow line is connected to the post-oxygenator de-airing port. The CRRT outflow line is connected to the pre-pump side of the ECMO circuit. Pigtails allow for these connections and act as resistors negating the large range of pressures generated by the ECMO centrifugal pump.

RESULTS

We implemented this configuration in 11 patients with 100% success rate allowing for alarms to be maintained in all patients. The median number of interruptions per 100 CRRT days was 11.7. The median CRRT filter lifespan was 2.2 days, and the average blood flow was maintained at 311 mL/min.

CONCLUSIONS

This configuration allows for efficient use of CRRT in ECMO patients while maintaining the safety alarms on the CRRT machine.

Extracorporeal membrane oxygenation and acute kidney injury: a single-center retrospective cohort

To assess the relationship between acute kidney injury (AKI) with outcomes among patients requiring extracorporeal membrane oxygenation (ECMO). This is a single-center, retrospective cohort study of adult patients admitted to intensive care units (ICU) at a tertiary referral hospital requiring ECMO from July 1, 2015, to August 30, 2019. We assessed the temporal relationship of AKI and renal replacement therapy with ECMO type (VV vs. VA). The primary outcome was in-hospital mortality rates. We used Kruskal-Wallis or chi-square tests for pairwise comparisons, cause-specific Cox proportional hazards models were utilized for the association between AKI prevalence and in-hospital mortality, and a time-dependent Cox model was used to describe the association between AKI incidence and mortality. After the screening, 190 patients met eligibility criteria [133 (70%) AKI, 81 (43%) required RRT]. The median age was 61 years, and 61% were males. Among AKI patients, 48 (36%) and 85 (64%) patients developed AKI before and after ECMO, respectively. The SOFA Day 1, baseline creatinine, respiratory rate (RR), use of vasopressin, vancomycin, proton pump inhibitor, antibiotics, duration of mechanical ventilation and ECMO, and ICU length of stay were higher in AKI patients compared with those without AKI (P < 0.01). While ICU and in-hospital mortality rates were 46% and 50%, respectively, there were no differences based on the AKI status. The type and characteristics of ECMO support were not associated with AKI risk. Among AKI patients, 77 (58%) were oliguric, and 46 (60%) of them received diuretics. Urine output in the diuretic group was only higher on the first day than in those who did not receive diuretics (P = 0.03). Among ECMO patients, AKI was not associated with increased mortality but was associated with prolonged duration of mechanical ventilation and ICU length of stay.

Impact of connecting methods of continuous renal replacement therapy device on patients underwent extracorporeal membrane oxygenation: A retrospectively observational study

OBJECTIVE

The objective of this study was to compare the safety and efficiency of different extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) connection methods.

BACKGROUND

The number of patients receiving ECMO is increasing, and the fields of application are getting wider. However, patients receiving ECMO are prone to acute kidney injury and fluid overload requiring CRRT. There are few comparative studies of two different systems of connecting CRRT device and ECMO from safety and efficacy perspective.

METHODS

This retrospective observational study included patients receiving ECMO in the extracorporeal life support centre of the First Affiliated Hospital of Nanjing Medical University from June, 2015, to December, 2020. Patients were divided into the parallel system group and integrated system group according to the connecting method between ECMO circuit and CRRT line. The outcomes were discharge survival rate, CRRT therapeutic dose completion rate, CRRT catheterisation time, CRRT initiating time, local bleeding at the CRRT catheter site, mean filter life, ECMO circuit thrombosis, ECMO air leakage, or blood leakage due to CRRT.

RESULTS

Thirty patients in the parallel system group and 70 patients in the integrated system group were finally included. The discharge survival rate and CRRT therapeutic dose completion rate were not significantly different between the two groups. The parallel system group had significant longer CRRT initiating time (49.0 ± 12.1 min vs. 14.6 ± 2.1 min, P < 0.001) and shorter filter life (11.5 ± 3.2 h vs. 47.3 ± 14.0 h, P < 0.001) than the integrated system group. The occurrence rate of local bleeding was 93.3% in the parallel system group, and there is no bleeding case in the integrated system group. There was no case of ECMO circuit thrombosis from CRRT as well as ECMO air or blood leakage caused by CRRT in either group. ECMO therapy can be adapted by adjusting the position of the CRRT outlet in the integrated system.

CONCLUSIONS

Connecting CRRT and ECMO as an integrated system might accelerate CRRT initiation, avoid local bleeding, and prolong filter life compared to the parallel system. The chance of developing CRRT-related ECMO circuit leak and thrombosis is manageable.

Safety and Effectiveness of Veno-Venous Extracorporeal Membrane Oxygenation Combined with Continuous Renal Replacement Therapy

Patients receiving extracorporeal membrane oxygenation (ECMO) often suffer from acute kidney injury (AKI), requiring continuous renal replacement therapy (CRRT). In our clinical practice, we connected the inlet line of a CRRT machine to the postoxygenator Luer port and the outlet line to the inlet Luer port of the oxygenator. In this case series, we analyzed the interaction between the two machines. Between December 31, 2017, and December 31, 2019, we enrolled 15 patients from the ICU of the San Matteo Hospital, Pavia, Italy. All of them suffered from severe acute respiratory distress syndrome and AKI stage 3. We analyzed 570 hours of CRRT combined with venovenous ECMO and collected 261,751 CRRT data. No discontinuation of CRRT occurred before 48 hours. Most of the alarms occurred within 24 hours of the connection: 22/10,831 (0.2%) showed an outranged inlet pressure, 11/10831 (0.11%) showed an outranged transmembrane pressure, 14/10,831 (0.13%) showed an outranged inlet pressure, and 138/10,831 (1.27%) an outranged effluent pressure. The rate per minute set for the ECMO circuit was correlated with the inlet (β = 5.38; CI, 95% 1.42-9.35; p = 0.008), transmembrane (β = 4.6; CI, 95% 1.97-7.24; p = 0.001), effluent (β = 3.02; CI, 95% 1.15-4.90; p = 0.002), and outlet pressures (β = 597; CI, 95% 2.31-9.63; p = 0.001) of the CRRT circuit. We reported that our configuration could be safe and effective, however well-designed studies would be beneficial for determining the potential risks and benefits.

Trends, Advantages and Disadvantages in Combined Extracorporeal Lung and Kidney Support From a Technical Point of View

Extracorporeal membrane oxygenation (ECMO) provides pulmonary and/or cardiac support for critically ill patients. Due to their diseases, they are at high risk of developing acute kidney injury. In that case, continuous renal replacement therapy (CRRT) is applied to provide renal support and fluid management. The ECMO and CRRT circuits can be combined by an integrated or parallel approach. So far, all methods used for combined extracorporeal lung and kidney support present serious drawbacks. This includes not only high risks of circuit related complications such as bleeding, thrombus formation, and hemolysis, but also increase in technical workload and health care costs. In this sense, the development of a novel optimized artificial lung device with integrated renal support could offer important treatment benefits. Therefore, we conducted a review to provide technical background on existing techniques for extracorporeal lung and kidney support and give insight on important aspects to be addressed in the development of this novel highly integrated artificial lung device.

Extracorporeal membrane oxygenation in children: An update of a single tertiary center 11-Year experience from Croatia

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is an important treatment option for organ support in respiratory insufficiency, cardiac failure, or as an advanced tool for cardiopulmonary resuscitation. Reports on pediatric ECMO use in our region are lacking.

METHODS

This study is a retrospective review of all pediatric cases that underwent a veno-arterial (VA) or veno-venous (VV) ECMO protocol between November 2009 and August 2020 at the Department of Pediatrics, University Hospital Center Zagreb, Croatia.

RESULTS

Fifty-two ECMO runs identified over the period; data were complete for 45 cases, of which 23 (51%) were female, and median age was 8 months. Thirty-eight (84%) patients were treated using the VA-and 7 (16%) using VV-ECMO. The overall survival rate was 51%. Circulatory failure was the most common indication for ECMO (N = 38, 84%), and in 17 patients ECMO was started after cardiopulmonary resuscitation (E-CPR). Among survivors, 74% had no or minor neurological sequelae. Variables associated with poor outcome were renal failure with renal replacement therapy (p < .001) and intracranial injury (p < .001).

CONCLUSION

Overall survival rate in our cohort is comparable to the data published in the literature. The use of hemodialysis was shown to be associated with higher mortality. High rates of full neurological recovery among survivors are a strong case for further ECMO program development in our institution.

Extracorporeal membrane oxygenation combined with continuous renal replacement therapy for the treatment of severe burns: current status and challenges

Severe burns often cause various systemic complications and multiple organ dysfunction syndrome, which is the main cause of death. The lungs and kidneys are vulnerable organs in patients with multiple organ dysfunction syndrome after burns. Extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) have been gradually applied in clinical practice and are beneficial for severe burn patients with refractory respiratory failure or renal dysfunction. However, the literature on ECMO combined with CRRT for the treatment of severe burns is limited. Here, we focus on the current status of ECMO combined with CRRT for the treatment of severe burns and the associated challenges, including the timing of treatment, nutrition support, heparinization and wound management, catheter-related infection and drug dosing in CRRT. With the advancement of medical technology, ECMO combined with CRRT will be further optimized to improve the outcomes of patients with severe burns.

Continuous renal replacement therapy in patients treated with extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is a life‐saving therapy utilized for patients with severe life‐threatening cardiorespiratory failure. Patients treated with ECMO are among the most severely ill encountered in critical care and are at high‐risk of developing multiple organ dysfunction, including acute kidney injury (AKI) and fluid overload. Continuous renal replacement therapy (CRRT) is increasingly utilized inpatients on ECMO to manage AKI and treat fluid overload. The indications for renal replacement therapy for patients on ECMO are similar to those of other critically ill populations; however, there is wide practice variation in how renal supportive therapies are utilized during ECMO. For patients requiring both CRRT and ECMO, CRRT may be connected directly to the ECMO circuit, or CRRT and ECMO may be performed independently. This review will summarize current knowledge of the epidemiology of AKI, indications and timing of CRRT, delivery of CRRT, and the outcomes of patients requiring CRRT with ECMO.

Parallel veno-venous and veno-arterial extracorporeal membrane circuits for coexisting refractory hypoxemia and cardiovascular failure: a case report

Background

The complexity of extracorporeal membrane oxygenation (ECMO) techniques continues to evolve. Different cannulation methods and configurations have been proposed as a response to a challenging cardiovascular and pulmonary physiology of the patients. The use of parallel ECMO circuits represents a unique and novel approach for patients with refractory respiratory failure and cardiovascular collapse with very large body surface areas.

Case presentation

We present the case of a 25-year-old morbidly obese male patient admitted for severe acute respiratory distress syndrome (ARDS) and refractory hypoxemia, requiring institution of double cannulation for veno-venous ECMO. Since his hypoxemia persisted, likely due to insufficient flows given his large body surface area, an additional drainage venous cannula was implemented to provide higher flows, temporarily addressing his oxygenation status. Unfortunately, the patient developed concomitant cardiogenic shock refractory to inotropic support and extracorporeal fluid removal, further worsening his oxygenation status, thus the decision was to institute four-cannulation/parallel-circuits veno-venous and veno-arterial ECMO, successfully controlling both refractory hypoxemia and cardiogenic shock.

Conclusions

Our case illustrates a novel and complex approach for combined severe ARDS and cardiovascular collapse through the use of parallel veno-venous and veno-arterial ECMO circuits, and exemplifies the expansion of ECMO techniques and its life-saving capabilities when conservative approaches are futile.

Extracorporeal Membrane Oxygenation and Continuous Kidney Replacement Therapy: Technology and Outcomes - A Narrative Review

The number of patients using critical care is increasing as our populations live longer thanks to advances in medical therapies. This is reflected by an increase in both usage and number of critical care beds as compared with total hospital beds across the United States. As this aging population suffers more and more from multiorgan dysfunction, including but not limited to respiratory failure, cardiac failure, and acute kidney injury, technologies are used to facilitate recovery in those that would have assuredly passed away years ago. Some of these advancements include extracorporeal membrane oxygenation and continuous kidney replacement therapy. In this article, we review the literature regarding the history, technology, indications, and outcomes of synchronous extracorporeal membrane oxygenation and kidney replacement therapy.

How To Prescribe And Troubleshoot Continuous Renal Replacement Therapy: A Case-Based Review

Continuous RRT (CRRT) is the preferred dialysis modality for solute management, acid-base stability, and volume control in patients who are critically ill with AKI in the intensive care unit (ICU). CRRT offers multiple advantages over conventional hemodialysis in the critically ill population, such as greater hemodynamic stability, better fluid management, greater solute control, lower bleeding risk, and a more continuous (physiologic) approach of kidney support. Despite its frequent use, several aspects of CRRT delivery are still not fully standardized, or do not have solid evidence-based foundations. In this study, we provide a case-based review and recommendations of common scenarios and interventions encountered during the provision of CRRT to patients who are critically ill. Specific focus is on initial prescription, CRRT dosing, and adjustments related to severe hyponatremia management, concomitant extracorporeal membrane oxygenation support, dialysis catheter placement, use of regional citrate anticoagulation, and antibiotic dosing. This case-driven simulation is made as the clinical status of the patient evolves, and is on the basis of step-wise decisions made during the care of this patient, according to the specific patient's needs and the logistics available at the corresponding institution.

Renal replacement therapy in patients on extracorporeal membrane oxygenation support: Who and how

Patients undergoing extracorporeal membrane oxygenation (ECMO) support frequently develop renal failure requiring renal replacement therapy (RRT). RRT may be performed via a dialysis catheter based approach or via the ECMO circuit. We describe our experience with both techniques. A total of 68 patients undergoing ECMO support at our institution were retrospectively analyzed. Predictors of renal failure requiring RRT were determined. Patients undergoing RRT via a dialysis catheter were compared with those undergoing RRT via the ECMO circuit. 10 of the 68 patients required RRT support prior to ECMO. Of the remaining 58 patients, 25 (43%) required new RRT support on ECMO. Lower albumin levels and postcardiotomy shock were predictive of new renal failure requiring RRT on ECMO. RRT performed via the ECMO circuit demonstrated similar efficacy as via a dialysis catheter. Outcomes were much worse for patients requiring new RRT on ECMO support, with a doubling of the length of ECMO support and less that one-third the survival rate of patients not requiring RRT on ECMO support. New renal failure requiring RRT occurs in nearly one-half of patients on ECMO support, with poor outcomes. RRT may be performed via the ECMO circuit with similar efficacy as via a dialysis catheter.

Continuous Renal Replacement Therapy in Venovenous Extracorporeal Membrane Oxygenation: A Retrospective Study on Regional Citrate Anticoagulation

Systemic infusion of unfractionated heparin (UFH) is the standard anticoagulation technique for continuous renal replacement therapy (CRRT) during extracorporeal membrane oxygenation (ECMO), but often fails to avoid CRRT circuit clotting. The aim of this study was to assess, in patients undergoing CRRT during venovenous ECMO (vv-ECMO), the efficacy and safety of adding regional citrate anticoagulation (RCA) for CRRT circuit anticoagulation (RCA + UFH group) compared with the sole systemic heparin anticoagulation (UFH group). We performed a retrospective chart review (2009-2018) of patients treated with CRRT during ECMO. We evaluated filter life span, rate of CRRT circuit clotting, and coagulation parameters. The incidence of citrate anticoagulation-related complications was recorded. Forty-eight consecutive adult patients underwent CRRT during vv-ECMO in the study period. The incidence of CRRT circuit clotting was lower in the RCA + UFH group (11% vs. 38% in the UFH group, p < 0.001). Log-rank survival analysis demonstrated longer circuit lifetime for RCA + UFH group. No complication ascribable to citrate anticoagulation was recorded. Regional citrate anticoagulation resulted a feasible, safe, and effective technique as additional anticoagulation for CRRT circuits during ECMO. Compared with systemic heparinization only, this technique allowed to reduce the rate of CRRT circuit clotting.

Controversies in acute kidney injury: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Conference

In 2012, Kidney Disease: Improving Global Outcomes (KDIGO) published a guideline on the classification and management of acute kidney injury (AKI). The guideline was derived from evidence available through February 2011. Since then, new evidence has emerged that has important implications for clinical practice in diagnosing and managing AKI. In April of 2019, KDIGO held a controversies conference entitled Acute Kidney Injury with the following goals: determine best practices and areas of uncertainty in treating AKI; review key relevant literature published since the 2012 KDIGO AKI guideline; address ongoing controversial issues; identify new topics or issues to be revisited for the next iteration of the KDIGO AKI guideline; and outline research needed to improve AKI management. Here, we present the findings of this conference and describe key areas that future guidelines may address.

Optimizing renal replacement therapy for patients who need extracorporeal membrane oxygenation: cross-talk between two organ support machines

Following a substantial increase in the utilization of extracorporeal membrane oxygenation (ECMO) during the last decade, its associated benefits and complications, including acute kidney injury have become more apparent. Acute kidney injury requiring dialysis during the ECMO treatment is very common and is associated with adverse outcomes. Cross talk between ECMO and dialysis equipment has been debated in the literature in order to enhance the quality of dialysis and avoid its potential adverse events.

Na et al. recently published the results of a prospective experiment by using three different methods for integration of the continuous renal replacement therapy device into the ECMO circuit. In this experiment, the investigators showed that by using three different connection strategies between continuous renal replacement therapy device and ECMO and the utilization of three separate structures of pressure control lines, the dialyzer lifespan could be optimized.

In this commentary, following a brief review of the ECMO and dialysis devices history and cross talk, we discuss the findings by Na et al. and provide additional insights for future investigations.

A 266 Patient Experience of a Quaternary Care Referral Center for Extracorporeal Membrane Oxygenation with Assessment of Outcomes for Transferred Versus In-House Patients

OBJECTIVE

Patients undergoing venoarterial extracorporeal membrane oxygenation (VA-ECMO) require highly trained specialists and resources to be cared for safely. Interestingly, comparisons of outcomes for patients cannulated for VA-ECMO by outside institutions and transferred to referral centers for further care versus those cannulated and taken care of in house at the referral center have not been reported on a large scale. This study aimed to perform the first comparison of these 2 populations based on the experience of a single quaternary referral center.

DESIGN

A retrospective chart review-based study in a single quaternary care center of patients cannulated by referring institutions for VA-ECMO then transferred versus patients who were cannulated in house was performed to assess for a difference in survival (both of ECMO therapy and survival to discharge).

SETTING

Single quaternary academic referral center for ECMO.

PARTICIPANTS

All patients undergoing VA-ECMO who were at least 18 years old from 2011-2018 (266 patients).

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

The study comprised 215 patients cannulated for VA-ECMO in house and 51 patients cannulated by 17 different outside institutions then transferred. Survival of the ECMO run for in-house patients (122/215) was 56.7% (95% confidence interval [CI] 50.1-63.3), and survival of transferred patients (31/51) for the ECMO run was 60.8% (95% CI 47.4-74.2; p = 0.58). Survival to discharge in patients cannulated in house (82/215) was 38.1% (95% CI 31.6-44.6) and for outside hospital transfers (24/51 patients) was 47.1% (95% CI 33.4-60.8; p = 0.23).

CONCLUSIONS

This retrospective chart review of 266 patients found no difference in survival of the ECMO therapy or survival to discharge in patients cannulated by other institutions and transferred versus those who were cannulated in house. Even though analysis on the feasibility of transfer centers has been performed extensively in patients with respiratory failure requiring venovenous ECMO, minimal investigation has been performed in patients requiring VA-ECMO. These results should be considered hypothesis-generating because larger sample sizes are necessary to guide care of these patients more definitively.

The Effect of Simultaneous Renal Replacement Therapy on Extracorporeal Membrane Oxygenation Support for Postcardiotomy Patients with Cardiogenic Shock: A Pilot Randomized Controlled Trial

OBJECTIVE

The objectives of this study were to determine the feasibility and safety of simultaneous renal replacement therapy (RRT) during extracorporeal membrane oxygenation (ECMO) support for postcardiotomy patients with cardiogenic shock and whether simultaneous RRT with ECMO would improve survival and reduce morbidity. The authors hypothesized that simultaneous RRT could facilitate effective fluid management and rapid metabolic control in postcardiotomy patients with cardiogenic shock who were undergoing ECMO support.

DESIGN

A parallel, open-label, single-center pilot randomized trial.

SETTING

University-affiliated cardiac surgery intensive care unit.

PARTICIPANTS

The study comprised 41 postcardiotomy patients with cardiogenic shock who received ECMO support.

INTERVENTIONS

Participants were enrolled and randomly assigned via a 1:1 allocation to a simultaneous RRT arm versus a standard care arm. The patients in the simultaneous RRT arm received RRT within 12 hours of the start of ECMO regardless of the conventional RRT indication. Simultaneous RRT was delivered with the RRT machine connected to the ECMO circuit. The patients in the standard care arm did not receive RRT at the start of ECMO unless the conventional RRT indications were fulfilled.

MEASUREMENTS AND MAIN RESULTS

All 41 patients enrolled were followed-up for 30 days and the results analyzed. The primary feasibility outcome was the time from randomization to simultaneous RRT of <12 hours in the simultaneous RRT arm. All participants in simultaneous RRT arm fulfilled with a median time from randomization to simultaneous RRT of 4.4 (2.7-5.6) hours. The 30-day all-cause mortality was 61.9% in the simultaneous RRT arm and 75.0% in the standard care arm (p = 0.51). The lactate clearance was higher in the simultaneous RRT arm (0.56 ± 0.4 v 0.28 ± 0.4 mmol/L/h; p = 0.04). There was lower cumulative fluid balance in the simultaneous RRT arm on ECMO day 3 (-1,510 [-3560 to 1,162] v -332 [-2,027 to 2,181]; p = 0.38) and ECMO day 5 (-2,671 [-5,197 to 3,334] v -1,509 [-3,595 to 1,162]; p = 0.41) without significance. There were no significant differences in adverse events reported and no hemodynamic instability owing to simultaneous RRT delivery.

CONCLUSIONS

This pilot study suggests the feasibility and safety of simultaneous RRT during ECMO support for postcardiotomy patients with cardiogenic shock, providing an efficient means for controlling fluid status and metabolics. A large trial based on this pilot study is required to confirm the clinical benefits.

Using additional pressure control lines when connecting a continuous renal replacement therapy device to an extracorporeal membrane oxygenation circuit

Background

The introduction of a continuous renal replacement therapy (CRRT) device into the extracorporeal membrane oxygenation (ECMO) circuit is widely used. However, excessive pressure transmitted to the CRRT device is a major disadvantage. We investigated the effects of using additional pressure control lines on the pressure and the lifespan of the CRRT circuit connected to the ECMO.

Methods

This is an observational study using prospectively collected data from consecutive patients receiving CRRT connected into the ECMO circuit at a university-affiliated, tertiary hospital from January 2013 to December 2016. The CRRT circuit was connected into the ECMO circuit through the Luer Lock connection without an additional pressure control line in 16 patients (9%, no line group), an additional pressure control line on the inlet line in 36 patients (23%, single line group), and additional pressure control lines on both the inlet and outlet lines in 118 patients (77%, double line group). The outcome measures of interest were compared among the three groups.

Results

The median access pressure was higher in the no line group compared to the groups. However, median filter pressure, effluent pressure, and return pressure were higher in the double line group compared to the other groups. There were no significant differences in platelets, lactate dehydrogenase, and plasma hemoglobin among the 3 groups over the time period studied. Median lifespan of the CRRT circuits in the double line group was 45.0 (29.0–63.7) hours, which was higher compared to 21.8 (11.6–31.8) hours in the no line group and 23.0 (15.0–34.6) hours in the single line group, respectively. In addition, in-hospital mortality was lower in the double line group (48.3%) compared to the no line group (68.8%) and the single line group (75.0%).

Conclusions

Additional tubing can be considered a simple and safe method for pressure control and lengthening circuit survival when connecting the CRRT device to the ECMO circuit.

Impact of connecting continuous renal replacement therapy to the extracorporeal membrane oxygenation circuit

PURPOSE

Continuous veno-venous haemofiltration (CVVH) directly connected to extracorporeal membrane oxygenation (ECMO) may ensure better blood flow and allow prolonged circuit life. The objective of this study was to assess circuit life of CVVH connected to ECMO and to a dialysis catheter.

MATERIALS AND METHODS

In this prospective observational study, patients receiving CVVH via ECMO were compared to time-matched patients receiving CVVH via a conventional dialysis catheter. CVVH circuit life and the safety and efficacy of the two CVVH procedures were analysed. Time to event was estimated using Kaplan-Meier analysis and compared using the log-rank test.

RESULTS

Seventeen patients were included in each group, with 43 sessions in the ECMO group and 56 sessions in the DC group. Median CVVH circuit life was 48 [21-72] vs 20 [6-39] hours in the ECMO and DC groups, respectively (relative risk of termination of the session: 2.4, 95% CI [1.41-3.9], log rank P=0.0009). CVVH blood flow was higher in the ECMO group. Despite higher anticoagulant doses in the catheter group, the circuit clotting rate was lower in the ECMO group. Effluent volume was slightly higher in the ECMO group (39ml/kg/h [33-47] vs 34ml/kg/h [32-39]), but with no biological impact. CVVH via ECMO was well tolerated with no major drawbacks.

CONCLUSIONS

In patients requiring ECMO, CVVH connected to ECMO instead of DC could be proposed as an alternative approach, allowing more stable blood flow and prolonged CVVH circuit life.

High Hemoglobin Is an Independent Risk Factor for the Development of Hemolysis During Pediatric Extracorporeal Life Support

OBJECTIVE

To evaluate risk factors for hemolysis in pediatric extracorporeal life support.

DESIGN

Retrospective, single-center study.

SETTING

Pediatric intensive care unit.

PATIENTS

Two hundred thirty-six children who received extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Risk factors for hemolysis were retrospectively analyzed from a single center in a total of 236 neonatal and pediatric patients who received extracorporeal membrane oxygenation support (ECMO). There was no difference in the incidence of hemolysis between centrifugal (127 patients) and roller head (109 patients) pump type or between venoarterial and venovenous ECMO. High hemoglobin (Hb) was found to be an independent risk factor for hemolysis in both pump types. The Hb level >12 g/dL was significant in the roller group and the Hb level >13 g/dL was significant in the centrifugal group for the development of hemolysis for the cumulative ECMO run. The presence of high Hb levels on any given day increased the risk of hemolysis for that day of the ECMO run regardless of ECMO pump type. Higher revolutions per minute (RPMs) and higher inlet pressures on any given day increased the risk for the development of hemolysis in the centrifugal pump. Lower inlet venous pressures and RPMs were not associated with hemolysis in the roller group.

CONCLUSIONS

An Hb level greater than 13 g/dL was associated with an increased risk of hemolysis, and a high Hb on a given day was associated with a significantly higher risk of hemolysis on the same day. Higher RPMs and lower inlet venous pressures were associated with an increased risk of hemolysis in the centrifugal pump only.