Providing Continuous Renal Replacement Therapy in Patients on Extracorporeal Membrane Oxygenation

Optimizing the connection of CRRT and ECMO lines with additional pressure regulator on the therapeutic effect, filter life, and incidence of complications

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is used for severe cardiopulmonary failure, with veno-arterial ECMO for cardiogenic shock and veno-venous ECMO for acute respiratory failure. ECMO's application has expanded to ICUs, emergency departments, and operating rooms. ECMO patients are at high risk for complications, including acute kidney injury (AKI), often requiring renal replacement therapy (RRT), posing significant management challenges.

METHODS

From August 2015 to June 2022, 120 patients were cured with veno-venous ECMO (n = 60) or veno-arterial ECMO (VA-ECMO, n = 60) combined with CRRT in our hospital. In the control group (n = 60), the input end (arterial end) of CRRT was connected to the ECMO oxygenator. The reinfusion end (venous end) of CRRT was connected to the oxygenator of ECMO for CRRT + ECMO treatment. In the experimental group (n = 60), the input end (arterial end) of CRRT was connected to the oxygenator of ECMO, and an additional pressure regulating device was installed on the connection of the 2 lines. The observation indexes including clinical therapeutic effect, clinical therapeutic effect, the incidence of complications, and the incidence of complications were compared.

RESULTS

There was a notable decrease in serum creatinine, and the differences in blood urea nitrogen, procalcitonin, and C-reactive protein after operation were statistically significant (P < .05). The filter use time in the study group was notably longer (P < .01). There exhibited no remarkable difference in the incidences of bleeding, thrombosis, numbness of hands and feet, metabolic alkalosis, disseminated intravascular coagulation, organ dysfunction syndrome, hyperbilirubinemia, and infection.

CONCLUSION

This study demonstrates that additional pressure regulation devices are installed at the line connection between the CRRT input end and the CRRT return end to ensure that the flow rate of ECMO does not affect the CRRT treatment. ECMO and CRRT provide a safe pressure range so that the ECMO line can be safely connected to the CRRT machine at physiological pressure, reducing the occurrence of complications related to CRRT machine interruption and improving the efficiency of CRRT without affecting the efficiency of ECMO, ensuring patient safety.

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.

Concurrent use of continuous kidney replacement therapy during extracorporeal membrane oxygenation: what pediatric nephrologists need to know-PCRRT-ICONIC practice points

Extracorporeal membrane oxygenation (ECMO) provides temporary cardiorespiratory support for neonatal, pediatric, and adult patients when traditional management has failed. This lifesaving therapy has intrinsic risks, including the development of a robust inflammatory response, acute kidney injury (AKI), fluid overload (FO), and blood loss via consumption and coagulopathy. Continuous kidney replacement therapy (CKRT) has been proposed to reduce these side effects by mitigating the host inflammatory response and controlling FO, improving outcomes in patients requiring ECMO. The Pediatric Continuous Renal Replacement Therapy (PCRRT) Workgroup and the International Collaboration of Nephrologists and Intensivists for Critical Care Children (ICONIC) met to highlight current practice standards for ECMO use within the pediatric population. This review discusses ECMO modalities, the pathophysiology of inflammation during an ECMO run, its adverse effects, various anticoagulation strategies, and the technical aspects and outcomes of implementing CKRT during ECMO in neonatal and pediatric populations. Consensus practice points and guidelines are summarized. ECMO should be utilized in patients with severe acute respiratory failure despite the use of conventional treatment modalities. The Extracorporeal Life Support Organization (ELSO) offers guidelines for ECMO initiation and management while maintaining a clinical registry of over 195,000 patients to assess outcomes and complications. Monitoring and preventing fluid overload during ECMO and CKRT are imperative to reduce mortality risk. Clinical evidence, resources, and experience of the nephrologist and healthcare team should guide the selection of ECMO circuit.

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.

Integration of sustained low-efficiency dialysis into extracorporeal membrane oxygenation circuit in critically ill COVID-19 patients - a feasibility study

Background

Severe COVID‐19 can necessitate multiple organ support including veno‐venous extracorporeal membrane oxygenation (vvECMO) and renal replacement therapy. The therapy can be complicated by venous thromboembolism due to COVID‐19‐related hypercoagulability, thus restricting vascular access beyond the vvECMO cannula. Although continuous renal replacement therapy can be performed via a vvECMO circuit, studies addressing sustained low‐efficiency dialysis (SLED) integration into vvECMO circuits are scarce. Here we address the lack of evidence by evaluating feasibility of SLED integration into vvECMO circuits.

Methods

Retrospective cohort study on nine critically ill COVID‐19 patients, treated with integrated ECMO‐SLED on a single intensive care unit at a tertiary healthcare facility between December 2020 and November 2021. The SLED circuits were established between the accessory arterial oxygenator outlets of a double‐oxygenator vvECMO setup. Data on filter survival, quality of dialysis, and volume management were collected and compared with an internal control group receiving single SLED.

Results

This study demonstrates general feasibility of SLED integration into existing vvECMO circuits. Filter lifespans of ECMO‐SLED compared with single SLED are significantly prolonged (median 18.3 h vs. 10.3 h, p < 0.01). ECMO‐SLED treatment is furthermore able to sufficiently normalize creatinine, blood urea nitrogen, and serum sodium, and allows for adequate ultrafiltration rates.

Conclusions

We can show that ECMO‐SLED is practical, safe, results in adequate dialysis quality and enables sufficient electrolyte and volume management. Our data indicate that SLED devices can serve as potential alternative to continuous‐veno‐venous‐hemodialysis for integration in vvECMO circuits.

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.