3-month prognostic impact of severe acute renal failure under veno-venous ECMO support: Importance of time of onset

Factors associated with post-hospitalization dialysis dependence in ECMO patients who required continuous renal replacement therapy

OBJECTIVE

This single center retrospective study aimed to describe the variables associated with outpatient dialysis dependence in extracorporeal membrane oxygenation (ECMO) patients who needed continuous renal replacement therapy (CRRT) for acute kidney injury (AKI) during their hospitalization.

METHODS

Retrospective study of patients who required ECMO-CRRT.

RESULTS

Between the years of 2016 and 2022, 202 patients required ECMO-CRRT. One hundred and six patients (52.5%) survived their hospitalization and were followed up for a median of 391 [133, 1005] days. Eighty-one patients (76.5%) recovered kidney function and were dialysis-free before hospital discharge. Twenty-five patients (23.5%) were hemodialysis-dependent after hospitalization. On multivariate regression analysis, hyperlipidemia (odds ratio, OR 6.08 [1.67-22]) and CRRT duration (OR 1.09 [1.03-1.15]) were associated with the need for dialysis post-hospitalization. In this group, 16 patients eventually became dialysis-free, after a median of 49 [34.7, 78.5] days. These patients had a higher median baseline glomerular filtration rate (GFR) compared to those who never recovered renal function (93 mL/min/1.73 m2 [82.4, 104.3] vs. 63.8 mL/min/1.73 m2 [37.9, 83], p = .009). Their follow-up GFR was lower compared to those who recovered renal function before hospital discharge; (87 mL/min/1.73 m2 [68.2, 98.9] vs. 99 mL/min/1.73 m2 [79, 118], p = .07).

CONCLUSIONS

AKI requiring CRRT was associated with high mortality in patients receiving ECMO. Nonetheless, most ECMO survivors became dialysis-free before hospital discharge. Variables associated with the need for outpatient dialysis included hyperlipidemia and prolonged need for CRRT during hospitalization.

Vasoactive-Inotropic Score as a Promising Predictor of Acute Kidney Injury in Adult Patients Requiring Extracorporeal Membrane Oxygenation

Acute kidney injury (AKI) is a common complication in patients supported by extracorporeal membrane oxygenation (ECMO). Vasoactive-Inotropic Score (VIS) serves as an indicator of the extent of cardiovascular drug support provided. Our objective is to assess the relationship between the VIS and ECMO-associated AKI (EAKI). This single-center retrospective study extracted adult patients treated with ECMO between August 2016 and September 2022 from an intensive care unit (ICU) in a university hospital. A total of 126 patients requiring ECMO support were included in the study, of which 76% developed AKI. Multivariate logistic regression analysis identified VIS-max Day1 (odds ratio [OR]: 1.025, 95% confidence interval [CI]: 1.007-1.044, p = 0.006), VIS-max Day2 (OR: 1.038, 95% CI: 1.007-1.069, p = 0.015), VIS-mean Day1 (OR: 1.048, 95% CI: 1.013-1.084, p = 0.007), and VIS-mean Day2 (OR: 1.059, 95% CI: 1.014-1.107, p = 0.010) as independent risk factors for EAKI. VIS-max Day1 showing the best predictive effect (Area under the receiver operating characteristic curve (AUROC): 0.80, sensitivity: 71.87%, specificity: 80.00%) for EAKI with a cutoff value of 33.33. Surprisingly, VIS-mean Day2 was also excellent at predicting 7 day mortality (AUROC: 0.77, sensitivity: 87.50%, specificity: 56.38%) with a cutoff value of 8.67. In conclusion, VIS could independently predict EAKI and 7 day mortality in patients with ECMO implantation, which may help clinicians to recognize the poor prognosis in time for early intervention.

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.

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.

Early acute kidney injury and transition to renal replacement therapy in critically ill patients with SARS-CoV-2 requiring veno-venous extracorporeal membrane oxygenation

BACKGROUND

Critically ill patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requiring veno-venous extracorporeal membrane oxygenation (vv-ECMO) are at risk for acute kidney injury (AKI). Currently, the incidence of AKI and progression to kidney replacement therapy (RRT) in critically ill patients with vv-ECMO for severe COVID-19 and implications on outcome are still unclear.

METHODS

Retrospective analysis at the University Medical Center Hamburg-Eppendorf (Germany) between March 1st, 2020 and July 31st, 2021. Demographics, clinical parameters, AKI, type of organ support, length of ICU stay, mortality and severity scores were assessed.

RESULTS

Ninety-one critically ill patients with SARS-CoV-2 requiring ECMO were included. The median age of the study population was 57 (IQR 49-64) years and 67% (n = 61) were male. The median SAPS II and SOFA Score on admission were 40 (34-46) and 12 (10-14) points, respectively. We observed that 45% (n = 41) developed early-AKI, 38% (n = 35) late-AKI and 16% (n = 15) no AKI during the ICU stay. Overall, 70% (n = 64) of patients required RRT during the ICU stay, 93% with early-AKI and 74% with late-AKI. Risk factors for early-AKI were younger age (OR 0.94, 95% CI 0.90-0.99, p = 0.02) and SAPS II (OR 1.12, 95% CI 1.06-1.19, p < 0.001). Patients with and without RRT were comparable regarding baseline characteristics. SAPS II (41 vs. 37 points, p < 0.05) and SOFA score (13 vs. 12 points, p < 0.05) on admission were significantly higher in patients receiving RRT. The median duration of ICU (36 vs. 28 days, p = 0.27) stay was longer in patients with RRT. An ICU mortality rate in patients with RRT in 69% (n = 44) and in patients without RRT of 56% (n = 27) was observed (p = 0.23).

CONCLUSION

Critically ill patients with severe SARS-CoV-2 related ARDS requiring vv-ECMO are at high risk of early acute kidney injury. Early-AKI is associated with age and severity of illness, and presents with high need for RRT. Mortality in patients with RRT was comparable to patients without RRT.

Acute Kidney Injury Management Strategies Peri-Cardiovascular Interventions

In many countries, the aging population and the higher incidence of comorbid conditions have resulted in an ever-growing need for cardiac interventions. Acute kidney injury (AKI) is a common complication of these interventions, associated with higher mortalities, chronic or end-stage kidney disease, readmission rates, and hospital and post-discharge costs. The AKI pathophysiology includes contrast-associated AKI, hemodynamic changes, cardiorenal syndrome, and atheroembolism. Preventive measures include limiting contrast media dose, optimizing hemodynamic conditions, and limiting exposure to other nephrotoxins. This review article outlines the current state-of-art knowledge regarding AKI pathophysiology, risk factors, preventive measures, and management strategies in the peri-interventional period.

Effect of replacement therapy (CRRT) and hemodialysis (IHD) on severe acute renal failure

Hyperkalemia, metabolic acidosis, and acute uremia are the main symptoms in patients with severe acute renal failure (SARF). Its clinical symptoms are obvious, and it is extremely harmful. It needs to take active and effective measures for treatment. CRRT refers to any extracorporeal blood purification treatment technique designed to replace impaired renal function for 24 h or nearly 24 h. Hemodialysis treatment is a treatment process in which the patient's blood is discharged from the body, passes through the dialysis membrane and dialysis machine, removes excess toxins and water in the body, corrects electrolyte and acid-base disorders, and then returns the blood to the body. In order to explore the efficacy of replacement therapy and hemodialysis in the treatment of severe acute renal failure, the data samples were randomly divided into observation group and control group, who were given conventional treatment, hemodialysis and replacement therapy, respectively. Clinical data show that after replacement therapy and hemodialysis in patients with severe acute renal failure in the observation group, the levels of parathyroid hormone, renin, and quality of life were all improved, with an improvement rate of 9.47%, which has certain promotional value.

The impact of preservation and recovery of renal function on survival after veno-arterial extracorporeal life support: A retrospective cohort study

BACKGROUND

Veno-arterial extracorporeal life support (V-A ECLS) has become a cornerstone in the management of critical cardiogenic shock, but it can also precipitate organ injury, e.g., acute kidney injury (AKI). Available studies highlight the effect of non-cardiac organ injury on patient outcomes. Only very little is known about the impact of non-cardiac organ recovery on patient survival. AKI occurs frequently during cardiogenic shock and carries a poor prognosis. We have developed descriptive models to hypothesize on the role of AKI severity versus that of recovery of renal function for patient survival.

METHODS

Retrospective, observational study including 175 patients who were successfully decannulated from V-A ECLS. We assessed AKI severity using the "Kidney Disease: Improving Global Outcomes" (KDIGO) criteria. We defined recovered or preserved renal function (RPRF) prior to decannulation from V-A ECLS as 0 (AKI with no improvement) or 1 (no AKI or AKI with improvement). We classified patient outcomes as alive or dead at hospital discharge.

RESULTS

78% (n = 138) of all patients survived hospital discharge of which 38% (n = 67) never developed AKI. After adjusting for shock severity and non-renal organ injury, RPRF emerged as an independent predictor of survival in both the overall cohort [OR (95% CI) - 4.11 (1.72-9.79)] and the AKI-only sub-cohort [OR (95% CI) - 5.18 (1.8-14.92)]. Neither maximum KDIGO stage nor KDIGO stage at the end of V-A ECLS was independently associated with survival.

CONCLUSIONS

Our model identifies RPRF, but not AKI severity, as an independent predictor of hospital survival in patients undergoing V-A ECLS for cardiogenic shock. We hypothesize that recovered or preserved non-cardiac organ function during V-A ECLS is crucial for patient survival.

Veno-venous extracorporeal membrane oxygenation for the treatment of respiratory compromise

Extracorporeal membrane oxygenation for the purpose of intervening upon profound cardiovascular or pulmonary compromise has proven to be a worthy intervention. Technological advancements have allowed this mode of therapy to become more effective and widespread. Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is a commonly used strategy to help manage patients with pulmonary dysfunction refractory to traditional management methods. This review intends to focus upon common indications and the clinical considerations for the institution of VV-ECMO as well as some of its known complications.

Factors associated with acute kidney injury in patients undergoing extracorporeal membrane oxygenation: retrospective cohort

OBJECTIVE

To identify factors associated with acute kidney injury in patients undergoing extracorporeal membrane oxygenation.

METHOD

Retrospective cohort study conducted in an adult Intensive Care Unit with patients undergoing extracorporeal membrane oxygenation from 2012 to 2021. The research used the Kidney Disease Improving Global Outcomes as criteria for definition and classification of acute kidney injury. A multiple logistic regression model was developed to analyze the associated factors.

RESULTS

The sample was composed of 122 individuals, of these, 98 developed acute kidney injury (80.3%). In multiple regression, the associated factors found were vasopressin use, Nursing Activities Score, and glomerular filtration rate.

CONCLUSION

The use of vasopressin, the Nursing Activities Score, and the glomerular filtration rate were considered as factors related to the development of acute kidney injury in patients undergoing extracorporeal membrane oxygenation.

Long-term outcomes in patients who received veno-venous extracorporeal membrane oxygenation and renal replacement therapy: a retrospective cohort study

Background

Acute kidney injury (AKI) is a frequent complication in patients with severe respiratory failure receiving extracorporeal membrane oxygenation (ECMO). However, little is known of long-term kidney function in ECMO survivors. We aimed to assess the long-term mortality and kidney outcomes in adult patients treated with veno-venous ECMO (VV-ECMO).

Methods

This was a single-centre retrospective study of adult patients (≥ 18 years old) who were treated with VV-ECMO at a commissioned ECMO centre in the UK between 1st September 2010, and 30th November 2016. AKI was defined and staged using the serum creatinine and urine output criteria of the Kidney Diseases: Improving Global Outcomes (KDIGO) classification. The primary outcome was 1-year mortality. Secondary outcomes were long-term mortality (up to March 2020), 1-year incidence of end-stage kidney disease (ESKD) or chronic kidney disease (CKD) among AKI patients who received renal replacement therapy (AKI-RRT), AKI patients who did not receive RRT (AKI-no RRT) and patients without AKI (non-AKI).

Results

A total of 300 patients [57% male; median age 44.5; interquartile range (IQR) 34–54] were included in the final analysis. Past medical histories included diabetes (12%), hypertension (17%), and CKD (2.3%). The main cause of severe respiratory failure was pulmonary infection (72%). AKI occurred in 230 patients (76.7%) and 59.3% received renal replacement therapy (RRT). One-year mortality was 32% in AKI-RRT patients vs. 21.4% in non-AKI patients (p = 0.014). The median follow-up time was 4.35 years. Patients who received RRT had a higher risk of 1-year mortality than those who did not receive RRT (adjusted HR 1.80, 95% CI 1.06, 3.06; p = 0.029). ESKD occurred in 3 patients, all of whom were in the AKI-RRT group. At 1-year, 41.2% of survivors had serum creatinine results available. Among these, CKD was prevalent in 33.3% of AKI-RRT patients vs. 4.3% in non-AKI patients (p = 0.004).

Conclusions

VV-EMCO patients with AKI-RRT had high long-term mortality. Monitoring of kidney function after hospital discharge was poor. In patients with follow-up creatinine results available, the CKD prevalence was high at 1 year, especially in AKI-RRT patients. More awareness about this serious long-term complication and appropriate follow-up interventions are required.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-022-01046-0.

Complications Associated With Venovenous Extracorporeal Membrane Oxygenation-What Can Go Wrong?

OBJECTIVES

Despite increasing use and promising outcomes, venovenous extracorporeal membrane oxygenation (V-V ECMO) introduces the risk of a number of complications across the spectrum of ECMO care. This narrative review describes the variety of short- and long-term complications that can occur during treatment with ECMO and how patient selection and management decisions may influence the risk of these complications.

DATA SOURCES

English language articles were identified in PubMed using phrases related to V-V ECMO, acute respiratory distress syndrome, severe respiratory failure, and complications.

STUDY SELECTION

Original research, review articles, commentaries, and published guidelines from the Extracorporeal Life support Organization were considered.

DATA EXTRACTION

Data from relevant literature were identified, reviewed, and integrated into a concise narrative review.

DATA SYNTHESIS

Selecting patients for V-V ECMO exposes the patient to a number of complications. Adequate knowledge of these risks is needed to weigh them against the anticipated benefit of treatment. Timing of ECMO initiation and transfer to centers capable of providing ECMO affect patient outcomes. Choosing a configuration that insufficiently addresses the patient's physiologic deficit leads to consequences of inadequate physiologic support. Suboptimal mechanical ventilator management during ECMO may lead to worsening lung injury, delayed lung recovery, or ventilator-associated pneumonia. Premature decannulation from ECMO as lungs recover can lead to clinical worsening, and delayed decannulation can prolong exposure to complications unnecessarily. Short-term complications include bleeding, thrombosis, and hemolysis, renal and neurologic injury, concomitant infections, and technical and mechanical problems. Long-term complications reflect the physical, functional, and neurologic sequelae of critical illness. ECMO can introduce ethical and emotional challenges, particularly when bridging strategies fail.

CONCLUSIONS

V-V ECMO is associated with a number of complications. ECMO selection, timing of initiation, and management decisions impact the presence and severity of these potential harms.

Veno-Venous Extracorporeal Membrane Oxygenation in Minipigs as a Robust Tool to Model Acute Kidney Injury: Technical Notes and Characteristics

Objective

Veno-venous extracorporeal membrane oxygenation (vv-ECMO) can save lives in severe respiratory distress, but this innovative approach has serious side-effects and is accompanied by higher rates of iatrogenic morbidity. Our aims were, first, to establish a large animal model of vv-ECMO to study the pathomechanism of complications within a clinically relevant time frame and, second, to investigate renal reactions to increase the likelihood of identifying novel targets and to improve clinical outcomes of vv-ECMO-induced acute kidney injury (AKI).

Methods

Anesthetized Vietnamese miniature pigs were used. After cannulation of the right jugular and femoral veins, vv-ECMO was started and maintained for 24 hrs. In Group 1 (n = 6) ECMO was followed by a further 6-hr post-ECMO period, while (n = 6) cannulation was performed without ECMO in the control group, with observation maintained for 30 h. Systemic hemodynamics, blood gas values and hour diuresis were monitored. Renal artery flow (RAF) was measured in the post-ECMO period with an ultrasonic flowmeter. At the end of the experiments, renal tissue samples were taken for histology to measure myeloperoxidase (MPO) and xanthine oxidoreductase (XOR) activity and to examine mitochondrial function with high-resolution respirometry (HRR, Oroboros, Austria). Plasma and urine samples were collected every 6 hrs to determine neutrophil gelatinase-associated lipocalin (NGAL) concentrations.

Results

During the post-ECMO period, RAF dropped (96.3 ± 21 vs. 223.6 ± 32 ml/min) and, similarly, hour diuresis was significantly lower as compared to the control group (3.25 ± 0.4 ml/h/kg vs. 4.83 ± 0.6 ml/h/kg). Renal histology demonstrated significant structural damage characteristic of ischemic injury in the tubular system. In the vv-ECMO group NGAL levels, rose significantly in both urine (4.24 ± 0.25 vs. 2.57 ± 0.26 ng/ml) and plasma samples (4.67 ± 0.1 vs. 3.22 ± 0.2 ng/ml), while tissue XOR (5.88 ± 0.8 vs. 2.57 ± 0.2 pmol/min/mg protein) and MPO (11.93 ± 2.5 vs. 4.34 ± 0.6 mU/mg protein) activity was elevated. HRR showed renal mitochondrial dysfunction, including a significant drop in complex-I-dependent oxidative capacity (174.93 ± 12.7 vs. 249 ± 30.07 pmol/s/ml).

Conclusion

Significantly decreased renal function with signs of structural damage and impaired mitochondrial function developed in the vv-ECMO group. The vv-ECMO-induced acute renal impairment in this 30-hr research protocol provides a good basis to study the pathomechanism, biomarker combinations or possible therapeutic possibilities for AKI.

Extracorporeal Cardiopulmonary Resuscitation Guided by End-Tidal Carbon Dioxide-a Porcine Model

Extracorporeal membrane cardiopulmonary resuscitation (ECPR) during cardiopulmonary resuscitation (CPR) for selected cases and end-tidal carbon dioxide (ETCO₂) could be used to guide initiation of ECPR. Ventricular fibrillation was induced in 12 pigs and CPR was performed until ETCO₂ fell below 10 mmHg; then, ECPR was performed. Animals were divided into group short (G_Short) and group long (G_Long), according to time of CPR. Carotid blood flow was higher (p = 0.02) and mean arterial blood pressure lower in G_Long during CPR (p < 0.05). B-Lactate was lower and pH higher in G_Short (p < 0.01). In microdialysis lactate-pyruvate ratio, glycerol and glutamate increased in both groups during CPR, but considerably in G_Long (p < 0.01). No difference could be seen in histopathology of the brain or kidney post-ECPR. No apparent histological differences of tissue damage in brains or levels of S100B in plasma were detected between groups. This might suggest that ETCO₂ could be used as a marker for brain injury following ECPR.

Acute kidney injury in ECMO patients

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at  https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from  https://link.springer.com/bookseries/8901 .

Acute Kidney Injury During Extracorporeal Membrane Oxygenation: VA ECMO Versus VV ECMO

PURPOSE

Acute kidney injury (AKI) has been reported to be one of the most common complications in patients receiving extracorporeal membrane oxygenation (ECMO), yet variations in AKI between different types of ECMO remain unclear. This meta-analysis systematically compares AKI/severe AKI in adult patients requiring different types of ECMO.

METHODS

Two authors independently performed a literature search using PubMed, Web of Science, and Embase, encompassing publications up until April 20, 2020 (inclusive). The number of AKI patients, including patients who required/did not require renal replacement therapy (RRT), and deceased patients with AKI/severe AKI, who received different types of ECMO were collated and analyzed using STATA.

RESULTS

The results indicated that there were no significant differences in the risk of AKI/severe AKI among different types of ECMO. However, the presence of AKI and severe AKI during veno-arterial (VA) ECMO was more strongly associated with mortality.

CONCLUSIONS

Although mortality rates related to AKI/severe AKI during VV ECMO are high, the occurrence of AKI/severe AKI during VA ECMO should be given greater attention, as these instances are considered strong indicators of patient deterioration and even death. Additional studies are needed to corroborate these findings.

Risk Factors of Acute Kidney Injury in ECMO Patients: A Systematic Review and Meta-Analysis

PURPOSE

Acute kidney injury (AKI) is one of the most common complications in patients receiving extracorporeal membrane oxygenation (ECMO), but there is no systematic analysis regarding its risk factors. This meta-analysis aims to determine the risk factors of AKI in adult patients with ECMO treatment.

METHODS

Two authors independently carried out a systemic literature search using PubMed, Web of Science, and Embase until April 20, 2020 (inclusive) to enroll 12 studies reporting the necessary clinical characteristics. The Gender (male), age, APACHE II score, SOFA score, cancer, diabetes mellitus (DM), intra-aortic balloon pump (IABP), postcardiotomy, and ECMO supporting duration were pooled for further analysis by STATA.

RESULTS

Adult patients receiving ECMO who develop AKI and severe AKI incidents are usually older or have a higher APACHE II scores; in addition, severe AKI is related to higher SOFA scores, DM, and longer duration of ECMO support.

CONCLUSIONS

Patients with these clinical characteristics should be paid more attention during ECMO. There remains a need for additional studies to validate these conclusions and to detect additional AKI risk factors for ECMO patients.

Extracorporeal Membrane Oxygenation Therapy for Critically Ill Coronavirus Disease 2019 Patients in Wuhan, China: A Retrospective Multicenter Cohort Study

Currently, little in-depth evidence is known about the application of extracorporeal membrane oxygenation (ECMO) therapy in coronavirus disease 2019 (COVID-19) patients. This retrospective multicenter cohort study included patients with COVID-19 at 7 designated hospitals in Wuhan, China. The patients were followed up until June 30, 2020. Univariate and multivariate logistic regression analyses were performed to identify the risk factors associated with unsuccessful ECMO weaning. Propensity score matching was used to match patients who received veno-venous ECMO with those who received invasive mechanical ventilation (IMV)-only therapy. Of 88 patients receiving ECMO therapy, 27 and 61 patients were and were not successfully weaned from ECMO, respectively. Additionally, 15, 15, and 65 patients were further weaned from IMV, discharged from hospital, or died during hospitalization, respectively. In the multivariate logistic regression analysis, a lymphocyte count ≤0.5×10⁹/L and D-dimer concentration >4× the upper limit of normal level at ICU admission, a peak PaCO₂ >60 mmHg at 24 h before ECMO initiation, and no tracheotomy performed during the ICU stay were independently associated with lower odds of ECMO weaning. In the propensity score-matched analysis, a mixed-effect Cox model detected a lower hazard ratio for 120-day all-cause mortality after ICU admission during hospitalization in the ECMO group. The presence of lymphocytopenia, higher D-dimer concentrations at ICU admission and hypercapnia before ECMO initiation could help to identify patients with a poor prognosis. Tracheotomy could facilitate weaning from ECMO. ECMO relative to IMV-only therapy was associated with improved outcomes in critically ill COVID-19 patients.

Fluid Overload and Mortality in Patients with Severe Acute Kidney Injury and Extracorporeal Membrane Oxygenation

Background

Volume overload is increasingly being understood as an independent risk factor for increased mortality in the setting of AKI and critical illness, but little is known about its effect in the setting of extracorporeal membrane oxygenation (ECMO). We sought to evaluate the incidence of AKI and volume overload and their effect on all-cause mortality in adults after ECMO cannulation.

Methods

We identified all adult patients who underwent ECMO cannulation at the University of Chicago between January 2015 and March 2017. We evaluated the incidence of KDIGO-defined AKI, RRT, and volume overload. Volume overload was defined as achieving a positive fluid balance of 10% above admission weight over the first 72 hours after ECMO cannulation. The primary outcome collected was 90 day all-cause mortality. Secondary outcomes included 30-day mortality, duration of ECMO and RRT therapy, length of stay, and dialysis independence at 90 days.

Results

There were 98 eligible patients, 83 of whom developed AKI (85%); 48 (49%) required RRT and 19 (19%) developed volume overload at 72 hours. Patients with volume overload had increased risk of death at 90 days compared with those without volume overload (HR, 2.3; 95% CI, 1.3 to 4.2; P=0.004). Patients with AKI-D had increased risk of death at 90 days compared with those without AKI-D (HR, 2.2; 95% CI, 1.3 to 3.8; P=0.004). Volume overload remained an independent predictor of 90-day mortality when adjusting for RRT, APACHE score, weight (kg), diabetes, and heart failure (HR, 2.9; 95% CI, 1.4 to 6.0; P=0.003).

Conclusions

Volume overload and AKI are common and have significant prognostic value in patients treated with ECMO. Initiating RRT may help to control the deleterious effects of volume overload and improve mortality.

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.

Protective effects of resveratrol on acute kidney injury in rats with sepsis

AIM

To evaluate the protective effects of resveratrol on acute kidney injury (AKI) in septic rats.

METHODS

A septic rat model was established by cecal ligation and puncture (CLP). A total of 108 male Sprague Dawley rats were randomly divided into an observation group, a 6 h resveratrol intervention group and a 12 h resveratrol intervention group. Then each group was subdivided into Sham, Sham + Res, CLP and CLP + Res groups. After surgery, the survival and morphological changes in kidney tissues were observed. Serum creatinine and urea nitrogen levels, expression of GRP78, BiP, IRE1 and p65 in kidney tissues, and serum levels of TNF-α, IL-1β, IL-6 and IL-10 were investigated.

RESULTS

The survival rate of CLP + Res group (75.00%) significantly exceeded that of the CLP group (41.67%) (P<0.05). At postoperative 12 h, resveratrol significantly decreased serum creatinine and urea nitrogen levels (P<0.05). Resveratrol evidently relieved renal tubular swelling and luminal narrowing in CLP rats, and significantly reduced the high expressions of GRP78, BiP, phosphorylated IRE1 and p65 proteins (P<0.05). P65 was mainly located in the cytoplasm of Sham, Sham + Res and CLP + Res groups, and in the nucleus of the CLP group. At postoperative 12 h, resveratrol significantly reduced serum levels TNF-α, IL-1β and IL-6 in CLP rats (P<0.05), whereas elevated that of IL-10 (P<0.05).

CONCLUSION

Resveratrol significantly decreased the mortality rate of septic rats and alleviated AKI, probably by attenuating endoplasmic reticulum stress, inhibiting activation of the NF-κB pathway and mitigating the inflammatory response.

Extracorporeal Membrane Oxygenation Improving Survival and Alleviating Kidney Injury in a Swine Model of Cardiac Arrest Compared to Conventional Cardiopulmonary Resuscitation

Background

Acute kidney injury (AKI) frequently occurs in cardiopulmonary resuscitation patients. Studies comparing the effects of extracorporeal membrane oxygenation (ECMO) with conventional cardiopulmonary resuscitation (CCPR) on AKI were rare. This study aimed to compare the effects of ECMO with those of CCPR on survival rate and AKI and explore the underlying mechanisms in a swine model of cardiac arrest (CA).

Methods

Sixteen male pigs were treated with ventricular fibrillation to establish CA model and then underwent CCPR (CCPR group, n = 8) or ECMO during cardiopulmonary resuscitation (ECPR group, n = 8). The study endpoints were 6 h after return of spontaneous circulation (ROSC) or death. Serum and urine samples were collected at baseline and during the 6 h after ROSC. The biomarkers of AKI were detected by enzyme-linked immunosorbent assay. The apoptosis of renal tubular epithelial cells was discovered by transmission electron microscope (TEM) and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Apoptosis-related genes were detected by immune-staining and Western blotting. Data were compared by Student's t-test.

Results

All pigs in ECPR group were successfully resuscitated with a higher 6-h survival rate (8/8) compared to CCPR group (6/8). The expressions of AKI biomarkers including neutrophil gelatinase-associated lipocalin (NGAL), tissue inhibitor of metalloproteinase2 (TIMP2), insulin-like growth factor-binding protein 7 (IGFBP7), liver fatty acid-binding protein (LFABP), and kidney injury molecule1 (Kim-1) were all increased along with the time after ROSC in both groups and lower in ECPR group compared with CCPR group. Especially, products of urinary TIMP and IGFBP levels (TIMP*IGFBP) were significantly lower at ROSC4 (0.58 ± 0.10 ng²/ml² vs. 1.18 ± 0.38 ng²/ml², t = 4.33, P = 0.003) and ROSC6 (1.79 ± 0.45 ng²/ml² vs. 3.00 ± 0.44 ng²/ml², t = 5.49, P < 0.001); urinary LFABP was significantly lower at ROSC6 (0.74 ± 0.06 pg/ml vs. 0.85 ± 0.11 pg/ml, t = 2.41, P = 0.033); and urinary Kim-1 was significantly lower at ROSC4 (0.66 ± 0.09 pg/ml vs. 0.83 ± 0.06 pg/ml, t = 3.99, P = 0.002) and ROSC6 (0.73 ± 0.12 pg/ml vs. 0.89 ± 0.08 pg/ml, t = 2.82, P = 0.016). Under light microscope and TEM, the morphological injures in renal tissues were found to be improved in ECPR group. Moreover, apoptosis was also alleviated in ECPR group.

Conclusions

Compared with CCPR, ECMO improves survival rate and alleviates AKI in a swine model of CA. The mechanism of which might be via downregulating AKI biomarkers and apoptosis in kidney.