Technical advances in renal replacement therapy

Prognostic Prediction Using the Clinical Data and Ultrasomics-Based Model in Acute Respiratory Distress Syndrome (ARDS) Combined with Acute Kidney Injury (AKI)

OBJECTIVE

A model was constructed based on clinical and ultrasomics features to predict the prognosis of patients in the respiratory intensive unit (RICU) who had acute respiratory distress syndrome (ARDS) combined with acute kidney injury (AKI). AKI ensues after ARDS in RICU ordinarily. The prognostic prediction tool was further developed on this basis.

METHODS

We collected clinical and ultrasonic data from 145 patients who had ARDS combined with AKI and received continuous renal replacement therapy (CRRT) in the RICU of Xiangyang Hospital of Traditional Chinese Medicine from March 2016 to November 2019. The patients were divided into the survival group (n = 51) and the death group (n = 94), depending on the treatment outcome. The training set (n = 102) and the testing set (n = 43) were established based on patient data. The clinical and ultrasomics features and the CRRT parameters were compared between the two groups. The influence factors of death were analyzed by logistic regression, and four predictive models were established. The predictive performance of 4 models was compared using the R Software 4.1.3. The decision curve analysis graphs were drawn using the R language to determine the net benefit of each.

RESULT

Univariate analysis was conducted in the training set. The following risk factors for poor prognosis were identified: age, concurrent cancers, sequential organ failure assessment score (SOFA), number of organ dysfunctions, positive cumulative fluid balance at 72 h, time from ICU admission to CRRT, mean arterial pressure, oxygenation index, and gray-level size zone matrix, GLSZM (SumEntropy.239/SmallDependenceHighGrayLevelEmphasis.314/Maximum.327/Variance.338) (P < 0.05). Four models were built based on the above factors: clinical model, CRRT model, ultrasomics-based model, and combination model. Comparison using the MedCalc software indicated that the best predictive performance achieved with the combination model. The decision curve analysis also suggested that the combination model had the highest net benefit. Similar results were reported after validation on the testing set.

CONCLUSION

The prognosis of ARDS patients combined with AKI is usually poor. The combination model based on clinical and ultrasomics features had the highest predictive performance. This model can be used to improve the clinical outcome and prognosis.

Continuous Renal Replacement Therapy: Forty-year Anniversary

In 1977 Peter Kramer performed the first CAVH (continuous arteriovenous hemofiltration) treatment in Gottingen, Germany. CAVH soon became a reliable alternative to hemo- or peritoneal dialysis in critically ill patients. The limitations of CAVH spurred new research and the discovery of new treatments such as CVVH and CVVHD (continuous veno-venous hemofiltration and continuous veno-venous hemodialysis). The alliance with industry led to development of new specialized equipment with improved accuracy and performance in delivering continuous renal replacement therapies (CRRTs). Machines and filters have progressively undergone a series of technological steps, reaching a high level of sophistication. The evolution of technology has continued, leading to the development and clinical application of new membranes, new techniques and new treatment modalities. With the progress of technology, the entire field of critical care nephrology moved forward, expanding the areas of application of extracorporeal therapies to cardiac, liver and pulmonary support. A great deal of research made extracorporeal therapies an interesting option for the treatment of sepsis and intoxication and the additional use of sorbents was explored. With the progress in understanding the pathophysiology of acute kidney injury (AKI), new guidelines were developed, driving indications, modalities of prescription, monitoring techniques and quality assurance programs. Information technology and precision medicine have recently contributed to further evolution of CRRT, with the possibility of collecting data in large databases and evaluating policies and practice patterns. This is likely to ultimately result in improved patient care. CRRTs are 40 years old today, but they are still young and full of potential for further evolution.

We Restrict CRRT to Only the Most Hemodynamically Unstable Patients

From the initial version of an extended renal replacement therapy, the initiative to provide safer, more efficient means for detoxification and volume removal in comparison with intermittent renal replacement therapies (IRRT) has been evaluated. As a result, the Kidney Disease Improving Global Outcomes guidelines for acute kidney injury recommend the preferential use of continuous renal replacement therapy (CRRT) in patients who are hemodynamically unstable or who suffer from intracranial hypertension. The choice of dialysis modality is also influenced by other factors including clinical expertise, and the availability of each treatment option in individual medical centers. In the scientific community, there is an ongoing debate regarding the choice of dialysis modality. On one side, the inability of recent studies to demonstrate any mortality or renal recovery benefit for CRRT, the need for patient immobilization, and prohibitive additional costs impede widespread adoption of the method.On the other side, the physiological advantages of CRRT in detoxification and volume removal and the identified flaws related to the comparative literature regarding CRRT and IRRT fuel this debate. Fluid overload is a recognized and yet clinically underappreciated factor that increases morbidity and mortality in the intensive care unit (ICU). Continuous renal replacement therapy has a distinct advantage over IRRT in achieving euvolemia and thus the potential for improving outcomes in all patients in the ICU setting in which extensive fluid administration is often obligatory. With this in mind, perhaps CRRT should not be restricted to only those patients in whom their hemodynamic status requires it. This article reviews the current literature and the myths that may influence the selection of one mode of therapy over the other among patients requiring renal replacement therapy in the ICU.