Improvement of Oxygenation in Severe Acute Respiratory Distress Syndrome With High-Volume Continuous Veno-venous Hemofiltration

Abstract

The efficacy and therapeutic mechanisms of continuous renal replacement therapy (CRRT) for improvement of oxygenation in acute respiratory distress syndrome (ARDS) remain controversial. These questions were addressed by retrospective analysis of severe ARDS patients admitted to the pediatric intensive care unit of our hospital from 2009 to 2015 who received high-volume continuous veno-venous hemofiltration during mechanical ventilation. There was a significant improvement in partial oxygen pressure/fraction of inspired oxygen (PaO2/FiO2) 24 hours after CRRT onset compared with baseline (median change = 51.5; range = −19 to 450.5; P < .001) as well as decreases in FiO2, peak inspiratory pressure, positive end-expiratory pressure, and mean airway pressure (P < .05). The majority of patients had a negative fluid balance after 24 hours of CRRT. White blood cell (WBC) count decreased in the subgroup with high baseline WBC count (P < .05). PaO2/FiO2 was higher in ARDS patients with extrapulmonary etiology than in those with pulmonary etiology (P < .05). Improvement in oxygenation is likely related to both restoration of fluid balance and clearance of inflammatory mediators.

Effects of Early Continuous Venovenous Hemofiltration on E-Selectin, Hemodynamic Stability, and Ventilatory Function in Patients with Septic-Shock-Induced Acute Respiratory Distress Syndrome

“…CRRT, one of extracorporeal treatments, has been used for critically ill patients with or without AKI or acute kidney failure and ARDS is one of nonrenal indications for CRRT [11]. Studies showed that CRRT brought benefits to ARDS patients (non-AKI), including improvement of oxygenation and survival [14, 25]. We used CVVH, one of CRRT, in the current study and we found significant improvement of EVLWI in both groups after initiation of treatment.…”

“…Recent clinical and animal studies showed that CVVH was associated with improved oxygenation and organ function, facilitated fluid removal, and decreased EVLW in ALI/ARDS patients [25, 28]. Many cytokines and biomarkers, including endothelial and epithelial alveolar biomarkers, involved in the pathogenesis of ARDS and sepsis are released and it is believed that CVVH attenuates the entire inflammatory response and reduces the levels of biomarkers via removal of cytokines [14, 36]. …”

“…In addition, the stable ITBVI, CI, and SVRI and the decrease in norepinephrine dose demonstrate improved fluid responsiveness in the ECVVH group. CVVH stabilized hemodynamics in critically ill patients [39], and the effect could be associated with the suppression of inflammation and the removal of cytokines [14]. …”

“…Although CRRT has been extensively used as renal support for critically ill patients in intensive care unit (ICU) [10], nonrenal indications for CRRT have been reported recently [11]. Although the therapeutic mechanisms of CRRT for illnesses without acute kidney injury (AKI) or renal failure are not cleared adequately, CRRT for nonrenal indications has been studied in patients with severe sepsis/septic shock [12, 13], ARDS [14], and severe acute pancreatitis [15]. In addition, application of CRRT to children with septic shock or maple syrup urine disease is simple and safe and contributes to the management of various illnesses without renal failure [16].…”

Renal replacement therapy in patients with acute respiratory distress syndrome: a single-center retrospective study

“…Our results do not confirm some of the previous findings suggesting that early RRT was associated with favorable outcomes in critically ill patients. 1,10,11 One of the reasons for this discrepancy could be because the initiation of RRT in those studies occurred within a few hours of admission to the ICU. Interestingly, our survival analysis showed a trend toward a survival benefit for patients with RRT initiation after >48 hours but was not statistically significant.…”