OBSERVATIONAL STUDY OF CONTINUOUS RENAL REPLACEMENT THERAPY USING OXIRIS FILTER AND SUSTAINED LOW EFFICIENCY DIALYSIS IN PATIENTS WITH SEPTIC ACUTE KIDNEY INJURY

Introduction:

 Septic acute kidney injury (AKI) has a high mortality rate. The oXiris hemofilter combines the removal of cytokines and endotoxins in addition to uremic toxins during continuous renal replacement therapy. Studies using oXiris filter have been mainly retrospective in nature. Hence, we conducted a prospective study and compared continuous renal replacement therapy (CRRT)  using oXiris filter with slow low efficiency dialysis(SLED) with respect to ICU mortality and renal recovery.

Methods:

We included adult septic acute kidney injury patients with shock admitted in ICU, who underwent renal replacement therapy either with CRRT(blood flow = 100- 150 ml/min and target effluent rates = 20-35 ml/kg/hr) using oXiris filter or with SLED(blood flow =100-150 ml/min and dialysate flow 200-300 ml/min for a duration of 6-8 hours). The severity of illness was assessed by Acute Physiology And Chronic Health Evaluation (Apache) II Score and Sequential Organ Failure Assessment (SOFA) score. Ventilatory requirements, inotropic requirements, procalcitonin levels, lactate and bicarbonate levels were documented at admission and at three days. We compared mortality, renal recovery, weaning from ventilator, ICU stay and followed up the patients at 1 and 3 months post discharge from the hospital. Paired t-test, independent t –test and Chi square tests were used to compare outcomes between the two groups. Paired t- test is used to know the difference between two variables for the same subject. Chi Square test was used to compare observed results with expected results by proposing a null hypothesis. Independent–t test used to compare the means of two independent groups to know the difference. A P-value of <0.05 was considered statistically significant.

Results:

60 patients were included in this study, with 30 patients each in CRRT and SLED groups. We found a significantly higher mortality in the CRRT (n=25) group compared to the SLED(n=15) group (83.3% v/s 50%,p=0.006). Renal recovery(defined as patients becoming independent of dialysis) was significantly lower in the CRRT (n=3) group compared to the SLED(n=12) group(10% v/s 40%,p=0.006). Three patients in the SLED group and two in the CRRT group continued to remain on dialysis after three months of discharge. Patients in the CRRT group were more critically ill as evidenced by a number of clinical as well as lab parameters. Clinical and lab parameters assessed at presentation and at three days of admission were significantly worse in the CRRT group of patients in comparison to the SLED group of patients viz inotropic requirement(in figure), ventilatory requirements, SOFA score(in figure), procalcitonin levels and lactate levels .

Conclusions:

Previous studies of CRRT with oXiris filter have shown high mortality rates. Our prospective, observational study confirms the finding of higher mortality in the CRRT group of patients. The higher mortality is possibly due to patients in the CRRT group being more critically ill. Performing a randomised trial in this group of patients is difficult because it is largely the hemodynamics and cost that dictate the modality especially in the Indian context. 

I have no potential conflict of interest to disclose.

I did not use generative AI and AI-assisted technologies in the writing process.