Continuous renal replacement therapy applications on extracorporeal membrane oxygenation circuit (original) (raw)

2017, Indian Journal of Critical Care Medicine

Successful utilization of extracorporeal membrane oxygenation (ECMO) in children was defined as early as the 1970s. [1,2] Beginning of continuous renal replacement therapies (CRRTs) also dates back to 1970s, and expectations from the therapy as well as the technique has evolved since then. [3,4] In our day, continuous venovenous hemofiltration or hemodiafiltration is used frequently in Pediatric Intensive Care Units (PICUs) for renal replacement therapy, but experience of CRRT application on ECMO circuit is still limited. Acute kidney injury is frequently observed in ECMO patients. The hypoxic insult and systemic inflammatory response associated with the ECMO process or the underlying condition are the two important factors causing acute kidney injury. Reduced perfusion of the kidneys before ECMO, reperfusion injury after ECMO, and disrupted hormonal mechanisms are predisposing factors. [5] Acute kidney injury and requirement of renal replacement are associated with increased mortality in these patients. [6] Even when the kidneys are minimally injured and functioning as in a normal child, the massive fluid overload at the beginning of ECMO process cannot be easily overcome solely by the kidneys. It is well described that fluid overload affects survival in critically ill children and CRRT enhances fluid management in ECMO patients. [7,8] Slow but continuous nature of the renal replacement is superior to intermittent hemodialysis in this hemodynamically unstable patient group. [9] Background and Aims: Continuous venovenous hemofiltration or hemodiafiltration is used frequently in pediatric patients, but experience of continuous renal replacement therapy (CRRT) application on extracorporeal membrane oxygenation (ECMO) circuit is still limited. Among several methods used for applying CRRT on ECMO patients, we aim to share our experience on inclusion of a CRRT device in the ECMO circuit which we believe is easier and safer to apply. Materials and Methods: The data were collected on demographics, outcomes, and details of the treatment of ECMO patients who had CRRT. During the study period of 3 years, venous cannula of ECMO circuit before pump was used for CRRT access for both the filter inlet and outlet of CRRT machine to minimize the thromboembolic complications. The common indication for CRRT was fluid overload. Results: CRRT was used in 3.68% of a total number of patients admitted and 43% of patients on ECMO. The patients have undergone renal replacement therapy for periods of time ranging between 24 h and 25 days (260 h mean). The survival rate of this group of patients with multiorgan failure was 33%. Renal recovery occurred in all of the survivors. Complications such as electrolyte imbalance, hypothermia, and bradykinin syndrome were easily managed. Conclusions: Adding a CRRT device on ECMO circuit is a safe and effective technique. The major advantages of this technique are easy to access, applying CRRT without extra anticoagulation process, preventing potential hemodynamic disturbances, and increased clearance of solutes and fluid overload using larger hemofilter.