Combination of continuous renal replacement therapies (CRRT) and extracorporeal membrane oxygenation (ECMO) for...

The critically ill patients may require mechanical ventilation, cardiac mechanical support, and other types of critical support. Extracorporeal membrane oxygenation (ECMO) is a supportive therapy, which provides good cardiopulmonary and end-organ support. Continuous renal replacement therapies (CRRT) exhibit important advantages in terms of clinical tolerance and blood purification. This investigation aims to evaluate the acute renal failure in cardiac patients under ECMO, and assess the effect of combining these two technologies, ECMO and CRRT.

Between December 1998 and June 2001, 10 adult cardiac patients were treated on ECMO. Five of them were treated with both ECMO and CRRT. The clinical outcomes were retrospectively analyzed.

Of the 10 patients studied, five were men and five were women. The mean age of survivors and non-survivors was 37.00 +/- 14.54 years and 46.17 +/- 7.41 years, respectively. The overall mortality rate was 60%. Survivors did not differ significantly from non-survivors in age or gender. The APACHE II scores on the first day of ECMO support between survival and non-survival were 19.00 +/- 9.38 and 24.67 +/- 3.50 (P value = 0.392) (Table 2), which demonstrates no significant differences too. The cause of death in most patients was related to organ system failure during the 24 h immediately before ECMO started. Five patients with acute renal failure treated by CRRT were eventually died. The median and mean survival in this group on CRRT was 40.50 +/- 18.07 h and 92.60 +/- 60.50 h.

We conclude that mortality rate for acute renal failure in cardiac patients under ECMO continues to be high. Our data suggest that acute renal failure is generally a part of multiorgan failure. This unique form of acute renal failure, causes generalized edema and fluid overload despite still low serum creatinine and azotemia, and deteriorates rapidly to death. From this study shows, advanced cardiac failure may need more aggressive and early initiation of ECMO support before acute renal failure develops. Acute renal failure in advanced heart failure under ECMO support means a grave sign, need aggressive heart transplantation therapy as soon as possible. Combination of CRRT and ECMO might serve an alternative therapy bridging the temporary replacement treatment and heart transplantation in advanced cardiac patients.