Abstract: 【Abstract】Objective To explore the correlation between timing of continuous renal replacement therapy (CRRT) and efficacy in elderly patients with severe heart failure complicated with acute renal function injury (AKI). Methods Elderly severe heart failure patients with AKI treated in our hospital from August 2017 to June 2019 were enrolled. Patients were divided into 2 groups according to the timing of CRRT: experimental group (start CRRT Within 6 hours after admission) and control group (start CRRT at 6～12 hours after admission). The mechanical ventilation time, CRRT treatment time, ICU stay length, and mortality (within 14 days and 28 days) of patients were recorded. Meanwhile, patients were monitored for changes in vital signs, serum potassium and sodium level before and after CRRT. Results The treatment time and ICU stay length of patients in the experimental group were shorter than those in the control group (t=4.700 and 3.596,respectively, P=0.001). Meanwhile, the mortality within 28 days of patients in the experimental group was lower than that in the control group (χ2=4.043, P=0.044).However, no significant differences in mechanical ventilation time (t=0.071, P=0.472) and the mortality within 14 days (χ2=0.351,P=0.554) between the two groups. After CRRT, patients in the experimental group had higher heart rate, systolic blood pressure, diastolic blood pressure (t=6.276, 30.561, 10.887, P=0.001) and lower respiratory rate, serum potassium and sodium levels (t=4.224, 3.325, 10.646, P= 0.001) than those in the control group. Conclusion CRRT has good therapeutic effect on elderly patients with severe heart failure complicated with AKI. CRRT can shorten the hospitalization stay length and improve patient’s prognosis, which has good clinical application value.

Key words: Heart failure, continuous renal replacement therapy, acute kidney injury, electrolytes