Abstract: 【Abstract】Objective To study the effects of continuous extracorporeal circuit pressure and other factors on extracorporeal circuit lifespan during continuous renal replacement therapy (CRRT). Methods Eightyfive patients with 251 episodes of CRRT and a total of 10,322.2h were recruited in the intensive care unit. We extracted the pressure/minute data of extracorporeal circuit from CRRT machine, treatment parameters, and laboratory data to investigate the effects on extracorporeal circuit lifespan. Results Mild access outflow dysfunction (AOD) event did not affect the circuit lifespan. ModeratEto-severe AOD events had different effects on extracorporeal circuit life using various anticoagulants; moderatEto-severe AOD events significantly shortened the circuit lifespan when no anticoagulant or citrate was used (t=3.179, P=0.002; t=1.949 P=0.054) but had no effect on the circuit lifespan when low molecular weight heparin (LMWH) or heparin was used (t=0.630, P=0.950). Cox analysis suggested that moderatEto-severe AOD event was a risk factor for extracorporeal circuit survival (β=0.638, HR=1.893, 95% CI 1.300～2.756, P=0.001), while citrate (β =- 0.906, HR=0.404, 95% CI 0.304~0.537, P＜0.001) and CVVHDF (β =- 0.722, HR=0.486, 95% CI 0.335～0.704, P＜0.001) were the protective factors. Conclusions Using citrate as the anticoagulant and CVVHDF can prolong the lifespan of CRRT. Clinically, when moderatEto-severe AOD event occurred and citrate or no anticoagulant was used, we should adjust access outflow to extend the circuit lifespan rather than the increase of anticoagulant dose.

Key words: Continuous renal replacement therapy, Pressure data, Access outflow failure, Risk factor