# built-in calculator for calculating Filtration fraction~The calculator was built in prescription system since 2020/10/01~providing tempt filtration fraction for operators to adjust CVVH dose~the protocol of patient care didn't change between before and after group.
The goal of this observational study is to compare in ICU patients received CVVH treatment. The main questions it aims to answer are:~Control of Filtration fraction by built-in calculator~Reduced filter clotting and prolong filter lifespan~Improve patient mortality Participants will divided into before group and after group based on the day when built-in calculator for calculating Filtration fraction was utilized.~Researchers will compare before group to see if there were differences in clotting events, filter downtime, filter lifespan, mortality, etc.