Post by Chuck Weddle on Nov 14, 2021 13:42:08 GMT
I saw on a Facebook page that there supposedly biomeds telling the clinical staff that it's OK to bleach a machine first and then acid clean as long as they both get done. This is NOT true! With as many flow and pressure problems that are posted I wonder how many of them might be related to this practice. Especially the ones that the first thing people say to try is to replace the Diasafe filter.
CHEMISTRY 101
The calcium that's in dialysate will start to precipitate out of solution when the pH is above 7.2. Since normal dialysate pH is about 7.4, precipitate is being formed throughout the treatment. The fibers of a DF filter will be the first place affected by this as they will scale over just like RO membranes do and require cleaning. That's why B.Braun says to do an acid rinse between patients, to clean the DF filter.
The pH of bleach is about 12 so, if there is any residual dialysate left in the machine it will pretty instantly precipitate and can be as hard as concrete. Many years ago, we had Althin System 1000 machines. There was a manufacturer screw up and not enough acetic acid was put into the concentrate. At this time it was not required or common practice to test for pH. This resulted in the machines jamming up with precipitate after about 3 hours of treatment. In many of the machines it required us to manually remove the precipitate. The precipitate was about the size of grains of kosher salt and could be seen in the degassing chamber. When tested, we found the pH to be just under 8. It was a very busy and interesting 2 weeks before we could get a new supply of concentrate!
Please educate your staff about this. It might just make your life easier!
CHEMISTRY 101
The calcium that's in dialysate will start to precipitate out of solution when the pH is above 7.2. Since normal dialysate pH is about 7.4, precipitate is being formed throughout the treatment. The fibers of a DF filter will be the first place affected by this as they will scale over just like RO membranes do and require cleaning. That's why B.Braun says to do an acid rinse between patients, to clean the DF filter.
The pH of bleach is about 12 so, if there is any residual dialysate left in the machine it will pretty instantly precipitate and can be as hard as concrete. Many years ago, we had Althin System 1000 machines. There was a manufacturer screw up and not enough acetic acid was put into the concentrate. At this time it was not required or common practice to test for pH. This resulted in the machines jamming up with precipitate after about 3 hours of treatment. In many of the machines it required us to manually remove the precipitate. The precipitate was about the size of grains of kosher salt and could be seen in the degassing chamber. When tested, we found the pH to be just under 8. It was a very busy and interesting 2 weeks before we could get a new supply of concentrate!
Please educate your staff about this. It might just make your life easier!
