In the last of our 10 part series on Phaco Fundamentals, we present a video showing specific starting settings for all steps of cataract surgery. This video covers both the fluidic settings as well as the phaco settings for most cataracts.
Remember that these are starting points only and that the fluidic settings are specific to this particular phaco needle and tip. If you are using a smaller phaco tip with less fluid flow, then you will need to adjust the settings. This video shows a 2.75 (or 2.8) mm phaco tip but if you are using a 2.2 mm phaco tip then some changes will be needed: you will have less flow and therefore you should decrease the aspiration flow rate (lower the outflow) and increase the infusion pressure / bottle height (raise the inflow). You will also need higher vacuum levels if the bore of the needle is smaller.
If you are doing a case with a smaller anterior chamber, then more inflow pressure would be helpful. If the chamber is too deep, then lowering the inflow pressure is suggested. If the nuclear particles don’t flow towards the phaco tip then increase the aspiration flow rate. If the phaco probe doesn’t hold the nucleus well for chopping, then increase the vacuum level. If the ultrasound energy is too low to effectively bury the phaco tip for the chop technique, then increase the power level. You are smart and you can determine which adjustments will be needed to optimize the phaco machine to your technique and your specific patient.
click below to learn from this final video in the series:
I have a question about this statement that is in the report. “you will have less flow and therefore you should decrease the aspiration flow rate (lower the outflow) and increase the infusion pressure / bottle height (raise the inflow). You will also need higher vacuum levels if the bore of the needle is smaller.”
That if you reduce the aspiration diameter you also have more resistance and less outflow is understandable to me.
However, what I don’t understand is why is it recommended to further reduce the outflow? don’t you have to increase the outflow to have the same followability?
That’s what you say with the vacuum, and here you also recommend increasing it, which makes absolute sense, why not with the flow?