Hello, I am a current student. I was wondering if anyone could lead me in the right direction on information on the web to understand static and dynamic. It is coming up on a test Monday and I really want to make sure I understand the main concepts. Like are they inversely related, when one goes up or down does the other follow. I know the calculations just want to make sure I am understanding the important concepts.
Also, fluidic sort of lost me too. Our instructor was showing us diagrams in class but can't find any on the net or in our vent book. She was basically teaching. And/Nand, or/nor, I would like to find something on the net to see the diagrams and can't find anything. I really want to do well on this test. Thanks so much for your help.....
It is pretty simple... static means no movement whereas, dynamic means movement. In this case, that would be movement of gas flow. A static compliance uses a plateau pressure versus a peak pressure. A plateau pressure is measured by stopping airflow in the vent circuit by closing the exhalation valve. The pressure will drop from a peak value to a plateau or static value. In dynamic compliance calculations you use the peak pressure (which is almost always higher than the static or plateau pressure). Static compliance gives you a more accurate picture of the patient's compliance than does dynamic compliance because the peak pressure value changes from breath to breath (assuming you are in the volume ventilation mode) whereas, the static pressure is constant (at least until the patient's compliance changes).
As for fluidics, I don't know of a specific web site, but you could go to the library and get a book on the subject. I know most RT schools use, "Respiratory Therapy Equipment" by Steven McPherson. Fluidics is dealt with in that text.
SoontobeCRT, Dynamic comliance and static complians are not necessarily linked together. Like PCMS stated one is dealing with the movement of a gas and the other is dealing with no movement of a gas. Cdyn is change in volume over pip - PEEP so you are looking at the the change in pressure it takes to push in a given volume, this takes into account lung comliance and airway resistance. Cs is loking at the pressure that that given volume volume of gas is putting on the lungs when it is just sitting there. There is not direct link between the two due to Cdyn taking into account RAW as well. Basically Raw can change, changing your Cdyn but your Cs stayed the same, think of the as different things, but Cs as a part of Cdyn so if it Cs changes then Cdyn as to but not necessarly the other way around.
hi! thanks to ventworld for a good platform to exchange info, i would like to know to plot a trend what would be the max & min values for Cdyn; Rinsp; Rexp & Cstat i would be much obliged with this info. Thanks; novice (jr)
