flow rate vs minute ventilation

[jean]

hello.. i know that it might be a foolish thing to ask this, but in my place, we are not talking much about this, so my understanding about this basic thing is very little,,

i am learning about oxygen therapy and i realize that it involves talking about inspiratory peak flow rate and minute ventilation...now, my question is :
1. what is the difference between them?
2. why should we consider peak inspiratory flow rate in oxygen therapy?
3. what relationship does the peak inspiratory flow and minute ventilation have? i mean, how can they affect each other?

please help...thx u

[e.inet]

explaining in eg ----

volume you take in single breath --- 500ml
how many times you take breath in a minute -- 12
your minute ventilation = tidal volume * resp rate = 500 * 12 = 6000 ml/minute

your resp rate -- 12
or inspiration starts every 60/12 = 5 second
normal ratio  of inspiration : expiration = 1:2
so you take inspiration in 1.66 sec, expiration in 3.33 second
so you are taking 500ml in 1.66 sec
so you PIFL becomes 500 / 1.66 = 300 ml/sec = .3 L/sec = 18000 ml/minute
as an approximation, PIFR =(roughly)  3 to 4 * minute ventilation  (for setting up in ventilator)

in copd, asthma patients, high PIFR needed =(roughly) 60-80 L/min or 1 L/sec.
as you need to deliver volume quickly.