read that in France they are using RL mixed with dextrose
probably like RL (500ml) minus 20 ml plus 20 ml D25

Yes , the level of block cant be predicted by isobaric ropivacaine.
What i have experienced is that the fall in BP is less, mean that the number of bolus of ephedrine / termin required is less.

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.

Hi,
    Kindly help in practical use of halothane.
    How to induce and intubate a child/adult only by halothane?  How much time it will take?
    What are the most common problems faced practically?

  kindly tell your experiences in halothane.