My wife is on ventilater mechanical(8 days) for ards. but its difficult to extubate coz her heart rate becomes 150 and above after desedation. soln?

Cause ; rffext: Sorry to hear about this unfortunate illness. In cases of ARDS i've cared for the rapid heart rate is a barometer of the lung problems, not the primary reason why the patient is sick and not an impediment to extubation. Check with your docs there and confirm the rhythm isn't atrial fibrillation. If it isn't, then primary treatment remains healing the lungs well enough to withstand being off vent.