FCV Vs VCV in Obstructive and Asthmatic Patients

This study is comparing two modes of mechanical ventilation — flow-controlled ventilation (FCV) versus volume-controlled ventilation (VCV) — in patients who are on a breathing machine due to a severe asthma or COPD flare-up, to determine which method ventilates the lungs more evenly and causes less strain. **You may be eligible if...** - You are 18 or older - You are on a mechanical ventilator through a breathing tube (intubated) - You were intubated because of a severe flare-up of asthma or COPD - You have been intubated for 72 hours or less **You may NOT be eligible if...** - You have severe mucus buildup requiring suctioning more than 5 times per nursing shift - You have an untreated collapsed lung (pneumothorax without drainage) - You have dangerously low blood pressure not responding to fluids or medications - You have high pressure in your brain or skull - Your breathing tube has a very small inner diameter (6mm or less) - Withdrawal of life support or palliative care is being planned - You have a pacemaker (ICD) or recent lung surgery Talk to your doctor to see if this trial is right for you.