This review, based on relevant published evidence and the authors’ clinical experience, presents how to evaluate a patient with acute respiratory failure re- quiring ventilatory support. This patient must be care- fully evaluated by nurses, physiotherapists, respira- tory care practitioners and physicians regarding the elucidation of the cause of the acute episode of respi- ratory failure by means of physical examination with the measurement of respiratory parameters and as- sessment of arterial blood gases analysis to make a correct respiratory diagnosis. After the initial evalua- tion, the patient must quickly receive adequate oxy- gen and ventilatory support that has to be carefully monitored until its discontinuation. When available, a noninvasive ventilation trial must be done in patients presenting desaturation during oxygen mask and or PaCO2 retention, especially in cases of cardiogenic pulmonary edema and severe exacerbation of chronic obstructive pulmonary disease. In cases of noninva- sive ventilation trial-failure, endotracheal intubation and invasive protective mechanical ventilation must be promptly initiated. In severe ARDS patients, low tidal ventilation, higher PEEP levels, prone position-ing and recruitment maneuvers with adequate PEEP titration should be used. Recently, new modes of ven- tilation should allow a better patient-ventilator inter- action or synchrony permitting a sufficient unloading of respiratory muscles and increase patient comfort. Patients with chronic obstructive pulmonary disease may be considered for a trial for early extubation to noninvasive positive pressure ventilation in centers with extensive experience in noninvasive positive pres- sure ventilation
