Despite few scientific evidence that could support the use of ketamine in adult patients undergoing acute bronchospasm requiring mechanical ventilation (MV), ketamine is largely employed in this setting. The aim of this study is therefore assess more definitively the real benefit of using ketamine in patients with severe bronchospasm, requiring ICU stay and need for MV in order to establish or refute the use of this drug as "standard therapy" in these cases.

Inclusion Criteria:

• patients with acute exacerbation of COPD or status asthmaticus, undergoing controlled mechanical ventilation
• acute bronchospasm, defined as airway resistance value (Rsr max) greater than 12, use of inhaled therapy with bronchodilators and systemic corticosteroids
• patients requiring the use of continuous intravenous sedation for optimization of ventilation

Exclusion Criteria:

• contraindication or history of previous adverse events with the use of the studied drugs
• other diagnostic potential Rsr increase of not causing bronchospasm (bronchial obstruction, acute respiratory distress syndrome adult, pulmonary fibrosis)