 Noninvasive blood pressure was measured before induction as a baseline value, after induction just before laryngoscopy and in 3 minutes of interval during rigid bronchoscopy. Hypotension was defined as a systolic blood pressure lower than 60 mmHg for children under 2 years and 70 mmHg for children 2-12 years old. Hypotension was treated with an increase in IV crystalloid infusion and two consecutive measures of hypotension treated with ephedrine and a decrease in remifentanil infusion. Bradycardia was defined as a heart rate slower than 80 beatsmin for infants and 60 beatsmin for older children 11 and treated with atropine 0.01 mgkg. 