2 Laryngeal obstruction symptoms：inspiratory dyspneainspiratory stridordepression of suprasternal fossa, intercostal and supraclavicular space or epigastrium while inspirationhoarseness and even cyanosis
4 Laryngeal obstruction classification:Ⅰ°there is no symptoms at rest. But slight inspiratory dyspnea and stridor may occur during crying or on exertion
5 Laryngeal obstruction classification:Ⅱ°slight inspiratory dyspnea during quiet respiration, and exaggeration on exertion. Sleeping and taking the meal is nearly normal , no evidence of hypoxia.
6 Laryngeal obstruction classification:Ⅲ°：with marked inspiratory dyspnea, loud stridor, depression of suprasternal and supraclavicular fossae and intercostal spaces, cyanosis, restless and struggles for air hunger, with quick pulse, high blood pressure and refuse meals.
7 Laryngeal obstruction classification:Ⅳ°：extremely dyspneic, restless, sweating, cyanoticsis. Pulse is rapid, irregular, weak and thready. B.P. drops. Finally circulatory collapse may occur or may die of asphyxia or cardiac failure.
9 Laryngeal obstruction TreatmentⅡ°：etiological treatment .in case of tumors of the larynx, trauma, bilateral vocal cords paralysis, tracheotomy is indicated.
10 Laryngeal obstruction TreatmentⅢ°：If the laryngeal obstruction is caused by inflammation, medical treatment can be administrated under close observation.Tracheotomy should be prepared. If dyspnea is not relieved, tracheotomy should be performed immediately.
20 Tracheotomy Complications Hemorrhage Subcutaneous emphysema PneumothoraxDifficulty of decannulationLaryngeal or tracheal stenosis
21 Cricothyrotomy Employed in first-aid cases. Making an opening in the membrane between the cricoid cartilage and thyroid cartilage and insert a cannula.After the situation becomes stable, ordinary tracheotomy should be performed.