The purpose of this study is to determine whether the use of laryngeal mask classic as method for securing the airway in the population of 2 years to 14 years is associated with risk of laryngospasm as compared with the use of endotracheal tube.

Laryngospasm, defined as closure of the glottis as a protective reflex secondary to abnormal stimulation (7), with a reported incidence in the general population of 8.7 per 1000 patients undergoing surgical procedures (8), is considered the most common event among the complications in the management of pediatric airway, causing 40% of obstructive events after extubation (7-8), with incidents reported in the American pediatric population from 0.4% to 14% (8-9) for population under 6 years and 3.6% in > 6 years. Among the risk factors associated with the development of laryngospasm and anesthesia in children are: age, ASA (4), upper respiratory infection (10), among others, however in recent years has gained interest and generated dispute the association between this outcome and the type of device used to secure the airway during anesthesia. Although the endotracheal tube device is considered the "gold standard" for airway management, this has been associated with an increased incidence of laryngospasm (8), explained this phenomenon, apparently by direct stimulation because the tube into the larynx and trachea, which triggers, in theory, a posterior laryngeal reflex intense (11).

In recent years, with the advent of new devices for securing the airway, especially supraglottic use type Classic Laryngeal Mask (LM), it was thought that the main trigger of laryngospasm, laryngeal and tracheal stimulation caused by the endotracheal tube (ETT), would be resolved and will decrease the incidence of complications in the pediatric population; however, three recent prospective studies (10-11-12) is no statistically significant difference in incidence of laryngospasm among laryngeal mask and endotracheal tube. By contrast, two retrospective studies (6.4) have shown increased incidence of laryngospasm compared to ETT in children. In 2002, one of the aforementioned prospective studies (11), found an incidence of laryngospasm 11.2% versus 16.9% for ETT versus ML, respectively, but without an increase in relative risk statistically significant when comparing the ML to ETT.

In view of these findings and considering that most studies in this respect seem to have technical and methodological limitations, our objective is to determine by controlled clinical trial non inferiority the risk of laryngospasm with the endotracheal tube vs a device supraglottic, Classic Laryngeal Mask type as a method of airway patency in the pediatric population, assuming that the risk of laryngospasm with both devices is equal.

Inclusion Criteria:

• ASA I and III children, 1-14 years of age
• Children scheduled for surgery or therapeutic procedures under general anesthesia and fasting as defined in the fasting guidelines
• Responsible adult patients whose accept and sign the informed consent of study

Exclusion Criteria:

• Surgery of the head, neck, chest and/or abdomen (except the abdominal wall)
• Position different than the supine in surgery
• Malformations or anatomic abnormalities of the face and airway
• Procedures over 3 hours
• Patients with pulmonary aspiration risk: morbid obesity, intestinal obstruction, gastrointestinal bleeding, gastroparesis, gastroesophageal reflux
• Patients with limited mouth opening or cervical spine extension and classified as difficult airway