The hypothesis of this study is that ultrasound measurements may improve the preoperative detection of difficult laryngoscopy (DL) in pediatrics. The primary objective of this study will be to evaluate the usefulness for the prediction of a DL of five ultrasound measurements obtained from the neck skin to three structures of the upper airway (hyoid, epiglottis and anterior commissure of the vocal cords). Secondary objectives will include establishing, if possible, a cut-off point in these measurements; to compare these measures against the classic pre-intubation clinical screening tests.

Current advances in airway management training have reduced the risk associated with an unanticipated DL but have not been able to reduce its incidence in clinical practice. The addition of new video laryngoscopes in our clinical practice seems to offer a paradigm shift to face a DL with promising results. However, theses authors also indicated that expertise in video laryngoscopy requires prolonged training and practice. Otherwise, a growing number of publications have showed that some ultrasound measurements may improve our anticipation of a DL because of its high accuracy to offer detailed anatomical images of the airway, absence of ionizing radiations, accessibility and reproducibility. Among all the ultrasound parameters studied, distance from skin to epiglottis with a cut-off point of 2.10 cm, showed the best predictive ability with a sensitivity of 83.33%3 and a specificity of 73.33%, for predicting difficulty in airway management in routine clinical practice. The aim of this study is to investigate the efficacy of US-measured airway structures in predicting difficult laryngoscopy (defined as CL grade III and IV).

Inclusion Criteria:

• Gender both males and females
• ASA Class I and II
• Age 2 years to 6
• Children scheduled for elective surgery under general anesthesia requiring orotracheal intubation after classical laryngoscopy.

Exclusion Criteria:

• Congenital upper airway malformation,
• Head and neck swellings,
• Scars,
• Radiation to the neck,
• Tracheotomy,

Children aged 2-6 years, ASA I, II who will be scheduled for elective surgery under general anesthesia requiring orotracheal intubation after classical laryngoscopy.