Assessment of oropharyngeal distance in children using magnetic resonance imaging

Aerosol Drug Delivery Using Heliox and Nebulizer Reservoirs: Results from an MRI-Based Pediatric Model

An MRI-based model of the mouth, throat, and upper airways of a 5-year-old boy is used to evaluate methods for increasing the nebulized drug dose delivered to the lungs. Four methods are considered: (1) standard nebulizer delivery with air, (2) delivery with 70/30 helium-oxygen (heliox), (3) delivery with air and an aerosol-conserving reservoir, and (4) delivery with heliox and a reservoir. When comparing air and heliox, delivery flowrates were adjusted so that the aerosols produced were of similar size. The reservoir utilized was the Medicator Aerosol Maximizer (Healthline Medical, Baldwin Park, CA). It conserves the aerosol generated by the nebulizer during exhalation and makes it available for the next inhalation. Technetium-DTPA was utilized. The standard nebulizer driven by air delivered 2.2% of the dose loaded into the nebulizer to the lungs as fine droplets, versus 3.3% for the nebulizer with heliox (50% increase; p = 0.002 vs. air), 2.9% for the nebulizer plus reservoir driven by air (32% increase; p = 0.02 vs. no reservoir), and 4.0% for the nebulizer plus reservoir driven by heliox (82% increase; p = 0.002 vs. air without reservoir). The increased pulmonary dose when heliox was utilized occurred because of decreased deposition within the nebulizer and other delivery equipment. The increased pulmonary dose when the reservoirs were utilized occurred due to a decrease in the dose expelled from the nebulizer by exhalation.

New developments in the management of the paediatric airway: cuffed or uncuffed tracheal tubes, laryngeal mask airway, cuffed oropharyngeal airway, tracheostomy and one-lung ventilation devices

The use of a cuffed endotracheal tube should no longer be limited by the age of the child but by his or her clinical condition (e.g. poor lung compliance). To prevent pharyngeal damage, overinflation of the cuff of the laryngeal mask airway should be avoided by inflating it with the minimum volume required to maintain an effective seal and by monitoring intracuff pressure if nitrous oxide is used. Percutaneous tracheostomy in children is still in the experimental stage. New and older devices to perform one-lung ventilation in children are also described.