EVALUATION OF A NEW THIN-WALLED ENDOTRACHEAL-TUBE FOR USE IN CHILDREN

Conventional endotracheal tabes have high intrinsic resistive properti es due to their high outer-to-inner diameter ratio, This has significa nt disadvantages in the treatment of the small neonatal or pediatric p atient as work of breathing increases with decreasing internal radius, Diagnostic and therapeutic procedures, including suctioning, may be v ery difficult in patients with small endotracheal tubes, We therefore measured airway resistance and pressure differential during simulated mechanical ventilation using proximal and distal endotracheal tube Row transducers. Conventional and new, ultrathin-walled endotracheal tube s reinforced with flat stainless steel or a novel, crush-proof nickel- titanium alloy were compared using fixed ventilator settings, Ventilat ion through the ultrathin-walled tubes resulted in a significantly red uced airway resistance (p less than or equal to 0.01). These new ultra thin-walled endotracheal tubes showed flow characteristics typical of much larger conventional endotracheal tubes: the 3.2-mm internal diame ter had an airway resistance (Raw) of 36, while a standard 2.5-mm inte rnal diameter endotracheal tube had a Raw of 146, Both endotracheal tu bes have identical external diameters of 3.6 mm, We conclude that ultr athin-walled endotracheal tubes could have a significant role in the t reatment of the ventilated child by facilitating interactive ventilati on and maintenance of airway patency and may make procedures such as f iberoptic endoscopy and intrapulmonary ventilation using reverse-thrus t catheters possible in the small child.