Tracheal volume deformation in a developmental rabbit model.
Alterations in tracheal volume were evaluated in a developmental in vivo rabbit model during and following the application of continuous positive pressure (CPP). Sequential volume changes were recorded during 60 min of CPP to a bypassed tracheal segment. The distal trachea was utilized for spontaneous ventilation. CPP of 10 cm H2O was applied to three developmental groups: group I, 5 term newborn pups; group II, 5, 7-day-old pups, and group III, 5 adult female rabbits of 18 +/- 6 months old. Changes in tracheal volume were measured by a micropipette system. Following 60 min of CPP, tracheal volumes increased (p less than 0.01) by 39.8% in group I; 36.1% in group II and 5.1% in group III. During a recovery period (60 min), return towards initial resting volume was observed in all groups, though maximal persistent volume deformation was observed in groups I and II. Thus, these data indicate tracheal barotrauma in the form of persistent dimensional deformation at early stages of development in an in vivo rabbit model.
D000818:Animals; D000831:Animals, Newborn; D005260:Female; D008954:Models, Biological; D009130:Muscle, Smooth / Q000502:physiology*; D011175:Positive-Pressure Respiration; D011817:Rabbits; D014132:Trachea / Q000033:anatomy & histology / Q000502:physiology*