+ pressure respiration

can any 1 explain me what is positive pressure repiration? i could not understand it properly.thanks.

[Dr. X]

positive pressure respiration is employed as a treatment when theres a ventilation defect. Lets take Respiratory distress syndrome... its due to the fewer surfactant as there is fewer typeII pneumocyte (by prematurity). when the baby exhales.. there is a collapse of the alveoli resulting in atelectasis. normally, when the baby exhales, surfactant keeps the alveoli open with pressure by keeping the surface tension down. positive pressure respiration (through mechanical ventilation) - what it does is that when the baby exhales, the positive pressure is applied (mechanically) to keep the alveoli open.. ie. doing the job of surfactant, per se.

note that i used rds as example to illustrate the concept only. Rx for RDS (if premature baby).. give the mother some glucocorticoids (cortisol) prepartum and the baby is given surfactant.