Fig. 7 |. Alternative ventilation strategies in the treatment of heterogeneous lung disease in severe BPD.
Schematic of the physiological effects of small-volume, rapid-rate ventilator support (panel a) and larger tidal volume, prolonged inspiratory time strategies (panel b) in a lung that contains regional heterogeneity in the severity of lung disease, as is observed in infants with severe bronchopulmonary dysplasia (BPD). a | Small tidal volume breaths probably increase dead space ventilation, leading to atelectasis, hypercapnia and high oxygen requirements. b | Increased tidal volumes and inspiratory times may enhance the distribution of gas, leading to lower oxygen requirements, improved ventilation and less atelectasis. Compliance (C) is a measure of the lung’s ability to stretch and expand (distensibility of elastic tissue). Resistance (R) is the resistance of the respiratory tract to airflow during inhalation and expiration. FiO2, fraction of inspired oxygen; PCO2, partial pressure of carbon dioxide; VD, dead-space ventilation; VT, tidal ventilation. Adapted with permission from REF.200, Elsevier.