Abstract
High‐frequency jet ventilation (HFJV) is a lung protective ventilation strategy used for the prevention and treatment of ventilator induced lung injury in preterm infants. Despite its widespread use in neonatal intensive care units there is little data to support the patient management algorithms that are currently utilised. The strategies for alveolar recruitment during HFJV rely upon incrementing positive end‐expiratory pressure (PEEP) and delivering occasional conventional mechanical ventilator (CMV) breaths, but the impact of these recruitment manoeuvres on pulmonary blood flow, oxygenation, ventilation and lung injury is largely unknown. This thesis investigates the parameters that must be selected during HFJV and their impact upon pulmonary blood flow, physiological changes during ventilation and post mortem lung injury in a preterm lamb model. The first study examined the effect of incrementing PEEP during HFJV and found that alveolar recruitment was achieved by incrementing PEEP up to 12 cmH2O without detrimental effects on physiological parameters. The following 3 studies examined the delivery of CMV breaths during HFJV to compare the effect of 2 different CMV breath inspiratory times, peak inspiratory pressures and frequencies. A shorter inspiratory time CMV breath, a CMV breath delivered to a peak inspiratory pressure (PIP) above the HFJV breaths and CMV breaths delivered less frequently provided the most physiological benefit with the least evidence of harm while adequately ventilating and oxygenating the preterm lambs.
Original language | English |
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Qualification | Doctor of Philosophy |
Publication status | Unpublished - 2011 |