(approximately 40% of total lung capacity). Conventional mechanical ventilation delivers tidal volume breaths on top of it. This mode of liquid ventilation currently seems technologically more feasible than total liquid ventilation, because PLV could utilise technology currently in place in many neonatal intensive-care units (NICU) worldwide. The influence of PLV on oxygenation, carbon dioxide removal and lung mechanics has been investigated in several animal studies using different models of lung injury. Clinical applications of PLV have been reported in patients with acute respiratory distress syndrome (ARDS), meconium aspiration syndrome, congenital diaphragmatic hernia and respiratory distress syndrome (RDS) of neonates. In order to correctly and effectively conduct PLV, it is essential to properly dose a patient to a specific lung volume (10–15 ml/kg) to recruit alveolar volume redose the lung with PFC liquid (1–2 ml/kg/h) to oppose PFC evaporation from the lung. If PFC liquid is not maintained in the lung, PLV can not effectively protect the lung from biophysical forces associated with the gas ventilator. New application modes for PFC have been developed. Partial liquid ventilation (PLV) involves filling the lungs with a liquid. This liquid is a perfluorocarbon such as perflubron (brand name Liquivent). The liquid has some unique properties. It has a very low surface tension, similar to the surfactant substances produced in the lungs to prevent the alveoli from collapsing and sticking together during exhalation. It also has a high density, oxygen readily diffuses through it, and it may have some anti-inflammatory properties. In PLV, the lungs are filled with the liquid, the patient is then ventilated with a conventional ventilator using a protective lung ventilation strategy. The hope is that the liquid will help the transport of oxygen to parts of the lung that are flooded and filled with debris, help remove this debris and open up more alveoli improving lung function. The study of PLV involves comparison to protocolized ventilator strategy designed to minimize lung damage. PFC vapor Vaporization of perfluorohexane with two anesthetic vaporizers calibrated for perfluorohexane has been shown to improve gas exchange in oleic acid-induced lung injury in sheep. Predominantly PFCs with high vapor pressure are suitable for vaporization. Aerosol-PFC With aerosolized perfluorooctane, significant improvement of oxygenation and pulmonary mechanics was shown in adult sheep with oleic acid-induced lung injury. In surfactant-depleted piglets, persistent improvement of gas exchange and lung mechanics was demonstrated with Aerosol-PFC. The aerosol device is of decisive importance