Enhanced mortality from perfluorocarbon administration in a rat model of kerosene aspiration

Background: Aspiration of low-viscosity hydrocarbons may lead to fulminant pneumonitis and acute respiratory distress syndrome. Animal and human studi es suggest that partial liquid ventilation with perfluorocarbon improves ga s exchange and pulmonary function in acute respiratory failure. The objecti ve of this investigation was to determine the effect of intratracheal perfl uorocarbon administration and a brief period of partial liquid ventilation on survival in a rat model of severe hydrocarbon aspiration. Methods: Two r andomized, nonblinded, controlled experiments were performed. First, male W istar rats (n = 12) were given 0.3 mL/kg kerosene via direct intratracheal instillation and after 5 minutes were randomized to partial liquid ventilat ion or standard gas ventilation (control) groups. Partial liquid ventilatio n rats (n = 6) received 20 mL/kg of pre-oxygenated FC-77 intratracheally an d positive-pressure gas ventilation (FiO(2) = 1.0), and control rats (n = 6 ) received positive-pressure gas ventilation alone. Animals were observed f or survival and 7-day mortality was compared using the Fisher Exact test. T he study was then repeated in 12 additional animals using a 15-minute inter val between kerosene instillation and treatment (PLV vs control). Results: Mortality was significantly greater in the partial liquid ventilation group (5 of 6; 83%) as compared to the control group (1 of 6; 17% [p = 0.039]). Results were identical in the repeat study. All animals that died succumbed from acute respiratory failure within 24 hours of kerosene instillation. C onclusion: In this rat model of severe kerosene aspiration, intratracheal p erfluorocarbon administration and a brief period of partial liquid ventilat ion proved detrimental and significantly increased mortality.