TY - JOUR T1 - Learning from critical care management of sheep receiving extra-corporeal membrane oxygenation for smoke-induced acute lung injury as a tool for processing large clinical datasets JF - bioRxiv DO - 10.1101/058511 SP - 058511 AU - Chemonges Saul Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/06/12/058511.abstract N2 - Background: Many successful therapies developed for human medicine involve animal experimentation. With competition for public research funding and career advancement opportunities, animal studies focused on the translational potential may not sufficiently document unexpected outcomes. Such studies often have hastily developed methods with ad hoc modifications including the use of additional animals, leading to considerable amounts of idle, unprocessed data that could be used to advance veterinary science, or to refine the base animal model. Sheep, for example, are poorly understood models of intensive care and therefore, any experimental data arising from them should be interpreted with care. The hypothesis was that there is little information describing the development of methods of physiological data processing in multifaceted sheep models of intensive care and the author aimed to develop a suitable data processing method and to analyse the data, once processed.Methods: Data from 19 adult mechanically ventilated ewes undergoing intensive care in a previous study evaluating a form of extracorporeal life support (treatment) for acute lung injury were used to develop a comprehensive method for processing manual and electronically gathered clinical observations. Eight sheep were injured by acute smoke inhalation prior to treatment (injured/treated), while another eight were not injured but treated (uninjured/treated). Two sheep were injured but not treated (injured/untreated), while one received room air instead of smoke as the injury, and was not treated (placebo/untreated). The data were then analysed for 11 physiological categories and compared between the two treated groups.Results: The analysis revealed that compared with the baseline, treatment contributed to and exacerbated the deterioration of pulmonary pathology by reducing lung compliance and PaO2/FiO2 ratio. The oxygen extraction index changes mirrored those of the PaO2/FiO2 ratio. Decreasing coronary perfusion pressure predicted the severity of cardiopulmonary injury.Conclusions: These novel observations could help in understanding similar pathology such as that which occurs in smoke inhalation animal victims of house and bush fires. A similar data processing method could be used when evaluating the effectiveness of other clinical interventions such as potentially reversible aspiration pneumonia secondary to tick paralysis in veterinary patients.List of abbreviationsANOVAAnalysis of varianceC24HControl experiment for 24 hoursCaO2Arterial oxygen contentCCOContinuous cardiac outputCICardiac indexCOCardiac outputCPPCoronary perfusion pressure[Hb]Haemoglobin concentrationCVPCentral venous pressureDO2IOxygen delivery indexE24HExtracorporeal life support for 24 hoursE2HExtracorporeal life support for 24 hoursECLSExtracorporeal life supportECMOExtracorporeal membrane oxygenationetCO2End tidal carbon dioxide tensionFCOHbFraction of carboxyhaemoglobinFiO2Fraction of inspired oxygenFO2HbFraction of oxyhaemoglobinHRHeart rateLVSWILeft ventricular stroke work indexMAPMean arterial pressureMERFMedical Engineering FacilityMetHbMethaemoglobinMPAPMean pulmonary artery pressureO2EIOxygen extraction indexPaO2Arterial partial pressure of oxygenPAPPulmonary artery pressurepCO2Partial pressure of carbon dioxidePCVPacked cell volumePEEPPositive end-expiratory pressurepO2Partial pressure of blood oxygenPVRIPulmonary vascular resistance indexQUTQueensland University of TechnologyQUT-MERFQueensland University of Technology Medical Engineering Research FacilitySC24Smoke control experiment for 24 hoursSDStandard DeviationSE24HSmoke injury and extracorporeal life support for 24 hoursSEA24HSmoke injury, stored blood transfusion and extracorporeal life support for 24 hoursSEF24HSmoke injury, fresh blood transfusion and extracorporeal life support for 24 hoursSPO2Blood oxygen saturationSVStroke volumeSVIStroke volume indexSvO2Mixed venous oxygen saturationSVRSystemic vascular resistanceSVRISystemic vascular resistance indexTPPTotal plasma proteinUQThe University of Queensland ER -