Ophthalmic assessment of newborns with hypoxic-ischemic encephalopathy treated with therapeutic hypothermia – retrospective study

Background The aim of the study was to evaluate the visual organ in children with severe hypoxic-ischemic encephalopathy treated with controlled hypothermia.Methods Controlled hypothermia was performed in the Neonatal Intensive Care Unit in Zabrze using the CritiCool & Cure Wrap System. Children were qualified and examined by neonatologists. All children were treated with whole-body hypothermia for 72 hours with a target temperature of 33 to 34ºC in analgosedation with through biophysical monitoring. After recovery from controlled hypothermia, an ophthalmic examination was performed. The study included 74 newborns. Results: In all newborns transparent optical media were found. Subconjunctival hemorrhage was present in 6 eyes. Only in one case, the retinal blood vessels were dilated as a consequence of circulatory system disorders. Conclusions Ophthalmic examination of children after controlled hypothermia allows early implementation of local and general treatment in case of abnormality.

Hypothermia effects on liver and kidney oxidative stress parameters in an experimental model of sepsis in rats

IntroductionOxidative stress (OS) seems to be an important mediator of cellular injury, from which sepsis can proceed. Studies have demonstrated the protective effect of controlled hypothermia in sepsis. This study aimed to evaluate its effects on OS parameters in rat hepatic and renal tissue septic after caecal ligation and puncture (CLP).Material and MethodsThree groups were appointed (10 rats/group): C (control), SN (sepsis normothermic), and SH (sepsis hypothermic). Ten hours from CLP, the liver and kidneys were harvested and total protein concentration, superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, lipid peroxidation level (malondialdehyde (MDA), carbonylated proteins (2,4-dinitrophenylhydrazine (DNPH), and fatty acid profile were analysed.ResultsSepsis significantly increased SOD and GPx activities in the liver, regardless of the temperature. In renal tissue, GPx activity increased significantly in normothermic conditions and SOD tended to decrease in hypothermic conditions. MDA and DNPH concentrations increase in both tissues after CLP. Hypothermia significantly lowered MDA in the liver but only changed it insignificantly in the kidneys. The DNPH in the liver and kidneys was significantly lower in hypothermic conditions. The unsaturated-to-saturated fatty acids ratio was significantly lower in sepsis, and the fall in temperature raised this ratio.ConclusionExperimentally induced sepsis in rats enhances OS in the liver and kidneys. The effect of hypothermia on OS indices is dependent on the type of tissue.

THE PROPAGATION OF THE TEMPERATURE WAVE IN MYOCARDIUM

The method for estimating the rate of propagation of temperature waves in the myocardium during hypothermia and hyperthermia of the heart based on noninvasive temperature control on the heart surface in conditions of cardiopulmonary bypass is proposed. The solution of the heat conduction equation for temperature waves in the myocardium is presented, which allows determining at each point of the medium the temperature change function, as well as the amplitude and phasing velocity of the temperature wave upon cooling and warming of the heart in conditions of cardiopulmonary bypass. The velocity distribution for the temperature field on the surface of the myocardium and in the depth of tissues during the hypothermia and hyperthermia of the heart is obtained. The thermographic images of the heart during controlled hypothermia and hyperthermia of the heart under cardiopulmonary bypass are obtained. The study of the conditions for spreading the temperature wave in the myocardium is performed, which allows to improve the means of intraoperative protection of vital organs and tools for controlling its effectiveness. The results of introduction of methods of non-invasive temperature control in cardiac surgery and the process of intraoperative cardiac protection in the temperature range from +10°С to +38°С are presented.