Deliberate Hypothermia (PART 2)

TEMPERATURE  MANAGEMENT:(1,4,5) Rapid cooling is necessary if core temperature must be rapidly although body temperature typically decreases more than one degree C during the first hours of general anesthesia. Methods use to reduce brain temprature during animal experiments include packing ice,fanning,partial immersion in cold water,nasopharyngeal cooling and cardiopulnary bypass(CPB). Rapid reduction of core temprature for mild or moderate hypothermia can be facilitated by administration of refrigerated intravenous fluid,circulating water mattresses ,forced aircooling and extracorporal means. Intravenous administration of refrigerated (1-6) degrees C 5% albumen 5cc/kg...

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Deliberate Hypothermia (PART 1)

INTRODUCTION:(1,2,6,7) Core central temperature is defined as the temperature blood perfusion vital major organ system. Nasopharyngeal and esophageal temperature are more representative of core temperature.  Core temperature varies not only interindividually and diurnally but also between different parts of the body. In unanesthetized persons thermoregulatory response is not triggered by temperature range of 0,2 degree C. Physiologic termoregulatory response normally triggered by hypothermia.Therefore if normothermia is not actively maintained general anesthesia may lead to unintentional low body temperature. Perioperative hypothermia commonly results from anesthe- tic...

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Brain Ischemia And Protection (PART 2)

BRAIN PROTECTION:(1,2,5) Cerebral protection implies intervention designed to prevent pathophysiological process from occuring whilst cerebral resuscitation refers to intervention instituted after onset of the ischemic insult in other to interrupt process. To prevent neuronal death from ischemic or hypoxaemia, two basic strategies can be employed : Prevention of tissue hypoxia primarily or modification of the event that lead to cell injury and death subsquent to energy failure. The prevention of tissue hypoxia can be devided into two general categories decreasing tissue O2 demand and increasing O2 supply. Supplementary pharmacological brain protection includes intervention that increase...

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Brain Ischemia and Protection (PART 1)

INTRODUCTION :(1,4,5) Cerebral perfusion pressure(CPP) is the driving force for substrate(O2,glucose) delivery to the brain is defined as mean arterial pressure(MAP) minus intracranial pressure (ICP) and MAP is diastolic pressure plus 1/3(systolic pressure minus diastolic pressure). The main substance use for energy production in the brain is glucose and O2. Cerebral blood flow(CBF) can be used to calculate 0xygen delivery to the brain. A standard formula is used  DO2 =CaO2 xCBF which : DO2 is delivered oxygen, CaO2 is arterial oxygen content. CaO2 is dependent on Hb content and PaO2,normal CaO2 is 16-20ml O2/100ml arterial blood and normal CBF is 50ml/100 gmin. Normal...

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