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Background and purpose: closed head trauma (closed brain injury) are very common in modern warfare and ordinary social life, traumatic brain hemorrhage the (traumatic intracerebral hemorrhage, tICH) is an important part of the closed head trauma. With the social and economic development, the population has increased year by year to the plateau region development and tourism, traumatic brain bleeding disease has also become a serious threat stationed in the highland areas of population health. But the altitude environment tICH secondary brain injury mechanisms do not know much. The purpose of this study is to intracranial pressure (intracranial pressure, ICP), brain tissue oxygen tension (brain tissue oxygen pressure PbtO 2 ), regional cerebral tissue blood flow (regional cerebral blood flow of rCBF) microdialysis of brain tissue interstitial fluid (cerebral microdialysis, CMD), noninvasive brain edema monitoring (non-invasive cerebral edema monitoring, NCEM) the craniocerebral multi-mode monitor (multimodal monitoring) method for the simulation of radical plateau environment miniature pigs tICH model , the comprehensive observation tICH after the 168h ICP changes and perihematoma in organizations PbtO 2 Blood Flow (rCBF), CMD change combined with computed tomography (computerized tomography scaning, CT), magnetic resonance imaging (magnetic resonance imaging, MRI) and other imaging technologies, and pathological examination, further study of secondary brain injury after tICH plateau environment evolution and pathophysiological mechanisms, and expectations of the occurrence of cerebral edema by noninvasive monitoring instrument capable of convenient and effective monitoring of special circumstances tICH Following hair development of brain injury. Methods: (1) select male adult Guizhou 29 from Jiang small miniature pig using a random number table miniature pigs were randomly divided into plain blood injection group (plain blood infusion group, PI), the plateau NOTE blood group (high altitude blood infusion group HI), plain sham group (the plain the sham operation group, PS), plateau sham surgery group (high altitude sham operation group, HS), PI and HI group 11, PS Group 3, HS Group 4; (2 ) the use of animals low pressure oxygen chamber to simulate the a 4000m Altitude environmental (cabin pressure 61 6kPa, of a cabin temperature 19 ° C), confirmed by CT animals autologous blood 3 ml (equivalent to the human brain 60ml hematoma pro-rata basis) injected into the right side of the The basal ganglia District establish the plateau tICH animal model. Plains animals reared in low-pressure oxygen chamber, HS and PS animals operative with blood injection group, but does not inject blood; (3), weight, blood glucose, mean arterial pressure, rectal temperature, and arterial blood gas analysis and other basic physiological indicators for monitoring , to determine whether the simulated high altitude environment exists comparable HI group and other groups; (4) stereology were observed calculated HI, PI in both groups after the preparation of animal model the 2h and 168h hematoma volume, Purdy score were observed 2 h before the preparation of the four groups of animal models and model preparation after 24 h, 72h, 168h at each time point, animal behavior, pathological observation of the end of the experiment hematoma surrounding brain tissue HE, Nissl staining to determine a reliable model sex; (5) were observed 2 h before the preparation of the four groups of animal models and model preparation after 2 h, 6 h, 24-h, 72h, the 168h at each time point ICP PbtO 2 Blood Flow (rCBF), CMD NCEM's In the development and changes, dynamic MRI observation, the end of the experiment, the hematoma surrounding brain tissue brain water content was measured and transmission electron microscopy. Results: (1) the experimental choose to male miniature pigs, to exclude the protective effect of estrogen of hormones on tICH the surrounding brain tissue. Plateau group mainly blood gas values ??SaO2, PaO2 were significantly lower than the plain group (P lt; 0.05), the plateau environment simulation successfully. (2) monitoring weight, blood glucose, mean arterial pressure, rectal temperature and other basic physiological indicators, PI, HI between the two groups there was no statistical significance (P gt; 0.05), the existence of other the neurocranium monitoring results comparable between the two groups sex. (3) immediately after blood injection cranial coronal CT scan, display hematoma was high density, is located in the right basal ganglia, ventricular compression and midline shift to the left, and 168 h after the general sections showed hematoma persists. HI, PI of two groups hematoma volume before and after each difference significant (P lt; 0.05), while the the hematoma volume two groups at the same point in time the difference was not significant (P gt; 0.05). Nerve function score three time points after injection of blood (4) HI group were higher than PI and HS group, a statistically significant difference (P lt; 0.05), and HI group at all time points neurological function score and previous time point differences were statistically significant (P lt; 0.05). (5) ICP Monitoring HI, PI in both groups exist 2h after blood injection ICP peak, but there were no significant differences (P gt; 0.05), then gradually decreased 24h after HI group was significantly higher than the PI group ( P lt; 0.05), HI group ICP to 168h end of the experiment was still significantly higher than the baseline value (P lt; 0.05) and the other three groups (P lt; 0.05). (6) PbtO 2 monitoring found that injection of blood after the PI the HI two groups of PbtO 2 compared with respective sham group was significantly lower, the difference was statistically significance (P lt; 0.05), followed by a slow rise, still lower than at the end of each of the sham group to 168h experiment observed a statistically significant difference (P lt; 0.05). Blood injection observed time points, the HI group PbtO 2 were lower than the PI group, there were significant differences between the two groups (P lt; 0.05). (7) rCBF monitoring found after the injection of blood PI, the the HI two groups of rCBF compared with sham group significantly reduce (P lt; 0.05), followed by a slow rise, to the end of 168h Experimental observation the HI group still lower than the HS group, differences statistically significant (P lt; 0.05). After blood injection observed 24h and 72h, the HI group rCBF lower than PI group, the differences between the two groups was statistically significant (P lt; 0.05). (8) the the hematoma surrounding CMD monitoring at each time point, HI PI two sets of comparisons between the glucose concentration differences were not statistically significant (P gt; 0.05). H after injection of blood, 168h, HI group lactate concentration higher than the PI group differences were statistically significant (P lt; 0.05). Injecting blood after 24h, 72h, 168h, pyruvate concentration of the HI group than PI group, the difference was statistically significant (P lt; 0.05). At each time point after the injection of blood, HI group L / P values ??were higher than the PI group, the differences were statistically significant (P lt; 0.05). In addition to 24h after blood injection, the rest of the time points when the glutamate concentration in the HI group than PI group differences were statistically significant (P lt; 0.05). (9) NCEM monitoring found that injection of blood 2h, 6h, 24h when the PI group noninvasive brain edema values ??were lower than pre2h base value and the PS group, the difference was statistically significant (P lt; 0.05); blood injection 2h, 6h, the HI group noninvasive cerebral edema value were lower than pre2h base value and the HS group, the difference was statistically significant (P lt; 0.05). PI, HI two groups compared to 24 h when noninvasive brain edema monitoring the value of the difference was statistically significant (P lt; 0.05). (10) brain water content determination 168h, PI, HI two groups hematoma surrounding brain tissue water content after the injection of blood were higher than their respective sham group, the differences were statistically significant (P lt; 0.05). HI group brain water content is also higher than the PI group, the difference was statistically significant (P lt; 0.05). (11) HE staining, Nissl staining and transmission electron microscopy were found the HI group hematoma surrounding brain tissue edema and neuronal damage is more obvious than the PI group. (12) MRI check found that blood injection 24 h PI, HI two groups hematoma was T1 signal, etc., or slightly longer T2 signal midline shift to the left, and the the HI group hematoma around long T2 signal edema. 168 h, PI, HI two sets of the hematoma Center layer was T1, short T2 signal hematoma outer layer were short T1 and short T2 signal around the hematoma showed long T1, long T2 signal ring 24h coronal T2WI display edema and extend. Conclusion: (1) the experimental animals low pressure oxygen chamber to simulate 4000m altitude environment, right basal ganglia secondary injection of autologous arterial preparation of urgency into the plateau the small pig tICH model. This model hematoma formation stability, a high success rate, animal Survivability and operability, good repeatability, can simulate tICH the evolutionary process. (2) the extent of brain damage plateau tICH secondary compared to the heavier plains environment, and lead to more severe neurological damage. (3) lack of oxygen, energy metabolism and glutamate the abnormal release plays an important role in the secondary plateau tICH brain injury. (4) non-invasive monitor of cerebral edema after traumatic brain injury monitoring the occurrence of acute intracranial hematoma can be used for monitoring the development of secondary brain injury, help guide early treatment; and portable, real-time monitoring, non-invasive advantages can to make up for the lack of large-scale screening devices suitable for the use of special environment of the plateau, wild.
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