Objective: To observe the circulation and microcirculation characteristics of healthy han people in Qinghai at different Guoluo (4 100 m) and Huzhu (2 600 m) and in Shanghai in plain area (4 m). Methods: The 28 healthy han people aged (45.62±10.15) from Guoluo in Qinghai, 27 healthy han people aged (47.25±8.43) from Huzhu in Qinghai and 20 healthy han people aged (43.12±8.28) from Shanghai were divided into three groups: Guoluo group (GL), Huzhu group (HZ) and Shanghai group (SH); Venous blood was collected for routine blood test: red blood cells count(RBC), hemoglobin(HGB), hematocrit(HCT), platelet(PLT); and coagulation index: prothrombin time(PT), interntionl normlized ratio(INR), fibrin(Fib), activated partial thromboplastin time (APTT), thrombin time(TT), continuous non - invasive hemodynamic monitor (CNAP) was used for continuous measurement: cardiac output (CO), heart rate (HR), stroke volume (SV), pulse pressure variation rate (PPV), systemic vascular resistance index (SVRI), mean arterial pressure (MAP); pulse oxygen monitoring instrument is used for monitoring SPO2 (pulse oxygen); the total vascular density (TVD), perfusion vascular density (PVD), proportion of perfused vascular(PPV), and microvascular flow index (MFI) of sublingual microcirculation were observed by using peripheral dark field imaging (SDF) monitoring technique. Results: Compared with the Shanghai group, the RBC and HGB levels in the Huzhu group and the Guoluo group were significantly increased (P＜0.05), while PLT levels were significantly decreased (P＜0.05); The levels of PT, Fib, APTT, TT, CO, HR, SV, MAP and SPO2 in the Huzhu group were significantly decreased (P＜0.05), while the levels of TVD, PVD, PPV and MFI were significantly increased (P＜0.05). In Guoluo group, the levels of HCT, Fib, CO, SV, PPV, MAP, TVD and PVD were significantly increased (P＜0.05), while the levels of PT, INR, TT and SPO2 were significantly decreased (P＜0.05). Compared with the Huzhu group, the levels of RBC, HGB, HCT, Fib and APTT of Guoluo group were significantly increased (P＜0.05); while the levels of SPO2, TVD, PVD, INR and TT were significantly decreased (P＜0.05). Conclusion: The microcirculation of healthy people in different altitude areas is significantly different, and the microcirculation density of healthy people in high altitude areas is significantly higher than that in plain areas, especially in moderate altitude areas. Its special physiological significance is of guiding significance for the treatment of infectious shock and chronic altitude disease in plateau areas.

The present study was aimed to observe the characteristics of sublingual microcirculation and the changes of humoral factors in healthy people of three different high altitude populations. Three groups of healthy subjects in Guoluo area of Qinghai province (4 100 m) were included: Tibetan group: 30 Tibetans, (45.62 ± 10.15) years old; Han group: 22 two-generation of Han immigrants, (46.23 ± 8.59) years old; migrant group: 23 migrants living at high altitude for 2-5 years, (43.45 ± 8.31) years old. Blood routine test was performed to determine white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (HGB), hematocrit (HCT), platelet (PLT) count, and neutrophil (NEUT) count. The changes of serum humoral factors including endothelin-1 (ET-1), CD31, CD34, CD105, vascular endothelial growth factor (VEGF), nitric oxide (NO) and noradrenaline (NE) were detected by ELISA. Continuous noninvasive hemodynamics monitor was used to continuously measure the changes of systemic circulation indexes: cardiac output (CO), cardiac index (CI), heart rate (HR), stroke volume (SV), pulse pressure variation (PPV), systemic vascular resistance index (SVRI), and mean arterial pressure (MAP). Blood oxygen was measured by pulse oximeter. Sublingual microcirculation indexes including total vascular density (TVD), perfused vessel density (PVD), proportion of perfused vessels (PPV), and microvascular flow index (MFI) were determined by sidestream dark field imaging. The results showed that there were no difference in systemic circulation among the 3 groups. Compared with Tibetan group, TVD and PVD of microcirculation in Han group and migrant group were significantly increased (P < 0.05). Compared with Tibetan group and Han group, WBC, RBC, HGB and HCT of migrant group were significantly increased (P < 0.05). Compared with Han group and Migrant group, PLT of Tibetan group was significantly increased (P < 0.05). Compared with the Tibetan group, the levels of serum humoral factors CD105 and VEGF were significantly higher in the migrant group (P < 0.05), while compared with Han and migration groups, NO in Tibetan group was significantly increased (P < 0.05). It is suggested that there were significant differences in microcirculation (TVD, PVD), blood routine (WBC, RBC, HGB, HCT) and humoral factors (CD105, VEGF) among different populations in high altitude area. Importantly, the increased microcirculation, erythrocytosis and increased pro-angiogenic factors due to hypoxic environment were observed in long-term residents and migrants, except for permanent residents. These physiological changes have clinical significance in the treatment of septic shock and chronic altitude sickness for different plateau populations.

Objective To observe the changes in microcirculation after induction of anesthesia in patients in plateau region. Methods Ten patients of both sexes, aged 35-58 yr, weighing 52-87 kg, of American Society of Anesthesiologists physical statusⅠ or Ⅱ, were enrolled in this study. Anesthesia was induced with intravenous etomidate 0. 3 mg∕kg, sufentanil 0. 75 μg∕kg and vecuronium 0. 10 mg∕kg. Me-chanical ventilation was performed after tracheal intubation. Fluid was replaced by intravenously infusing lactated Ringer′s solution 500 ml over 30-45 min after completion of anesthesia induction. At 5 min before anesthesia induction, 5 min after induction and after the end of fluid replacement, the hemodynamic pa-rameters such as heart rate (HR), SpO2and mean arterial pressure (MAP) were recorded, and microcir-culatory indices such as total vascular density (TVD), perfused vessel density (PVD), proportion of per-fused small vessels (PPV) and microvascular flow index (MFI) were measured. Results Compared with the baseline value before anesthesia induction, HR was significantly increased, SpO2and MAP were de-creased, TVD, PVD, PPV and MFI were decreased at 5 min after anesthesia induction (P＜0. 05). Com-pared with the baseline value at 5 min after anesthesia induction, HR was significantly decreased, and SpO2and MAP were increased immediately after fluid replacement (P＜0. 05), and no significant change was found in TVD, PVD, PPV or MFI immediately after fluid replacement (P＞0. 05). Conclusion Mi- crocirculatory disturbance is obvious after induction of general anesthesia in patients undergoing operation in plateau region, and no marked improvement is found in microcirculation after rapid fluid replacement, which may be the main cause of metabolic disorders such as acidosis after operation.