Change and Relationship of Hematocrit and Electrocardiogram of the Crew in High Altitude Span Transportation

Objective: To investigate the effect of high altitude span transportation on the change of hematocrit and electrocardiogram of the crew in the plateau construction, and discuss their relationship. Method: By SPSS 11.0 statistical software, to treat hematocrit and electrocardiogram in the examination data of the the crew, who took part in the construction of Qinghai-Tibetan railway in 2003, before, during and after the construction. Then, we compared the data among the constructors in the fixed altitude during the same period. Result: The hematocrit of the crew slowly and continually rose to the maximum(p<0.01) after the construction in the high altitude span during one construction year, and the abnormal rate of electrocardiogram obviously decreased(p<0.05). The abnormal rate of electrocardiogram apparently improved when hematocrit reached 52% among the range from 45.12% to 52.24%, and the correlation analysis showed that the electrocardiographic change was closely and negatively correlated with the hematocrit among the range of hematocrit(p<0.05). Conclusion: Although the higher-level stress state of the crew made the hematocrit in the blood continually increase in the long-term high altitude span construction, the hematocrit reached the more reasonable hematocrit compensation and made it the optimum state of Hct in the end. As a result, the perfusion of tissues and organs was improved. The abnormal rate of electrocardiogram apparently improved because the oxygen delivery of the myocardium reached the optimum compensation.

Effect of Factors on Physiology Acclimatization of Construction Groups Entering Again into Plateau in Early Days

Purpose: To find out the relationship between duration of break, gender, age and the early physical conditions of the people who go to the Plateau again after the break. Means: The pre-work physical inspection data of 2528 people,who participated the construction on the Plateau (altitude 3080 m) during 2002-2004, and then returned during 2003-2005, were studied. Before the inspections, these people had been on the Plateau for 7～15 days to get them adaptable to the altitude conditions. These people were divided randomly into Long Break Group (break time≥90 d, n=984) and Short Break Group (break time ≤60 d, n=1544). Then they were divided into sub-Groups based on gender and age. Statistical analysis was then done using SPSS 12.0 software. Results: (1)The means of sBP,dBP,HR, and Hb of the Long Break Group, after 7～15 days of adaptability period, were lower than that of Short Break Group; while SpO2 of Long Break Group was slightly higher than that of Short Break Group.(Mean p≤0.001;The abnormal rates of ALT,BUN, BP of the Long Break Group were also significantly lower than that of Short Break Group (p<0.05, or p<0.001;(2)In the same group, or different groups, the BP,Hb of female sub-Group was better than male sub-Group(p<0.05, or p<0.001. The BP,ECG of <40 y sub-Group is better than ≥40 y sub-Group(p<0.05 or, p<0.001. Conclusion: 3-month, or even longer break in winter has positive impacts on the early physical conditions of the constructors on the Plateau (esp. males over 40 years old)