Physiological adaptability of members of Chinese National Earthquake Disaster Emergency Rescue Team (CNEDERT) in altitude of Yushu area of Qinghai province and prevention of acute mountain sickness.

Objective As members of CNEDERT, we were trusted to take the mission of medical rescue in April of this year in Yushu area of Qinghai province. As soon as we heard of the news of earthquake with shock of 7.1 on Richter scale happened on 14th April 2010, our team of 32 members from the General Hospital of Armed Police Force rapidly rushed to get there at 19 o'clock on 14th April. It is a cold plateau with 4000 meters in average above sea level. Of course, they would face many difficult problems and some of them could not be figured out in advance. It was really a new and big challenge. First of all, we had to bear the very low barometric pressure,threatening lives of team members. In order to fulfill the mission of medical rescue, and to prevent the acute mountain sickness (AMS) ,we monitored the physiological changes of every member. Method A total of 32 members aged from 27 - 42 years old with average age of (33.26 + 12.54) years, 6 male and 6 female, gathered at Peking, 50 meters above sea level, 6 hours ahead of getting to Yushu and received physical examination with measurements of SaO2, HR, Hb and breath holding test. The team worked in Yushu area for 13 days and returned back to Peking on 27th April at 13 o'clock. The measurements of SaO2, HR and He were kept on from 14th April to 4th May, 21 days in total. The occurrence of AMS was surveyed by questionnaire from 18 to 48 hours after arrival,and the AMSA was diagnosed and scored according to the Lake Louise consensus on the definition and quantification of altitude illness. When the score was equal or above 3, it was considered to be AMS. Our work activities included searching the victims under the collapsed building, carrying out treatment and operation as soon as possible in the mobile hospital, doing medical round visiting, public health and disease prevention, work of joint rescue of multiple professions and psychological counseling. Results Of them 26 (81.25%) members suffered from AMS of various severities and few of them had pulmonary edema and hematuria, and those with SaO2 below 60% were sent down to the plain of low level above sea. The average level of SaO2 at Peking was ( 98.21 + 2.63) %, and it suddenly dropped to (66.31 ± 4.24)% on the first day of entering Yushu area, and from the 2nd day on, it gradually increased to (84.80 ± 4.20)% on the 13th day of stay in Yushu. On the 14th day, we returned back to Peking, the average SaO2 gradually went up from ( 85.57 + 2.73) % to (85.70 + 3.11 ) % on the 15th day,(87.93±2.63)% on the 17th day, (92.21 ±3.62)% on the 18th day, and (98.2333 ± 1.78)% On the 21st day (5th May ). At plain the average HR was (78 ± 11 ) beats/min, and it went up abruptly to ( 121 ± 18) beats/min on the first day of arrival to Yushu, and from the 2nd day on, it slowly lowered down to (99± 12) beats/min at the end day of stay in Yushu area. When we got back to Peking, the average HR gradually normalized from (91± 18) beats/min to (77 + 16) beats on the 5th May. The average Hb in Peking was ( 118 ± 32) g/L, and it gradually increased to ( 137 ± 18) g/L on the 5th day and to ( 161 ± 27) g/L on the 11th day after arrival, and it gradually dropped to (127:± 13) g/L on the 17th day and to (120± 13) g/L on the 21st day. Various measures were taken to treat and prevent the AMS with Chinese herbal medicines such as hongjingtian (Rholiola sacra [Prain ex Hamet] Fu), droplet-sized pill of danshen (salva miltiorrhiza Bge), slice of xiyangshen (Panax quinquefolium L)for lozenge which had some effect of minimizing the symptoms of AMS, and with easily digestible diet catered for in less amount of food in each meal and more meals every day, and diet was composed of mainly carbohydrate and vitamins. Large amount of fluid was required at least 4000 - 6000 mL daily guided by the number of urination at least once or twice a day. For the severe case with shortness of breath and sense of oppression over chest, the oxygen inhalation and intravenous glucose saline with small dose of hydrocortisone were given. Conclusions There were great changes in SaO2, HR and Hb of individuals rushed into high altitude area from plain of low level above sea in a short length of time. But those individuals had the capability of adaptation to ameliorate bit by bit those changes day by day until 13 days of stay, the end of stay at high altitude. On that day, the levels of SaO2, HR and He were still far away from normal. And those changes took 6 days to resume the original levels after the members retumed to the plain. Of them, 81.25% (26/32) members suffered from AMS of various severities. Various measures taken to treat and prevent the AMS are very important. In addition, working at high altitude area, the medical equipment and facilities should be miniaturized for easy portability on the rugged and narrow footpath in order to preserve the energy of medical members. Key words: China International Search and Rescue Team; Earthquake relief; Altitude sickness; Oxygen saturation; Heart rate; Hemoglobin; Hypoxia