Incidence and risk factors associated with acute mountain sickness in children trekking on Jade Mountain, Taiwan. Vascular endothelial growth factor and acute mountain sickness Ginkgo biloba Does—and Does Not—Prevent Acute Mountain Sickness Reproducibility of Acute Mountain Sickness in Children and Adults: A Prospective Study
BACKGROUND Acute mountain sickness ( AMS ) is a pathophysiological symptom complex that occurs in high-altitude areas . The incidence of AMS on Jade Mountain , the highest peak in Taiwan ( 3952 m ) , has been reported to be ∼36 % . There is a lack of data in children trekking at altitude in Taiwan . The purpose of this study was to determine the incidence , risk factors and symptoms of AMS in children trekking on Jade Mountain , Taiwan . METHODS This prospect i ve cohort study included a total of 96 healthy non-acclimatized children aged 11 - 12 years who trekked from an elevation of 2600 - 3952 m in 3 days .  The Lake Louise AMS score  was used to record symptoms associated with AMS . RESULTS AMS were reported in 59 % of children trekking on Jade Mountain over a 3 day period . AMS incidence increased significantly with increasing altitude . The most common AMS symptom was headache , followed by fatigue or weakness , difficulty sleeping , dizziness or lightheadedness and gastrointestinal symptoms . Children who had experienced upper respiratory infection ( URI ) within the 7 days before their trek tended to have a greater risk for development of AMS . AMS incidence did not significantly differ according to gender , recent acute gastroenteritis , menstruation and body mass index . CONCLUSIONS The incidence of AMS in children trekking on Jade Mountain is greater than that observed in adults , and was associated with altitude and recent URI Study Objective : Despite causing significant morbidity throughout the mountainous regions of the world , the pathophysiology of acute mountain sickness ( AMS ) remains poorly understood . This study aims to improve the underst and ing of altitude illness by determining if vascular endothelial growth factor ( VEGF ) plays a role in the development of AMS . The purpose of this study was to determine if elevated plasma VEGF correlates with increased symptoms of AMS at high altitude . Patients and Methods : This is a prospect i ve study of a cohort of healthy climbers on Denali ( Mount McKinley ) in Alaska at 14 , 200 feet . Baseline demographics , medications , rates of ascent , and AMS scores were recorded .  Pulse oximetry measurements and venous blood sample s were obtained . Comparisons were made between mountaineers with and without AMS . Results : Seventy-two climbers were approached for participation in the study ; 21 ( 29 % ) refused . Of the 51 climbers participating in the study , 14 subjects ( 27.5 % ) had symptoms of AMS and 37 subjects ( 72.5 % ) were free of symptoms of AMS . Plasma VEGF levels were 79.14 pg/dl ( SD : 121.44 ) and 57.57pg/dl ( SD : 102.71 ) in the AMS and non-AMS groups , respectively . These results were nonsignificant . Similarly , comparison of sex , age , rate of ascent , pulse oximetry values , or history of altitude illness did not reveal significant differences between the AMS and non-AMS groups . Conclusion : This study does not provide evidence in support of the theory that plasma VEGF correlates with symptoms of AMS Abstract Objective .—To determine the efficacy of 2 different sources of Ginkgo biloba extract ( GBE ) in reducing the incidence and severity of acute mountain sickness ( AMS ) following rapid ascent to high altitude . Methods .—Two r and omized , double-blind , placebo-controlled cohort studies were conducted in which participants were treated with GBE ( 240 mg·d−1 ) or placebo prior to and including the day of ascent from 1600 m to 4300 m ( ascent in 2 hours by car ) . Acute mountain sickness was diagnosed if the Environmental Symptom Question naire III acute mountain sickness – cerebral ( AMS-C ) score was ≥0.7 and the Lake Louise Symptom ( LLS ) score was ≥3 and the participant reported a headache . Symptom severity was also determined by these scores . Results .— Results were conflicting : Ginkgo biloba  reduced the incidence and severity of AMS compared to placebo in the first but not the second study . In the first study , GBE reduced AMS incidence ( 7/21 ) vs placebo ( 13/19 ) ( P = .027 , number needed to treat = 3 ) , and it also reduced severity ( AMS-C = 0.77 ± 0.26 vs 1.59 ± 0.27 , P = .029 ) . In the second study , GBE did not reduce incidence or severity of AMS ( GBE 4/15 vs placebo 10/22 , P = .247 ; AMS-C = 0.48 ± 0.13 vs 0.58 ± 0.11 , P = .272 ) . The primary difference between the 2 studies was the source of GBE . Conclusions .—The source and composition of GBE products may determine the effectiveness of GBE for prophylaxis of AMS OBJECTIVE : Although a history of previous acute mountain sickness ( AMS ) is commonly used for providing advice and recommending its prophylaxis during subsequent exposure , the intraindividual reproducibility of AMS during repeated high-altitude exposure has never been examined in a prospect i ve controlled study . METHODS : In 27 nonacclimatized children and 29 adults ,  AMS  was assessed during the first 48 hours after rapid ascent to 3450 m on 2 consecutive occasions 9 to 12 months apart . RESULTS : During the first exposure , 18 adults ( 62 % ) and 6 children ( 22 % ) suffered from AMS ; during the second exposure , 14 adults ( 48 % ) and 4 children ( 15 % ) suffered from this problem ( adults versus children , P ≤ .01 ) . Most importantly , the intraindividual reproducibility of AMS  was very different ( P < .001 ) between children and adults . None of the 6 children having suffered from AMS during the first exposure suffered from AMS during the second exposure , but 4 children with no AMS during the first exposure did experience this problem during the second exposure . In contrast , 14 of the 18 adults who suffered from AMS on the first occasion also presented with this problem during the second exposure , and no new case developed in those who had not experienced AMS on the first occasion . CONCLUSIONS : In adults , a history of AMS is highly predictable of the disease on subsequent exposure , whereas in children it has no predictive value . A history of AMS should not prompt practitioners to advise against reexposure to high altitude or to prescribe drugs for its prophylaxis in children
Ensuring that the characteristics of the history and future ascents are similar may improve the clinical utility of AMS history
PURPOSE The goal of this meta- analysis was to determine the clinical utility of  acute mountain sickness ( AMS ) history to predict future incidents of AMS .