Prevention Of Acute Mountain Sickness Research Articles

Gastrointestinal syndrome encountered during a train voyage to high altitudes: A 14-day survey of 69 passengers in China

BackgroundThe diagnosis and evaluation of the severity of acute mountain sickness (AMS) continue to be problematic due to a lack of consensus on the inclusion of symptoms in a scoring system. Recent investigations highlight the significance of gastrointestinal symptoms in identifying this condition. However, the specific gastrointestinal symptoms associated with AMS have not been thoroughly elucidated in previous studies, and the underlying risk factors remain inadequately comprehended. MethodsThis study aimed to investigate the characteristics, trends, and risk factors related to gastrointestinal symptoms encountered during train travel to high altitude. A total of 69 passengers, specifically all with medical backgrounds, were surveyed 6 times over a period of 14 days. ResultsThe daily incidence of abdominal discomfort was higher than non-gastrointestinal symptoms within 14 days. Gastrointestinal symptoms demonstrated a greater prevalence, longer duration, and increased risk compared to non-gastrointestinal symptoms, such as headaches. The symptoms of abdominal distension and bowel sound hyperaction were found to be prevalent and persistent among patients diagnosed with AMS, exhibiting a high incidence rate. Gender, age, body mass index (BMI), smoking habits, and alcohol consumption were identified as risk factors associated with the occurrence and duration of gastrointestinal symptoms. ConclusionThis study suggests that gastrointestinal symptoms are more common and persistent when traveling to the plateau by train. These symptoms should be taken into consideration in the further diagnosis and prevention of AMS. Therefore, this study provides a significant theoretical foundation for the prevention and treatment of AMS.

Ibuprofen Compared to Acetazolamide for the Prevention of Acute Mountain Sickness: A Randomized Placebo-Controlled Trial.

Acetazolamide is recommended for the prevention of acute mountain sickness (AMS); however, its use is limited in some areas because of side effects. Previous studies report ibuprofen to be similar to or slightly inferior to acetazolamide. This randomized, triple-blinded, parallel-group, placebo-controlled trial was designed to compare ibuprofen with acetazolamide for the prevention of AMS. Four hundred forty-three healthy Asian Indian men with a mean age of 29 (range: 20-49) years were randomized into three groups A, B, and P at 350m (SL). Acetazolamide (A): 85 mg; ibuprofen (B): 600 mg; or placebo (P): calcium carbonate was administered thrice daily, starting one day prior and continuing for three days after arrival at 3500m (HA). Participants were evaluated for AMS using the Lake Louise Questionnaire and for pulse, BP, SpO2, and respiratory rate twice daily for the first two days during rest and once a day for days three to six at HA. Of the 443 participants recruited at SL, 139 could not be airlifted due to logistical limitations, and 304 were available for follow-up at HA. Among these, 254 had ascended as per protocol. By intent to treat (IT) (N = 304; A = 99, B = 102, P = 103), the incidence of AMS (LLQS>/=3) was 12%, 5%, and 13%, and the incidence of severe AMS was 1%, 2%, and 6%, in groups A, B, and P, respectively. Using per protocol analysis (PP) (N = 254; A = 83, B = 87, P = 84), the incidence of AMS was 12%, 6%, and 13%in groups A, B, and P, respectively. The relative risk for developing AMS vs. placebo was A-0.96 (CI:0.46-2.0, p=0.91), B-0.39 (CI:0.14-1.04, p=0.06), A-0.94 (CI:0.42-2.1, p=0.88), and B-0.45 (0.16-1.24, p=0.12) by IT and PP, respectively. Ibuprofen is effective in males for the prevention of AMS with rapid ascent to 3500 m-rest for the first two days. Acetazolamide was superior to ibuprofen in the prevention of moderate-to-severe AMS.

Effect of altitude and acetazolamide on postural control in healthy lowlanders 40years of age or older. Randomized, placebo-controlled trial.

Background: Hypoxia and old age impair postural control and may therefore enhance the risk of accidents. We investigated whether acetazolamide, the recommended drug for prevention of acute mountain sickness, may prevent altitude-induced deterioration of postural control in older persons. Methods: In this parallel-design trial, 95 healthy volunteers, 40 years of age or older, living <1,000m, were randomized to preventive therapy with acetazolamide (375mg/d) or placebo starting 24h before and during a 2-day sojourn at 3,100m. Instability of postural control was quantified by a balance platform with the center of pressure path length (COPL) as primary outcome while pulse oximetry (SpO2) was monitored. Effects of altitude and treatment on COPL were evaluated by ordered logistic regression. www.ClinicalTrials.gov NCT03536429. Results: In participants taking placebo, ascent from 760m to 3,100m increased median COPL from 25.8cm to 27.6cm (odds ratio 3.80, 95%CI 2.53-5.70) and decreased SpO2 from 96% to 91% (odds ratio 0.0003, 95%CI 0.0002-0.0007); in participants taking acetazolamide, altitude ascent increased COPL from 24.6cm to 27.3cm (odds ratio 2.22, 95%CI 1.57-3.13), while SpO2 decreased from 96% to 93% (odds ratio 0.007, 95%CI 0.004-0.012). Altitude-induced increases in COPL were smaller with acetazolamide vs. placebo (odds ratio 0.58, 95%CI 0.34-0.99) while drops in SpO2 were mitigated (odds ratio 19.2, 95%CI 9.9-37.6). Conclusion: In healthy individuals, 40 years of age or older, postural control was impaired after spending a night at 3,100m. The altitude-induced deterioration of postural control was mitigated by acetazolamide, most likely due to the associated improvement in oxygenation.

A Randomized Phase 2 Study to Evaluate Efficacy and Safety of AR36 for Prevention of Acute Mountain Sickness

Introduction AR36 is a pharmaceutical-grade plant extract used to support cardiovascular health in traditional Chinese medicine. Studies suggest that AR36 may prevent acute mountain sickness (AMS) during gradual ascent to high altitude. This randomized, placebo-controlled Phase 2 trial aimed to evaluate dosing regimens and assess efficacy and safety of AR36 for AMS prevention during rapid ascent. Methods Participants received placebo, low-dose AR36 (225 mg twice daily for 14 d prior and 5 d at altitude), or high-dose AR36 (12 d placebo, 300 mg twice daily for 2 d prior and 5 d at altitude). The primary efficacy outcome was 1993 Lake Louise Scoring System (LLSS) score on the morning after ascent. Safety was assessed through the proportion of treatment-emergent adverse events (TEAEs). Results One hundred thirty-two participants were randomized. Mean±SD age was 31.4±8.6 (range, 19–54) y. Baseline characteristics did not differ across groups. Lake Louise Scoring System scores on Day 16 in the placebo, low-dose, and high-dose groups were 4.03 (2.88), 4.42 (3.17), and 3.5 (2.31), respectively (placebo versus low-dose, P=0.462; placebo versus high-dose, P=0.574; n=110). The incidence of AMS on Day 16 was 66.7% in the placebo, 61.1% in the low-dose, and 55.3% in the high-dose group ( P=0.66). The proportion of TEAEs in the placebo, low-dose, and high-dose groups was 38.4% (81), 28.4% (60), and 33.2% (70), respectively ( P=0.205; n=127). There was no statistical difference between groups in LLSS, incidence of AMS, or TEAEs. Conclusions AR36 did not improve LLSS or AMS incidence using the current regimens. AR36 was well tolerated.

Prevention of Acute Mountain Sickness (AMS) with particular emphasis on hydration: a review

Acute mountain sickness (AMS) causes a number of symptoms within the human body, associated with staying at altitudes higher than 2,500 meters above sea level without prior acclimatization. The human body begins to adapt its functioning to the conditions of hypobaric hypoxia in order to maintain homeostasis. Its disturbance can lead to respiratory failure, pulmonary, or cerebral oedema, and, consequently, death. The best method of AMS prevention is slow acclimatization. A high-carbohydrate diet, thermal protection, and pharmacological agents could be listed as additional prevention measures. The development of AMS is influenced by many factors such as ambient temperature, wind speed, altitude, physical preparation of participants, and appropriate protection against adverse effects of these factors. Nevertheless, both dehydration and overhydration may worsen the AMS symptoms. The body’s exposure to altitude and dehydration alone reduces aerobic performance. Appropriate hydration throughout a climb is necessary due to both intense physical exercise and a hypoxic environment.

Traditional Chinese medicine for acute mountain sickness prevention: A systematic review and meta-analysis of randomized controlled trials

To evaluate the efficacy of traditional Chinese medicine (TCM) for preventing acute mountain sickness (AMS). We included randomized controlled trials (RCTs) which evalueded the effect of TCM for preventing AMS, compared with a placebo, no treatment or acetazolamide. The literature was searched in 6 major databases. RevMan 5.4 software was used for the meta-analysis. The relative risk for discrete variables and the mean difference for continuous variables with 95% confidence intervals (CIs) were applied to express the effect size. The risk of bias in the included studies was evaluated using the Cochrane risk assessment tool 2.0 (RoB 2.0), and the evidence certainty was assessed using the Grading of Recommendations Assessment and the Development and Evaluation (GRADE) approach. Twenty RCTs involving 3015 participants and 16 TCM patent drugs were included. The overall risk of bias in the majority of studies (15/20) was of some concerns. In terms of the AMS incidence, Rhodiola rosea (R. rosea, Hong Jing Tian) and Ginkgo biloba (G. biloba, Yin Xing Ye) were equivalent to the placebo/no treatment [RR (95% CI): 0.66 (0.43–1.01), 0.82 (0.63–1.06), respectively]. The AMS incidence in the G. biloba group was higher than that in the acetazolamide group [RR (95% CI): 2.92 (1.69–5.06)]. In terms of improving the AMS symptom score on days 1 and 3 in the plateau, R. rosea and G. biloba were superior to the placebo or no treatment [MD (95% CI): -0.98 (-1.71, -0.25), -2.05 (-3.14, -0.95), respectively]. The other 14 Chinese patent medicines were evaluated in a single trial, and the majority of the results were negative. The subgroup analysis showed that the effect of R. rosea was related to the intervention time, way of ascending, and altitude. R. rosea and G. biloba were effective in improving AMS symptoms but had no effect in reducing the AMS incidence. There was insufficient evidence to support the use of other TCM patent drugs to prevent AMS. More randomized double-blind placebo-controlled trials are warranted to evaluate and screen effective Chinese patent medicines for AMS prevention.

Can acute high-altitude sickness be predicted in advance?

In high-altitude environments, the oxygen andair density are decreased, and the temperature and humidity are low. When individuals enter high-altitude areas, they are prone to suffering from acute mountain sickness (AMS) because they cannot tolerate hypoxia. Headache, fatigue, dizziness, and gastrointestinal reactions are the main symptoms of AMS. When these symptoms cannot be effectively alleviated, they can progress to life-threatening high-altitude pulmonary edema or high-altitude cerebral edema. If the risk of AMS can be effectively assessed before people enter high-altitude areas, then the high-risk population can be promptly discouraged from entering the area, or drug intervention can be established in advance to prevent AMS occurrence and avoid serious outcomes. This article reviews recent studies related to the early-warning biological indicators of AMS to provide a new perspective on the prevention of AMS.

Voluntary Increase of Minute Ventilation for Prevention of Acute Mountain Sickness.

This study evaluated the feasibility and efficacy of voluntary sustained hyperventilation during rapid ascent to high altitude for the prevention of acute mountain sickness (AMS). Study subjects (n=32) were volunteer participants in a 2-day expedition to Mount Leoneras (4954 m), starting at 2800m (base camp at 4120 m). Subjects were randomized to either: 1) an intervention group using the voluntary hyperventilation (VH) technique targeting an end-tidal CO2 (ETCO2)<20 mmHg; or 2) a group using acetazolamide (AZ). During the expedition, respiratory rate (28±20 vs. 18±5 breaths/min, mean±SD, P<0.01) and SpO2 (95%±4% vs. 89%±5%, mean±SD, P<0.01) were higher, and ETCO2 (17±4 vs. 26±4 mmHg, mean±SD, P<0.01) was lower in the VH group compared to the AZ group - as repeatedly measured at equal fixed intervals during the ascent - showing the feasibility of the VH technique. Regarding efficacy, the incidence of 6 (40%) subjects registering an LLS score≥3 in the VH group was non-inferior to the 3 (18%) subjects in the acetazolamide group (P=0.16, power 28%). Voluntary increase in minute ventilation is a feasible technique, but - despite the underpowered non-inferiority in this small-scale proof-of-concept trial - it is not likely to be as effective as acetazolamide to prevent AMS.

[The preventive effect of four drugs on acute mountain sickness: a Bayesian network meta-analysis].

Objective: To compare and predict the preventive effects of acetazolamide and other drugs on acute mountain sickness(AMS). Methods: Following the retrieval strategy of PRISMA statement of systematic review and meta-analysis, we searched the databases of PubMed, Embase, Cochrane Library, Web of Science, CNKI, Wanfang, etc. from January 1, 1980 to November 30, 2020, and randomized controlled trials (RCT) consistent with drug prevention of AMS were conducted. Using R and other statistical software, Markov chain-Monte Carlo method was carried out for network meta-analysis under Bayesian framework, and node separation method was performed to check the consistency of closed-loop research. Results: Twenty-three literatures (25 studies) were included to compare the preventive effects of 4 drugs on AMS. Bayesian network meta-analysis showed that the incidence of AMS in acetazolamide group (ACE), dexamethasone group (DEX), ginkgo biloba extract group (GBE) and rhodiola group (RHO) was lower than that in placebo group (PLA). In the comparison of drug groups, the incidence of AMS in ACE, DEX and RHO was lower than that in GBE. There was no statistically significant difference in the incidence of AMS among ACE, DEX and RHO groups. Eight of these studies reported the effects of two drugs on pulse oxygen saturation (SpO2) in people entering the target altitude. Bayesian network meta-analysis showed that SpO2 in RHO was higher than that in ACE and PLA, but there was no statistically significant difference in SpO2 between ACE and PLA. The probability ranking of prevention AMS effect grade showed that the rank 5th probability of AMS in ACE, DEX, GBE, RHO and PLA was 45.72%, 48.80%, 0, 5.48% and 0, respectively. The probability ranking of improving the SpO2 level of the target altitude population showed that the probability of the ACE, RHO and PLA ranking 1st in improving the SpO2 effect at the target altitude was 2.27%, 97.66% and 0.07%, respectively; the results of direct comparison were in good agreement with those of Bayesian prediction model indirectly, and there was no statistical difference. Conclusions: Acetazolamide and dexamethasone can effectively prevent AMS, and should be the first choice for related supplementary research in the future. Rhodiola not only improves the SpO2 of people entering high altitude, but also reduces the incidence of AMS, which needs more attention. Ginkgo biloba extract is not as effective as the above three drugs in preventing AMS and should be used depending on clinical situations.

Predictive Capacity of Pulmonary Function Tests for Acute Mountain Sickness.

Small, Elan, Nicholas Juul, David Pomeranz, Patrick Burns, Caleb Phillips, Mary Cheffers, and Grant S. Lipman. Predictive capacity of pulmonary function tests for acute mountain sickness. High Alt Med Biol. 22: 193-200, 2021. Background: Pulmonary function as measured by spirometry has been investigated at altitude with heterogenous results, though data focused on spirometry and acute mountain sickness (AMS) are limited. The objective of this study was to investigate the capacity of pulmonary function tests (PFTs) to predict the development of AMS. Materials and Methods: This study was a blinded prospective observational study run during a randomized controlled trial comparing acetazolamide, budesonide, and placebo for AMS prevention on White Mountain, CA. Spirometry measurements of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow were taken at a baseline altitude of 1,250 m, and the evening of and morning after ascent to 3,810 m. Measurements were assessed for correlation with AMS. Results: One hundred three participants were analyzed with well-matched baseline demographics and AMS incidence of 75 (73%) and severe AMS of 48 (47%). There were no statistically significant associations between changes in mean spirometry values on ascent to high altitude with incidence of AMS or severe AMS. Lake Louise Questionnaire scores were negatively correlated with FVC (r = -0.31) and FEV1 (r = -0.29) the night of ascent. Baseline PFT had a predictive accuracy of 65%-73% for AMS, with a receiver operating characteristic of 0.51-0.65. Conclusions: Spirometry did not demonstrate statistically significant changes on ascent to high altitude, nor were there significant associations with incidence of AMS or severe AMS. Low-altitude spirometry did not accurately predict development of AMS, and it should not be recommended for risk stratification.

Efficacy of acetazolamide for the prophylaxis of acute mountain sickness: A systematic review, meta-analysis, and trial sequential analysis of randomized clinical trials.

BACKGROUND:Acute mountain sickness (AMS) is a benign and self-limiting syndrome, but can progress to life-threatening conditions if leave untreated. This study aimed to assess the efficacy of acetazolamide for the prophylaxis of AMS, and disclose factors that affect the treatment effect of acetazolamide.METHODS:Randomized controlled trials comparing the use of acetazolamide versus placebo for the prevention of AMS were included. The incidence of AMS was our primary endpoint. Meta-regression analysis was conducted to explore factors that associated with acetazolamide efficacy. Trial sequential analyses were conducted to estimate the statistical power of the available data.RESULTS:A total of 22 trials were included. Acetazolamide at 125, 250, and 375 mg/bid significantly reduced incidence of AMS compared to placebo. TAS indicated that the current evidence was adequate confirming the efficacy of acetazolamide at 125, 250, and 375 mg/bid in lowering incidence of AMS. There was no evidence of an association between efficacy and dose of acetazolamide, timing at start of acetazolamide treatment, mode of ascent, AMS assessment score, timing of AMS assessment, baseline altitude, and endpoint altitude.CONCLUSION:Acetazolamide is effective prophylaxis for the prevention of AMS at 125, 250, and 375 mg/bid. Future investigation should focus on personal characteristics, disclosing the correlation between acetazolamide efficacy and body mass, height, degree of prior acclimatization, individual inborn susceptibility, and history of AMS.

Incidence and Determinants of Acute Mountain Sickness in Mount Kinabalu, Malaysia.

Yang, Su Lan, Nor At'fina Ibrahim, Grazele Jenarun, and Houng Bang Liew. Incidence and determinants of acute mountain sickness in Mount Kinabalu, Malaysia. High Alt Med Biol. 21:265–272, 2020.Background: Acute mountain sickness (AMS) is the most common type of high-altitude sickness. The incidence of AMS varies by mountain location, trail characteristics, and study design. The lack of local epidemiology data has driven us to investigate the incidence and severity of AMS and its associated factors at Mount Kinabalu, Malaysia.Methods: A cohort study was conducted to collect data from climbers after days 1 (3272 m) and 2 (4095 m) of ascent. A self-administered questionnaire was used to explore climbers' demographic and climb characteristics, history of AMS, alcohol exposure, and AMS prevention measures. The Lake Louis score 2018 was used to assess the presence and severity of AMS (cutoff ≥3). Univariate and multivariable logistic regressions were performed to determine the factors associated with the development of AMS on day 2.Results: Data from 345 climbers were analyzed. The incidence of AMS was 23.9% (95% confidence interval [CI] 19.5%–28.7%) and 21.7% (95% CI 17.5%–26.3%) on days 1 and 2, respectively. The majority were mild cases. Experiencing AMS on day 1 (odds ratio [OR] = 12.88; 95% CI 6.71–24.75), alcohol consumption (OR = 3.73; 95% CI 1.66–8.39), receiving guide advice on day 1 (OR = 0.49; 95% CI 0.26–0.93), and age (OR = 0.96; 95% CI 0.93–0.99) were significant determinants of AMS at Mount Kinabalu. Gender, history of AMS, past exposure to high altitude, ascending time, water intake, acetazolamide use, physical fitness, pulse rate, and peripheral capillary oxygen saturation (SpO2) were not associated with AMS at Mount Kinabalu.Conclusion: Future analysis with age strata is required to ascertain the association of age with AMS. Our research has signposted a strong call for collaborative efforts to improve the provision of hiking advice and discourage alcohol sales to mitigate the risk of AMS among Mount Kinabalu climbers.

Inclusion of resistance routines in a hypoxia training program does not interfere with prevention of acute mountain sickness

ABSTRACT Objectives Acclimatization strategies have been shown to be the best solutions to avoid acute mountain sickness. In this context, we have designed a protocol performed in hypoxia that includes resistance routines in combination with classical endurance training exercises with mountain trekking at mid altitude. Methods Thirty-two volunteers preparing different mountain expeditions participated in the study distributed into two groups. One group trained at 2000 m, while another group trained at 4500–5800 m of simulated altitude in a hypoxic chamber. Acute mountain sickness was monitored by answering the Lake Louise Scale questionnaire during 2 sleeping sessions at 4800 m of simulated altitude at the beginning and at the end of the study. At the same time, oxygen saturation was determined in both groups to monitor physiologic adaptation. Data were also collected from the base camps in each expedition before ascension. Results Acute mountain sickness incidence in the hypoxic group decreased from 100% at the beginning to 12% of individuals at the end of the training period, and it was 25% at the base camps of expeditions. On the other hand, the control group passed from 100% to 88% of individuals at the end of the intervention and 70% at the base camps. At the same time, acute mountain sickness severity was mild in the experimental group compared to moderate-severe in the control group. These data were supported by the oxygen saturation values, indicating adequate adaptation changes for altitude in the hypoxic group. Conclusion The inclusion of resistance workouts in combination with endurance exercises, all performed in hypoxic conditions, does not interfere with an optimal adaptation to altitude and to prevent acute mountain sickness.

A Randomized Controlled Trial of the Lowest Effective Dose of Acetazolamide for Acute Mountain Sickness Prevention

BackgroundAcetazolamide is the most common medication used for acute mountain sickness prevention, with speculation that a reduced dose may be as efficacious as standard dosing with fewer side effects. MethodsThis double-blind, randomized, controlled noninferiority trial compared acetazolamide 62.5 mg twice daily to the standard dose acetazolamide 125 mg twice daily starting the evening prior to ascent from 1240 m (4100 ft) to 3810 m (12,570 ft) over 4 hours. The primary outcome was acute mountain sickness incidence (ie, headache, Lake Louise Questionnaire ≥3, and another symptom). ResultsA total of 106 participants were analyzed, with 51 (48%) randomized to 125 mg and 55 (52%) to 62.5 mg, with a combined acute mountain sickness incidence of 53 (50%) and mean severity of 3 (± 2.1). The 62.5-mg group failed to fall within the prespecified 26% noninferiority margin for acute mountain sickness incidence (62.5 mg = 30 [55%] vs 125 mg = 23 [45%], 95% confidence interval [CI] -11% to 30%). Participants in the 62.5-mg group had a higher risk of acute mountain sickness (odds ratio = 1.5, 95% CI 0.7-3.2) and moderate acute mountain sickness (odds ratio = 1.8, 95% CI 0.6-5.9), with a number needed to harm (NNH) of 9, with a number needed to treat (NNT) in the 125-mg group of 4.8. Increased acute mountain sickness incidence and symptom severity corresponded to lower weight-based and body mass index dosing, with similar side effects between groups. ConclusionAcetazolamide 62.5 mg twice daily failed to demonstrate equal effectiveness to 125 mg twice daily for prevention of acute mountain sickness. With increased risk and no demonstrable symptomatic or physiologic benefits, acetazolamide 62.5 mg twice daily should not be recommended for acute mountain sickness prevention.

N-Quinary heterocycle-4-sulphamoylbenzamides exert anti-hypoxic effects as dual inhibitors of carbonic anhydrases I/II.

Acute mountain sickness (AMS) affects approximately 25-50% of newcomers to high altitudes. Two human carbonic anhydrase isoforms, hCA I and II, play key roles in developing high altitude illnesses. However, the only FDA-approved drug for AMS is acetazolamide (AAZ), which has a nearly 100 times weaker inhibitory activity against hCA I (Ki=1237.10nM) than hCA II (Ki=13.22nM). Hence, developing potent dual hCA I/II inhibitors for AMS prevention and treatment is a critical medical need. Here we identified N-quinary heterocycle-4-sulphamoylbenzamides as potent hCA I/II inhibitors. The newly designed compounds 2b, 5b, 5f, 6d, and 6f possessed the desired inhibitory activities (hCA I: Ki=16.95-52.71nM; hCA II: Ki=8.61-18.64nM). Their hCA I inhibitory capacity was 22- to 76-fold stronger than that of AAZ. Relative to the control group for survival in a mouse model of hypoxia, 2b and 6d prolonged the survival time of mice by 21.7% and 29.3%, respectively, which was longer than those of AAZ (6.5%). These compounds did not display any apparent toxicity in vitro and in vivo. In addition, docking simulations suggested that the quinary aromatic heterocycle groups stabilised the interaction between hCA I/II and the inhibitors, which could be further exploited in structure optimization studies. Hence, future functional studies may confirm 2b and 6d as potential clinical candidate compounds with anti-hypoxic activity against AMS.

Efficacy\xa0and safety of inhaled budesonide on prevention of acute mountain sickness during emergent ascent: a meta-analysis of randomized controlled trials

BackgroundAcute Mountain Sickness (AMS) is a pathophysiologic process that occurs in non-acclimated susceptible individuals rapidly ascending to high-altitude. Barometric pressure falls at high altitude and it translates to a decreased partial pressure of alveolar oxygen (PAO2) and arterial oxygen (PaO2). A gradual staged ascent with sufficient acclimatization can prevent AMS but emergent circumstances requiring exposure to rapid atmospheric pressure changes – such as for climbers, disaster or rescue team procedures, and military operations – establishes a need for effective prophylactic medications. This systematic review and meta-analysis aim to analyze the incidence of AMS during emergent ascent of non-acclimatized individuals receiving inhaled budesonide compared to placebo.MethodsThis current meta-analysis was conducted according to the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. We searched PubMed, Google Scholar and Embase for relevant studies. The efficacy of budesonide in reducing incidence of AMS was evaluated by calculating the pooled ORs and 95% CIs. The efficacy of budesonide in maintaining hemoglobin-oxygen saturation was evaluated by calculating standard mean difference (SMD) and 95% confidence intervals.ResultsWe found that at high altitude, inhaled budesonide was effective in reducing the incidence of mild AMS [OR: 0.37; 95% CI, 0.14 to 0.9, p = 0.042] but was ineffective in reducing the incidence of severe AMS [OR: 0.46; 95% CI, 0.14 to 1.41, p = 0.17]. Inhaled budesonide was also effective in maintaining SpO2 (SMD: 0.47; 95% CI, 0.09 to 0.84, p = 0.014) at high altitude. However, it was not effective in maintaining or improving pulmonary function at high altitude. Systematic-review found no adverse effects of budesoide in the dose used for prophylaxis of AMS.ConclusionsOur systematic review showed that prophylactic inhaled budesonide is effective in preventing mild AMS during emergency ascent but not effective in preventing severe AMS. Though statistically significant, authors recommend caution in interpretation of data and questions for further well designed randomized studies to evaluate the role of budesonide in prophylaxis of AMS during an emergent ascent.

Prevention and treatment of high altitude cerebral edema (HACE)

High altitude cerebral edema (HACE) is often a severe and potentially fatal manifestation of acute mountain sickness (AMS). It usually develops within the first 2 in individuals rapidly ascending at altitudes above 4000 m. The main cause of HACE is hypoxia, because of reduced oxygen level at high altitude.The aim of this study was to to assess the methods of prevention and treatment of high altitude cerebral edema (HACE).  Our study material consisted of publications, which were found in PubMed, ResearchGate and Google Scholar databases. The first step was to find proper publications from the last 30 years. The second step was to carry out an overview of the found publications.Methods of prevention of acute mountain sickness are highly effective in high altitude cerebral edema prevention. Many studies estabilished the role of gradual ascent and staged ascent as well as administration of acetazolamide and dexamethasone in AMS prevention, and therefore in HACE prevention. Methods of treatments of acute mountain sickness are highly effective in high altitude cerebral edema treatment. Several researches proved the role of descent, administration of acetazolamide and dexamethasone, oxygen therapy as well as use of portable hyperbaric chamber in AMS treatment, and therefore in HACE treatment. However HACE treatment requires greater descent and larger doses of dexamethasone. Also duration of recovery is longer.

Significance of the proper acclimatization, use of the acetazolamide and dexamethasone in prevention of acute mountain sickness (AMS) – literature review

Acute mountain sickness (AMS) is an ilness, that occurs in non-acclimatized individuals after rapid ascent to high altitude, typically above 2,500 metres (8,000 ft). The main causes of the AMS are: reduced air pressure and lower oxygen levels at high altitudes. The early symptoms of AMS are non-specific such as: headache, anorexia, nausea, vomiting, fatigue, dizziness, and sleep disturbance, but not all need to be present at one time. It is very important to recognise the early symptoms of AMS and to start the treatment, because untreated AMS can progress to the life‐threatening: high altitude cerebral edema (HACE) and high altitude pulmonary edema (HAPE). Treatment of AMS consists of stabilization of the patient conditon, descent to lower altitude, oxygen therapy and administering acetazolamide and dexamethasone. The aim of this study was to evaluate the significance of the proper acclimatization, use of the acetazolamide and dexamethasone in prevention of acute mountain sickness (AMS).Proper acclimatization, use of the acetazolamide and dexamethasone are highly effective  in prevention of occurrence and reducing the symptoms of acute mountain sickness (AMS). Pharmacological prophylaxis is not necessary in low-risk situations but should be considered in addition to gradual ascent for use in moderate- to high-risk situations  Acetazolamide should be strongly considered in climbers and travelers at moderate or high risk of AMS with ascent to high altitude. Dexamethasone can be used as an alternative in individuals with a history of intolerance of or allergic reaction to acetazolamide. In rare circumstances (eg, military or rescue teams that must ascend rapidly to and perform physical work at &gt;3500 m), consideration can be given to concurrent use of acetazolamide and dexamethasone.

Efficacy of Danshen (Salvia miltiorrhiza) Dripping Pills for Prevention of Acute Mountain Sickness: A Randomized, Double-Blind, Placebo-Controlled Trial

Efficacy of Danshen (Salvia miltiorrhiza) Dripping Pills for Prevention of Acute Mountain Sickness: A Randomized, Double-Blind, Placebo-Controlled Trial

The role of iron repletion in adult iron deficiency anemia and other diseases.

Iron deficiency anemia (IDA) is the most prevalent and treatable form of anemia worldwide. The clinical management of patients with IDA requires a comprehensive understanding of the many etiologies that can lead to iron deficiency including pregnancy, blood loss, renal disease, heavy menstrual bleeding, inflammatory bowel disease, bariatric surgery, or extremely rare genetic disorders. The treatment landscape for many causes of IDA is currently shifting toward more abundant use of intravenous (IV) iron due to its effectiveness and improved formulations that decrease the likelihood of adverse effects. IV iron has found applications beyond treatment of IDA, and there is accruing data about its efficacy in patients with heart failure, restless leg syndrome, fatigue, and prevention of acute mountain sickness. This review provides a framework to diagnose, manage, and treat patients presenting with IDA and discusses other conditions that benefit from iron supplementation.