Database: Ovid MEDLINE(R) <1966 to January Week 3 2004> Search Strategy: -------------------------------------------------------------------------------1 Altitude Sickness/ (1625) 2 Altitude Sickness/pc, dt, th [Prevention & Control, Drug Therapy, Therapy] (480) 3 *Altitude Sickness/pc, dt, th (263) 4 exp sports/ or exp exertion/ (111424) 5 1 and 4 (455) 6 *Altitude Sickness/ and 5 (353) 7 high altitude.tw. and 6 (179) 8 limit 7 to (human and english language) (151) 9 limit 8 to yr=1996-2004 (82) 10 limit 9 to ovid full text available (1) 11 limit 9 to local holdings (24) 12 10 or 11 (25) 13 9 not 12 (57) 14 from 13 keep 5,14-15,23,38,41-42,51,55 (9) 15 12 or 14 (34) 16 from 15 keep 1-34 (34) 17 from 16 keep 1-34 (34) *************************** <1> Unique Identifier 10902930 Authors Bonnon M. Noel-Jorand MC. Therme P. Institution Universite de la Mediterranee Aix-Marseille II, Faculte des Sciences du Sport, La Timone, Marseille, France. Title Effects of different stay durations on attentional performance during two mountain expeditions. Source Aviation Space & Environmental Medicine. 71(7):678-84, 2000 Jul. Abstract BACKGROUND: Hypoxia-induced deficits in intellectual performance are linked to the altitude level reached, the speed of the ascent and the time spent at high altitude. This study analyzes attentional changes during adaptation to two different types of stay at high altitude on two different expeditions: one involving a 16-d trip between 2,000 m and 5,600 m, followed by a 2-d ascent to 6,440 m and back again; the other, a 21-d stay at 6,542 m. We tested the hypothesis that, at similar high altitudes, decrements in attentional performance would only occur during a long duration stay. METHODS: Indexes for attentional performance were calculated for two experimental groups under normoxia before the climb, under acute and chronic hypoxia during the climb, and under normoxia after the climb. They were compared for two control groups tested only under normoxia. RESULTS: The altitude stay was found to have an effect on the 6,542 m group when compared with the controls. Group performance differed at 2 d and 21 d after their arrival at 6,542 m and after their return to normoxia. When all the test administrations were pooled together for this expedition we noted an interaction between the level of difficulty of the task and the experimental and control groups: namely the difference between the groups was greater for the difficult task than it was for the easy task. No effect was found for the other expedition (at 5,600 m) when the group tested was compared with the controls. CONCLUSION: For a 21-d stay at an altitude of 6,542 m with the same ascent protocol as a group climbing to a lower altitude (16 d between 2,000 m and 5,600 m followed by a 2 d ascent to 6,440 m and back again), subjects appeared to suffer from attentional performance deficits which persisted for several days after the subjects returned to normoxic conditions. <2> Unique Identifier 12498553 Authors Cauchy E. Larmignat P. Boussuges A. Le Roux G. Charniot JC. Dumas JL. Richalet JP. Institution Departement de Medecine de Montagne de l'Hopital de Chamonix, Chamonix, France. m.cauchy@ch-sallanches-chamonix.fr Title Transient neurological disorders during a simulated ascent of Mount Everest. Source Aviation Space & Environmental Medicine. 73(12):1224-9, 2002 Dec. Abstract BACKGROUND: Transient neurological disorders are often observed at high altitude but are poorly documented under field conditions. The mechanism usually invoked is a hypocapnic vasoconstriction due to severe hypoxic hyperventilation. During a simulated ascent of Mount Everest in a hypobaric chamber by eight volunteer alpinists (Operation Everest III, Comex '97), three subjects presented neurological symptoms. We report here on the clinical observations and testing to detect mechanisms in addition to hypocapnic vasoconstriction. METHODS: The experiment was designed to investigate factors limiting physiological performance at altitude and the pathophysiology of acute mountain sickness. A retrospective analysis was made comparing the three cases of transient neurological disorder at high altitude (TNDHA) with the five subjects who had no neurological symptoms. RESULTS: Analysis of clinical and blood parameters showed no difference between cases and controls. The cases showed no neurological sequelae following the experiment and were normal on cardiac imaging. However, one case had a history of migraine in his youth, leading us to hypothesize that segmental vasoconstriction was a factor. In another case, gas bubbles were detected in the pulmonary artery by transthoracic echocardiography when he was symptomatic, suggesting that gas emboli may have played a role. All three cases shared a possible triggering factor in that each experienced hyperventilation alternating with straining against a closed glottis shortly before the onset of symptoms. CONCLUSION: Mechanisms other than hypocapnic vasoconstriction in hypoxia may be causal factors of TNDHA. The existence of triggering factors and evidence of a possible embolic mechanism should be further explored. <3> Unique Identifier 10902931 Authors Purkayastha SS. Bhaumik G. Sharma RP. Arora BS. Selvamurthy W. Institution Defence Institute of Physiology & Allied Sciences, Timarpur, Dehli, India. Title Effects of mountaineering training at high altitude (4,350 m) on physical work performance of women. Source Aviation Space & Environmental Medicine. 71(7):685-91, 2000 Jul. Abstract BACKGROUND: Little is known about work performance of women in hypobaric hypoxia. Moreover, whether native women of moderate altitude (2,000-2,100 m) differ from their lowland counterparts in their ability to adjust to hypobaric hypoxia is also not known. Hence, physiological alterations on work performance due to mountaineering training with altitude adaptation was evaluated in two groups of women and compared to the differences in the responses of the native women of moderate altitudes (Highlanders-HL) with those of the plains (Lowlanders-LL). METHODS: Pre-training tests were conducted at 2,100 m, then during sojourn to 4,350 m and re-tested again after return to 2,100 m. Physical work performance was assessed following standard step-test-exercise on a 30 cm stool with 24 cycles x min(-1) for 5 min. Heart rate, BP, ventilation, oxygen consumption and oxygen saturation were monitored at rest and during exercise followed by 5 min recovery in all three situations. RESULTS: During initial assessment, HL showed higher cardiovascular efficiency with faster recovery of exercise heart rate. Both groups showed significant improvement in physical performance due to mountaineering training at high altitude (HA). The difference in performance between two groups narrowed down at 4,350 m and further reduced during re-test with maintenance of initial superiority of the HL. CONCLUSIONS: a) Native women of moderate altitude (HL) are more fit compared with their plains counterparts (LL); b) All women achieved marked improvement in cardiovascular and respiratory efficiency as well as the step-test score due to intense mountaineering training at HA, and the rate of improvement in physical performance was higher in LL; c) Further, induction by trekking under progressive hypoxia coupled with rigorous mountaineering activity at HA merits in understanding better acclimatization and improved physical performance. <4> Unique Identifier 11086670 Authors Hendricks DM. Pollock NW. Natoli MJ. Vann RD. Institution Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Durham, NC 27710, USA. Title Mountaineering oxygen mask performance at 4572 m. Source Aviation Space & Environmental Medicine. 71(11):1142-7, 2000 Nov. Abstract BACKGROUND: Supplemental oxygen delivered by mask at high altitude is used to increase arterial oxygen saturation (SaO2) thereby mitigating physiological and cognitive dysfunction secondary to hypoxemia. Historically, mask performance has not been well documented although it may be a critical factor in determining the success of an expedition. METHODS: Three mountaineering masks were used by ten healthy, nonaltitude-acclimatized participants (eight males, two females) to compare ventilatory responses, SaO2, heart rate, and end-tidal gases. Masks tested were: Life Support Engineering Ltd. (LSEL); Zvezda Enterprise (ZE); and a prototype of our own design (Duke). Test conditions were as follows: simulated altitude at 0 and 4572 m (15,000 ft); rest and cycle exercise at 75 W; and supplemental oxygen flow at 0, 1.1 +/- 0.05, and 1.7 +/- 0.06 L x min(-1) (mean +/- SD). Statistical analysis was completed using GLM (SAS software). RESULTS: As there were no differences between the 1.1 and 1.7 L x min(-1) flow rates, the data were pooled. All three masks improved SaO2 with the ZE and Duke masks being more effective during exercise, maintaining mean SaO2 >90%. CONCLUSIONS: All three masks provided at least partial protection of physiological norms during rest and exercise at 4572 m. The ZE and Duke systems offered the best performance. The need for performance evaluation as part of system design is evident as subtle differences in design can significantly affect performance. <5> Unique Identifier 10807827 Authors Bartsch P. Eichenberger U. Mayatepek E. Institution Ballmer PE. Gibbs JS. Schirlo C. Oelz O. Institute of Sportsmedicine, University Hospital, Heidelberg, Germany. peter_bartsch@med.uni-heidelberg.de Title Urinary leukotriene E(4) levels are not increased prior to high-altitude pulmonary edema. Source Chest. 117(5):1393-8, 2000 May. Abstract STUDY OBJECTIVE: To examine whether increased urinary cysteinyl-leukotriene E(4) (LTE(4)) excretion, which has been found to be elevated in patients presenting with high-altitude pulmonary edema (HAPE), precedes edema formation. DESIGN: Prospective studies in a total of 12 subjects with susceptibility to HAPE. SETTING: In a chamber study, seven subjects susceptible to HAPE and five nonsusceptible control subjects were exposed for 24 h to an altitude of 450 m (control day), and exposed for 20 h to 4,000 m after slow decompression over 4 h. In a field study, prospective measurements at low and high altitude were performed in five subjects developing HAPE at 4,559 m. PARTICIPANTS: Mountaineers with a radiographically documented history of HAPE and control subjects who did not develop HAPE with identical high-altitude exposure. INTERVENTIONS: 24-h urine collections. MEASUREMENTS AND RESULTS: In the hypobaric chamber, none of the subjects developed HAPE. The 24-h urinary LTE(4) did not differ between HAPE susceptible and control subjects, nor between hypoxia and normoxic control day. In the field study, urinary LTE(4) was not increased in subjects with HAPE compared to values obtained prior to HAPE at high altitude and during 2 control days at low altitude. CONCLUSIONS: These data do not provide evidence that cysteinyl-leukotriene-mediated inflammatory response is associated with HAPE susceptibility or the development of HAPE within the context of our studies. <6> Unique Identifier 9596338 Authors Toepfer M. Hartmann G. Schlosshauer M. Hautmann H. Huber RM. Title Adrenomedullin: a player at high altitude?. Source Chest. 113(5):1428, 1998 May. Tschop M. Fischer R. <7> Unique Identifier 9404756 Authors Grissom CK. Zimmerman GA. Whatley RE. Institution Pulmonary Division and the Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, USA. ldcgriss@ihc.com Title Endothelial selectins in acute mountain sickness and high-altitude pulmonary edema. Source Chest. 112(6):1572-8, 1997 Dec. Abstract STUDY OBJECTIVES: Mechanical or inflammatory injury to pulmonary endothelial cells may cause impaired pulmonary gas exchange in acute mountain sickness (AMS) and noncardiogenic pulmonary edema in high-altitude pulmonary edema (HAPE). This study was designed to determine whether markers of endothelial cell activation or injury, plasma E- and P-selectin, were increased after ascent to high altitude, in AMS or in HAPE. DESIGN: We collected clinical data and plasma specimens in control subjects at sea level and after ascent to 4,200 m, and in climbers with AMS or HAPE at 4,200 m. Data analysis was performed using standard nonparametric statistical methods, and results reported as mean+/-SD. SETTING: National Park Service medical camp at 4,200 m on Mt. McKinley (Denali), Alaska. PATIENTS: Blood samples and clinical data were collected from 17 healthy climbers at sea level and again after ascent to 4,200 m, and from a different group of 13 climbers with AMS and 8 climbers with HAPE at 4,200 m. Climbers with AMS were divided into normoxic (n=7) and hypoxemic (n=6) groups. MEASUREMENTS AND RESULTS: Using an enzyme immunoassay technique, plasma E-selectin concentrations were found to be increased in the 17 control subjects after ascent to 4,200 m (17.2+/-8.2 ng/mL) as compared to sea level (12.9+/-8.2 ng/mL) (p=0.001). Plasma E-selectin concentrations were also increased in subjects with hypoxemic AMS (30.6+/-13.4 ng/mL) and HAPE (23.3+/-9.1 ng/mL) compared to control subjects at sea level (p=0.009). Increased plasma E-selectin concentration significantly correlated with hypoxemia (p=0.006). Plasma Pselectin concentrations were unchanged after ascent to 4,200 m and in subjects with AMS and HAPE. CONCLUSION: Because E-selectin is produced only by endothelial cells, increased plasma E-selectin after ascent to high altitude and in hypoxemic climbers with AMS and HAPE provides evidence that endothelial cell activation or injury is a component of hypoxic altitude illness. <8> Unique Identifier 12793625 Authors Kuo DC. Jerrard DA. Institution Division of Emergency Medicine, University of Maryland School of Medicine. 419 West Redwood Street, Suite 280, Baltimore, MD 21201, USA. dkuo@umaryland.edu Title Environmental insults: smoke inhalation, submersion, diving, and high altitude. [Review] [127 refs] Source Emergency Medicine Clinics of North America. 21(2):475-97, x, 2003 May. Abstract In the expanding search for recreation, we spend more and more of our time in various environments. Whether the air is thin or compressed or smoke-filled or there is no air at all, emergency physicians continue to meet and treat the various pulmonary emergencies that the environment may create. The authors present the background, diagnosis, and management of a few of the more common pulmonary emergencies that the environment may produce. [References: 127] <9> Unique Identifier 9056576 Authors Zafren K. Honigman B. Institution Columbia Alaska Regional Hospital and Providence Alaska Medical Center, Anchorage, USA. Title High-altitude medicine. [Review] [201 refs] Source Emergency Medicine Clinics of North America. 15(1):191-222, 1997 Feb. Abstract This article discusses prevention, recognition, and treatment of altitude illnesses, especially acute mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. Physicians advising travelers and trekkers who will be visiting high-altitude areas will find an organized approach to giving pretravel advice. Physicians practicing in or visiting high-altitude areas will find guidelines for diagnosis and treatment. This article also addresses the issue of patients with underlying diseases who wish to travel to high-altitude destinations. [References: 201] <10> Unique Identifier 11513303 Authors Walter R. Maggiorini M. Scherrer U. Contesse J. Reinhart WH. Institution Department Innere Medizin, Kantonsspital, Chur, Switzerland. roland.walter@dim.usz.ch Title Effects of high-altitude exposure on vascular endothelial growth factor levels in man. Source European Journal of Applied Physiology. 85(1-2):113-7, 2001 Jul. Abstract Vascular endothelial growth factor (VEGF) is an endothelial cell mitogen and permeability factor that is inducible by hypoxia. Its contribution to highaltitude illness in man is unknown. We measured VEGF levels in 14 mountaineers at low altitude (490 m) and 24 h after their arrival at high altitude (4,559 m). At high altitude, VEGF increased from [mean (SEM)] 32.5 (9.2) to 60.9 (18.5) pg.ml(-1) (P < 0.004) in the arterial blood, and from 15.9 (2.9) to 49.3 (15.9) pg.ml(-1) (P= 0.0001) in the mixed venous blood. Whereas at low altitude venous and arterial VEGF levels were not statistically different from each other (P= 0.065), the VEGF concentration was significantly lower in venous than in arterial blood samples at high altitude (P=0.004). The pulmonary capillary VEGF concentration remained unchanged at high altitude [14.8 (2.5) vs 17.1 (5.4) pg.ml(-1), P=0.85]. VEGF levels in the nine mountaineers who developed symptoms of acute mountain sickness (AMS), and in the six subjects who had radiographic evidence of high-altitude pulmonary edema were similar to those in subjects without symptoms. VEGF was not correlated with either AMS scores, mean pulmonary arterial pressures, arterial partial pressure of O2, or alveolar-arterial O2 gradients. We conclude that VEGF release is stimulated at high altitude, but that VEGF is probably not related to high-altitude illness. <11> Unique Identifier 8880116 Authors Droma Y. Hayano T. Takabayashi Y. Koizumi T. Kubo K. Kobayashi T. Sekiguchi M. Institution First Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Japan. Title Endothelin-1 and interleukin-8 in high altitude pulmonary oedema. Source European Respiratory Journal. 9(9):1947-9, 1996 Sep. Abstract We present a case of high altitude pulmonary oedema (HAPE) with pulmonary hypertension and polymorphonuclear leucocyte (PMN) accumulation in bronchoalveolar lavage fluid (BALF), which occurred in a 21 year old man. Plasma endothelin-1 (ET-1) and interleukin-8 (IL-8) concentration in BALF were elevated on admission, and returned to normal level at recovery, when the pulmonary artery pressure and the PMN counts in BALF were normal. In addition, E-selectin and intercellular adhesion molecule-1 (ICAM-1) in BALF were also slightly increased on admission. These findings suggest that endothelin-1 is a vasoconstrictor which contributes to the pulmonary hypertension in high altitude pulmonary oedema, and that some of the inflammatory mediators play an important role in chemotaxis and accumulation of polymorphonuclear leucocytes in the development of high altitude pulmonary oedema. <12> Unique Identifier 9630030 Authors Litch JA. Tuggy M. Institution Himalayan Rescue Association, Kathmandu, Nepal. Title Cough induced stress fracture and arthropathy of the ribs at extreme altitude. Source International Journal of Sports Medicine. 19(3):220-2, 1998 Apr. Abstract Cough and chest wall pain at high altitude have only received passing mention in the medical literature. Increased minute ventilation of cold dry air at very high altitude is likely to cause airway irritation. This in turn may result in airway drying, mucus production, postnasal drip from vasomotor rhinitis, and bronchospasm acting individually or in combination to stimulate the vagal cough reflex. The cough is exacerbated further at extreme altitudes above 5500 m, and may result in intercostal muscle strain and single or multiple rib fractures. We present a case of multiple cough induced stress fractures and arthropathy documented by technetium-99 bone scan in a high altitude climber and suggest the addition of the term High Altitude Cough Syndrome (HACS) to the medical syntax to identify this discrete medical problem of exposure to very high altitude. <13> Unique Identifier 12165883 Authors Tannheimer M. Thomas A. Gerngross H. Institution Bundeswehrkrankenhaus Ulm Department of Surgery, Ulm, Germany. arkus.tannheimer@arcormail.de Title Oxygen saturation course and altitude symptomatology during an expedition to broad peak (8047 m). Source International Journal of Sports Medicine. 23(5):329-35, 2002 Jul. Abstract Thirteen healthy European mountaineers (11 male, 2 female) participated in the 62-day German-Pakistani Research Expedition to Broad Peak (8047 m) in the Karakorum, Pakistan. During ascent, base camp stay and approach to the summit, oxygen saturation was measured by pulse oximetry at rest, during exercise and during sleep; in addition, questionnaires on high altitude symptomatic had to be answered. We found a dramatic decrease in oxygen saturation especially at extreme altitudes (7100 m: Median 63%, Min 59%, Max 65%) and a long time required for real acclimatization. The lowest figures at 4850 m were found during maximal exercise, 77.5% (69 - 85%) and during sleep, 81% (73 - 88%), the highest ones at rest, 86.5% (77 - 89%). There was a significant correlation (Spearman rank correlation coefficient with ties) between measured oxygen saturation during the ascent to/stay at base camp and high altitude illness (p = 0.005 - 0.05), as well as with high altitude performance (p = 0.025 - 0.01). The limiting values of "no high altitude symptomatic", "high altitude discomfort", AMS and the malignant forms could be estimated for acclimatized (>90%/>80%/>70%/<70%) and unacclimatized (>80%/>70%/>65%/<65%) condition. Pulse oximetry is an objective non-invasive method of measurement that is easy to handle. It is a suitable device besides clinical examination and questionnairetest in the diagnosis of high altitude illness even in the hands of nonprofessionals. The measurement at sleep can possibly explain present high altitude symptomatic despite of (nearly) normal oxygen saturation values at rest. <14> Unique Identifier 8872664 Authors Podolsky A. Eldridge MW. Richardson RS. Knight DR. Johnson EC. Hopkins SR. Johnson DH. Michimata H. Grassi B. Feiner J. Kurdak SS. Bickler PE. Severinghaus JW. Wagner PD. Institution Department of Medicine, University of California, San Diego, La Jolla 920930623, USA. Title Exercise-induced VA/Q inequality in subjects with prior high-altitude pulmonary edema. Source Journal of Applied Physiology. 81(2):922-32, 1996 Aug. Abstract Ventilation-perfusion (VA/Q) mismatch has been shown to increase during exercise, especially in hypoxia. A possible explanation is subclinical interstitial edema due to high pulmonary capillary pressures. We hypothesized that this may be pathogenetically similar to high-altitude pulmonary edema (HAPE) so that HAPE-susceptible people with higher vascular pressures would develop more exercise-induced VA/Q mismatch. To examine this, seven healthy people with a history of HAPE and nine with similar altitude exposure but no HAPE history (control) were studied at rest and during exercise at 35, 65, and 85% of maximum 1) at sea level and then 2) after 2 days at altitude (3,810 m) breathing both normoxic (inspired Po2 = 148 Torr) and hypoxic (inspired Po2 = 91 Torr) gas at both locations. We measured cardiac output and respiratory and inert gas exchange. In both groups, VA/Q mismatch (assessed by log standard deviation of the perfusion distribution) increased with exercise. At sea level, log standard deviation of the perfusion distribution was slightly higher in the HAPE-susceptible group than in the control group during heavy exercise. At altitude, these differences disappeared. Because a history of HAPE was associated with greater exercise-induced VA/Q mismatch and higher pulmonary capillary pressures, our findings are consistent with the hypothesis that exercise-induced mismatch is due to a temporary extravascular fluid accumulation. <15> Unique Identifier 10658026 Authors Roach RC. Maes D. Sandoval D. Robergs RA. Icenogle M. Hinghofer-Szalkay H. Lium D. Loeppky JA. Investigator: Loeppky JA. Institution Division of Physiology, Department of Life Sciences, New Mexico Highlands University, Las Vegas 87701-9000, New Mexico, USA. rroach@hypoxia.net Investigator Affiliation: Lovelace Resp Res Inst, Albuquerque, NM Title Exercise exacerbates acute mountain sickness at simulated high altitude. Source Journal of Applied Physiology. 88(2):581-5, 2000 Feb. Abstract We hypothesized that exercise would cause greater severity and incidence of acute mountain sickness (AMS) in the early hours of exposure to altitude. After passive ascent to simulated high altitude in a decompression chamber [barometric pressure = 429 Torr, approximately 4,800 m (J. B. West, J. Appl. Physiol. 81: 1850-1854, 1996)], seven men exercised (Ex) at 50% of their altitude-specific maximal workload four times for 30 min in the first 6 h of a 10-h exposure. On another day they completed the same protocol but were sedentary (Sed). Measurements included an AMS symptom score, resting minute ventilation (VE), pulmonary function, arterial oxygen saturation (Sa(O(2))), fluid input, and urine volume. Symptoms of AMS were worse in Ex than Sed, with peak AMS scores of 4.4 +/- 1.0 and 1.3 +/- 0.4 in Ex and Sed, respectively (P < 0.01); but resting VE and Sa(O(2)) were not different between trials. However, Sa(O(2)) during the exercise bouts in Ex was at 76.3 +/- 1.7%, lower than during either Sed or at rest in Ex (81.4 +/- 1.8 and 82.2 +/- 2.6%, respectively, P < 0.01). Fluid intake-urine volume shifted to slightly positive values in Ex at 3-6 h (P = 0.06). The mechanism(s) responsible for the rise in severity and incidence of AMS in Ex may be sought in the observed exercise-induced exaggeration of arterial hypoxemia, in the minor fluid shift, or in a combination of these factors. <16> Unique Identifier 8872663 Authors Eldridge MW. Podolsky A. Richardson RS. Johnson DH. Knight DR. Johnson EC. Hopkins SR. Michimata H. Grassi B. Feiner J. Kurdak SS. Bickler PE. Wagner PD. Severinghaus JW. Institution Cardiovascular Research Institute, University of California, San Francisco 94143-0542, USA. mweldridge@ucdavis.edu Title Pulmonary hemodynamic response to exercise in subjects with prior highaltitude pulmonary edema. Source Journal of Applied Physiology. 81(2):911-21, 1996 Aug. Abstract Individuals with a prior history of (susceptible to high altitude pulmonary edema (HAPE-S) have high resting pulmonary arterial pressures, but little data are available on their vascular response to exercise. We studied the pulmonary vascular response to exercise in seven HAPE-S and nine control subjects at sea level and at 3,810 m altitude. At each location, both normoxic (inspired PO2 = 148 Torr) and hypoxic (inspired PO2 = 91 Torr) studies were conducted. Pulmonary hemodynamic measurements included pulmonary arterial and pulmonary arterial occlusion pressures. A multiple regression analysis demonstrated that the pulmonary arterial pressure reactivity to exercise was significantly greater in the HAPE-S group. This reactivity was not influenced by altitude or oxygenation, implying that the response was intrinsic to the pulmonary circulation. Pulmonary arterial occlusion pressure reactivity to exercise was also greater in the HAPES group, increasing with altitude but independent of oxygenation. These findings suggest an augmented flow-dependent pulmonary vasoconstriction and/or a reduced vascular cross-sectional area in HAPE-S subjects. <17> Unique Identifier 8872664 Authors Podolsky A. Eldridge MW. Richardson RS. Knight DR. Johnson EC. Hopkins SR. Johnson DH. Michimata H. Grassi B. Feiner J. Kurdak SS. Bickler PE. Severinghaus JW. Wagner PD. Institution Department of Medicine, University of California, San Diego, La Jolla 920930623, USA. Title Exercise-induced VA/Q inequality in subjects with prior high-altitude pulmonary edema. Source Journal of Applied Physiology. 81(2):922-32, 1996 Aug. Abstract Ventilation-perfusion (VA/Q) mismatch has been shown to increase during exercise, especially in hypoxia. A possible explanation is subclinical interstitial edema due to high pulmonary capillary pressures. We hypothesized that this may be pathogenetically similar to high-altitude pulmonary edema (HAPE) so that HAPE-susceptible people with higher vascular pressures would develop more exercise-induced VA/Q mismatch. To examine this, seven healthy people with a history of HAPE and nine with similar altitude exposure but no HAPE history (control) were studied at rest and during exercise at 35, 65, and 85% of maximum 1) at sea level and then 2) after 2 days at altitude (3,810 m) breathing both normoxic (inspired Po2 = 148 Torr) and hypoxic (inspired Po2 = 91 Torr) gas at both locations. We measured cardiac output and respiratory and inert gas exchange. In both groups, VA/Q mismatch (assessed by log standard deviation of the perfusion distribution) increased with exercise. At sea level, log standard deviation of the perfusion distribution was slightly higher in the HAPE-susceptible group than in the control group during heavy exercise. At altitude, these differences disappeared. Because a history of HAPE was associated with greater exercise-induced VA/Q mismatch and higher pulmonary capillary pressures, our findings are consistent with the hypothesis that exercise-induced mismatch is due to a temporary extravascular fluid accumulation. <18> Unique Identifier 8872663 Authors Eldridge MW. Podolsky A. Richardson RS. Johnson DH. Knight DR. Johnson EC. Hopkins SR. Michimata H. Grassi B. Feiner J. Kurdak SS. Bickler PE. Wagner PD. Severinghaus JW. Institution Cardiovascular Research Institute, University of California, San Francisco 94143-0542, USA. mweldridge@ucdavis.edu Title Pulmonary hemodynamic response to exercise in subjects with prior highaltitude pulmonary edema. Source Journal of Applied Physiology. 81(2):911-21, 1996 Aug. Abstract Individuals with a prior history of (susceptible to high altitude pulmonary edema (HAPE-S) have high resting pulmonary arterial pressures, but little data are available on their vascular response to exercise. We studied the pulmonary vascular response to exercise in seven HAPE-S and nine control subjects at sea level and at 3,810 m altitude. At each location, both normoxic (inspired PO2 = 148 Torr) and hypoxic (inspired PO2 = 91 Torr) studies were conducted. Pulmonary hemodynamic measurements included pulmonary arterial and pulmonary arterial occlusion pressures. A multiple regression analysis demonstrated that the pulmonary arterial pressure reactivity to exercise was significantly greater in the HAPE-S group. This reactivity was not influenced by altitude or oxygenation, implying that the response was intrinsic to the pulmonary circulation. Pulmonary arterial occlusion pressure reactivity to exercise was also greater in the HAPES group, increasing with altitude but independent of oxygenation. These findings suggest an augmented flow-dependent pulmonary vasoconstriction and/or a reduced vascular cross-sectional area in HAPE-S subjects. <19> Unique Identifier 10904032 Authors Robach P. Dechaux M. Jarrot S. Vaysse J. Schneider JC. Mason NP. Herry JP. Gardette B. Richalet JP. Institution Ecole Nationale de Ski et d'alpinisme, 74401 Chamonix, France. med@ensa.jeunesse-sports.fr Title Operation Everest III: role of plasma volume expansion on VO(2)(max) during prolonged high-altitude exposure. Source Journal of Applied Physiology. 89(1):29-37, 2000 Jul. Abstract We hypothesize that plasma volume decrease (DeltaPV) induced by high-altitude (HA) exposure and intense exercise is involved in the limitation of maximal O(2) uptake (VO(2)(max)) at HA. Eight male subjects were decompressed for 31 days in a hypobaric chamber to the barometric equivalent of Mt. Everest (8,848 m). Maximal exercise was performed with and without plasma volume expansion (PVX, 219-292 ml) during exercise, at sea level (SL), at HA (370 mmHg, equivalent to 6, 000 m after 10-12 days) and after return to SL (RSL, 1-3 days). Plasma volume (PV) was determined at rest at SL, HA, and RSL by Evans blue dilution. PV was decreased by 26% (P < 0.01) at HA and was 10% higher at RSL than at SL. Exercise-induced DeltaPV was reduced both by PVX and HA (P < 0.05). Compared with SL, VO(2)(max) was decreased by 58 and 11% at HA and RSL, respectively. VO(2)(max) was enhanced by PVX at HA (+9%, P < 0.05) but not at SL or RSL. The more PV was decreased at HA, the more VO(2)(max) was improved by PVX (P < 0.05). At exhaustion, plasma renin and aldosterone were not modified at HA compared with SL but were higher at RSL, whereas plasma atrial natriuretic factor was lower at HA. The present results suggest that PV contributes to the limitation of VO(2)(max) during acclimatization to HA. RSL-induced PVX, which may be due to increased activity of the renin-aldosterone system, could also influence the recovery of VO(2)(max). <20> Unique Identifier 11160051 Authors Imoberdorf R. Garlick PJ. McNurlan MA. Casella GA. Peheim E. Turgay M. Bartsch P. Ballmer PE. Institution Department of Internal Medicine, University of Berne, CH-3010 Berne, Switzerland. R.Imoberdorf@ksw.ch Title Enhanced synthesis of albumin and fibrinogen at high altitude. Source Journal of Applied Physiology. 90(2):528-37, 2001 Feb. Abstract The acute effects of active and passive ascent to high altitude on plasma volume (PV) and rates of synthesis of albumin and fibrinogen have been examined. Measurements were made in two groups of healthy volunteers, initially at low altitude (550 m) and again on the day after ascent to high altitude (4,559 m). One group ascended by helicopter (air group, n = 8), whereas the other group climbed (foot group, n = 9), so that the separate contribution of physical exertion to the response could be delineated. PV was measured by dilution of (125)I-labeled albumin, whereas synthesis rates of albumin and fibrinogen were determined from the incorporation of isotope into protein after injection of [ring-(2)H(5)]phenylalanine. In the air group, there was no change in PV at high altitude, whereas, in the foot group, there was a 10% increase in PV (P < 0.01). Albumin synthesis (mg. kg(-1). day(-1)) increased by 13% in the air group (P = 0.058) and by 32% in the foot group (P < 0.001). Fibrinogen synthesis (mg. kg(1). day(-1)) increased by 40% in the air group (P = 0.068) and by 100% in the foot group (P < 0.001). Hypoxia and alkalosis at high altitude did not differ between the groups. Plasma interleukin-6 was increased modestly in both groups but C-reactive protein was not changed in either group. It is concluded that increases in PV and plasma protein synthesis at high altitude result mainly from the physical exercise associated with climbing. However, a small stimulation of albumin and fibrinogen synthesis may be attributable to hypobaric hypoxia alone. <21> Unique Identifier 11543191 Authors Nicolas M. Thullier-Lestienne F. Bouquet C. Gardette B. Gortan C. Joulia F. Bonnon M. Richalet JP. Therme P. Abraini JH. Institution Laboratoire de Neurosciences Integratives, Universite Henri Poincare Nancy 1, Vandoeuvre-les-Nancy, France. Title An anxiety, personality and altitude symptomatology study during a 31-day period of hypoxia in a hypobaric chamber (experiment 'Everest-Comex 1997'). Source Journal of Environmental Psychology. 19(4):407-14, 1999 Dec. Abstract Extreme environmental situations are useful tools for the investigation of the general processes of adaptation. Among such situations, high altitude of more than 3000 m produces a set of pathological disorders that includes both cerebral (cAS) and respiratory (RAS) altitude symptoms. High altitude exposure further induces anxiety responses and behavioural disturbances. The authors report an investigation on anxiety responses, personality traits, and altitude symptoms (AS) in climbers participating in a 31-day period of confinement and gradual decompression in a hypobaric chamber equivalent to a climb from sea-level to Mount Everest (8848 m altitude). Personality traits, state-trait anxiety, and AS were assessed, using the Cattell 16 Personality Factor questionnaire (16PF), the Spielberger's State-Trait Anxiety Inventory (STAI), and the Lake Louise concensus questionnaire. Results show significant group effect for state-anxiety and AS; state-anxiety and AS increased as altitude increased. They also show that state-type anxiety shows a similar time-course to cAS, but not RAS. Alternatively, our results demonstrate a significant negative correlation between Factor M of the 16PF questionnaire, which is a personality trait that ranges from praxernia to autia. In contrast, no significant correlation was found between personality traits and AS. This suggests that AS could not be predicted using personality traits and further support that personality traits, such as praxernia (happening sensitivity), could play a major role in the occurrence of state-type anxiety responses in extreme environments. In addition, the general processes of coping and adaptation in individuals participating in extreme environmental experiments are discussed. <22> Unique Identifier 9509829 Authors Fiorenzano G. Papalia MA. Parravicini M. Rastelli V. Bigi R. Dottorini M. Institution Department of Pulmonary Medicine, E. Morelli Hospital, Sondalo (Sondrio), Italy. Title Prolonged ECG abnormalities in a subject with high altitude pulmonary edema (HAPE). Source Journal of Sports Medicine & Physical Fitness. 37(4):292-6, 1997 Dec. Abstract High Altitude Pulmonary Edema (HAPE) is an uncommon type of non-cardiogenic pulmonary edema. Few data are available regarding ECG abnormalities in patients with HAPE. They are usually slight and related to acute pulmonary hypertension. This paper describes a case of prolonged ECG abnormalities in a subject with HAPE, with no proven cardiac diseases. The Authors discuss the pathopysiological aspects of this kind of hypoxic-induced right ventricular overload with extensive T-wave negativity in precordial leads. <23> Unique Identifier 10732898 Authors Grunig E. Mereles D. Hildebrandt W. Swenson ER. Kubler W. Kuecherer H. Bartsch P. Institution Department of Cardiology, University of Heidelberg, Germany. ekkehard_gruenig@med.uni-heidelberg.de Title Stress Doppler echocardiography for identification of susceptibility to high altitude pulmonary edema. Source Journal of the American College of Cardiology. 35(4):980-7, 2000 Mar 15. Abstract OBJECTIVE: This prospective single-blinded study was performed to quantitate noninvasive pulmonary artery systolic pressure (PASP) responses to prolonged acute hypoxia and normoxic exercise. BACKGROUND: Hypoxia-induced excessive rise in pulmonary artery pressure is a key factor in high-altitude pulmonary edema (HAPE). We hypothesized that subjects susceptible to HAPE (HAPE-S) have increased pulmonary artery pressure response not only to hypoxia but also to exercise. METHODS: PASP was estimated at 45, 90 and 240 min of hypoxia (FiO2 = 12%) and during supine bicycle exercise in normoxia using Dopplerechocardiography in nine HAPE-S and in 11 control subjects. RESULTS: In the control group, mean PASP increased from 26+/-2 to 37+/-4 mm Hg (deltaPASP 10.3+/-2 mm Hg) after 90 min of hypoxia and from 27+/-4 to 36+/-3 mm Hg (deltaPASP 8+/-2 mm Hg) during exercise. In contrast, all HAPE-S subjects revealed significantly greater increases (p = 0.002 vs. controls) in mean PASP both during hypoxia (from 28+/-4 to 57+/-10 mm Hg, deltaPASP 28.7+/-6 mm Hg) and during exercise (from 28+/-4 to 55+/-11 mm Hg, deltaPASP 27+/-8 mm Hg) than did control subjects. Stress echocardiography allowed discrimination between groups without overlap using a cut off PASP value of 45 mm Hg at work rates less than 150 W. CONCLUSIONS: These data indicate that HAPE-S subjects may have abnormal pulmonary vascular responses not only to hypoxia but also to supine bicycle exercise under normoxic conditions. Thus, Doppler echocardiography during supine bicycle exercise or after 90 min of hypoxia may be useful noninvasive screening methods to identify subjects susceptible to HAPE. <24> Unique Identifier 10192076 Authors Clarke CR. Institution National Hospital for Neurology, London. Title Three journeys to high altitude: medicine, Tibetan thangkas, and Sepu Kangri. Source Journal of the Royal College of Physicians of London. 33(1):78-84, 1999 JanFeb. Abstract This article begins by highlighting the work of several pioneers of altitude medicine, and their achievements in physiology and clinical observation. Tibetan medicine of the 17th century is then introduced, particularly the medical paintings (thangkas) and the conduct of traditional physicians. Finally, I mention recent British mountain exploration in central Tibet during 1996, 1997 and 1998 and the challenge of Sepu Kangri which, at 6,995m, is the highest peak of the eastern Nyangla Qen Tangla Shan. <25> Unique Identifier 11989137 Authors Brundrett G. Institution geoffbrundrett@waitrose.com Title Sickness at high altitude: a literature review. [Review] [67 refs] Source Journal of the Royal Society of Health. 122(1):14-20, 2002 Mar. Abstract When some individuals spend just a few hours at low atmospheric pressure above 1,500 m (5,000 ft)--such as when climbing a mountain or flying in a plane at high altitude--they become ill. Altitude sickness studies originally concentrated on life-threatening illnesses which beset determined and athletic climbers at extreme altitudes. In recent years, however, research attention is moving towards milder forms of sickness reported by a significant proportion of the growing number of visitors to mountain and ski resorts at more moderate altitude. Some of this research is also relevant in understanding the problems experienced by passengers in newer planes that fly at a significantly higher equivalent cabin altitude, i.e. 2,440 m (8,000 ft), than earlier designs. Engineering solutions--such as enriched oxygen in enclosed spaces at altitude, or in the case of aircraft, lower cabin altitudes--are possible, but for an economic assessment to be realistic an engineer needs to identify the scale of the problem and to understand the factors determining susceptibility. This review concentrates on the problems of mountain sickness in the ordinary population at altitudes of around 3,000 m (10,000 ft); this is a problem of growing concern as ski resorts develop, mountain trekking increases in popularity, and as higher altitude cabin pressures are achieved in aircraft. [References: 67] <26> Unique Identifier 11830197 Authors Cremona G. Asnaghi R. Baderna P. Brunetto A. Brutsaert T. Cavallaro C. Clark TM. Cogo A. Donis R. Lanfranchi P. Luks A. Novello N. Panzetta S. Perini L. Putnam M. Spagnolatti L. Wagner H. Wagner PD. Institution Unit of Respiratory Medicine, San Raffaele University Scientific Institute, Via Olgettina 60, 20132 Milano, Italy. george.cremona@hsr.it Title Pulmonary extravascular fluid accumulation in recreational climbers: a prospective study.[see comment]. Comments Comment in: Lancet. 2002 Aug 17;360(9332):570-1; author reply 571-2; PMID: 12241684, Comment in: Lancet. 2002 Aug 17;360(9332):570; author reply 571-2; PMID: 12241683, Comment in: Lancet. 2002 Aug 17;360(9332):571; author reply 5712; PMID: 12241685, Comment in: Lancet. 2002 Jan 26;359(9303):276-7; PMID: 11830190 Source Lancet. 359(9303):303-9, 2002 Jan 26. Abstract BACKGROUND: High altitude pulmonary oedema (HAPE) that is severe enough to require urgent medical care is infrequent. We hypothesised that subclinical HAPE is far more frequent than suspected during even modest climbs of average effort. METHODS: We assessed 262 consecutive climbers of Monte Rosa (4559 m), before ascent and about 24 h later on the summit 1 h after arriving, by clinical examination, electrocardiography, oximetry, spirometry, carbon monoxide transfer, and closing volume. A chest radiograph was taken at altitude. FINDINGS: Only one climber was evacuated for HAPE, but 40 (15%) of 262 climbers had chest rales or interstitial oedema on radiograph after ascent. Of 37 of these climbers, 34 (92%) showed increased closing volume. Of the 197 climbers without oedema, 146 (74%) had an increase in closing volume at altitude. With no change in vital capacity, forced expiratory volume in 1 s and forced expiratory flow at 25-75% of forced vital capacity increased slightly at altitude, without evidence of oedema. If we assume that an increased closing volume at altitude indicates increased pulmonary extravascular fluid, our data suggest that three of every four healthy, recreational climbers have mild subclinical HAPE shortly after a modest climb. INTERPRETATION: The risk of HAPE might not be confined to a small group of genetically susceptible people, but likely exists for most climbers if the rate of ascent and degree of physical effort are great enough, especially if lung size is normal or low. <27> Unique Identifier 9690443 Authors Zafren K. Title Gamow bag for high-altitude cerebral oedema.[comment]. Comments Comment on: Lancet. 1998 Jun 13;351(9118):1815; PMID: 9635981 Source Lancet. 352(9124):325-6, 1998 Jul 25. <28> Unique Identifier 9798594 Authors Tschop M. Strasburger CJ. Hartmann G. Biollaz J. Bartsch P. Title Raised leptin concentrations at high altitude associated with loss of appetite. Source Lancet. 352(9134):1119-20, 1998 Oct 3. <29> Unique Identifier 10416557 Authors Anooshiravani M. Dumont L. Mardirosoff C. Soto-Debeuf G. Delavelle J. Institution Department of Radiology, Hopital des Enfants Reine Fabiola, Brussels, Belgium. alpamayo@usa.net Title Brain magnetic resonance imaging (MRI) and neurological changes after a single high altitude climb. Source Medicine & Science in Sports & Exercise. 31(7):969-72, 1999 Jul. Abstract PURPOSE: Neurological impairment, mental dysfunction, and brain imaging changes caused by severe hypoxia have been described by several authors. However, the occurrence of transitory, long lasting, or permanent brain damage has been debated. Although climbing to 8000 m is reserved to a small number of climbers, there are hundreds of lowlanders spending relatively short holidays climbing peaks up to 6000 m in the Andes or in the Himalayas. They are usually not well acclimated and often suffer from acute mountain sickness (AMS). The aim of this study was to examine the effect of a single high altitude exposure on the changes in brain MRI and neuropsychological testing in climbers. METHODS: Brain MRI, medical history, and a battery of neuropsychological tests were obtained in eight male climbers between 31 and 48 yr of age a few days before and between 5 and 10 d after returning to sea level following ascent to altitudes of over 6000 m without oxygen. RESULTS: The mean AMS symptom score recorded at 5500 m was three in all climbers, headache being the predominant symptom. CONCLUSION: We did not observe the changes in brain imaging and in neuropsychological testing observed by other authors. The residual central nervous system impairment following return from high altitude was not observed in our study, and the good results in neuropsychological testing were well correlated with the unchanged brain MRI imaging. <30> Unique Identifier 11143435 Authors Sonna LA. Kain JE. Hoyt RW. Muza SR. Sawka MN. Institution Thermal and Mountain Medicine Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA. Title Ambulatory physiological status monitoring during a mountaineering expedition. Source Military Medicine. 165(11):860-6, 2000 Nov. Abstract OBJECTIVE: To evaluate an ambulatory physiological monitoring system during a mountaineering expedition. We hypothesized that the Environmental Symptoms Questionnaire, combined with frequent measurement of oxygen saturation and core temperature, would accurately identify cases of environmental illness. METHODS: Twelve military mountaineers took a daily Environmental Symptoms Questionnaire, monitored fingertip oxygen saturations, and recorded core temperatures while climbing a 4,949-m peak. Illnesses identified by the system were compared with those identified by spontaneous reports. RESULTS: The system correctly identified one case of high-altitude pulmonary edema and two illnesses that were not reported to the physician (one case of acute mountain sickness and one of self-limited symptomatic desaturation). However, it did not identify two illnesses that were severe enough to preclude further climbing (one case of sinus headache and one of generalized fatigue). CONCLUSIONS: Our monitoring system may complement, but cannot replace, on-site medical personnel during mountaineering expeditions. <31> Unique Identifier 10519586 Authors Wiedman M. Tabin GC. Institution Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114, USA. Title High-altitude retinopathy and altitude illness.[see comment]. Comments Comment in: Ophthalmology. 2000 Jul;107(7):1212; PMID: 10889073 Source Ophthalmology. 106(10):1924-6; discussion 1927, 1999 Oct. Abstract OBJECTIVE: To determine the relationship between high-altitude retinopathy (HAR) and other altitude-related illnesses and establish a classification system for HAR. DESIGN: Observational case series. PARTICIPANTS: All 40 climbers among 3 Himalayan expeditions who ascended to altitudes between 16,000 and 29,028 feet above sea level (summit of Mt. Everest) were examined for signs of HAR and altitude illness (AI). METHODS: All subjects had dilated fundus examinations before the ascent, intermittent fundus, and medical examinations during the climb and a dilated fundus and medical examination within 2 days after attaining their highest altitude. MAIN OUTCOME MEASURES: Careful fundus drawings or fundus photography or both were obtained for all participants. All subjects gave a subjective assessment of their symptoms of acute mountain sickness (AMS) and were assessed clinically for signs of high-altitude cerebral edema (HACE). RESULTS: Nineteen of 21 climbers who ascended above 25,000 feet developed HAR. Fourteen of 19 climbers who attained altitudes between 16,000 and 25,000 feet were found to have retinopathy. A grading system for HAR describing the severity of the retinopathy was developed. Correlation of the retinopathy with other AI showed that AMS was endemic and that a statistically significant correlation exists between HAR and HACE (P = 0.0240). CONCLUSION: Recognizing advancing grades of HAR may allow physicians to recommend initiating empiric treatment with oxygen, steroids, diuretics and immediate descent to prevent HAR progression, macular involvement, or potentially fatal HACE. High-altitude retinopathy is both a significant component of and a predictor of progressive AI. <32> Unique Identifier 10889073 Authors Murdoch DR. Title High-altitude illness.[comment]. Comments Comment on: Ophthalmology. 1999 Oct;106(10):1924-6; discussion 1927; PMID: 10519586 Source Ophthalmology. 107(7):1212, 2000 Jul. <33> Unique Identifier 10946741 Authors Yarnell PR. Heit J. Hackett PH. Institution Department of Neurology, University of Colorado School of Medicine, St. Anthony's Hospital Denver, USA. Title High-altitude cerebral edema (HACE): the Denver/Front Range experience. [Review] [22 refs] Source Seminars in Neurology. 20(2):209-17, 2000. Abstract High-altitude cerebral edema (HACE) is a potentially fatal metabolic encephalopathy associated with a time-dependent exposure to the hypobaric hypoxia of altitude. Symptoms commonly are headache, ataxia, and confusion progressing to stupor and coma. HACE is often preceded by symptoms of acute mountain sickness and coupled, in its severe form, with high-altitude pulmonary edema. Although HACE is mostly seen at altitudes above that of the Denver/Front Range visitor-skier locations, we report our observations over a 13-year period of skier-visitor HACE patients. It is believed that this is a form of vasogenic edema, and it is responsive to expeditious treatment with a successful outcome. [References: 22] <34> Unique Identifier 11858498 Authors Mannucci PM. Gringeri A. Peyvandi F. Di Paolantonio T. Mariani G. Title Short-term exposure to high altitude causes coagulation activation and inhibits fibrinolysis. Source Thrombosis & Haemostasis. 87(2):342-3, 2002 Feb.