The Effect of Oxygen Enrichment on Cardiorespiratory and Neuropsychological Responses in Workers With Chronic Intermittent Exposure to High Altitude (ALMA, 5,050 m)

Abstract

It is estimated that labor activity at high altitudes in Chile will increase from 60,000 to 120,000 workers by the year 2020. Oxygenation of spaces improves the quality of life for workers at high geographic altitudes (<5,000 m). The aim of this study was to determine the effect of a mobile oxygen module system on cardiorespiratory and neuropsychological performance in a population of workers from Atacama Large Millimeter/submillimeter Array (ALMA, 5,050 m) radiotelescope in the Chajnantor Valley, Chile. We evaluated pulse oximetry, systolic and diastolic arterial pressure (SAP/DAP), and performed neuropsychological tests (Mini-Mental State examination, Rey-Osterrieth Complex Figure test) at environmental oxygen conditions (5,050 m), and subsequently in a mobile oxygenation module that increases the fraction of oxygen in order to mimic the higher oxygen partial pressure of lower altitudes (2,900 m). The use of module oxygenation at an altitude of 5,050 m, simulating an altitude of 2,900 m, increased oxygen saturation from 84 ± 0.8 to 91 ± 0.8% (p < 0.00001), decreased heart rate from 90 ± 8 to 77 ± 12 bpm (p < 0.01) and DAP from 96 ± 3 to 87 ± 5 mmHg (p < 0.01). In addition, mental cognitive state of workers (Mini-Mental State Examination) shown an increased from 19 to 31 points (p < 0.02). Furthermore, the Rey-Osterrieth Complex Figure test (memory) shown a significant increase from 35 to 70 (p < 0.0001). The results demonstrate that the use of an oxygen module system at 5,050 m, simulating an altitude equivalent to 2,900 m, by increasing FiO2 at 28%, significantly improves cardiorespiratory response and enhances neuropsychological performance in workers exposed to an altitude of 5,050 m.

Cognitive Effects of Repeated Acute Exposure to Very High Altitude Among Altitude-Experienced Workers at 5050 m

“…4). In fact, these findings are in line with the findings from Moraga et al (2018), who reported beneficial effects of oxygen supplementation among ALMA workers leading to improvements in some of the assessed cognitive domains. Our findings, together with the ones reported by Moraga et al, support the long-standing advocacy for oxygen enrichment in high-altitude workstations as well as for permanent dwellers, to improve overall performance (West 2016a, b).…”

“…The altitude of OSF (2900 m), where we took the first measurements, is already an elevation that can affect performance. Previous studies have shown that ALMA workers do have impairments in cognitive functioning, which improve with oxygenation supplementation (Moraga et al, 2018).…”

“…Shift-workers at the Atacama Large Millimeter/submillimeter Array (ALMA) Observatory (5050 m) on the Chajnantor Plateau, Chile, are exposed to high altitude during alternate weeks in their work cycle (Moraga et al, 2018). Typically, the workers quickly ascend to a moderate altitude on the first day of their shift, traveling from Santiago (520 m) to the Operation Support Facility of ALMA (OSF, 2900 m).…”

“…The high-altitude workers at the ALMA Observatory (5050 m) repeatedly experience periodic high-altitude hypoxia for several years. Only one other study (Moraga et al, 2018) has investigated the cognitive effects of high-altitude exposure in ALMA workers. This research specifically examined constructive praxis and visuospatial memory through the use of the Folstein Mini-Mental State Examination Test and the Rey-Osterrieth Complex Figure Test (Moraga et al, 2018).…”

“…Only one other study (Moraga et al, 2018) has investigated the cognitive effects of high-altitude exposure in ALMA workers. This research specifically examined constructive praxis and visuospatial memory through the use of the Folstein Mini-Mental State Examination Test and the Rey-Osterrieth Complex Figure Test (Moraga et al, 2018). The results demonstrated that cognitive function was impaired at high altitude, but that it improved following oxygen supplementation.…”