Response to Limper et al. re: “Positional Changes in Arterial Oxygen Saturation and End-Tidal Carbon Dioxide at High Altitude: Medex 2015”

2020 ◽  
Vol 21 (3) ◽  
pp. 307-307
Author(s):  
James D. Anholm ◽  
Arlena Kuenzel
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
End Tidal Carbon Dioxide ◽  
End Tidal

Re: “Positional Changes in Arterial Oxygen Saturation and End-Tidal Carbon Dioxide at High Altitude: Medex 2015” by Kuenzel et al.

2020 ◽  
Vol 21 (3) ◽  
pp. 305-306
Author(s):  
Ulrich Limper ◽  
Vera Fiala ◽  
Eva M. Elmenhorst ◽  
Jens Tank ◽  
Gereon Schaelte ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
End Tidal Carbon Dioxide ◽  
End Tidal

Effects of Skin Pigmentation on Pulse Oximeter Accuracy at Low Saturation

2005 ◽  
Vol 102 (4) ◽  
pp. 715-719 ◽  
Author(s):  
Philip E. Bickler ◽  
John R. Feiner ◽  
John W. Severinghaus
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Saturation ◽  
Pulse Oximeter ◽  
Arterial Oxygen Saturation ◽  
Skin Pigmentation ◽  
Arterial Oxygen ◽  
Dark Light ◽  
Light Skin ◽  
End Tidal ◽  
Pulse Oximeters

Background It is uncertain whether skin pigmentation affects pulse oximeter accuracy at low HbO2 saturation. Methods The accuracy of finger pulse oximeters during stable, plateau levels of arterial oxygen saturation (Sao2) between 60 and 100% were evaluated in 11 subjects with darkly pigmented skin and in 10 with light skin pigmentation. Oximeters tested were the Nellcor N-595 with the OxiMax-A probe (Nellcor Inc., Pleasanton, CA), the Novametrix 513 (Novametrix Inc., Wallingford, CT), and the Nonin Onyx (Nonin Inc., Plymouth, MN). Semisupine subjects breathed air-nitrogen-carbon dioxide mixtures through a mouthpiece. A computer used end-tidal oxygen and carbon dioxide concentrations determined by mass spectrometry to estimate breath-by-breath Sao2, from which an operator adjusted inspired gas to rapidly achieve 2- to 3-min stable plateaus of desaturation. Comparisons of oxygen saturation measured by pulse oximetry (Spo2) with Sao2 (by Radiometer OSM3) were used in a multivariate model to determine the interrelation between saturation, skin pigmentation, and oximeter bias (Spo2 - Sao2). Results At 60-70% Sao2, Spo2 (mean of three oximeters) overestimated Sao2 (bias +/- SD) by 3.56 +/- 2.45% (n = 29) in darkly pigmented subjects, compared with 0.37 +/- 3.20% (n = 58) in lightly pigmented subjects (P < 0.0001). The SD of bias was not greater with dark than light skin. The dark-light skin differences at 60-70% Sao2 were 2.35% (Nonin), 3.38% (Novametrix), and 4.30% (Nellcor). Skin pigment-related differences were significant with Nonin below 70% Sao2, with Novametrix below 90%, and with Nellcor at all ranges. Pigment-related bias increased approximately in proportion to desaturation. Conclusions The three tested pulse oximeters overestimated arterial oxygen saturation during hypoxia in dark-skinned individuals.

P6480Asymmetric dimethylarginine (ADMA) predicts altitude-associated hypoxic pulmonary arterial hypertension

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
R H Boeger ◽  
P Siques ◽  
J Brito ◽  
E Schwedhelm ◽  
E Pena ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Logistic Regression ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Sea Level ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Arterial Blood ◽  
Pulmonary Arterial

Abstract Prolonged exposure to altitude-associated chronic hypoxia (CH) may cause high altitude pulmonary hypertension (HAPH). Chronic intermittent hypobaric hypoxia (CIH) occurs in individuals who commute between sea level and high altitude. CIH is associated with repetitive acute hypoxic acclimatization and conveys the long-term risk of HAPH. As nitric oxide (NO) is an important regulator of systemic and pulmonary vascular tone and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthesis that increases in hypoxia, we aimed to investigate whether ADMA predicts the incidence of HAPH among Chilean frontiers personnel exposed to six months of CIH. We performed a prospective study of 123 healthy male subjects who were subjected to CIH (5 days at appr. 3,550 m, followed by 2 days at sea level) for six months. ADMA, SDMA, L-arginine, arterial oxygen saturation, systemic arterial blood pressure, and haematocrit were measured at baseline and at months 1, 4, and 6 at high altitude. Acclimatization to high altitude was determined using the Lake Louise Score and the presence of acute mountain sickness (AMS). Echocardiography was performed after six months of CIH in a subgroup of 43 individuals with either good (n=23) or poor (n=20) aclimatization to altitude, respectively. Logistic regression was used to assess the association of biomarkers with HAPH. 100 study participants aged 18.3±1.3 years with complete data sets were included in the final analysis. Arterial oxygen saturation decreased upon the first ascent to altitude and plateaued at about 90% during the further course of the study. Haematocrit increased to about 47% after one month and remained stable thereafter. ADMA continuously increased and SDMA decreased during the study course, whilst L-arginine levels showed no distinct pattern. The incidence of AMS and the Lake Louise Score were high after the first ascent (53 and 3.1±2.4, respectively) and at one month of CIH (47 and 3.0±2.6, respectively), but decreased to 20 and 1.4±2.0 at month 6, respectively (both p<0.001 for trend). In echocardiography, 18 participants (42%) showed a mean pulmonary arterial pressure (mPAP) greater than 25 mm Hg (mean ± SD, 30.4±3.9 mm Hg), out of which 9 (21%) were classified as HAPH (mPAP ≥30 mm Hg; mean ± SD, 33.9±2.2 mm Hg). Baseline ADMA, but not SDMA, was significantly associated with mPAP at month 6 in univariate logistic regression analysis (R = 0.413; p=0.007). In ROC analysis, a cut-off for baseline ADMA of 0.665 μmol/l was determined as the optimal cut-off level to predict HAPH (mPAP >30 mm Hg) with a sensitivity of 100% and a specificity of 63.6%. ADMA concentration increases during long-term CIH. It is an independent predictive biomarker for the incidence of HAPH. SDMA concentration decreases during CIH and shows no association with HAPH. Our data support a role of impaired NO-mediated pulmonary vasodilation in the pathogenesis of high altitude pulmonary hypertension. Acknowledgement/Funding CONICYT/FONDEF/FONIS Sa 09I20007; FIC Tarapaca BIP 30477541-0; BMBF grant 01DN17046 (DECIPHER); Georg & Jürgen Rickertsen Foundation, Hamburg

scholarly journals Associations between arterial oxygen saturation, body size and limb measurements among high-altitude andean children

2013 ◽  
Vol 25 (5) ◽  
pp. 629-636 ◽  
Author(s):  
Emma Pomeroy ◽  
Jay T. Stock ◽  
Sanja Stanojevic ◽  
J. Jaime Miranda ◽  
Tim J. Cole ◽  
...  
Keyword(s):  
Body Size ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen

scholarly journals Pulmonary artery pressure and arterial oxygen saturation in people living at high or low altitude: systematic review and meta-analysis

2016 ◽  
Vol 121 (5) ◽  
pp. 1151-1159 ◽  
Author(s):  
Rodrigo Soria ◽  
Matthias Egger ◽  
Urs Scherrer ◽  
Nicole Bender ◽  
Stefano F. Rimoldi
Keyword(s):  
Systematic Review ◽  
Pulmonary Artery ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Pulmonary Artery Pressure ◽  
Meta Analysis ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Low Altitude ◽  
Apparently Healthy

More than 140 million people are living at high altitude worldwide. An increase of pulmonary artery pressure (PAP) is a hallmark of high-altitude exposure and, if pronounced, may be associated with important morbidity and mortality. Surprisingly, there is little information on the usual PAP in high-altitude populations. We, therefore, conducted a systematic review (MEDLINE and EMBASE) and meta-analysis of studies published (in English or Spanish) between 2000 and 2015 on echocardiographic estimations of PAP and measurements of arterial oxygen saturation in apparently healthy participants from general populations of high-altitude dwellers (>2,500 m). For comparison, we similarly analyzed data published on these variables during the same period for populations living at low altitude. Twelve high-altitude studies comprising 834 participants and 18 low-altitude studies (710 participants) fulfilled the inclusion criteria. All but one high-altitude studies were performed between 3,600 and 4,350 m. The combined mean systolic PAP (right ventricular-to-right atrial pressure gradient) at high altitude [25.3 mmHg, 95% confidence interval (CI) 24.0, 26.7], as expected was significantly (P < 0.001) higher than at low altitude (18.4 mmHg, 95% CI 17.1,19.7), and arterial oxygen saturation was significantly lower (90.4%, 95% CI 89.3, 91.5) than at low altitude (98.1%; 95% CI 97.7, 98.4). These findings indicate that at an altitude where the very large majority of high-altitude populations are living, pulmonary hypertension appears to be rare. The reference values and distributions for PAP and arterial oxygen saturation in apparently healthy high-altitude dwellers provided by this meta-analysis will be useful to future studies on the adjustments to high altitude in humans.

scholarly journals Angiotensin-Converting Enzyme Genotype and Arterial Oxygen Saturation at High Altitude in Peruvian Quechua

2008 ◽  
Vol 9 (2) ◽  
pp. 167-178 ◽  
Author(s):  
Abigail W. Bigham ◽  
Melisa Kiyamu ◽  
Fabiola León-Velarde ◽  
Esteban J. Parra ◽  
Maria Rivera-Ch ◽  
...  
Keyword(s):  
Angiotensin Converting Enzyme ◽  
Oxygen Saturation ◽  
High Altitude ◽  
Arterial Oxygen Saturation ◽  
Arterial Oxygen ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme Genotype
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