Browsing by Author "Araneda, Oscar F."
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- ItemDetermination of the Respiratory Compensation Point by Detecting Changes in Intercostal Muscles Oxygenation by Using Near-Infrared Spectroscopy(MDPI, 2022) Contreras Briceño, Felipe; Espinosa Ramírez, Maximiliano; Keim Bagnara, Vicente; Carreño Roman, Matías Ignacio; Rodríguez Villagra, Rafael Alejandro; Villegas Belmar, Fernanda; Viscor, Gines; Gabrielli Nervi, Luigi Arnaldo; Andia, Marcelo E.; Araneda, Oscar F.; Hurtado, Daniel E.This study aimed to evaluate if the changes in oxygen saturation levels at intercostal muscles (SmO2 m.intercostales) assessed by near-infrared spectroscopy (NIRS) using a wearable device could determine the respiratory compensation point (RCP) during exercise. Fifteen healthy competitive triathletes (eight males; 29 +/- 6 years; height 167.6 +/- 25.6 cm; weight 69.2 +/- 9.4 kg; (V) over dotO(2)-max 58.4 +/- 8.1 mL.kg(-1).min(-1)) were evaluated in a cycle ergometer during the maximal oxygen-uptake test ((V) over dotO(2)-max), while lung ventilation ((V) over dotE), power output (watts, W) and SmO2 mantercostales were measured. RCP was determined by visual method (RCPvisual : changes at ventilatory equivalents ((V) over dotE.CO2-1, (V) over dotE.(V) over dotO(2)(-1)) and end-tidal respiratory pressure (PetO(2), PetCO(2)) and NIRS method (RCP NIRS : breakpoint of fall in SmO2 m.intercostales). During exercise, SmO2 m.intercostales decreased continuously showing a higher decrease when (V) over dotE increased abruptly. A good agreement between methods used to determine RCP was found (visual vs NIRS) at %(V) over dotO(2)-max, (V) over dotO(2), (V) over dotE, and W (Bland-Altman test). Correlations were found to each parameters analyzed (r = 0.854; r = 0.865; r = 0.981; and r = 0,968; respectively. p < 0.001 in all variables, Pearson test), with no differences (p < 0.001 in all variables, Student's t-test) between methods used (RCPvisual and RCPNIRS). We concluded that changes at SmO2 m.intercostales measured by NIRS could adequately determine RCP in triathletes.
- ItemHumidity prevents the exercise-induced formation of hydrogen peroxide and nitrite in exhaled breath condensate in recreational cyclists(2020) Contreras Briceño, Felipe; Espinosa Ramírez, Maximiliano; Viscor, Ginés; Araneda, Oscar F.Purpose The aerobic exercise affects the respiratory redox-state. The influence of different relative humidity (RH) levels on the formation of respiratory reactive chemical species associated with redox-state altered by exercise has been poorly explored. Our aim was to evaluate the effect of two different RH conditions (40% vs. 90%) on the concentration of hydrogen peroxide and nitrite in exhaled breath condensate ([H2O2](EBC)and [NO2-](EBC)) and spirometry parameters in recreational cyclists. Methods Sixteen men and women (12/4) (mean age +/- SD: 23.5 +/- 2.2 years) completed 60-min of cycling at 166.3 +/- 26.9 watts (70% of maximum load of (V) over dotO(2)-max. test, 49.3 +/- 7.6 mL center dot min(-1)center dot kg(-1)) at random 40%-RH and 90%-RH conditions separated by 7 days. The two-way RM-ANOVA test was applied to compare [H2O2](EBC), [NO2-](EBC), [NO2-](EBC)/[NO2-](Plasma)at rest and 80-min post-exercise (80-post); and spirometry parameters at rest, 20-post and 80-post.. Results The interaction of factors (humidity x time) was significant in [H2O2](EBC), [NO2-](EBC), [NO2-](EBC)/[NO2-](Plasma)(p = 0.005,p = 0.030,p = 0.043, respectively). At 40%-RH conditions, the same parameters were higher in 80-post than at rest (p < 0.001,p = 0.001,p = 0.014, respectively). At the same time, the [H2O2](EBC)and [NO2-](EBC)/[NO2-](Plasma)were higher in 40%-RH than 90%-RH (p = 0.010,p < 0.001, respectively). The interaction was significant in FEV1(p = 0.013) and FEF25-75%(p = 0.023), but not in FEV1/FVC (p = 0.362). At 80-post, the changes are kept in 90%-RH (p < 0.001), diminishing in 40%-RH being similar to rest. Conclusion In recreational cyclists, 90%-RH prevents the increase of hydrogen peroxide and nitrite in exhaled breath condensate samples observed at 40%-RH and prolonging the bronchodilation until 80-post cycling exercise.
- ItemIntercostal Muscles Oxygenation and Breathing Pattern during Exercise in Competitive Marathon Runners(Wiley, 2021) Contreras Briceño, Felipe; Espinosa Ramirez, Maximiliano Andres; Moya Gallardo, Eduardo Sebastián; Fuentes Kloss, Rodrigo Alejandro; Gabrielli Nervi, Luigi Arnaldo; Araneda, Oscar F.; Viscor, GinesThe study aimed to evaluate the association between the changes in ventilatory variables (tidal volume (Vt), respiratory rate (RR) and lung ventilation (VE)) and deoxygenation of m.intescostales (Delta SmO2-m.intercostales) during a maximal incremental exercise in 19 male high-level competitive marathon runners. The ventilatory variables and oxygen consumption (VO2) were recorded breath-by-breath by exhaled gas analysis. A near-infrared spectroscopy device (MOXY (R)) located in the right-hemithorax allowed the recording of SmO2-m.intercostales. To explore changes in oxygen levels in muscles with high demand during exercise, a second MOXY (R) records SmO2-m.vastus laterallis. The triphasic model of exercise intensity was used for evaluating changes in SmO2 in both muscle groups. We found that ASmO(2)-m.intercostales correlated with VO2-peak (r = 0.65; p = 0.002) and the increase of VE (r = 0.78; p = 0.001), RR (r = 0.54; p = 0.001), but not Vt (p = 0.210). The interaction of factors (muscles x exercise-phases) in SmO2 expressed as an arbitrary unit (a.u) was significant (p = 0.005). At VT1 there was no difference (p = 0.177), but SmO2-m.intercostales was higher at VT2 (p < 0.001) and VO2-peak (p < 0.001). In high-level competitive marathon runners, the m.intercostales deoxygenation during incremental exercise is directly associated with the aerobic capacity and increased lung ventilation and respiratory rate, but not tidal volume. Moreover, it shows less deoxygenation than m.vastus laterallis at intensities above the aerobic ventilatory threshold.
- ItemMonitoring Changes in Oxygen Muscle during Exercise with High-Flow Nasal Cannula Using Wearable NIRS Biosensors(2023) Contreras Briceño, Felipe; Espinosa Ramírez, Maximiliano; Rivera Greene, Augusta; Guerra Venegas, Camila Isidora; Lungenstrass Poulsen, Antonia Isabel; Villagra Reyes, Victoria Paz; Caulier Cisterna, Raúl; Araneda, Oscar F.; Viscor, GinésExercise increases the cost of breathing (COB) due to increased lung ventilation (V˙ E), inducing respiratory muscles deoxygenation (∇ SmO2), while the increase in workload implies ∇ SmO2 in locomotor muscles. This phenomenon has been proposed as a leading cause of exercise intolerance, especially in clinical contexts. The use of high-flow nasal cannula (HFNC) during exercise routines in rehabilitation programs has gained significant interest because it is proposed as a therapeutic intervention for reducing symptoms associated with exercise intolerance, such as fatigue and dyspnea, assuming that HFNC could reduce exercise-induced ∇ SmO2. SmO2 can be detected using optical wearable devices provided by near-infrared spectroscopy (NIRS) technology, which measures the changes in the amount of oxygen bound to chromophores (e.g., hemoglobin, myoglobin, cytochrome oxidase) at the target tissue level. We tested in a study with a cross-over design whether the muscular desaturation of m.vastus lateralis and m.intercostales during a high-intensity constant-load exercise can be reduced when it was supported with HFNC in non-physically active adults. Eighteen participants (nine women; age: 22 ± 2 years, weight: 65.1 ± 11.2 kg, height: 173.0 ± 5.8 cm, BMI: 21.6 ± 2.8 kg·m−2) were evaluated in a cycle ergometer (15 min, 70% maximum watts achieved in ergospirometry (V˙ O2-peak)) breathing spontaneously (control, CTRL) or with HFNC support (HFNC; 50 L·min−1, fiO2: 21%, 30 °C), separated by seven days in randomized order. Two-way ANOVA tests analyzed the ∇ SmO2 (m.intercostales and m.vastus lateralis), and changes in V˙ E and ∇ SmO2·V˙ E−1. Dyspnea, leg fatigue, and effort level (RPE) were compared between trials by the Wilcoxon matched-paired signed rank test. We found that the interaction of factors (trial × exercise-time) was significant in ∇ SmO2-m.intercostales, V˙ E, and (∇ SmO2-m.intercostales)/V˙ E (p < 0.05, all) but not in ∇ SmO2-m.vastus lateralis. ∇ SmO2-m.intercostales was more pronounced in CTRL during exercise since 5′ (p < 0.05). Hyperventilation was higher in CTRL since 10′ (p < 0.05). The ∇ SmO2·V˙ E−1 decreased during exercise, being lowest in CTRL since 5′. Lower dyspnea was reported in HFNC, with no differences in leg fatigue and RPE. We concluded that wearable optical biosensors documented the beneficial effect of HFNC in COB due to lower respiratory ∇ SmO2 induced by exercise. We suggest incorporating NIRS devices in rehabilitation programs to monitor physiological changes that can support the clinical impact of the therapeutic intervention implemented.
- ItemSex-Differences in the Oxygenation Levels of Intercostal and Vastus Lateralis Muscles During Incremental Exercise(Wiley, 2021) Espinosa Ramírez, Maximiliano Andrés; Moya Gallardo, Eduardo Sebastián; Araya Román, Felipe Andrés; Riquelme Sánchez, Santiago Martín; Rodríguez García, Guido Hernán Antonio; Reid, W. Darlene; Viscor, Gines; Araneda, Oscar F.; Gabrielli Nervi, Luigi Arnaldo; Contreras Briceño, FelipeThis study aimed to examine sex differences in oxygen saturation in respiratory (SmO2-m.intercostales) and locomotor muscles (SmO2-m.vastus lateralis) while performing physical exercise. Twenty-five (12 women) healthy and physically active participants were evaluated during an incremental test with a cycle ergometer, while ventilatory variables [lung ventilation (V.E), tidal volume (Vt), and respiratory rate (RR)] were acquired through the breath-by-breath method. SmO2 was acquired using the MOXY(R) devices on the m.intercostales and m.vastus lateralis. A two-way ANOVA (sex x time) indicated that women showed a greater significant decrease of SmO2-m.intercostales, and men showed a greater significant decrease of SmO2-m.vastus lateralis. Additionally, women reached a higher level of Delta SmO2-m.intercostales normalized to V.E (L.min(-1)) (p < 0.001), whereas men had a higher level of Delta SmO2-m.vastus lateralis normalized to peak workload-to-weight (watts.kg(-1), PtW) (p = 0.049), as confirmed by Student's t-test. During an incremental physical exercise, women experienced a greater cost of breathing, reflected by greater deoxygenation of the respiratory muscles, whereas men had a higher peripheral load, indicated by greater deoxygenation of the locomotor muscles.
- ItemSwimming versus running : effects on exhaled breath condensate pro-oxidants and pH(2018) Araneda, Oscar F.; Contreras Briceño, Felipe; Cavada, Gabriel; Viscor, Ginés
- ItemSystemic and Pulmonary Inflammation/Oxidative Damage: Implications of General and Respiratory Muscle Training in Chronic Spinal-Cord-Injured Patients(2023) Araneda, Oscar F.; Rosales-Antequera, Cristián; Contreras Briceño, Felipe; Tuesta, Marcelo; Rossi-Serrano, Rafael; Magalhães, José; Viscor, GinésChronic spinal cord injury affects several respiratory-function-related parameters, such as a decrease in respiratory volumes associated with weakness and a tendency to fibrosis of the perithoracic muscles, a predominance of vagal over sympathetic action inducing airway obstructions, and a difficulty in mobilizing secretions. Altogether, these changes result in both restrictive and obstructive patterns. Moreover, low pulmonary ventilation and reduced cardiovascular system functionality (low venous return and right stroke volume) will hinder adequate alveolar recruitment and low O2 diffusion, leading to a drop in peak physical performance. In addition to the functional effects described above, systemic and localized effects on this organ chronically increase oxidative damage and tissue inflammation. This narrative review describes both the deleterious effects of chronic spinal cord injury on the functional effects of the respiratory system as well as the role of oxidative damage/inflammation in this clinical context. In addition, the evidence for the effect of general and respiratory muscular training on the skeletal muscle as a possible preventive and treatment strategy for both functional effects and underlying tissue mechanisms is summarized.