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American Journal of Physiology. Heart... Nov 2022We sought to determine the effects of prolonged moderate hypobaric hypoxia (HH) on cardiac baroreflex sensitivity (cBRS) in young women and whether these effects are a...
We sought to determine the effects of prolonged moderate hypobaric hypoxia (HH) on cardiac baroreflex sensitivity (cBRS) in young women and whether these effects are a consequence of the reduced arterial oxygen (O) tension and/or increased pulmonary ventilation in HH. We hypothesized that HH would reduce cBRS and that this effect would be counteracted by acute restoration of the inspiratory partial pressure of O ([Formula: see text]) and/or voluntary attenuation of pulmonary ventilation. Twelve healthy women (24.0 ± 4.2 yr) were studied before () and twice during a sojourn in a hypobaric chamber (∼8 h, ; 4 days, ) where barometric pressure corresponded to ∼3,500-m altitude. Minute ventilation (V̇e; pneumotachometer), heart rate (electrocardiogram), and arterial pressure (finger volume clamp method) were recorded. cBRS was calculated using transfer function analysis between systolic pressure and RR interval. Assessments were made during ) spontaneous breathing and (in HH only), ) controlled breathing (reducing V̇e by ∼1 to 2 L/min), and ) breathing a hyperoxic gas mixture that normalized [Formula: see text]. During spontaneous breathing, HH decreased cBRS (12.5 ± 7.1, 8.9 ± 4.4, and 7.4 ± 3.0 ms/mmHg on , , and , respectively; = 0.018). The normalization of [Formula: see text] increased cBRS (10.6 ± 3.3 and 10.7 ± 6.1 ms/mmHg on and ) in HH compared with values observed during spontaneous breathing ( < 0.001), whereas controlled breathing had no effect on cBRS ( = 0.708). These findings indicate that ongoing arterial chemoreflex activation by the reduced arterial O tension, independently of the hypoxic ventilatory response, reduces cBRS in young women exposed to extended HH. We examined the effects of prolonged hypobaric hypoxia (corresponding to ∼3,500-m altitude) on cardiac baroreflex sensitivity (cBRS) in young women and investigated underlying mechanisms. We found that cBRS was reduced in hypoxia and that this reduction was attenuated by acute restoration of inspiratory oxygen partial pressure but not by volitional restraint of pulmonary ventilation. These findings help to elucidate the role of arterial chemoreflex mechanisms in the control of cBRS during hypobaric hypoxia in young women.
Topics: Humans; Female; Baroreflex; Hypoxia; Altitude; Altitude Sickness; Oxygen; Heart Rate
PubMed: 36240437
DOI: 10.1152/ajpheart.00452.2022 -
Anaesthesia Nov 2022We performed a systematic review and meta-analysis to identify, classify and evaluate the body of evidence on novel wearable and contactless devices that measure heart... (Meta-Analysis)
Meta-Analysis Review
We performed a systematic review and meta-analysis to identify, classify and evaluate the body of evidence on novel wearable and contactless devices that measure heart rate, respiratory rate and oxygen saturations in the clinical setting. We included any studies of hospital inpatients, including sleep study clinics. Eighty-four studies were included in the final review. There were 56 studies of wearable devices and 29 of contactless devices. One study assessed both types of device. A high risk of patient selection and rater bias was present in proportionally more studies assessing contactless devices compared with studies assessing wearable devices (p = 0.023 and p < 0.0001, respectively). There was high but equivalent likelihood of blinding bias between the two types of studies (p = 0.076). Wearable device studies were commercially available devices validated in acute clinical settings by clinical staff and had more real-time data analysis (p = 0.04). Contactless devices were more experimental, and data were analysed post-hoc. Pooled estimates of mean (95%CI) heart rate and respiratory rate bias in wearable devices were 1.25 (-0.31-2.82) beats.min (pooled 95% limits of agreement -9.36-10.08) and 0.68 (0.05-1.32) breaths.min (pooled 95% limits of agreement -5.65-6.85). The pooled estimate for mean (95%CI) heart rate and respiratory rate bias in contactless devices was 2.18 (3.31-7.66) beats.min (pooled limits of agreement -6.71-10.88) and 0.30 (-0.26-0.87) breaths.min (pooled 95% limits of agreement -3.94-4.29). Only two studies of wearable devices measured S O ; these reported mean measurement biases of 3.54% (limits of agreement -5.65-11.45%) and 2.9% (-7.4-1.7%). Heterogeneity was observed across studies, but absent when devices were grouped by measurement modality and reference standard. We conclude that, while studies of wearable devices were of slightly better quality than contactless devices, in general all studies of novel devices were of low quality, with small (< 100) patient datasets, typically not blinded and often using inappropriate statistical techniques. Both types of devices were statistically equivalent in accuracy and precision, but wearable devices demonstrated less measurement bias and more precision at extreme vital signs. The statistical variability in precision and accuracy between studies is partially explained by differences in reference standards.
Topics: Heart Rate; Humans; Monitoring, Physiologic; Oxygen; Oxygen Saturation; Respiratory Rate; Wearable Electronic Devices
PubMed: 35947876
DOI: 10.1111/anae.15834 -
Sensors (Basel, Switzerland) Jul 2022Early diagnosis and continuous monitoring of respiratory failure (RF) in the course of the most prevalent chronic cardio-vascular (CVD) and respiratory diseases (CRD)...
Early diagnosis and continuous monitoring of respiratory failure (RF) in the course of the most prevalent chronic cardio-vascular (CVD) and respiratory diseases (CRD) are a clinical, unresolved problem because wearable, non-invasive, and user-friendly medical devices, which could grant reliable measures of the oxygen saturation (SpO2) and heart rate (HR) in real-life during daily activities are still lacking. In this study, we investigated the agreement between a new medical wrist-worn device (BrOxy M) and a reference, medical pulseoximeter (Nellcor PM 1000N). Twelve healthy volunteers (aged 20−51 years, 84% males, 33% with black skin, obtaining, during the controlled hypoxia test, the simultaneous registration of 219 data pairs, homogeneously deployed in the levels of Sat.O2 97%, 92%, 87%, 82% [ISO 80601-2-61:2017 standard (paragraph EE.3)]) were included. The paired T test 0 and the Bland-Altman plot were performed to assess bias and accuracy. SpO2 and HR readings by the two devices resulted significantly correlated (r = 0.91 and 0.96, p < 0.001, respectively). Analyses excluded the presence of proportional bias. For SpO2, the mean bias was −0.18% and the accuracy (ARMS) was 2.7%. For HR the mean bias was 0.25 bpm and the ARMS3.7 bpm. The sensitivity to detect SpO2 ≤ 94% was 94.4%. The agreement between BrOxy M and the reference pulse oximeter was “substantial” (for SpO2 cut-off 94% and 90%, k = 0.79 and k = 0.80, respectively). We conclude that BrOxy M demonstrated accuracy, reliability and consistency in measuring SpO2 and HR, being fully comparable with a reference medical pulseoxymeter, with no adverse effects. As a wearable device, Broxy M can measure continually SpO2 and HR in everyday life, helping in detecting and following up CVD and CRD subjects.
Topics: Cardiovascular Diseases; Female; Heart Rate; Humans; Male; Oximetry; Oxygen; Oxygen Saturation; Reproducibility of Results
PubMed: 35808526
DOI: 10.3390/s22135031 -
Journal of the American Veterinary... Nov 2022To evaluate the accuracy for 2 smartwatches with oximetry technology and optical wrist heart rate (HR) or single-lead Electrocardiography (ECG) technology (Fenix 5X Plus...
Two different smartwatches exhibit high accuracy in evaluating heart rate and peripheral oxygen saturation in cats when compared with the electrocardiography and transmittance pulse oximetry.
OBJECTIVE
To evaluate the accuracy for 2 smartwatches with oximetry technology and optical wrist heart rate (HR) or single-lead Electrocardiography (ECG) technology (Fenix 5X Plus [GF5xp], Garmin Ltd and Apple Watch 6 [AppW6], Apple Inc, respectively) versus reference methods (ECG and transmittance pulse oximetry [TPO], respectively) in measuring HR and peripheral oxygen saturation of hemoglobin (SpO2) in cats.
ANIMALS
10 male client-owned cats aged 8 to 12 months and weighing 3.2 to 4.5 kg.
PROCEDURES
All cats that were presented for elective castration at the Atatürk University Animal Hospital between March 10 and April 15, 2022, were considered for enrollment. Monitoring of HR and SpO2 during anesthesia was performed with a 3-lead ECG and transmittance pulse oximetry, respectively, connected to a multiparameter monitor (reference methods) along with a GF5xp and a AppW6. Agreement between reference methods and the smartwatches were assessed by the Bland-Altman plot, in which the differences (%) between methods were plotted against their mean HR or SpO2 (reference method measurement - test device measurement) and the limits of agreement (mean ± 1.96 × SD).
RESULTS
Compared with ECG measurements of HR, GF5xp had superior bias (-0.1%) and limit of agreement (LoA, 3.0 to -3.3%) versus those of the AppW6 (bias, 0.2%; LoA, 3.7 to -3.4%). Compared with TPO measurements of SpO2, AppW6 had superior bias (0.2%) and LoA (3.0% and -2.5%) versus those of the GF5xp (bias, -2.1%; LoA, 0.2 to -4.4%).
CLINICAL RELEVANCE
Results indicated that the GF5xp and AppW6 exhibited high accuracy in evaluating HR and SpO2 in cats when compared with the reference methods. However, it should be noted that these comparisons were made in anesthetized patients without any systemic disease.
Topics: Male; Cats; Animals; Oxygen Saturation; Oxygen; Heart Rate; Oximetry; Electrocardiography
PubMed: 36322488
DOI: 10.2460/javma.22.08.0357 -
Einstein (Sao Paulo, Brazil) 2023The World Health Organization and Centers for Disease Control and Prevention recommend the use of face masks in public. This study aimed to evaluate the effects of face...
OBJECTIVE
The World Health Organization and Centers for Disease Control and Prevention recommend the use of face masks in public. This study aimed to evaluate the effects of face masks on pulse rate and partial blood oxygen saturation in patients without cardiorespiratory disorders.
METHODS
A total of 150 volunteers of both sexes were divided into three groups (n=50) according to age (children, young adults, and older adults). The partial blood oxygen saturation and pulse rate were measured for each volunteer using a digital oximeter while wearing a facial mask and remaining at rest. The masks were removed for two minutes, and partial blood oxygen saturation and pulse rate were remeasured. The materials and types of masks used were recorded. The t -test for paired samples was used to compare the mean values obtained before and after removing the masks.
RESULTS
The most frequently used mask was a two-layered cloth (64.7%). A decrease in pulse rate was observed after removing the face mask in males, particularly in children (p=0.006) and young adults (p=0.034). Partial blood oxygen saturation levels increased in young adult males after mask removal (p=0.01).
CONCLUSION
The two-layer cotton tissue face masks are associated with a higher pulse rate and reduced arterial blood oxygen saturation without associated clinical disorders, mainly in adult men with a lower tolerance to breathing and ear discomfort.
Topics: Male; Child; Female; Young Adult; Humans; Aged; Masks; Heart Rate; Lung; Oxygen
PubMed: 37970950
DOI: 10.31744/einstein_journal/2023AO0349 -
Brazilian Journal of Cardiovascular... Aug 2021This quasi-experimental study aimed to evaluate the impact of early and regular mobilization on vital signs and oxygen saturation in open-heart surgery patients.
INTRODUCTION
This quasi-experimental study aimed to evaluate the impact of early and regular mobilization on vital signs and oxygen saturation in open-heart surgery patients.
METHODS
The study universe comprised patients undergoing open-heart surgery in the cardiovascular intensive care unit of a heart center. The study sample consisted of patients who underwent open-heart surgery from November 2016 to April 2017, met the inclusion criteria, and voluntarily agreed to participate in the study. The study included 75 patients. Of these, 67 completed the mobilization program in two days, starting on the first postoperative day. Each patient was mobilized three times: twice on the first postoperative day and once on the second postoperative day. Vital signs and oxygen saturation for each patient were measured 10 minutes before and 20 minutes after each mobilization.
RESULTS
The difference between pulse and systolic blood pressure values measured before and after the first mobilization was statistically significant (P<0.05). In addition, the difference between the mean systolic blood pressure values before the first mobilization and after the third mobilization (123.43±14.09 mmHg and 117.94±14.05 mmHg, respectively) was statistically significant (P<0.05). The other parameters measured in relation to the mobilizations were in the normal range.
CONCLUSION
Early and frequent mobilization did not cause vital signs and oxygen saturation to deviate from normal limits in open-heart surgery patients.
Topics: Cardiac Surgical Procedures; Heart Rate; Humans; Intensive Care Units; Oxygen; Vital Signs
PubMed: 33355786
DOI: 10.21470/1678-9741-2019-0481 -
Journal of Biomedical Optics Jul 2019To refine animal research, vital signs, activity, stress, and pain must be monitored. In chronic studies, some measures can be assessed using telemetry sensors. Although... (Review)
Review
To refine animal research, vital signs, activity, stress, and pain must be monitored. In chronic studies, some measures can be assessed using telemetry sensors. Although this methodology provides high-precision data, an initial surgery for device implantation is necessary, potentially leading to stress, wound infections, and restriction of motion. Recently, camera systems have been adapted for animal research. We give an overview of parameters that can be assessed using imaging in the visible, near-infrared, and thermal spectrum of light. It focuses on heart activity, respiration, oxygen saturation, and motion, as well as on wound analysis. For each parameter, we offer recommendations on the minimum technical requirements of appropriate systems, regions of interest, and light conditions, among others. In general, these systems demonstrate great performance. For heart and respiratory rate, the error was <4 beats / min and 5 breaths/min. Furthermore, the systems are capable of tracking animals during different behavioral tasks. Finally, studies indicate that inhomogeneous temperature distribution around wounds might be an indicator of (pending) infections. In sum, camera-based techniques have several applications in animal research. As vital parameters are currently only assessed in sedated animals, the next step should be the integration of these modalities in home-cage monitoring.
Topics: Animals; Heart Rate; Laboratory Animal Science; Mice; Monitoring, Physiologic; Movement; Optical Imaging; Oxygen; Rats; Thermography; Video Recording; Wound Healing
PubMed: 31286726
DOI: 10.1117/1.JBO.24.7.070601 -
Journal of Dairy Science Feb 2023A linear relationship between heart rate (HR) and oxygen consumption (VO) has been reported in homeothermic animals, indicating that is possible to estimate heat...
A linear relationship between heart rate (HR) and oxygen consumption (VO) has been reported in homeothermic animals, indicating that is possible to estimate heat production through HR measurements. This relationship may depend on the animal activity and environmental conditions. The main objective of the present study was to evaluate the effect of the air temperature and animal posture and activity on heat production and VO in relation to HR. In addition, as a secondary objective, the energy cost of eating and ruminating versus idling and standing versus lying down was determined. Twelve Holstein lactating cows were housed inside climate-controlled respiration chambers for 8 d, where the air temperature was gradually increased from 7 to 21°C during the night and from 16 to 30°C during the day with daily increments of 2°C for both daytime and nighttime. During the 8-d data collection period, HR and gaseous exchange measurements were performed, and animal posture and activity were recorded continuously. The oxygen pulse (OP), which represents the amount of oxygen that is consumed by the cow per heartbeat, was calculated as the ratio between VO and HR. Results showed that heat production and VO were linearly and positively associated with HR, but this relationship largely varied between individual cows. Within the range tested, OP was unaffected by temperature, but we detected a tendency for an interaction of OP with the temperature range tested during the night versus during the day. This indicates that the effect of air temperature on OP is nonlinear. Standing and eating slightly increased OP (1.0 and 2.5%) compared with lying down and idling, respectively, whereas rumination increased OP by 5.1% compared with idling. It was concluded that the potential bias introduced by these effects on the OP for the application of the technique is limited. The energy cost of eating and ruminating over idling was 223 ± 11 and 45 ± 6 kJ/kg per day, respectively, whereas the energy cost of standing over lying down was 53 ± 6 kJ/kg per day. We concluded that OP in dairy cows was slightly affected by both animal posture and activity, but remained unaffected by air temperature within 8 to 32°C. Nonlinearity of the relationship between the OP and air temperature suggests that caution is required extrapolating OP beyond the temperature range evaluated in our experiment.
Topics: Female; Cattle; Animals; Temperature; Heart Rate; Lactation; Thermogenesis; Oxygen; Hot Temperature
PubMed: 36494233
DOI: 10.3168/jds.2022-22257 -
British Journal of Sports Medicine Mar 1994The purpose of the investigation was to determine the relative oxygen consumption (VO2), heart rate and oxygen pulse associated with the constituent elements of an...
The purpose of the investigation was to determine the relative oxygen consumption (VO2), heart rate and oxygen pulse associated with the constituent elements of an exercise-to-music class. Six women exercise-to-music leaders with a mean(s.d.) age, weight and height of 33.2(5.2) years, 51.0(2.8) kg and 157.9(5.6) cm respectively, completed five distinct exercise-to-music movement elements. The movement elements were of a locomoter (circuit, jump and low impact) and callisthenic (prone and side/supine) nature. The movement elements were distinguishable from one another in terms of their movement patterns, posture and tempo. Relative VO2 values were greatest for the circuit element (40.6 ml kg-1 min-1) and least for the side/supine element (20.0 ml kg-1 min-1). The differences in VO2 between the locomotrr and callisthenic elements were significant (circuit approximately jump approximately low impact > prone approximately side/supine). However, effect size data suggested that the differences between the low impact and jump elements and the prone and side/supine elements were of practical significance (circuit approximately jump > low impact > prone > side/supine). With a single exception similar parametric statistics and effect size trends were identified for absolute heart rate. Specifically, the heart rate associated with the low impact element was not significantly greater than the prone element. The oxygen pulse associated with the locomotor elements was significantly greater than the callisthenic elements (circuit approximately jump approximately low impact > prone > side/supine). This suggested that heart rate may be an inappropriate index for making comparisons between exercise-to-music elements. Reasons for differences in oxygen uptake values between movement elements are discussed.
Topics: Adult; Exercise; Female; Heart Rate; Humans; Locomotion; Music; Oxygen Consumption; Prone Position; Pulmonary Gas Exchange; Pulse; Running; Supine Position; Weight-Bearing
PubMed: 8044493
DOI: 10.1136/bjsm.28.1.43 -
Journal of Applied Physiology... Dec 2019Arterial oxygen tension and oxyhemoglobin saturation () decrease in parallel during hypoxia. Distinguishing between changes in oxygen tension and oxygen content as the...
Arterial oxygen tension and oxyhemoglobin saturation () decrease in parallel during hypoxia. Distinguishing between changes in oxygen tension and oxygen content as the relevant physiological stimulus for cardiorespiratory alterations remains challenging. To overcome this, we recruited nine individuals with hemoglobinopathy manifesting as high-affinity hemoglobin [HAH; partial pressure at 50% (P) = 16 ± 0.4 mmHg] causing greater at a given oxygen partial pressure compared with control subjects ( = 12, P = 26 ± 0.4 mmHg). We assessed ventilatory and cardiovascular responses to acute isocapnic hypoxia, iso-oxic hypercapnia, and 20 min of isocapnic hypoxia (arterial Po = 50 mmHg). Blood gas alterations were achieved with dynamic end-tidal forcing. When expressed as a function of the logarithm of oxygen partial pressure, ventilatory sensitivity to hypoxia was not different between groups. However, there was a significant difference when expressed as a function of . Conversely, the rise in heart rate was blunted in HAH subjects when expressed as a function of partial pressure but similar when expressed as a function of . Ventilatory sensitivity to hypercapnia was not different between groups. During sustained isocapnic hypoxia, the rise in minute ventilation was similar between groups; however, heart rate was significantly greater in the controls during 3 to 9 min of exposure. Our results support the notion that oxygen tension, not content, alters cellular Po in the chemosensors and drives the hypoxic ventilatory response. Our study suggests that in addition to oxygen partial pressure, oxygen content may also influence the heart rate response to hypoxia. We dissociated the effects of oxygen content and pressure of cardiorespiratory regulation studying individuals with high-affinity hemoglobin (HAH). During hypoxia, the ventilatory response, expressed as a function of oxygen tension, was similar between HAH variants and controls; however, the rise in heart rate was blunted in the variants. Our work supports the notion that the hypoxic ventilatory response is regulated by oxygen tension, whereas cardiovascular regulation may be influenced by arterial oxygen content and tension.
Topics: Adult; Blood Gas Analysis; Female; Heart Rate; Humans; Hypercapnia; Hypoxia; Male; Oxygen; Partial Pressure; Respiration
PubMed: 31647724
DOI: 10.1152/japplphysiol.00569.2019