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Revista Brasileira de Terapia Intensiva 2017To review the literature on the effects of expiratory rib cage compression on ventilatory mechanics, airway clearance, and oxygen and hemodynamic indices in mechanically... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE:
To review the literature on the effects of expiratory rib cage compression on ventilatory mechanics, airway clearance, and oxygen and hemodynamic indices in mechanically ventilated adults.
METHODS:
Systematic review with meta-analysis of randomized clinical trials in the databases MEDLINE (via PubMed), EMBASE, Cochrane CENTRAL, PEDro, and LILACS. Studies on adult patients hospitalized in intensive care units and under mechanical ventilation that analyzed the effects of expiratory rib cage compression with respect to a control group (without expiratory rib cage compression) and evaluated the outcomes static and dynamic compliance, sputum volume, systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, peripheral oxygen saturation, and ratio of arterial oxygen partial pressure to fraction of inspired oxygen were included. Experimental studies with animals and those with incomplete data were excluded.
RESULTS:
The search strategy produced 5,816 studies, of which only three randomized crossover trials were included, totaling 93 patients. With respect to the outcome of heart rate, values were reduced in the expiratory rib cage compression group compared with the control group [-2.81 bpm (95% confidence interval [95%CI]: -4.73 to 0.89; I2: 0%)]. Regarding dynamic compliance, there was no significant difference between groups [-0.58mL/cmH2O (95%CI: -2.98 to 1.82; I2: 1%)]. Regarding the variables systolic blood pressure and diastolic blood pressure, significant differences were found after descriptive evaluation. However, there was no difference between groups regarding the variables secretion volume, static compliance, ratio of arterial oxygen partial pressure to fraction of inspired oxygen, and peripheral oxygen saturation.
CONCLUSION:
There is a lack of evidence to support the use of expiratory rib cage compression in routine care, given that the literature on this topic offers low methodological quality and is inconclusive.
Topics: Adult; Blood Gas Analysis; Blood Pressure; Exhalation; Heart Rate; Humans; Oxygen; Pressure; Pulmonary Gas Exchange; Randomized Controlled Trials as Topic; Respiration, Artificial; Rib Cage
PubMed: 28444078
DOI: 10.5935/0103-507X.20170014 -
The Journal of Experimental Biology Sep 2020Marine mammals endure extended breath-holds while performing active behaviors, which has fascinated scientists for over a century. It is now known that these animals... (Review)
Review
Marine mammals endure extended breath-holds while performing active behaviors, which has fascinated scientists for over a century. It is now known that these animals have large onboard oxygen stores and utilize oxygen-conserving mechanisms to prolong aerobically supported dives to great depths, while typically avoiding (or tolerating) hypoxia, hypercarbia, acidosis and decompression sickness (DCS). Over the last few decades, research has revealed that diving physiology is underdeveloped at birth. Here, I review the postnatal development of the body's oxygen stores, cardiorespiratory system and other attributes of diving physiology for pinnipeds and cetaceans to assess how physiological immaturity makes young marine mammals vulnerable to disturbance. Generally, the duration required for body oxygen stores to mature varies across species in accordance with the maternal dependency period, which can be over 2 years long in some species. However, some Arctic and deep-diving species achieve mature oxygen stores comparatively early in life (prior to weaning). Accelerated development in these species supports survival during prolonged hypoxic periods when calves accompany their mothers under sea ice and to the bathypelagic zone, respectively. Studies on oxygen utilization patterns and heart rates while diving are limited, but the data indicate that immature marine mammals have a limited capacity to regulate heart rate (and hence oxygen utilization) during breath-hold. Underdeveloped diving physiology, in combination with small body size, limits diving and swimming performance. This makes immature marine mammals particularly vulnerable to mortality during periods of food limitation, habitat alterations associated with global climate change, fishery interactions and other anthropogenic disturbances, such as exposure to sonar.
Topics: Animals; Breath Holding; Caniformia; Cattle; Cetacea; Heart Rate; Oxygen
PubMed: 32917778
DOI: 10.1242/jeb.227736 -
Canadian Journal of Anaesthesia =... Dec 2015Photoplethysmography permits continuous measurement of heart rate and peripheral oxygen saturation and has been widely used to inform clinical decisions. Recently, a... (Review)
Review
PURPOSE
Photoplethysmography permits continuous measurement of heart rate and peripheral oxygen saturation and has been widely used to inform clinical decisions. Recently, a myriad of noninvasive hemodynamic monitoring devices using this same technology have been increasingly available. This narrative review aims to summarize the principles that form the basis for the function of these devices as well as to comment on trials evaluating their accuracy and clinical application.
PRINCIPAL FINDINGS
Advanced monitoring devices extend photoplethysmography technology beyond measuring oxygen concentration and heart rate. Quantification of respiratory variation of the photoplethysmographic waveform reflects respiratory variation of the arterial pressure waveform and can be used to gauge volume responsiveness. Both the volume-clamp and physiocal techniques are extensions of conventional photoplethysmography and permit continuous measurement of finger arterial blood pressure. Finger arterial pressure waveforms can subsequently inform estimations of cardiac output.
CONCLUSIONS
Although respiratory variations of the plethysmographic waveform correlate only modestly with the arterial blood pressure waveform, fluid responsiveness can be relatively consistently assessed using both approaches. Continuous blood pressure measurements obtained using the volume-clamp technique may be as accurate as conventional brachial noninvasive blood pressure measurements. Most importantly, clinical comparative effectiveness studies are still needed in order to determine if these technologies can be translated into improvement of relevant patient outcomes.
Topics: Arterial Pressure; Cardiac Output; Heart Rate; Humans; Monitoring, Physiologic; Oxygen; Photoplethysmography
PubMed: 26286382
DOI: 10.1007/s12630-015-0458-0 -
Critical Care (London, England) Feb 2018In clinical practice, oxygen is generally administered to patients with the intention of increasing oxygen delivery. Supplemental oxygen may, however, cause arterial... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
In clinical practice, oxygen is generally administered to patients with the intention of increasing oxygen delivery. Supplemental oxygen may, however, cause arterial hyperoxia, which is associated with hemodynamic alterations. We performed a systematic review and meta-analysis of the literature to determine the effect of hyperoxia on central hemodynamics and oxygen delivery in healthy volunteers and cardiovascular-compromised patients.
METHODS
PubMed and EMBASE were searched up to March 2017. Studies with adult humans investigating changes in central hemodynamics or oxygen delivery induced by acute normobaric hyperoxia were included. Studies focusing on lung, retinal, or brain parameters were not included. We extracted subject and oxygen exposure characteristics, indexed and unindexed values for heart rate, stroke volume, cardiac output, mean arterial pressure (MAP), systemic vascular resistance, and oxygen delivery during normoxia and hyperoxia. For quantitative synthesis of the data, a random-effects ratio of means (RoM) model was used.
RESULTS
We identified 33 studies with 42 datasets. Study categories included healthy volunteers (n = 22 datasets), patients with coronary artery disease (CAD; n = 6), heart failure (HF; n = 6), coronary artery bypass graft (CABG; n = 3) and sepsis (n = 5). Hyperoxia (arterial oxygen tension of 234-617 mmHg) reduced cardiac output (CO) by 10-15% in both healthy volunteers (-10.2%, 95% confidence interval (CI) -12.9% to -7.3%) and CAD (-9.6%, 95% CI -12.3% to -6.9%) or HF patients (-15.2%, 95% CI -21.7% to -8.2%). No significant changes in cardiac output were seen in CABG or septic patients (-3%). Systemic vascular resistance increased remarkably in patients with heart failure (24.6%, 95% CI 19.3% to 30.1%). In healthy volunteers, and those with CAD and CABG, the effect was smaller (11-16%) and was virtually absent in patients with sepsis (4.3%, 95% CI -3.2% to 12.3%). No notable effect on MAP was found in any group (2-3%). Oxygen delivery was not altered by hyperoxia. Considerable heterogeneity existed between study results, likely due to methodological differences.
CONCLUSIONS
Hyperoxia may considerably decrease cardiac output and increase systemic vascular resistance, but effects differ between patient categories. Heart failure patients were the most sensitive while no hemodynamic effects were seen in septic patients. There is currently no evidence supporting the notion that oxygen supplementation increases oxygen delivery.
Topics: Blood Gas Analysis; Blood Pressure; Cardiac Output; Heart Rate; Hemodynamics; Humans; Hyperoxia; Oxygen; Vascular Resistance
PubMed: 29477145
DOI: 10.1186/s13054-018-1968-2 -
Journal of Strength and Conditioning... Sep 2021Godoy, DF, Cadore, EL, Feitosa, WG, Correia, RdA, and Castro, FAdS. Oxygen uptake of wave surfers and complementary parameters in front crawl and surfing-paddling tests....
Godoy, DF, Cadore, EL, Feitosa, WG, Correia, RdA, and Castro, FAdS. Oxygen uptake of wave surfers and complementary parameters in front crawl and surfing-paddling tests. J Strength Cond Res 35(9): 2645-2650, 2021-The aim of this study was to assess the reliability of the oxygen uptake and complementary parameters (heart rate [HR], blood lactate concentration, and rate of perceived exertion [RPE]) obtained from surfers swimming and paddling in a swimming pool. Fourteen recreational male surfers (37.7 ± 4.7 years old) were evaluated in (a) a maximal 300-m front crawl test and (b) paddling in a surfboard test, both at the same intensity and for the same duration. Peak oxygen uptake (V̇o2peak) during the tests (direct method), HR, blood lactate concentration (LA), and RPE were assessed. Two-way analysis of variance, a simple Student t test, effect size calculation, intraclass correlation coefficient, and limits of agreement were applied. In general, the tests presented similar results (except for HR), with low agreement, high intraclass correlation, and average to large effect sizes between swimming and paddling. The results suggest that surfers training in a swimming pool should not simply be swimming. Front crawl swimming and surf paddling are 2 distinct actions that should be practiced and tested on their own merits rather than assumed to be interchangeable.
Topics: Adult; Heart Rate; Humans; Lactic Acid; Male; Oxygen; Oxygen Consumption; Reproducibility of Results; Swimming
PubMed: 31373983
DOI: 10.1519/JSC.0000000000003205 -
Critical Care Clinics Oct 2016This article discusses commonly used methods of monitoring and determining the end points of resuscitation. Each end point of resuscitation is examined as it relates to... (Review)
Review
This article discusses commonly used methods of monitoring and determining the end points of resuscitation. Each end point of resuscitation is examined as it relates to use in critically ill burn patients. Published medical literature, clinical trials, consensus trials, and expert opinion regarding end points of resuscitation were gathered and reviewed. Specific goals were a detailed examination of each method in the critical care population and how this methodology can be used in the burn patient. Although burn resuscitation is monitored and administered using the methodology as seen in medical/surgical intensive care settings, special consideration for excessive edema formation, metabolic derangements, and frequent operative interventions must be considered.
Topics: Acid-Base Imbalance; Biomarkers; Blood Gas Analysis; Burns; Echocardiography; Endpoint Determination; Heart Rate; Humans; Lactic Acid; Monitoring, Physiologic; Oxygen; Pulse Wave Analysis; Resuscitation; Urine
PubMed: 27600124
DOI: 10.1016/j.ccc.2016.06.012 -
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 -
International Journal of Environmental... Sep 2022Cardiovascular capacity, expressed as maximal oxygen uptake (VO), is a strong predictor of health and fitness and is considered a key measure of physiological function...
BACKGROUND
Cardiovascular capacity, expressed as maximal oxygen uptake (VO), is a strong predictor of health and fitness and is considered a key measure of physiological function in the healthy adult population. The purpose of this study was to validate a specific step test (StepTest4all) as an adequate procedure to estimate cardiovascular capacity in young adults.
METHODS
The sample was composed of 56 participants, including 19 women (aged 21.05 ± 2.39 years, body mass = 57.50 ± 6.64 kg, height = 1.62 ± 0.05 m, body mass index = 22.00 ± 2.92 kg/m) and 37 men (aged 22.05 ± 3.14 years, body mass = 72.50 ± 7.73 kg, height = 1.76 ± 0.07 m, body mass index = 23.34 ± 2.17 kg/m). Participants were included in one of the following groups: (i) the group used to predict the VO, and (ii) the group used to validate the prediction model. All participants performed the StepTest4all protocol. The step height and the intensity of the effort was determined individually. Heart rate and oxygen uptake were measured continuously during rest, effort, and recovery phases. The validation process included the following three stages: (i) mean data comparison, (ii) simple linear regression, and (iii) Bland-Altman analysis.
RESULTS
The linear regression retained, as significant predictors of the VO, sex ( < 0.001) and heart rate recovery for one minute ( = 0.003). The prediction equation revealed a high relationship between measurements (R = 63.0%, SEE = 5.58). The validation procedure revealed non-significant differences ( > 0.05) between the measured and estimated maximal oxygen uptake, high relationship (R = 63.3%), and high agreement with Bland-Altman plots. Thus, VO can be estimated with the formula: VO = 22 + 0.3 · (HRR) + 12 · (sex), where HRR is the magnitude of the HR decrease (bpm) in one minute immediately after the step was stopped, and sex: men = 1, women = 0.
CONCLUSIONS
The StepTest4all is an adequate procedure to estimate cardiovascular capacity, expressed as VO, in young adults. In addition, it is possible to determine the qualitative level of cardiovascular capacity from the heart rate recovery for one minute, more specifically, poor: <20, moderate: 20 to 34, good: 35 to 49, and excellent: ≥50. This procedure has the benefit of being simple to apply and can be used by everyone, even at home, without specialist supervision.
Topics: Exercise; Exercise Test; Female; Heart Rate; Humans; Male; Oxygen; Oxygen Consumption; Young Adult
PubMed: 36141547
DOI: 10.3390/ijerph191811274 -
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 -
Philosophical Transactions of the Royal... Aug 2021In the 1940s, Scholander and Irving revealed fundamental physiological responses to forced diving of marine mammals and birds, setting the stage for the study of diving... (Review)
Review
In the 1940s, Scholander and Irving revealed fundamental physiological responses to forced diving of marine mammals and birds, setting the stage for the study of diving physiology. Since then, diving physiology research has moved from the laboratory to the field. Modern biologging, with the development of microprocessor technology, recorder memory capacity and battery life, has advanced and expanded investigations of the diving physiology of marine mammals and birds. This review describes a brief history of the start of field diving physiology investigations, including the invention of the time depth recorder, and then tracks the use of biologging studies in four key diving physiology topics: heart rate, blood flow, body temperature and oxygen store management. Investigations of diving heart rates in cetaceans and O store management in diving emperor penguins are highlighted to emphasize the value of diving physiology biologging research. The review concludes with current challenges, remaining diving physiology questions and what technologies are needed to advance the field. This article is part of the theme issue 'Measuring physiology in free-living animals (Part I)'.
Topics: Animals; Aquatic Organisms; Birds; Blood Circulation; Body Temperature; Diving; Heart Rate; Mammals; Oxygen
PubMed: 34121464
DOI: 10.1098/rstb.2020.0211