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Medicina (Kaunas, Lithuania) Oct 2022Background: The hyperventilation test is used in clinical practice for diagnosis and therapeutic purposes; however, in the absence of a standardized protocol, the...
Background: The hyperventilation test is used in clinical practice for diagnosis and therapeutic purposes; however, in the absence of a standardized protocol, the procedure varies significantly, predisposing tested subjects to risks such as cerebral hypoxia and ischemia. Near-infrared spectroscopy (NIRS), a noninvasive technique performed for cerebral oximetry monitoring, was used in the present study to identify the minimum decrease in the end-tidal CO2 (ETCO2) during hyperventilation necessary to induce changes on NIRS. Materials and Methods: We recruited 46 volunteers with no preexisting medical conditions. Each subject was asked to breathe at a baseline rate (8−14 breaths/min) for 2 min and then to hyperventilate at a double respiratory rate for the next 4 min. The parameters recorded during the procedure were the regional cerebral oxyhemoglobin and deoxyhemoglobin concentrations via NIRS, ETCO2, and the respiratory rate. Results: During hyperventilation, ETCO2 values dropped (31.4 ± 12.2%) vs. baseline in all subjects. Changes in cerebral oximetry were observed only in those subjects (n = 30) who registered a decrease (%) in ETCO2 of 37.58 ± 10.34%, but not in the subjects (n = 16) for which the decrease in ETCO2 was 20.31 ± 5.6%. According to AUC-ROC analysis, a cutoff value of ETCO2 decrease >26% was found to predict changes in oximetry (AUC-ROC = 0.93, p < 0.0001). Seven subjects reported symptoms, such as dizziness, vertigo, and numbness, throughout the procedure. Conclusions: The rise in the respiratory rate alone cannot effectively predict the occurrence of a cerebral vasoconstrictor response induced by hyperventilation, and synchronous ETCO2 and cerebral oximetry monitoring could be used to validate this clinical test. NIRS seems to be a useful tool in predicting vasoconstriction following hyperventilation.
Topics: Humans; Hyperventilation; Spectroscopy, Near-Infrared; Oximetry; Oxyhemoglobins; Cerebrovascular Circulation; Carbon Dioxide; Vasoconstrictor Agents
PubMed: 36295560
DOI: 10.3390/medicina58101396 -
Respiratory Care Oct 2020Respiratory monitoring in patients receiving oxygen therapy for acute care is mandatory at the initial stage of in-hospital management given the potential risk of...
Respiratory monitoring in patients receiving oxygen therapy for acute care is mandatory at the initial stage of in-hospital management given the potential risk of clinical worsening. Although some patients benefit from close monitoring in the ICU, the vast majority of them are managed in general wards with reduced staff and clinical supervision. The objective of monitoring is to detect early clinical deterioration, which may help prevent in-hospital cardiac arrest. In addition to the clinical and usual evaluations (eg, breathing frequency, breathing pattern, oximetry, and oxygen flow requirements), early warning scoring systems have been developed to detect clinical deterioration in acutely ill patients. The monitoring of these scores is recommended for patients receiving oxygen therapy. These scores have several limitations, among which is the absence of oxygen flow evaluation. Manual and intermittent monitoring of these scores in the ward is time-consuming and may not be sufficient to accurately detect deterioration of patient's clinical condition in a timely manner. Automated and continuous monitoring, in addition to clinical evaluation and arterial blood gases analysis, which remain necessary, may improve the detection of clinical worsening in specific patients. Devices that automatically titrate and wean oxygen flow on the basis of [Formula: see text] enable measurement of several major cardiorespiratory parameters (eg, [Formula: see text], oxygen flow, heart rate, breathing frequency, and heart rate variability). The combination of these parameters into new scores is at least as accurate and well-evaluated, and recommended early warning scores and may be useful in monitoring patients receiving oxygen therapy.
Topics: Critical Care; Humans; Monitoring, Physiologic; Oximetry; Oxygen; Oxygen Inhalation Therapy
PubMed: 32753529
DOI: 10.4187/respcare.07623 -
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 -
BMJ Open Sep 2021To characterise adoption and explore specific clinical and patient factors that might influence pulse oximetry and oxygen use in low-income and middle-income countries...
OBJECTIVES
To characterise adoption and explore specific clinical and patient factors that might influence pulse oximetry and oxygen use in low-income and middle-income countries (LMICs) over time; to highlight useful considerations for entities working on programmes to improve access to pulse oximetry and oxygen.
DESIGN
A multihospital retrospective cohort study.
SETTINGS
All admissions (n=132 737) to paediatric wards of 18 purposely selected public hospitals in Kenya that joined a Clinical Information Network (CIN) between March 2014 and December 2020.
OUTCOMES
Pulse oximetry use and oxygen prescription on admission; we performed growth-curve modelling to investigate the association of patient factors with study outcomes over time while adjusting for hospital factors.
RESULTS
Overall, pulse oximetry was used in 48.8% (64 722/132 737) of all admission cases. Use rose on average with each month of participation in the CIN (OR: 1.11, 95% CI 1.05 to 1.18) but patterns of adoption were highly variable across hospitals suggesting important factors at hospital level influence use of pulse oximetry. Of those with pulse oximetry measurement, 7% (4510/64 722) had hypoxaemia (SpO <90%). Across the same period, 8.6% (11 428/132 737) had oxygen prescribed but in 87%, pulse oximetry was either not done or the hypoxaemia threshold (SpO <90%) was not met. Lower chest-wall indrawing and other respiratory symptoms were associated with pulse oximetry use at admission and were also associated with oxygen prescription in the absence of pulse oximetry or hypoxaemia.
CONCLUSION
The adoption of pulse oximetry recommended in international guidelines for assessing children with severe illness has been slow and erratic, reflecting system and organisational weaknesses. Most oxygen orders at admission seem driven by clinical and situational factors other than the presence of hypoxaemia. Programmes aiming to implement pulse oximetry and oxygen systems will likely need a long-term vision to promote adoption, guideline development and adherence and continuously examine impact.
Topics: Child; Humans; Hypoxia; Kenya; Oximetry; Oxygen; Prospective Studies; Retrospective Studies
PubMed: 34493522
DOI: 10.1136/bmjopen-2021-050995 -
PloS One 2022Neonatal multiparameter continuous physiological monitoring (MCPM) technologies assist with early detection of preventable and treatable causes of neonatal mortality....
BACKGROUND
Neonatal multiparameter continuous physiological monitoring (MCPM) technologies assist with early detection of preventable and treatable causes of neonatal mortality. Evaluating accuracy of novel MCPM technologies is critical for their appropriate use and adoption.
METHODS
We prospectively compared the accuracy of Sibel's Advanced Neonatal Epidermal (ANNE) technology with Masimo's Rad-97 pulse CO-oximeter with capnography and Spengler's Tempo Easy reference technologies during four evaluation rounds. We compared accuracy of heart rate (HR), respiratory rate (RR), oxygen saturation (SpO2), and skin temperature using Bland-Altman plots and root-mean-square deviation analyses (RMSD). Sibel's ANNE algorithms were optimized between each round. We created Clarke error grids with zones of 20% to aid with clinical interpretation of HR and RR results.
RESULTS
Between November 2019 and August 2020 we collected 320 hours of data from 84 neonates. In the final round, Sibel's ANNE technology demonstrated a normalized bias of 0% for HR and 3.1% for RR, and a non-normalized bias of -0.3% for SpO2 and 0.2°C for temperature. The normalized spread between 95% upper and lower limits-of-agreement (LOA) was 4.7% for HR and 29.3% for RR. RMSD for SpO2 was 1.9% and 1.5°C for temperature. Agreement between Sibel's ANNE technology and the reference technologies met the a priori-defined thresholds for 95% spread of LOA and RMSD. Clarke error grids showed that all HR and RR observations were within a 20% difference.
CONCLUSION
Our findings suggest acceptable agreement between Sibel's ANNE and reference technologies. Clinical effectiveness, feasibility, usability, acceptability, and cost-effectiveness investigations are necessary for large-scale implementation.
Topics: Humans; Infant, Newborn; Kenya; Monitoring, Physiologic; Oximetry; Oxygen; Respiratory Rate
PubMed: 35771801
DOI: 10.1371/journal.pone.0267026 -
Tropical Medicine & International... Oct 2022We aimed to determine the cost-effectiveness of supplementing standard care with pulse oximetry among children <5 years with acute respiratory infection (ARI)... (Review)
Review
OBJECTIVES
We aimed to determine the cost-effectiveness of supplementing standard care with pulse oximetry among children <5 years with acute respiratory infection (ARI) presenting to 32 primary care units in a rural district (total population 241,436) of Chiang Rai province, Thailand, and to assess the economic effects of extending pulse oximetry to older patients with ARI in this setting.
METHODS
We performed a model-based cost-effectiveness analysis from a health systems perspective. Decision trees were constructed for three patient categories (children <5 years, children 5-14 years, and adults), with a 1-year time horizon. Model parameters were based on data from 49,958 patients included in a review of acute infection management in the 32 primary care units, published studies, and procurement price lists. Parameters were varied in deterministic sensitivity analyses. Costs were expressed in 2021 US dollars with a willingness-to-pay threshold per DALY averted of $8624.
RESULTS
The annual direct cost of pulse oximetry, associated staff, training, and monitoring was $24,243. It reduced deaths from severe lower respiratory tract infections in children <5 years by 0.19 per 100,000 patients annually. In our population of 14,075 children <5 years, this was equivalent to 2.0 DALYs averted per year. When downstream costs such as those related to hospitalisation and inappropriate antibiotic prescription were considered, pulse oximetry dominated standard care, saving $12,757 annually. This intervention yielded smaller mortality gains in older patients but resulted in further cost savings, primarily by reducing inappropriate antibiotic prescriptions in these age groups. The dominance of the intervention was also demonstrated in all sensitivity analyses.
CONCLUSIONS
Pulse oximetry is a life-saving, cost-effective adjunct in ARI primary care management in rural northern Thailand. This finding is likely to be generalisable to neighbouring countries with similar disease epidemiology and health systems.
Topics: Adult; Aged; Anti-Bacterial Agents; Child; Cost-Benefit Analysis; Humans; Oximetry; Primary Health Care; Respiratory Tract Infections; Thailand
PubMed: 36054516
DOI: 10.1111/tmi.13812 -
Advanced Science (Weinheim,... Nov 2023Flexible and wearable biosensors are the next-generation healthcare devices that can efficiently monitor human health conditions in day-to-day life. Moreover, the rapid... (Review)
Review
Flexible and wearable biosensors are the next-generation healthcare devices that can efficiently monitor human health conditions in day-to-day life. Moreover, the rapid growth and technological advancements in wearable optoelectronics have promoted the development of flexible organic photoplethysmography (PPG) biosensor systems that can be implanted directly onto the human body without any additional interface for efficient bio-signal monitoring. As an example, the pulse oximeter utilizes PPG signals to monitor the oxygen saturation (SpO ) in the blood volume using two distinct wavelengths with organic light emitting diode (OLED) as light source and an organic photodiode (OPD) as light sensor. Utilizing the flexible and soft properties of organic semiconductors, pulse oximeter can be both flexible and conformal when fabricated on thin polymeric substrates. It can also provide highly efficient human-machine interface systems that can allow for long-time biological integration and flawless measurement of signal data. In this work, a clear and systematic overview of the latest progress and updates in flexible and wearable all-organic pulse oximetry sensors for SpO monitoring, including design and geometry, processing techniques and materials, encapsulation and various factors affecting the device performance, and limitations are provided. Finally, some of the research challenges and future opportunities in the field are mentioned.
Topics: Humans; Photoplethysmography; Oximetry; Biosensing Techniques; Oxygen; Wearable Electronic Devices
PubMed: 37740697
DOI: 10.1002/advs.202302752 -
BMJ Open Jun 2023In general, caesarean sections are performed under spinal anaesthesia. Hypotension after spinal anaesthesia adversely affects both the mother and fetus. Although several...
INTRODUCTION
In general, caesarean sections are performed under spinal anaesthesia. Hypotension after spinal anaesthesia adversely affects both the mother and fetus. Although several studies have used pulse oximetry-derived indices, such as pulse perfusion index (PI) and Pleth variability index (PVI), to predict hypotension after spinal anaesthesia, the predictive ability of the PI and PVI remain controversial.
METHODS AND ANALYSIS
We prepared this protocol following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. We will conduct searches of MEDLINE, Embase, Web of Science, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Clinicaltrial.gov, European Union Clinical Trials Register (EU-CTR), WHO International Clinical Trials Registry Platform (ICTRP) and University Hospital Medical Information Network Clinical Trials Registry (UMIN) from inception until 8 October 2022. We will include retrospective and prospective observational studies and randomised controlled trials that evaluated the predictive ability of PI and PVI for hypotension after spinal anaesthesia for caesarean section, published in any language. We will exclude case reports, case series and animal studies. Two authors will independently scan and select eligible studies and perform data extraction and assessment of risk of bias. We will estimate predictive ability of PI and PVI as indices of hypotension after spinal anaesthesia for caesarean section using the Reitsma-type bivariate random-effects synthesis model and the hierarchical summary receiver operating characteristic curve. We will assess the quality of evidence using the Grading of Recommendation Assessment, Development and Evaluation approach.
ETHICS AND DISSEMINATION
Ethics approval is not required as the systematic review will use existing published data. The results will be submitted for publication in a peer-reviewed journal.
PROSPERO REGISTRATION NUMBER
CRD42022362596.
Topics: Pregnancy; Female; Humans; Anesthesia, Spinal; Cesarean Section; Retrospective Studies; Systematic Reviews as Topic; Meta-Analysis as Topic; Hypotension; Oximetry; Observational Studies as Topic
PubMed: 37355260
DOI: 10.1136/bmjopen-2022-069309 -
Experimental Physiology Sep 2020What is the topic of this review? Symmetric Projection Attractor Reconstruction (SPAR) is a relatively new mathematical method that can extract additional information... (Review)
Review
NEW FINDINGS
What is the topic of this review? Symmetric Projection Attractor Reconstruction (SPAR) is a relatively new mathematical method that can extract additional information pertaining to the morphology and variability of physiological waveforms, such as arterial pulse pressure. Herein, we describe the potential utility of the method for more sensitive quantification of cardiovascular changes. What advances does it highlight? We use a simple example of a human tilt table to illustrate these concepts. SPAR can be used on any approximately periodic waveform and may add value to experimental and clinical settings, where such signals are collected routinely.
ABSTRACT
Periodic physiological waveform data, such as blood pressure, pulse oximetry and ECG, are routinely sampled between 100 and 1000 Hz in preclinical research and in the clinical setting from a wide variety of implantable, bedside and wearable monitoring devices. Despite the underlying numerical waveform data being captured at such high fidelity, conventional analysis tends to reside in reporting only averages of minimum, maximum, amplitude and rate, as single point averages. Although these averages are undoubtedly of value, simplification of the data in this way means that most of the available numerical data are discarded. In turn, this may lead to subtle physiological changes being missed when investigating the cardiovascular system over time. We have developed a mathematical method (symmetric projection attractor reconstruction) that uses all the numerical data, replotting and revisualizing them in a manner that allows unique quantification of multiple changes in waveform morphology and variability. We propose that the additional quantification of these features will allow the complex behaviour of the cardiovascular system to be mapped more sensitively in different physiological and pathophysiological settings.
Topics: Blood Pressure; Cardiovascular Physiological Phenomena; Electrocardiography; Heart Rate; Humans; Models, Theoretical; Oximetry; Signal Processing, Computer-Assisted
PubMed: 32347611
DOI: 10.1113/EP087873 -
JAMA Network Open Sep 2021National guidelines recommend against continuous pulse oximetry use for hospitalized children with bronchiolitis who are not receiving supplemental oxygen, yet... (Clinical Trial)
Clinical Trial
Evaluation of an Educational Outreach and Audit and Feedback Program to Reduce Continuous Pulse Oximetry Use in Hospitalized Infants With Stable Bronchiolitis: A Nonrandomized Clinical Trial.
IMPORTANCE
National guidelines recommend against continuous pulse oximetry use for hospitalized children with bronchiolitis who are not receiving supplemental oxygen, yet guideline-discordant use remains high.
OBJECTIVES
To evaluate deimplementation outcomes of educational outreach and audit and feedback strategies aiming to reduce guideline-discordant continuous pulse oximetry use in children hospitalized with bronchiolitis who are not receiving supplemental oxygen.
DESIGN, SETTING, AND PARTICIPANTS
A nonrandomized clinical single-group deimplementation trial was conducted in 14 non-intensive care units in 5 freestanding children's hospitals and 1 community hospital from December 1, 2019, through March 14, 2020, among 847 nurses and physicians caring for hospitalized children with bronchiolitis who were not receiving supplemental oxygen.
INTERVENTIONS
Educational outreach focused on communicating details of the existing guidelines and evidence. Audit and feedback strategies included 2 formats: (1) weekly aggregate data feedback to multidisciplinary teams with review of unit-level and hospital-level use of continuous pulse oximetry, and (2) real-time 1:1 feedback to clinicians when guideline-discordant continuous pulse oximetry use was discovered during in-person data audits.
MAIN OUTCOMES AND MEASURES
Clinician ratings of acceptability, appropriateness, feasibility, and perceived safety were assessed using a questionnaire. Guideline-discordant continuous pulse oximetry use in hospitalized children was measured using direct observation of a convenience sample of patients with bronchiolitis who were not receiving supplemental oxygen.
RESULTS
A total of 847 of 1193 eligible clinicians (695 women [82.1%]) responded to a Likert scale-based questionnaire (71% response rate). Most respondents rated the deimplementation strategies of education and audit and feedback as acceptable (education, 435 of 474 [92%]; audit and feedback, 615 of 664 [93%]), appropriate (education, 457 of 474 [96%]; audit and feedback, 622 of 664 [94%]), feasible (education, 424 of 474 [89%]; audit and feedback, 557 of 664 [84%]), and safe (803 of 847 [95%]). Sites collected 1051 audit observations (range, 47-403 per site) on 709 unique patient admissions (range, 31-251 per site) during a 3.5-month period of continuous pulse oximetry use in children with bronchiolitis not receiving supplemental oxygen, which were compared with 579 observations (range, 57-154 per site) from the same hospitals during the baseline 4-month period (prior season) to determine whether the strategies were associated with a reduction in use. Sites conducted 148 in-person educational outreach and aggregate data feedback sessions and provided real-time 1:1 feedback 171 of 236 times (72% of the time when guideline-discordant monitoring was identified). Adjusted for age, gestational age, time since weaning from supplemental oxygen, and other characteristics, guideline-discordant continuous pulse oximetry use decreased from 53% (95% CI, 49%-57%) to 23% (95% CI, 20%-25%) (P < .001) during the intervention period. There were no adverse events attributable to reduced monitoring.
CONCLUSIONS AND RELEVANCE
In this nonrandomized clinical trial, educational outreach and audit and feedback deimplementation strategies for guideline-discordant continuous pulse oximetry use among hospitalized children with bronchiolitis who were not receiving supplemental oxygen were positively associated with clinician perceptions of feasibility, acceptability, appropriateness, and safety. Evaluating the sustainability of deimplementation beyond the intervention period is an essential next step.
TRIAL REGISTRATION
ClinicalTrials.gov Identifier: NCT04178941.
Topics: Bronchiolitis; Feedback; Female; Hospitalization; Humans; Infant; Infant, Newborn; Inservice Training; Male; Medical Audit; Oximetry; Practice Guidelines as Topic; Practice Patterns, Nurses'; Practice Patterns, Physicians'; Prospective Studies; Surveys and Questionnaires; United States
PubMed: 34473258
DOI: 10.1001/jamanetworkopen.2021.22826