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Nigerian Journal of Clinical Practice Nov 2023The physical examination is a key part of a continuum that extends from the history of the present illness to the therapeutic outcome. An understanding of the... (Review)
Review
The physical examination is a key part of a continuum that extends from the history of the present illness to the therapeutic outcome. An understanding of the pathophysiological mechanism behind a physical sign is essential for arriving at the correct diagnosis. Early detection of deteriorating physical/vital signs and their appropriate interpretation is thus the key to achieve correct and timely management. By definition, vital signs are "the signs of life that may be monitored or measured, namely pulse rate, respiratory rate, body temperature, and blood pressure." Vital signs are the simplest, cheapest and probably the most inexpensive information gathered bedside in outpatient or hospitalized patients. The pulse oximeter was introduced in the 1980s. It is an accurate and non-invasive method for the measurement of arterial hemoglobin oxygen saturation (SaO2). Pulse oximetry-based arterial oxygen saturation can be effectively used bedside in in-hospital and ambulatory patients with diagnosed or suspected lung disease. The present pandemic of COVID-19 should be considered as a wake-up call. Articles related to arterial oxygen saturation and its importance as a vital sign in patient care were searched online especially in PubMed. Available studies were studied in full length and data was extracted. Discussion: A. Clinical Utility of Oxygen Saturation Monitoring: There are many studies reporting the clinical applicability and usefulness of pulse oximetry in the early detection of hypoxemic events during intraoperative and postoperative periods. B. Role of clinical expertise accompanied by knowledge of physiology: A diagnostic sign is useful only if it is interpreted accurately and applied appropriately while evaluating a patient. The World Health Organisation also appreciates these facts and published "The WHO Pulse Oximetry Training Manual." Understanding the physiology behind and overcoming limitations of the diagnostic sign by clinical expertise is important. While using pulse oximetry, a clinician needs to keep in mind the sigmoidal nature of the oxygen-Hb dissociation curve. Considering these benefits of SaO2 measurement, there have been several references in the past to consider oxygen saturation as the fifth vital sign. In the present pandemic oxygen saturation i.e., SpO2 (arterial oxygen saturation) measured by pulse oxymeter, has been the single most important warning and prognostic sign be it for households, offices, street vendors, hospitals or governments. Measurement of trends of SaO2 added with respiratory rate will provide clinicians with a holistic overview of respiratory functions and multidimensional conditions associated with hypoxemia.
Topics: Humans; Heart Rate; Hypoxia; Oximetry; Oxygen; Oxygen Saturation
PubMed: 38044759
DOI: 10.4103/njcp.njcp_2026_21 -
Anaesthesia Jan 2022Surgery and anaesthesia subject the brain to considerable stress in the peri-operative period. This may be caused by potentially neurotoxic anaesthetic drugs, impaired... (Review)
Review
Surgery and anaesthesia subject the brain to considerable stress in the peri-operative period. This may be caused by potentially neurotoxic anaesthetic drugs, impaired cerebral perfusion and reperfusion injury related to surgery or thromboembolic events. Patient monitoring using electroencephalogram and cerebral oximetry can assist in optimising depth of anaesthesia and assessment of cerebral metabolic activity. However, research findings have been contradictory as to whether these monitors can help ameliorate peri-operative neurocognitive complications. In this narrative review, we will discuss recent evidence in the use of electroencephalography and cerebral oximetry and the underlying scientific principles. It is important to appreciate the raw electroencephalographic changes under anaesthesia and those associated with ageing, in order to interpret depth of anaesthesia indices correctly. Cerebral oximetry is useful not only for the detection of cerebral desaturation but also to identify those patients who are particularly vulnerable to injury, for better risk stratification. An algorithm-based approach may be most effective in managing the episodes of cerebral desaturation.
Topics: Anesthesia; Brain; Cerebrovascular Circulation; Electroencephalography; Humans; Monitoring, Intraoperative; Oximetry; Perioperative Care; Postoperative Complications
PubMed: 35001382
DOI: 10.1111/anae.15616 -
The Canadian Veterinary Journal = La... Nov 2017Monitoring equipment has become reliable and affordable for use in general veterinary practice. This article provides a guide to technology, troubleshooting, and... (Review)
Review
Monitoring equipment has become reliable and affordable for use in general veterinary practice. This article provides a guide to technology, troubleshooting, and obtaining quality data using 4 non-invasive techniques that are commonly used in practice. Pulse oximetry estimates oxygen saturation of hemoglobin in arterial blood, capnography measures the carbon dioxide content of inspired and expired gas, and either Doppler shift detection or oscillometry can be used to measure blood pressure. These useful non-invasive techniques all rely on adequate perfusion of the tissues for optimum function.
Topics: Animals; Blood Pressure Determination; Capnography; Mammals; Monitoring, Intraoperative; Monitoring, Physiologic; Oximetry
PubMed: 29089659
DOI: No ID Found -
Anaesthesia Dec 2007Global Oximetry (GO) is an initiative launched recently in Uganda, India, the Philippines and Vietnam. The overall aims are to promote oximetry utilisation and reduce... (Review)
Review
Global Oximetry (GO) is an initiative launched recently in Uganda, India, the Philippines and Vietnam. The overall aims are to promote oximetry utilisation and reduce oximetry costs in lower income countries. Research objectives include studying the feasibility of cost reduction; overcoming non-cost barriers to global oximetry including issues of prioritization; education and guidelines; servicing and access to parts. Promotional objectives include creating new policy, influencing oximetry design, and setting new global standards for safer monitoring.
Topics: Costs and Cost Analysis; Developing Countries; Humans; International Cooperation; Monitoring, Intraoperative; Oximetry
PubMed: 17937720
DOI: 10.1111/j.1365-2044.2007.05305.x -
Journal of Ayub Medical College,... 2017Studies have shown maintaining good cerebral perfusion during Cardiac Surgeries is very important in terms of patient outcomes and reducing the hospital stay, which may... (Review)
Review
BACKGROUND
Studies have shown maintaining good cerebral perfusion during Cardiac Surgeries is very important in terms of patient outcomes and reducing the hospital stay, which may have its financial and clinical implications. The aim of this review study was to determine the effectiveness of Cerebral Oximetry (Transcranial Near-Infrared Spectroscopy-NIRS to monitor cerebral oxygenation) for Cardiac Surgery and to propose a possible concluding remark about its potential applications, overall clinical value and whether to keep using it or not.
METHODS
Medical database and archives including Pubmed, Embase, index medicus, index copernicus and Medline were searched. Different papers were looked upon and each had an argument, scientific evidence and background. Fifteen research papers were selected and brought under review after carefully consideration.
RESULTS
The papers were carefully reviewed and findings were given in favour of not using NIRS technique for Cerebral Oximetry in Cardiac Surgery.
CONCLUSIONS
This can rightly be concluded from this study that NIRS Cerebral Oximetry does not carry the clinical significance and relevance which was previously thought. The subject under observation needs further studies and research to evaluate the effectiveness of the Cerebral Oximetry Use for Cardiac Surgery.
Topics: Cardiac Surgical Procedures; Cerebrovascular Circulation; Heart Diseases; Humans; Monitoring, Physiologic; Oximetry; Spectroscopy, Near-Infrared
PubMed: 28718260
DOI: No ID Found -
Respiratory Care Apr 2003The pulse oximeter has become a vital instrument in the care of infants and children with cardiopulmonary disease. Recent advances in pulse oximetry technology have... (Review)
Review
The pulse oximeter has become a vital instrument in the care of infants and children with cardiopulmonary disease. Recent advances in pulse oximetry technology have improved some aspects of pulse oximeter performance. However, the reliability, accuracy, and clinical utility of pulse oximetry remain problematic in some types of patients under certain conditions. Improved signal processing technology has substantially improved the ability of certain oximeters to work reliably under conditions of poor perfusion and motion artifact. There is a growing body of evidence describing the effect of pulse oximeter utilization on processes and outcomes. This article describes the principles, limitations, current state of oximetry technology, and the impact of oximetry data and alarms on diagnosis and clinical decision-making.
Topics: Artifacts; Child; Equipment Failure; Humans; Infant; Infant, Newborn; Oximetry; Pulmonary Heart Disease; ROC Curve; Reproducibility of Results; Signal Processing, Computer-Assisted; Treatment Outcome
PubMed: 12667266
DOI: No ID Found -
Journal of Biomedical Optics Aug 2022Measurement and imaging of hemoglobin oxygenation are used extensively in the detection and diagnosis of disease; however, the applied instruments vary widely in their... (Review)
Review
SIGNIFICANCE
Measurement and imaging of hemoglobin oxygenation are used extensively in the detection and diagnosis of disease; however, the applied instruments vary widely in their depth of imaging, spatiotemporal resolution, sensitivity, accuracy, complexity, physical size, and cost. The wide variation in available instrumentation can make it challenging for end users to select the appropriate tools for their application and to understand the relative limitations of different methods.
AIM
We aim to provide a systematic overview of the field of hemoglobin imaging and sensing.
APPROACH
We reviewed the sensing and imaging methods used to analyze hemoglobin oxygenation, including pulse oximetry, spectral reflectance imaging, diffuse optical imaging, spectroscopic optical coherence tomography, photoacoustic imaging, and diffuse correlation spectroscopy.
RESULTS
We compared and contrasted the ability of different methods to determine hemoglobin biomarkers such as oxygenation while considering factors that influence their practical application.
CONCLUSIONS
We highlight key limitations in the current state-of-the-art and make suggestions for routes to advance the clinical use and interpretation of hemoglobin oxygenation information.
Topics: Hemoglobins; Oximetry; Spectrum Analysis; Tomography, Optical Coherence
PubMed: 35922891
DOI: 10.1117/1.JBO.27.8.080901 -
Academic Radiology Feb 2014Electron paramagnetic resonance (EPR) spectroscopy has been well established as a viable technique for measurement of free radicals and oxygen in biological systems,... (Review)
Review
Electron paramagnetic resonance (EPR) spectroscopy has been well established as a viable technique for measurement of free radicals and oxygen in biological systems, from in vitro cellular systems to in vivo small animal models of disease. However, the use of EPR in human subjects in the clinical setting, although attractive for a variety of important applications such as oxygen measurement, is challenged with several factors including the need for instrumentation customized for human subjects, probe, and regulatory constraints. This article describes the rationale and development of the first clinical EPR systems for two important clinical applications, namely, measurement of tissue oxygen (oximetry) and radiation dose (dosimetry) in humans. The clinical spectrometers operate at 1.2 GHz frequency and use surface-loop resonators capable of providing topical measurements up to 1 cm depth in tissues. Tissue pO2 measurements can be carried out noninvasively and repeatedly after placement of an oxygen-sensitive paramagnetic material (currently India ink) at the site of interest. Our EPR dosimetry system is capable of measuring radiation-induced free radicals in the tooth of irradiated human subjects to determine the exposure dose. These developments offer potential opportunities for clinical dosimetry and oximetry, which include guiding therapy for individual patients with tumors or vascular disease by monitoring of tissue oxygenation. Further work is in progress to translate this unique technology to routine clinical practice.
Topics: Electron Spin Resonance Spectroscopy; Equipment Design; Equipment Failure Analysis; Humans; Oximetry; Radiometry
PubMed: 24439333
DOI: 10.1016/j.acra.2013.10.011 -
Korean Journal of Anesthesiology Oct 2022Cerebral oximetry using near-infrared spectroscopy (NIRS) is used for monitoring cerebral oxygen saturation during cardiac surgery and is correlated with clinical... (Observational Study)
Observational Study
BACKGROUND
Cerebral oximetry using near-infrared spectroscopy (NIRS) is used for monitoring cerebral oxygen saturation during cardiac surgery and is correlated with clinical outcomes. Our goal was to explore cerebral and somatic NIRS in liver resections as a predictor of post-operative complications.
METHODS
Prospective observational and non-interventional study from a tertiary care university hospital including adult patients undergoing liver resection monitored using NIRS at four sites before and during surgery. Those sites were: frontotemporal left and right zones, right thigh, and right arm. Anesthesiologists and surgeons were blinded to oximetry values. Correlations were assessed between baseline oximetry values and cerebro-somatic desaturation load (threshold of 80% from baseline) values with peri-operative events and complications.
RESULTS
Ninety patients were distributed equally among gender with a mean age of 59.7 ± 13.1 years. Lower baseline cerebral and/or somatic values were associated with increased risk of delirium, respiratory failure, surgical and renal complications, blood transfusions, and length of stay in the intensive care unit and in the hospital (P < 0.05). The severity of somatic desaturation below 80% was the only parameter associated with blood losses (P = 0.030) and length of hospital stay (P = 0.047).
CONCLUSIONS
Cerebral and somatic desaturation does occur in liver resection and can be used simultaneously during liver surgery. Both baseline cerebral and somatic NIRS values are correlated with complications and outcomes. However, thigh desaturation appears more sensitive than cerebral NIRS values in predicting some of these complications.
Topics: Adult; Aged; Cardiac Surgical Procedures; Cerebrovascular Circulation; Humans; Liver; Middle Aged; Oximetry; Spectroscopy, Near-Infrared
PubMed: 35045594
DOI: 10.4097/kja.21414 -
Acta Ophthalmologica Aug 2013
Topics: Humans; Oximetry; Reproducibility of Results; Retina; Retinal Diseases
PubMed: 23844858
DOI: 10.1111/aos.12239