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The American Journal of Emergency... Apr 2023The Roth score is an alternative strategy to estimate oxygen saturation by using a simple verbal test. We designed this clinical study to assess the validity of the Roth... (Observational Study)
Observational Study
INTRODUCTION
The Roth score is an alternative strategy to estimate oxygen saturation by using a simple verbal test. We designed this clinical study to assess the validity of the Roth score (Spanish version) as a screening test for hypoxemia. A secondary objective was to evaluate the agreement and consistency between the oxygen saturation obtained via pulse oximetry (SpO) and arterial blood gas test (SaO).
METHODS
An observational study was conducted in two hospital emergency departments. Adult patients who underwent arterial blood gas tests were included in the analysis. Pulse oximetry values were determined, and the Roth score was applied in the Spanish language. The validity of the Roth score was assessed in terms of sensitivity and specificity by creating ROC curves and by calculating the area under the curve (AUC) for SpO, SaO, and oxygen pressure in the arterial blood (PaO). Agreement between SpO and SaO values was assessed by using the intraclass correlation coefficient (ICC), and consistency between both measures was calculated by following the method of Bland and Altman.
RESULTS
The ROC curve models of the Roth score results that were obtained for SaO < 90%, ≤92%, and < 95% had AUCs of 0.574, 0.462, and 0.543, respectively, for the highest number that was obtained in the test, as well as AUCs of 0.403, 0.376, and 0.495, respectively, for the maximum time that was used. The AUCs for PaO ≤ 60, ≤70, and ≤80 mmHg were 0.534, 0.568, and 0.512, respectively, for the maximum number that was obtained in the test, as well as AUCs of 0.521, 0.515, and 0.519, respectively, for the maximum time that was spent. The ICC between SaO and SpO was 0.817 (p < 0.001); additionally, the mean difference between the two measurements was -0.55.
CONCLUSION
The Roth score performed in Spanish is not a valid test for hypoxemia screening. There is sufficient agreement and consistency between SaO and SpO measurements.
Topics: Adult; Humans; Oximetry; Hypoxia; Oxygen; Blood Gas Analysis; Sensitivity and Specificity
PubMed: 36753928
DOI: 10.1016/j.ajem.2023.01.034 -
Microsurgery Jan 2023Retrospective studies evaluating tissue oximetry in a more recent cohort have shown superiority in flap outcomes. This study compares the use of tissue oximetry in a...
BACKGROUND
Retrospective studies evaluating tissue oximetry in a more recent cohort have shown superiority in flap outcomes. This study compares the use of tissue oximetry in a historical cohort to clinical observation and handheld doppler in a more recent cohort. We hypothesize that there is no benefit to using tissue oximetry.
METHODS
A retrospective review was performed on patients who underwent abdominal-based autologous breast reconstruction by five microsurgeons at an academic institution from 2009 to 2020. Method of postoperative flap monitoring was determined then operative details and complications were analyzed.
RESULTS
1367 flaps were reviewed; 740 flaps in 460 patients were monitored with clinical observation and tissue oximetry, and 627 flaps in 391 patients were monitored with clinical observation and handheld doppler. There were no statistical differences in ischemic (p = .59) or congestive complications (p = .41), flap salvage rates when exploring for venous or arterial compromise (p = .52), or early flap loss (p = .56). Although not significant, acute flap-related return to the operating room was lower in the doppler group (4.6%) compared to the oximetry group (6.1%; p = .22). Flaps monitored with tissue oximetry had a statistical increase in length of stay (4.8 ± 1.4 days vs. 3.8 ± 1.6 days; p ≤ .001). The rates of late partial flap loss and fat necrosis were significantly higher in the oximetry group (2.6%, 19/740 vs. 0.3%, 2/740; p = .04) and (18.2%, 135/740 vs. 13.6%, 85/627; p = .02), respectively.
CONCLUSIONS
There is no statistical benefit to the use of tissue oximetry compared to handheld doppler in flap monitoring with regards to flap outcomes.
Topics: Humans; Free Tissue Flaps; Retrospective Studies; Mammaplasty; Breast; Oximetry; Postoperative Complications
PubMed: 35238069
DOI: 10.1002/micr.30873 -
Respiratory Care Dec 2016Newer pulse oximetry technology is available that uses multiple wavelengths of light and is thereby able to measure more than 2 forms of hemoglobin, including...
Newer pulse oximetry technology is available that uses multiple wavelengths of light and is thereby able to measure more than 2 forms of hemoglobin, including carboxyhemoglobin (SpCO), methemoglobin (SpMet), and total hemoglobin (SpHb). Several studies have shown relatively low bias, but poor precision, for SpCO compared with HbCO. Evaluations of SpMet have been conducted primarily in normal subjects. Clinical evaluations of SpHb suggest that it might not yet be accurate enough to make transfusion decisions. Respiratory waveform variability of the pulse oximeter plethysmogram might be useful to assess pulsus paradoxus in patients with airway obstruction; it might also be used to measure the breathing frequency. The change in pulse pressure over the respiratory cycle has been used to assess fluid responsiveness in mechanically ventilated patients, and similarly, the pulse oximetry plethysmogram waveform amplitude variability might be used to assess fluid responsiveness. However, there are limitations to this approach, and it remains to be determined how well it can be applied clinically using existing pulse oximetry technology. The pulse oximeter signal is probably useful for applications beyond S However, the current technology is not mature, and improvements are necessary. With technology improvements, the use of pulse oximetry to detect SpCO, SpMet, SpHb, pulsus paradoxus, breathing frequency, and fluid responsiveness is likely to improve in the future.
Topics: Blood Pressure; Carboxyhemoglobin; Hemoglobins; Humans; Methemoglobin; Oximetry; Plethysmography; Respiration
PubMed: 27899542
DOI: 10.4187/respcare.05208 -
PloS One 2021Retinal oximetry is a technique based on spectrophotometry where images are analyzed with software capable of calculating vessel oxygen saturation and vessel diameter....
PURPOSE
Retinal oximetry is a technique based on spectrophotometry where images are analyzed with software capable of calculating vessel oxygen saturation and vessel diameter. In this study, the effect of automation of measurements of retinal vessel oxygen saturation and vessel diameter is explored.
METHODS
Until now, operators have had to choose each vessel segment to be measured explicitly. A new, automatic version of the software automatically selects the vessels once the operator defines a measurement area. Five operators analyzed image pairs from the right eye of 23 healthy subjects with semiautomated retinal oximetry analysis software, Oxymap Analyzer (v2.5.1), and an automated version (v3.0). Inter- and intra-operator variability was investigated using the intraclass correlation coefficient (ICC) between oxygen saturation measurements of vessel segments in the same area of the retina.
RESULTS
For semiautomated saturation measurements, the inter-rater ICC was 0.80 for arterioles and venules. For automated saturation measurements, the inter-rater ICC was 0.97 for arterioles and 0.96 for venules. For semiautomated diameter measurements, the inter-rater ICC was 0.71 for arterioles and venules. For automated diameter measurements the inter-rater ICC was 0.97 for arterioles and 0.95 for venules. The inter-rater ICCs were different (p < 0.01) between the semiautomated and automated version in all instances.
CONCLUSION
Automated measurements of retinal oximetry values are more repeatable compared to measurements where vessels are selected manually.
Topics: Adult; Automation; Humans; Oximetry; Oxygen; Reproducibility of Results; Retinal Vessels; Software; Venules; Young Adult
PubMed: 34914738
DOI: 10.1371/journal.pone.0260120 -
Neonatal Network : NN Jul 2017Near-infrared spectroscopy (NIRS) is a clinical tool that provides a bedside method of noninvasively measuring continuous, "real-time" oxygen consumption and monitoring... (Review)
Review
Near-infrared spectroscopy (NIRS) is a clinical tool that provides a bedside method of noninvasively measuring continuous, "real-time" oxygen consumption and monitoring for potential ischemia of somatic tissues, particularly the brain, kidneys, and intestine in neonates. Although the concept of NIRS seems promising, its implementation into clinical practice has been inconsistent for various reasons, including difficulty in interpreting regional oxygen saturation (rSO2), the wide variation in types of NIRS monitors and probes, the cost of new equipment, different monitoring modalities, large discrepancies in both intra- and interindividual use, a lack of defined universal normative values, and little to no data on outcomes or potentially harmful interventions made based on rSO2 readings. We combine findings from previously published informational articles and studies on the use of NIRS in neonatal medicine to provide a comprehensive overview of this tool and identify potential indications for clinical use.
Topics: Brain; Education, Nursing, Continuing; Female; Humans; Infant, Newborn; Intensive Care Units, Neonatal; Male; Monitoring, Physiologic; Oximetry; Spectroscopy, Near-Infrared
PubMed: 28764821
DOI: 10.1891/0730-0832.36.4.189 -
Pediatric Critical Care Medicine : a... Jun 2023Pulse oximetry (Sp o2 ) may overestimate arterial oxygen saturation (Sa o2 ) in blood laboratory testing. This study aimed to assess Sp o2 -Sa o2 difference in relation...
OBJECTIVES
Pulse oximetry (Sp o2 ) may overestimate arterial oxygen saturation (Sa o2 ) in blood laboratory testing. This study aimed to assess Sp o2 -Sa o2 difference in relation to race (i.e., patient self-reporting as Black or White), occult hypoxemia, and length of stay (LOS) in pediatric patients with COVID-19.
DESIGN
Single-center retrospective study in pediatric COVID-19 patients. We used multivariable linear regressions to examine the association between race and oximetry measurements and between occult hypoxemia and LOS. Oximetry bias was defined using Sp o2 and Sa o2 data according to approved comparisons. Occult hypoxemia was defined as Sp o2 greater than 92% and Sa o2 less than 88%.
SETTING
Quaternary pediatric hospital.
PATIENTS
Pediatric COVID-19 patients admitted to Texas Children's Hospital between May 2020 and December 2021.
INTERVENTIONS
None.
MEASUREMENTS AND MAIN RESULTS
There were 2713 patients with complete physiological data in the analysis. Of the total, 61% were Black, and 39% were White. Oximetry bias was greater in Black compared with White patients ( p < 0.001), and this bias increased as the oxygen saturations decreased ( p < 0.001). Black and White patients had a 12% and 4% prevalence of occult hypoxemia, respectively ( p < 0.001). LOS was not associated with oximetry bias or occult hypoxemia once controlled for the level of support (intensive care, respiratory, circulatory).
CONCLUSIONS
We found an oximetry bias in the measurement of Sp o2 with respect to Sa o2 in symptomatic hospitalized pediatric patients with the diagnosis of COVID-19. Furthermore, race is related to an increased oximetry bias. However, we did not find a relationship between oximetry bias and the LOS in the hospital in this cohort of patients.
Topics: Humans; Child; Retrospective Studies; Oxygen; COVID-19; Oximetry; Hypoxia
PubMed: 36825900
DOI: 10.1097/PCC.0000000000003208 -
Journal of Biomedical Optics Oct 2020The arterial carbon dioxide (CO2) partial pressure PaCO2 is a clinically relevant variable. However, its measurement requires arterial blood sampling or bulky and...
SIGNIFICANCE
The arterial carbon dioxide (CO2) partial pressure PaCO2 is a clinically relevant variable. However, its measurement requires arterial blood sampling or bulky and expensive transcutaneous PtcCO2 meters. While the spectrophotometric determination of hemoglobin species-such as oxy-hemoglobin (O2Hb) and deoxy-hemoglobin (HHb)-allowed for the development of pulse oximetry, the measurement of CO2 blood content with minimal discomfort has not been addressed yet.
AIM
Characterizing human carbamino-hemoglobin (CO2Hb) absorption spectrum, which is missing from the literature. Providing the theoretical background that will allow for transcutaneous, noninvasive PaCO2 measurements.
APPROACH
A tonometry-based approach was used to obtain gas-equilibrated, lysed, diluted human blood. Equilibration was performed with both CO2, dinitrogen (N2), and ambient air. Spectrophotometric measurements were carried out on the 235- to 1000-nm range. A theoretical background was also derived from that of pulse oximetry.
RESULTS
The absorption spectra of both CO2Hb and HHb were extremely close and comparable with that of state-of-the-art HHb. The above-mentioned theoretical background led to an estimated relative error above 30% on the measured amount of CO2Hb in a subject's blood. Auxiliary measurements revealed that the use of ethylene diamine tetraacetic acid did not interfere with spectrophotometric measurements, whereas sodium metabisulfite did.
CONCLUSIONS
CO2Hb absorption spectrum was measured for the first time. Such spectrum being close to that of HHb, the use of a theoretical background based on pulse oximetry theory for noninvasive PaCO2 measurement seems extremely challenging.
Topics: Blood Gas Monitoring, Transcutaneous; Carbon Dioxide; Humans; Oximetry; Oxyhemoglobins; Partial Pressure
PubMed: 33098280
DOI: 10.1117/1.JBO.25.10.105001 -
Anaesthesia Jan 2017Monitors using near-infra red spectroscopy to assess cerebral oxygenation levels non-invasively in discrete areas of the brain have been used clinically for over... (Review)
Review
Monitors using near-infra red spectroscopy to assess cerebral oxygenation levels non-invasively in discrete areas of the brain have been used clinically for over 20 years. Interest has intensified recently, especially during cardiac surgery, and there are now five commercially available devices. Despite the attraction of being able to measure oxygen supply/demand in such a critical area, there has been only limited uptake of this technology in overall clinical anaesthetic practice. This narrative review aims to explore not only the rationale for using this technology but also the factors which have restricted its more widespread use.
Topics: Adult; Brain; Cardiac Surgical Procedures; Cardiopulmonary Resuscitation; Humans; Oximetry; Oxygen
PubMed: 28044331
DOI: 10.1111/anae.13740 -
Clinics in Perinatology Sep 2019Formerly, assessing oxygenation relied on recognizing cyanosis; however, this is unreliable. Also, in neonates, a pink color, suggesting absence of severe hypoxemia, is... (Review)
Review
Formerly, assessing oxygenation relied on recognizing cyanosis; however, this is unreliable. Also, in neonates, a pink color, suggesting absence of severe hypoxemia, is difficult to assess. An objective and continuous assessment of oxygenation is necessary. Currently, this is best achieved noninvasively by transcutaneous partial pressure of oxygen (PTcO) monitoring or pulse oximetry. Because both PTcO and oxygen saturation monitors (pulse oximeters) may display erroneous measurements, thorough understanding of their operating principles is required. Also, clinicians must recognize the range of values expected in healthy neonates. In this article, data on these issues are reviewed.
Topics: Humans; Infant; Monitoring, Physiologic; Oximetry; Oxygen
PubMed: 31345538
DOI: 10.1016/j.clp.2019.05.010 -
The Hastings Center Report 2015
Topics: Humans; Infant, Newborn; Infant, Premature; Mortality; Oximetry; Oxygen; Parental Consent; Positive-Pressure Respiration; Randomized Controlled Trials as Topic; Research Design; Retinopathy of Prematurity; Surface-Active Agents
PubMed: 25600377
DOI: 10.1002/hast.405