Measurement Of Oxygen Saturation Research Articles

Effect of Skin Pigmentation and Finger Choice on Accuracy of Oxygen Saturation Measurement in an IoT-Based Pulse Oximeter

Effect of Skin Pigmentation and Finger Choice on Accuracy of Oxygen Saturation Measurement in an IoT-Based Pulse Oximeter

Effects of traditional and dry bed baths on patients admitted in intensive units: A randomized crossover clinical trial.

The bed bath is an important part of nursing care. There are few studies evaluating the effects of traditional and dry bed baths on patients. This study was performed with the aim of investigating the effect of traditional and dry bed baths given to intensive care unit patients on the patients' hemodynamic parameters, the duration of the bathing procedure and the cost of consumable items. This was a randomized crossover clinical trial and a prospective study. The study was conducted in a General Surgery Intensive Care Unit with 22 intensive care patients aged 18 and over, who had a nursing diagnosis of bathing personal care deficiency. Each patient was given two types of bed baths at an interval of 24 h: a traditional bed bath and a dry bed bath performed with single-use tissues. Immediately before each bath, in the 5th, 10th and 15th minute of bathing, immediately after bathing and 30 min after bathing, body temperature, heart rate, blood pressure, breathing rate and peripheral oxygen saturation measurement changes over time were compared within the group using the Friedman test. The Wilcoxon signed ranks test was used to compare the variables of bathing duration and bathing consumable item costs between the bathing procedures. It was found that at the completion of traditional and dry bed bathing, the participants' body temperature, blood pressure, heart rate and breathing rate parameters were statistically significantly lower than before bathing, whereas peripheral oxygen saturation values showed a significant increase (p < 0.05). It was found that the dry bed bath took a statistically significantly shorter time than the traditional bed bath and that the cost of consumable bathing materials was less (p < 0.05). It was concluded that traditional and dry bed baths given to intensive care patients affected their hemodynamic parameters and that the dry bed bath was superior to the traditional bed bath in that it took less time and that it cost less.

Physiologic Determinants of Near-Infrared Spectroscopy-Derived Cerebral and Tissue Oxygen Saturation Measurements in Critically Ill Patients.

Near-infrared spectroscopy (NIRS) is a potentially valuable modality to monitor the adequacy of oxygen delivery to the brain and other tissues in critically ill patients, but little is known about the physiologic determinants of NIRS-derived tissue oxygen saturations. The purpose of this study was to assess the contribution of routinely measured physiologic parameters to tissue oxygen saturation measured by NIRS. An observational sub-study of patients enrolled in the Role of Active Deresuscitation After Resuscitation-2 (RADAR-2) randomized feasibility trial. Two ICUs in the United Kingdom. Patients were recruited for the RADAR-2 study, which compared a conservative approach to fluid therapy and deresuscitation with usual care. Those included in this sub-study underwent continuous NIRS monitoring of cerebral oxygen saturations (SctO2) and quadriceps muscle tissue saturations (SmtO2). Synchronized and continuous mean arterial pressure (MAP), heart rate (HR), and pulse oximetry (oxygen saturation, Spo2) measurements were recorded alongside NIRS data. Arterial Paco2, Pao2, and hemoglobin concentration were recorded 12 hourly. Linear mixed effect models were used to investigate the association between these physiologic variables and cerebral and muscle tissue oxygen saturations. Sixty-six patients were included in the analysis. Linear mixed models demonstrated that Paco2, Spo2, MAP, and HR were weakly associated with SctO2 but only explained 7.1% of the total variation. Spo2 and MAP were associated with SmtO2, but together only explained 0.8% of its total variation. The remaining variability was predominantly accounted for by between-subject differences. Our findings demonstrated that only a small proportion of variability in NIRS-derived cerebral and tissue oximetry measurements could be explained by routinely measured physiologic variables. We conclude that for NIRS to be a useful monitoring modality in critical care, considerable further research is required to understand physiologic determinants and prognostic significance.

Transcutaneous Discrimination of Fetal Heart Rate from Maternal Heart Rate: A Fetal Oximetry Proof-of-Concept.

Intrapartum care uses electronic fetal heart rate monitoring (EFHRM) for over 50years to indirectly assess fetal oxygenation. However, this approach has been associated with an increase in cesarean delivery rates and limited improvements in neonatal hypoxic outcome. To address these shortcomings, a novel transabdominal fetal pulse oximeter (TFO) is being developed to provide an objective measurement of fetal oxygenation. Previous studies have evaluated the performance of TFO on pregnant ewe. Building on the animal model, this study aims to determine whether TFO can successfully capture human fetal heart rate (FHR) signals during non-stress testing (NST) as a proof-of-concept. Eight ongoing pregnancies meeting specific inclusion criteria (18-40years old, singleton, and at least 36weeks' gestation) were enrolled with consent. Each study session was 15 to 20min long. Reference maternal heart rate (MHR) and FHR were obtained using finger pulse oximetry and cardiotocography for subsequent comparison. The overall root-mean-square error was 9.7BPM for FHR and 4.4 for MHR, while the overall mean-absolute error was 7.6BPM for FHR and 1.8 for MHR. Bland-Altman analysis displayed a mean bias ± standard deviation between TFO and reference of -3.9 ± 8.9BPM, with limits of agreement ranging from -21.4 to 13.6 BPM. Both maternal and fetal heart rate measurements obtained from TFO exhibited a p-value < 0.001, showing significant correlation with the reference. This proof-of-concept study successfully demonstrates that TFO can accurately differentiate maternal and fetal heart signals in human subjects. This achievement marks the initial step towards enabling fetal oxygen saturation measurement in humans using TFO.

Hospital Environmental Factors That Influence Peripheral Oxygen Saturation Measurements: A Cross-Sectional Study.

Pulse oximetry is a non-invasive, cost-effective, and generally reliable instrument measuring pulse rate and peripheral oxygen saturation (SpO2). However, these measurements can be affected by the patient's internal or external factors, including the type of pulse oximeter device (POD). (1) This study's objective was to identify potential environmental factors that may impact the measurements taken by three PODs. (2) Methods: A descriptive-analytical cross-sectional study was designed. The patients' SpO2 levels were measured using a standard monitor and two PODs owned by the professionals. The measurements were taken on the patients' fingers. Concurrently, we evaluated the surrounding environmental conditions, encompassing temperature, humidity, illuminance, and noise. (3) Results: This study involved 288 adult participants in the sample. For each 20-decibel increment in noise, there was a reduction in SpO2 by an average of 1%, whereas for every additional degree of ambient temperature, SpO2 decreased by an average of 2% (4) Conclusions: Significant correlations between SpO2 and age, as well as with noise and ambient temperature, were observed. No significant differences between oxygen saturation and lighting or humidity were observed. This study was prospectively registered with the Clinical Research Ethics Committee of Gran Canaria at the Dr. Negrín University Hospital, with protocol code 2019-247-1, and approved on 24 May 2019.

P070 Rheum to Empower: Home Spirometry and Oximetry Monitoring in Connective Tissue Related Interstitial Lung Disease

Abstract Background/Aims Interstitial lung disease (ILD) is a common cause of morbidity and mortality in connective tissue diseases (CTDs). Distinct challenges arise for individuals with impairments from rheumatic diseases, especially when coupled with respiratory symptoms. While home spirometry monitoring is valuable for patients with idiopathic pulmonary fibrosis (IPF), its applicability in CTD related ILD (CTD-ILD) is relatively unexplored. This study examines the feasibility and acceptability of home spirometry and oximetry monitoring in CTD-ILD patients compared with those with IPF. Methods Patients with CTD-ILD and IPF were recruited prospectively in a tertiary hospital. A portable handheld spirometer (MIR Spirobank Smart) and a Nonin finger oximeter linked to a smartphone app were provided, and patients were educated on its use. Spirometry and oximetry results were collated. At six months, a survey was conducted to assess patients’ perception of home monitoring. Results Fourty-one patients with CTD-ILD and 51 with IPF were recruited. The median ages were 66 and 71 years respectively (Table 1). 2946 FVC and 2787 oximetry readings were captured in the CTD-ILD cohort compared with 4984 FVC and 4778 oximetry readings in the IPF cohort. Among the 41 patients, 12 experienced Raynaud’s phenomenon. Only 7.32% (3/41) of CTD-ILD patients required an ear oximeter due to inaccurate oxygen saturation measurement caused by Raynaud’s phenomenon. Among the CTD-ILD cohort, 16.67% (6/36) experienced difficulty using the devices due to hand problems, while none of the IPF cohort encountered such issues. In the survey, patients reported barriers to long-term remote monitoring usage included forgetting to use, coughing or breathlessness. Less than one-third of patients indicated that spirometry and oximetry results contributed to health anxiety. A majority of patients found home monitoring useful and insightful, and would recommend this to others. Conclusion Our findings suggest the practicality of remotely monitoring FVC and oximetry in CTD-ILD patients, even with challenges like Raynaud’s phenomenon and impaired hand function. This not only underscores feasibility but also empowers patients through continuous monitoring despite physical limitations. Incorporating remote monitoring into standard care should be regarded as an essential approach for this understudied population, enhancing both clinical management and patient empowerment. Disclosure W. Ng: Grants/research support; StAR MD Scholarship, ISR Rheumatology Patient Initiative Fund. D. Howard: None. L. Durcan: None. K. Hurley: Grants/research support; Health Research Board, Ireland, Emerging Clinical Scientist Award (ECSA-2020-011).

Performance of a commercial smart watch compared to polysomnography reference for overnight continuous oximetry measurement and sleep apnea evaluation.

To evaluate the accuracy and precision of continuous overnight oxygen saturation (SpO2) measurement by a commercial wrist device (WD) incorporating high-grade sensors, and investigate WD estimation of sleep-disordered breathing by quantifying overnight oxygen desaturation index (ODI) compared to polysomnography (PSG) ODI and apnea-hypopnea index (AHI) with and without sleep questionnaire data, to assess WD ability to detect obstructive sleep apnea (OSA) and determine its severity. Participants completed sleep questionnaires, had a WD (Samsung Galaxy Watch 4) placed on their wrist, and underwent attending, in-lab overnight PSG (Nihon Kohden) with pulse oximetry probe secured either to a finger or ear lobe. PSG data was scored by a single experienced registered PSG technologist. Statistical analysis included demographic characteristics, continuous SpO2 measurement WD vs PSG root mean square error (RMSE) with Bland Altman plot and linear regression associations. Predictive models for PSG ODI and AHI severity were built using logistic regression with probability cutoffs determined via receiver operating curve (ROC) characteristics. The 51 participants analyzed had median age of 49 (range 22-78) years, 66.7% were male, with median body mass index (BMI) 28.1 (range 20.1, 47.3) kg/m2 with race/ethnicity distribution of 49.0% Caucasian, 25.5% Hispanic, 9.8% African-American, 9.8% Asian, and 5.9% Middle Eastern. WD vs PSG continuous SpO2 measurement in percentage points demonstrated bias of 0.91 (CI95 0.38, 1.45), standard deviation 2.37 (CI95 2.36, 2.38), and RMSE 2.54 (CI95 2.34, 2.73). WD area under the curve (AUC) ROC characteristics for predicting PSG were 0.882 ODI>15/h, 0.894 AHI>30/h, 0.800 AHI>15/h, and 0.803 AHI>5/h. WD plus select sleep questionnaire AUCs for predicting PSG were 0.943 AHI>30/h, 0.868 AHI>15/h, and 0.863 AHI>5/h. The WD conducted reliable overnight continuous SpO2 monitoring with RMSE <3% vs PSG. Predictive models of PSG AHI based on WD measurements alone, or plus sleep questionnaires, demonstrated excellent to outstanding discrimination for OSA identification and severity. Longitudinal WD use should be evaluated promptly based on WD potential to improve accessibility and accuracy of OSA testing, as well as support treatment follow-up.

Validation of Polar ElixirTM Pulse Oximeter against Arterial Blood Gases during Stepwise Steady State Inspired Hypoxia.

The purpose of this study was to evaluate the accuracy of peripheral oxygen saturation (SpO2) measurements from Polar ElixirTM pulse oximetry technology compared to arterial oxygen saturation (SaO2) measurements during acute stepwise steady state inspired hypoxia at rest. A post hoc objective was to determine if SpO2 measurements could be improved by recalibrating the Polar ElixirTM algorithm with SaO2 values from a random subset of participants. The International Organization for Standardization (ISO) protocol (ISO 80601-2-61:2017) for evaluating the SpO2 accuracy of pulse oximeter equipment was followed whereby five plateaus of SaO2 between 70-100% were achieved using stepwise reductions in inspired O2 during supine rest. Blood samples drawn through a radial arterial catheter from 25 participants were first used to compare SaO2 to SpO2 measurements from Polar ElixirTM. Then the Polar ElixirTM algorithm was recalibrated using SaO2 data from 13 random participants and SpO2 estimates were recalculated for the other 12 participants. For SaO2 values between 70-100%, root mean square error (RMSE), intraclass correlations (ICC), Pearson correlations, and Bland-Altman plots were used to assess the accuracy, agreement, and strength of relationship between SaO2 values and SpO2 values from Polar ElixirTM. The initial RMSE for Polar ElixirTM was 4.13%. After recalibrating the algorithm, the RMSE was improved to 2.67%. The ICC revealed excellent levels of agreement between SaO2 and Polar ElixirTM SpO2 values both before (ICC(3,1) = 0.837, df = 574, p < 0.001) and after (ICC(3,1) = 0.942, df = 287, p < 0.001) recalibration. Relative to ISO standards, Polar ElixirTM yielded accurate SpO2 measurements during stepwise inspired hypoxia at rest when compared to SaO2 values, which were improved by recalibrating the algorithm using a subset of the SaO2 data.

Prevalence of Aortic Root Pathologies in Platypnea-Orthodeoxia Syndrome Secondary to Intra-Cardiac Shunts.

Atrial septal defects can allow right to left shunting of venous blood which presents clinically as platypnea-orthodeoxia syndrome. It is believed that concomitant presence of aortic root pathologies increases the likelihood of shunting. The study included a review of 510 articles listed in PubMed of patients with platypnea-orthodeoxia syndrome. Case reports of patients with extra-cardiac etiologies of platypnea-orthodeoxia were excluded. We reviewed 191 case reports, and 98 cases (51.3%) had evidence of concomitant aortic root pathology. Furthermore, of the remaining 93 case reports, 69 ones excluded any mention of the nature of the aortic root altogether, further suggesting that this is an underreported number. There is a high prevalence of aortic root pathologies in patients with platypnea-orthodeoxia syndrome secondary to intra-cardiac shunts. In patients with unexplained hypoxemia and incidental finding of aortic root pathology, it may be worthwhile to obtain postural oxygen saturation measurements to exclude intra-cardiac shunts as the potential cause.

Validation of a Novel Noninvasive Technology to Estimate Blood Oxygen Saturation Using Green Light: Observational Study

Background Pulse oximeters work within the red-infrared wavelengths. Therefore, these oximeters produce erratic results in dark-skinned subjects and in subjects with cold extremities. Pulse oximetry is routinely performed in patients with fever; however, an elevation in body temperature decreases the affinity of hemoglobin for oxygen, causing a drop in oxygen saturation or oxyhemoglobin concentrations. Objective We aimed to determine whether our new investigational device, the Shani device or SH1 (US Patent 11191460), detects a drop in oxygen saturation or a decrease in oxyhemoglobin concentrations. Methods An observational study (phase 1) was performed in two separate groups to validate measurements of hemoglobin and oxygen concentrations, including 39 participants recruited among current university students and staff aged 20-40 years. All volunteers completed baseline readings using the SH1 device and the commercially available Food and Drug Administration–approved pulse oximeter Masimo. SH1 uses two light-emitting diodes in which the emitted wavelengths match with absorption peaks of oxyhemoglobin (hemoglobin combined with oxygen) and deoxyhemoglobin (hemoglobin without oxygen or reduced hemoglobin). Total hemoglobin was calculated as the sum of oxyhemoglobin and deoxyhemoglobin. Subsequently, 16 subjects completed the “heat jacket study” and the others completed the “blood donation study.” Masimo was consistently used on the finger for comparison. The melanin level was accounted for using the von Luschan skin color scale (VLS) and a specifically designed algorithm. We here focus on the results of the heat jacket study, in which the subject wore a double-layered heated jacket and pair of trousers including a network of polythene tubules along with an inlet and outlet. Warm water was circulated to increase the body temperature by 0.5-0.8 °C above the baseline body temperature. We expected a slight drop in oxyhemoglobin concentrations in the heating phase at the tissue level. Results The mean age of the participants was 24.1 (SD 0.8) years. The skin tone varied from 12 to 36 on the VLS, representing a uniform distribution with one-third of the participants having fair skin, brown skin, and dark skin, respectively. Using a specific algorithm and software, the reflection ratio for oxyhemoglobin was displayed on the screen of the device along with direct hemoglobin values. The SH1 device picked up more minor changes in oxyhemoglobin levels after a change in body temperature compared to the pulse oximeter, with a maximum drop in oxyhemoglobin concentration detected of 6.5% and 2.54%, respectively. Conclusions Our new investigational device SH1 measures oxygen saturation at the tissue level by reflectance spectroscopy using green wavelengths. This device fared well regardless of skin color. This device can thus eliminate racial disparity in these key biomarker assessments. Moreover, since the light is shone on the wrist, SH1 can be readily miniaturized into a wearable device.

The effectiveness of community health worker training, equipping, and deployment in reducing COVID-19 infections and deaths in rural Western Kenya: A comparison of two counties.

COVID-19 and other pandemics remain significant threats to population health, particularly in rural settings where health systems are disproportionately weak. There is a lack of evidence on whether trained, equipped, and deployed community health workers (CHWs) can lead to significant reductions in COVID-19 infections and deaths. Our objective was to measure the effectiveness of deploying trained and equipped CHWs in reducing COVID-19 infections and deaths by comparing outcomes in two counties in rural Western Kenya, a setting with limited critical care capacity and limited access to COVID-19 vaccines and oral COVID-19 antivirals. In Siaya, trained CHWs equipped with thermometers, pulse oximeters, and KN95 masks, visited households to convey health information about COVID-19 prevention. They screened, isolated, and referred COVID-19 cases to facilities with oxygen capacity. They measured and digitally recorded vital signs at the household level. In Kisii county, the standard Kenya national COVID-19 protocol was implemented. We performed a comparative analysis of differences in CHW skills, activity, and COVID-19 infections and deaths using district health information system (DHIS2) data. Trained Siaya CHWs were more skilled in using pulse oximeters and digitally reporting vital signs at the household level. The mean number of oxygen saturation measurements conducted in Siaya was 24.19 per COVID-19 infection; and the mean number of temperature measurements per COVID-19 infection was 17.08. Siaya CHWs conducted significantly more household visits than Kisii CHWs (the mean monthly CHW household visits in Siaya was 146,648.5, standard deviation 11,066.5 versus 42,644.5 in Kisii, standard deviation 899.5, p value = 0.01). Deploying trained and equipped CHWs in rural Western Kenya was associated with lower risk ratios for COVID-19 infections and deaths: 0.54, 95% CI [0.48-0.61] and 0.29, CI [0.13-0.65], respectively, consistent with a beneficial effect.

Discrepancy between arterial oxygen saturation and pulse oximetry measurement in a Chinese pediatric patient cohort

BackgroundIncreasing evidence suggest a racial bias in pulse oximetry measurement, but this was under investigated in Asian pediatric populations. MethodsVia the Pediatric Intensive Care database, this retrospective study included pediatric patient records of arterial oxygen saturation (SaO2) and oxygen saturation on pulse oximetry (SpO2) measured within 10 min. Discrepancy was examined, and potential predictors of occult hypoxemia (defined as SaO2 <88% with the paired SpO2 ≥92%) as well as its association with outcomes were explored by logistic regression. ResultsA total of 390 patients were included with 454 pairs of SaO2-SpO2 readings. The study population consisted of Han Chinese (99.0%) and 43.6% were female. Occult hypoxemia was observed in 20.0% of the patients, with a mean SaO2 of 71.4 ± 15.8%. Potential predictors of occult hypoxemia included female, being first admitted to cardiac ICU, congenital heart disease, increased heart rate, while patients with prior surgery records were less likely to experience occult hypoxemia. Patients with occult hypoxemia had numerically higher in-ICU mortality (16.7% versus 10.9%) and in-hospital mortality (17.9% versus 10.9%), but the associations were not statistically significant. ConclusionsThere was a substantial proportion of hypoxemia that was not detected by pulse oximetry in the Chinese pediatric patients, which might be predicted by several characteristics and seemed to associate with mortality.

Identification of recreational cycling training dose as an effective physical therapy to elicit changes into active lifestyle

This study aims to determine the relationship of living habits during the new normal period with (1) body composition and (2) blood oxygen levels after cycling while wearing a mask. This research is a multicenter study between Indonesia and Malaysia, with the data presented here being specifically from the DI Yogyakarta region in Indonesia, involving an analytical observational study using a cross-sectional approach. The study included 71 research subjects. The instruments used to collect data were fitness behavior during the pandemic (exercise frequency and duration), anthropometric and oxygen saturation measurement after cycling during pandemic. Body composition was determined using the BMI formula, involving height and weight. Oxygen saturation during cycling was measured using the Pulse Oximeter FOX-1(N) by Elitech Technovision. The largest percentage of cycling is twice a week (42.25%), followed by three, one, fifth and fourth times a week. The majority of participants cycled for 120 minutes (35.21%), followed by durations of 180 minutes, 60 minutes, 30 minutes, and so on. Oxygen saturation data shows that most subjects have oxygen saturation of 98% (47.8% of respondents), none of them have 100%, but 97% saturation, 96% occupying the second and third distributions. From the primary data obtained in Indonesia, only oxygen saturation and cycling duration showed a highly significant relationship (p = 0.009), while other variables, such as BMI and cycling frequency, did not exhibit a significant correlation. It can be concluded that a significant relationship exists between exercise duration, specifically cycling, and oxygen saturation in Indonesian subjects.

Tissue mimicking materials and finger phantom design for pulse oximetry.

Pulse oximetry represents a ubiquitous clinical application of optics in modern medicine. Recent studies have raised concerns regarding the potential impact of confounders, such as variable skin pigmentation and perfusion, on blood oxygen saturation measurement accuracy in pulse oximeters. Tissue-mimicking phantom testing offers a low-cost, well-controlled solution for characterizing device performance and studying potential error sources, which may thus reduce the need for costly in vivo trials. The purpose of this study was to develop realistic phantom-based test methods for pulse oximetry. Material optical and mechanical properties were reviewed, selected, and tuned for optimal biological relevance, e.g., oxygenated tissue absorption and scattering, strength, elasticity, hardness, and other parameters representing the human finger's geometry and composition, such as blood vessel size and distribution, and perfusion. Relevant anatomical and physiological properties are summarized and implemented toward the creation of a preliminary finger phantom. To create a preliminary finger phantom, we synthesized a high-compliance silicone matrix with scatterers for embedding flexible tubing and investigated the addition of these scatterers to novel 3D printing resins for optical property control without altering mechanical stability, streamlining the production of phantoms with biologically relevant characteristics. Phantom utility was demonstrated by applying dynamic, pressure waveforms to produce tube volume change and resultant photoplethysmography (PPG) signals. 3D printed phantoms achieved more biologically relevant conditions compared to molded phantoms. These preliminary results indicate that the phantoms show strong potential to be developed into tools for evaluating pulse oximetry performance. Gaps, recommendations, and strategies are presented for continued phantom development.

Electronic health record data is unable to effectively characterize measurement error from pulse oximetry: a simulation study.

Large data sets from electronic health records (EHR) have been used in journal articles to demonstrate race-based imprecision in pulse oximetry (SpO2) measurements. These articles do not appear to recognize the impact of the variability of the SpO2 values with respect to time ("deviation time"). This manuscript seeks to demonstrate that due to this variability, EHR data should not be used to quantify SpO2 error.Using the MIMIC-IV Waveform dataset, SpO2 values are sampled from 198 patients admitted to an intensive care unit and used as reference samples. The error derived from the EHR data is simulated using a set of deviation times. The laboratory oxygen saturation measurements are also simulated such that the performance of three simulated pulse oximeter devices will produce an average root mean squared (ARMS) error of 2%. An analysis is then undertaken to reproduce a medical device submission to a regulatory body by quantifying the mean error, the standard deviation of the error, and the ARMS error. Bland-Altman plots were also generated with their Limits of Agreements. Each analysis was repeated to evaluate whether the measurement errors were affected by increasing the deviation time.All error values increased linearly with respect to the logarithm of the time deviation. At 10min, the ARMS error increased from a baseline of 2% to over 4%.EHR data cannot be reliably used to quantify SpO2 error. Caution should be used in interpreting prior manuscripts that rely on EHR data.

Laryngeal Mask Airway Versus Endotracheal Intubation during Lacrimal Duct Stenosis Surgery in Children-A Retrospective Analysis.

Background: The use of laryngeal masks in the surgical treatment of infantile lacrimal duct stenosis is controversial due to the potential risk of aspiration. Aims: This study investigates airway procedures in children aged <6 years for surgery of lacrimal duct stenosis in a tertiary care university hospital. Methods: After institutional approval, airway procedures, duration of anesthesiological measures, and airway-related complications were retrospectively analyzed. Patients were divided into two groups according to the airway procedures used (endotracheal tube [ET] vs. laryngeal mask [LMA] airway). Associations were calculated using the Chi-square test or Mann-Whitney U-test. Results: Clinical data of 84 patients (ET n = 36 [42.9%] vs. LMA n = 48 [57.1%]) were analyzed. There were no significant differences in surgical treatment, age distribution, and pre-existing conditions between the groups. None of the patients showed evidence of tracheal aspiration or changes in measured oxygen saturation. LMA airway shortened time for anesthesia induction (p = 0.006) and time for recovery/emergence period (p = 0.03). In contrast, the time to discharge from the recovery room was significantly prolonged using LMA (p = 0.001). A total of 7 adverse events were recorded. Five of these were directly or indirectly related to ET (laryngo-/bronchospasm; muscle relaxant residual). Conclusions: LMA airway for infantile lacrimal duct stenosis seems to be a safe procedure and should be used in appropriate pediatric patients due to its lower invasiveness, low complication rate, and time savings.

Continuous oxygen saturation and risk of retinopathy of prematurity in a Japanese cohort

Background/aimsWe assessed the associations between retinopathy of prematurity (ROP) and continuous measurements of oxygen saturation (SpO2), and developed a risk prediction model for severe ROP using birth data and SpO2...

A Self-Calibrated Single Wavelength Biosensor for Measuring Oxygen Saturation.

Traditional methods for measuring blood oxygen use multiple wavelengths, which produce an intrinsic error due to ratiometric measurements. These methods assume that the absorption changes with the wavelength, but in fact the scattering changes as well and cannot be neglected. We found that if one measures in a specific angle around a cylindrical tissue, called the iso-pathlength (IPL) point, the reemitted light intensity is unaffected by the tissue's scattering. Therefore, the absorption can be isolated from the scattering, which allows the extraction of the subject's oxygen saturation. In this work, we designed an optical biosensor for reading the light intensity reemitted from the tissue, using a single light source and multiple photodetectors (PDs), with one of them in the IPL point's location. Using this bio-device, we developed a methodology to extract the arterial oxygen saturation using a single wavelength light source. We proved this method is not dependent on the light source and is applicable to different measurement locations on the body, with an error of 0.5%. Moreover, we tested thirty-eight males and females with the biosensor under normal conditions. Finally, we show the results of measuring subjects in a hypoxic chamber that simulates extreme conditions with low oxygen.

A retrospective cohort study on early antibiotic use in vaccinated and unvaccinated COVID-19 patients.

The bacteriophage behavior of SARS-CoV-2 during the acute and post-COVID-19 phases appears to be an important factor in the development of the disease. The early use of antibiotics seems to be crucial to inhibit disease progression-to prevent viral replication in the gut microbiome, and control toxicological production from the human microbiome. To study the impact of specific antibiotics on recovery from COVID-19 and long COVID (LC) taking into account: vaccination status, comorbidities, SARS-CoV-2 wave, time of initiation of antibiotic therapy and concomitant use of corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs). A total of 211 COVID-19 patients were included in the study: of which 59 were vaccinated with mRNA vaccines against SARS-CoV-2 while 152 were unvaccinated. Patients were enrolled in three waves: from September 2020 to October 2022, corresponding to the emergence of the pre-Delta, Delta, and Omicron variants of the SARS-CoV-2 virus. The three criteria for enrolling patients were: oropharyngeal swab positivity or fecal findings; moderate symptoms with antibiotic intake; and measurement of blood oxygen saturation during the period of illness. The use of antibiotic combinations, such as amoxicillin with clavulanic acid (875 + 125 mg tablets, every 12 h) plus rifaximin (400 mg tablets every 12 h), as first choice, as suggested from the previous data, or azithromycin (500 mg tablets every 24 h), plus rifaximin as above, allows healthcare professionals to focus on the gut microbiome and its implications in COVID-19 disease during patient care. The primary outcome measured in this study was the estimated average treatment effect, which quantified the difference in mean recovery between patients receiving antibiotics and those not receiving antibiotics at 3 and 9 days after the start of treatment. In the analysis, both vaccinated and unvaccinated groups had a median illness duration of 7 days (interquartile range [IQR] 6-9 days for each; recovery crude hazard ratio [HR] = 0.94, p = 0.700). The median illness duration for the pre-Delta and Delta waves was 8 days (IQR 7-10 days), while it was shorter, 6.5 days, for Omicron (IQR 6-8 days; recovery crude HR = 1.71, p < 0.001). These results were confirmed by multivariate analysis. Patients with comorbidities had a significantly longer disease duration: median 8 days (IQR 7-10 days) compared to 7 days (IQR 6-8 days) for those without comorbidities (crude HR = 0.75, p = 0.038), but this result was not confirmed in multivariate analysis as statistical significance was lost. Early initiation of antibiotic therapy resulted in a significantly shorter recovery time (crude HR = 4.74, p < 0.001). Concomitant use of NSAIDs did not reduce disease duration and in multivariate analysis prolonged the disease (p = 0.041). A subgroup of 42 patients receiving corticosteroids for a median of 3 days (IQR 3-6 days) had a longer recovery time (median 9 days, IQR 8-10 days) compared to others (median 7 days, IQR 6-8 days; crude HR = 0.542, p < 0.001), as confirmed also by the adjusted HR. In this study, a statistically significant reduction in recovery time was observed among patients who received early antibiotic treatment. Early initiation of antibiotics played a crucial role in maintaining higher levels of blood oxygen saturation. In addition, it is worth noting that a significant number of patients who received antibiotics in the first 3 days and for a duration of 7 days, during the acute phase did not develop LC.

Intraoperative Near-infrared Spectroscopy Can Predict Skin Flap Necrosis.

The study aimed to validate the previously identified capacity of near-infrared spectroscopy (NIRS) to detect clinically relevant differences in tissue perfusion intraoperatively. Consecutive patients undergoing oncologic resection requiring flap reconstruction were analyzed. Clinicians were blinded to tissue oxygen saturation (StO2) measurements taken intraoperatively. Measurements were taken at (1) control areas not affected by the procedure, (2) areas at risk of necrosis based on distal location, and (3) areas of skin flap necrosis (SFN) identified during the follow-up period. Mean StO2 values were compared using a single-sample t test and analysis of variance (ANOVA) to determine differences in oxygenation. There were 102 patients included from April 2018 to May 2019. Reconstruction was undertaken following resection for breast cancer (46), melanoma (35), sarcoma (9), and other cutaneous malignancies (12). Breast reconstruction involved 38 alloplastic reconstructions and eight autologous free flaps. Other skin flap reconstruction involved 42 local/regional skin flaps, 13 pedicled flaps, and one free flap. Eighteen patients (17.6%) developed SFN. Mean intraoperative StO2 measurements for control areas, areas at risk, and areas of SFN were 74.8%, 70.9%, and 54.3%, respectively. StO2 values equal to or less than 60% were highly specific (96%) for SFN, whereas StO2 values above 85% were highly sensitive (96%) to rule out SFN. These results further support the use of NIRS to objectively assess variations in skin flap oxygenation and tissue perfusion that are correlated with the development of postoperative SFN.