Pulse Oximeter Readings Research Articles

Effect of positive end expiratory pressure on non-hypoxic apnea time and atelectasis during induction of anesthesia in infant: A randomized controlled trial.

This study aimed to assess the impact of positive-end-expiratory pressure (PEEP) on the non-hypoxic apnea time in infants during anesthesia induction with an inspired oxygen fraction of 0.8. This age stratified randomized controlled trial included patients under 1 year of age. Preoxygenation was performed using an inspired oxygen fraction of 0.8 for 2 min. Inspired oxygen fraction of 0.8 was administered via a face mask with volume-controlled ventilation at a tidal volume of 6 mL.kg-1, with or without 7 cmH2O of PEEP. Tracheal intubation was performed after 3 min of ventilation; however, it was disconnected from the breathing circuit. Ventilation was resumed once the pulse oximetry readings reached 95%. The primary outcome was the non-hypoxic apnea time, defined as the time from the cessation of ventilation to achieving a pulse oximeter reading of 95%. The secondary outcome measures included the degree of atelectasis assessed by ultrasonography and the presence of gastric air insufflation. Eighty-four patients were included in the final analysis. In the positive end-expiratory pressure group, the atelectasis score decreased (17.0 vs. 31.5, p < .001; mean difference and 95% CI of 11.6, 7.5-15.6), while the non-hypoxic apnea time increased (80.1 s vs. 70.6 s, p = .005; mean difference and 95% CI of -9.4, -16.0 to -2.9), compared to the zero end-expiratory pressure group, among infants who are 6 months old or younger, not in those aged older than 6 months. The application of positive end-expiratory pressure reduced the incidence of atelectasis and extended the non-hypoxic apnea time in infants who are 6 months old or younger. However, it did not affect the incidence of atelectasis nor the non-hypoxic apnea time in patients aged older than 6 months.

Randomised crossover study on pulse oximeter readings from different sensors in very preterm infants

ObjectiveIn extremely preterm infants, different target ranges for pulse oximeter saturation (SpO2) may affect mortality and morbidity. Thus, the impact of technical changes potentially affecting measurements should be assessed. We...

Low Perfusion and Missed Diagnosis of Hypoxemia by Pulse Oximetry in Darkly Pigmented Skin: A Prospective Study.

Retrospective clinical trials of pulse oximeter accuracy report more frequent missed diagnoses of hypoxemia in hospitalized Black patients than White patients, differences that may contribute to racial disparities in health and health care. Retrospective studies have limitations including mistiming of blood samples and oximeter readings, inconsistent use of functional versus fractional saturation, and self-reported race used as a surrogate for skin color. Our objective was to prospectively measure the contributions of skin pigmentation, perfusion index (PI), sex, and age on pulse oximeter errors in a laboratory setting. We enrolled 146 healthy subjects, including 25 with light skin (Fitzpatrick class I and II), 78 with medium (class III and IV), and 43 with dark (class V and VI) skin. We studied 2 pulse oximeters (Nellcor N-595 and Masimo Radical 7) in prevalent clinical use. We analyzed 9763 matched pulse oximeter readings (pulse oximeter measured functional saturation [Sp o2 ]) and arterial oxygen saturation (hemoximetry arterial functional oxygen saturation [Sa o2 ]) during stable hypoxemia (Sa o2 68%-100%). PI was measured as percent infrared light modulation by the pulse detected by the pulse oximeter probe, with low perfusion categorized as PI < 1%. The primary analysis was to assess the relationship between pulse oximeter bias (difference between Sa o2 and Sp o2 ) by skin pigment category in a multivariable mixed-effects model incorporating repeated-measures and different levels of Sa o2 and perfusion. Skin pigment, PI, and degree of hypoxemia significantly contributed to errors (bias) in both pulse oximeters. For PI values of 1.0% to 1.5%, 0.5% to 1.0%, and <0.5%, the P value of the relationship to mean bias or median absolute bias was <.00001. In lightly pigmented subjects, only PI was associated with positive bias, whereas in medium and dark subjects bias increased with both low perfusion and degree of hypoxemia. Sex and age was not related to pulse oximeter bias. The combined frequency of missed diagnosis of hypoxemia (pulse oximeter readings 92%-96% when arterial oxygen saturation was <88%) in low perfusion conditions was 1.1% for light, 8.2% for medium, and 21.1% for dark skin. Low peripheral perfusion combined with darker skin pigmentation leads to clinically significant high-reading pulse oximeter errors and missed diagnoses of hypoxemia. Darkly pigmented skin and low perfusion states are likely the cause of racial differences in pulse oximeter performance in retrospective studies.

Impacts of Skin Color and Hypoxemia on Noninvasive Assessment of Peripheral Blood Oxygen Saturation: A Scoping Review.

Standard pulse oximeters estimate arterial blood saturation (SaO2) non-invasively by emitting and detecting light of a specific wavelength through a cutaneous vascular bed, such as a digit or the ear lobe. The quantity measured at these peripheral sites is designated as oxygen saturation (SpO2). Most reliable pulse oximeters are calibrated from measurements of healthy volunteers using some form of oxygen desaturation method. As the degree of inducible hypoxemia is limited, the calibration below achievable desaturation levels is usually extrapolated, leading to potential measurement error at low SaO2 values, especially in highly pigmented skin. Such skin color-related errors (SCRE) are the topic of this scoping review. Specifically, this study aimed to identify the combined impact of skin color and reduced SaO2 on the non-invasive assessment of SpO2 and report the consequences of potential inaccuracies. Three databases were searched (Cumulated Index to Nursing and Allied Health Literature (CINAHL), PubMed, and Web of Science) for peer-reviewed prospective and retrospective studies published in English between 2000 and 2022 involving human patients with hypoxemia that included a measure of skin color (Fitzpatrick scale or race/ethnicity). Ten studies met the criteria and were included in the final review. Eight of these studies reported statistically significant higher pulse oximeter readingsin darker-skinned patients with hypoxia compared to their arterial blood gas measurements. Occult hypoxia was more prevalent in Black and Hispanic patients than in White patients. Minority patients overall (Black, Asian, and American Indian) were more likely to have a SaO2 < 88% that was not detected by pulse oximetry (occult hypoxemia) during hospitalization. With greater levels of hypoxemia, the differences between SpO2 and SaO2 were greater. If SaO2 was < 90%, then SpO2 was overestimated in all ethnicities but worse in minorities. In conclusion, the bias found in pulse oximeter readings in the skin of color broadly impacts patients with hypoxemia. The failure of SpO2 measuring devices to detect occult hypoxemia can delay the delivery of life-saving treatment to critically ill patients requiring respiratory rehabilitation and supplemental oxygen therapy. This may lead to adverse health outcomes, increased in-hospital mortality, and complications such as organ dysfunction. An improvement in pulse oximeter detection mechanisms that would include all skin pigmentations is therefore much desired to optimize individual healthcare status and minimize disparities in treatment.

COVID-19 Proactive Disease Management Using COVID Virtual Hospital in a Rural Community.

A community teaching hospital serving a rural population established an intensive "hospital at home" program for patients with COVID-19 utilizing disease risk stratification and pulse oximeter readings to dictate nurse and clinician contact. Herein, we report patient outcomes and provider experiences resulting from this "virtual" approach to triaging pandemic care. COVID-19-positive patients appropriate for outpatient management were enrolled in our COVID Virtual Hospital (CVH). Patients received pulse oximeters and instructions for home monitoring of vital signs. CVH nurses contacted the patient within 12-48 hours. The primary care provider was alerted of the patient's diagnosis and held a virtual visit with patient within 2-3 days. Nurses completed a triage form during each patient call; the resulting risk score determined timing of subsequent calls. CVH-relevant patient outcomes included emergency department (ED) visits, mortality, and disease-related hospitalization. Additionally, a survey of providers was conducted to assess CVH experience. From April 22, 2020, to December 21, 2020, 1916 patients were enrolled in the CVH, of which 195 (10.2%) had subsequent visits to the ED. Among those 195 ED visits, 102 (52.3%) were nurse-directed while 93 (47.7%) were patient self-directed; 88 (86.3%) nurse-directed ED visits were subsequently admitted to inpatient care and 14 were discharged home. Of the 93 self-directed ED visits, 3 (3.2%) were admitted. A total of 91 CVH patients (4.7%) were ultimately admitted to inpatient care. Seven deaths occurred among CVH patients, 5 of whom had been admitted for inpatient care. Among 71 providers (23%) who responded to the survey, 94% and 93% agreed that the CVH was beneficial to providers and patients, respectively. Proactive in-home triage of patients with COVID-19 utilizing a virtual hospital model minimized unnecessary presentations to ED and likely prevented our rural hospital from becoming overwhelmed during year one of the pandemic.

Invited Commentary: Undiagnosed and Undertreated-the Suffocating Consequences ofthe Use of Racially Biased Medical Devices During the COVID-19 Pandemic.

While medical technology is typically considered neutral, many devices rely upon racially biased algorithms that prioritize care for White patients over Black patients, who may require more urgent medical attention. In their accompanying article, Sudat et al. (Am J Epidemiol. 2023;XXX(XX):XXX-XXX) document striking inaccuracies in pulse oximeter readings among Black patients, with significant clinical implications. Their findings suggest that this resulted in racial differences in delivery of evidence-based care during the coronavirus disease 2019 (COVID-19) pandemic, affecting admissions and treatment protocols. Despite the medical community's growing awareness of the pulse oximeter's significant design flaw, the device is still in use. In this article, I contextualize Sudat et al.'s study results within the larger history of racial bias in medical devices by highlighting the consequences of the continued underrepresentation of diverse populations in clinical trials. I probe the implications of racially biased assessments within clinical practice and research and illustrate the disproportionate impact on patients of color by examining 2 medical tools, the pulse oximeter and pulmonary function tests. Both cases result in the undertreatment and underdiagnosis of Black patients. I also demonstrate how the social underpinnings of racial bias in medical technology contribute to poor health outcomes and reproduce health disparities, and propose several recommendations for the field to rectify the harms of racial bias in medical technology.

Effects of positive end-expiratory pressure and oxygen concentration on non-hypoxemic apnea time during face mask ventilation of anesthesia induction: A randomized controlled trial.

Background: The optimal ventilatory strategy for the face mask ventilation during anesthesia induction is still unknow. Methods: We evaluated the effect of two positive end-expiratory pressure (PEEP) levels (0cmH2O and 6cmH2O) and two oxygen concentration levels (1.0 and .6) on non-hypoxemic apnea time during face mask ventilation of anesthesia induction. Sixty adult patients scheduled for elective surgery were enrolled in this study. The patients were randomized to receive anesthesia induction with four different ventilation strategy under volume-controlled ventilation. Patients assigned to the LOZP group received low fraction of inspiration O2 (FiO2 = .6) and 0 PEEP. Patients assigned to the LOHP group received low fraction of inspiration O2 (FiO2 = .6) and 6cmH2O PEEP. Patients assigned to the HOZP group received high fraction of inspiration O2 (FiO2 = 1.0) and 0 PEEP. Patients assigned to the HOHP group received high fraction of inspiration O2 (FiO2 = 1.0) and 6cmH2O PEEP. After 3min of ventilation, the patient was intubated but disconnected from the breathing circuit. Ventilation was not initiated until the pulse oximetry dropped to 90%. The primary outcome was non-hypoxemic apnea time defined as the time from cessation of ventilation to a pulse oximeter reading of 90%. The secondary outcome was the PaO2/FiO2 ratio immediately after ventilation. Results: The non-hypoxemic apnea time was significantly longer in the group of HOHP when compared to the other three groups (192s ± 70s, 221s ± 74s, 284s ± 101s, and 353s ± 85s in the LOZP, LOHP, HOZP, and HOHP group, respectively). The PaO2/FiO2 ratio immediately after ventilation was significantly higher in the group of LOHP when compared to the other three groups (LOZP 393 ± 130, LOHP 496 ± 97, HOZP 335 ± 58, HOHP 391 ± 50). When compared the PaO2/FiO2 ratio immediately after ventilation to its value before administration of anesthesia, the PaO2/FiO2 ratio in the group of LOHP was improved, the group LOZP and HOHP remained the same, while the group HOZP significantly decreased. Conclusion: Application of PEEP and 100% of oxygen during face mask ventilation of induction could maximize the non-hypoxemic apnea time. However, the use of PEEP and 60% of oxygen during preoxygenation resulted in improved PaO2/FiO2 ratio.

Efficacy of benzocaine and lidocaine bioadhesive patches in various minor oral surgical procedures in children - An evaluative study.

The key to successful management of a child in the dental clinic depends greatly on providing painless anaesthesia. Topical anaesthesia using bioadhesive patches may be a breakthrough in this field. The purpose of the study was to compare the efficacy of Benzocaine and Lidocaine bioadhesive patches in reducing pain associated with various minor oral surgical procedures in children. Hundred subjects, aged 6-9 years, requiring various minor oral surgical procedures such as extractions of primary teeth, nerve blocks, mucocele excision or drainage of abscesses were divided equally into Groups 1 and 2. In Group 1, custom fabricated Benzocaine patches were placed for 5 minutes at the target site prior to the procedure, and in Group 2, Lidocaine patches were used in the same manner. Each subject completed a visual analogue scale (VAS) and Wong-Baker Faces pain scale (FPS) after each procedure. Pulse rate and saturation of peripheral oxygen were assessed using pulse oximeter. The duration of the study was from September 2014 to September 2015. The statistical analysis was done using paired t test, ANOVA and Bonferroni post hoc analysis. P value less than 0.05 were considered as statistically significant. A significant difference in pain scores was observed favouring the use of Benzocaine over Lidocaine patches (P < 0.05). However, no significant differences in pulse oximeter readings were observed. A statistically significant reduction in pain rating scores was observed in the Benzocaine group after a five-minute application of the patch.

1040. Comparative Surge Data on SARS CoV-2 Variants in a Rural Community – A Virtual Hospital Experience

Abstract Background UNC Health Blue Ridge is a nonprofit community teaching hospital with 145 staffed beds. The COVID-19 pandemic has challenged rural hospitals like ours with high occupancy and periodic surges. UNC Health Blue Ridge COVID Virtual Hospital (CVH) created a home monitoring program for enrolled patients with severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection utilizing disease risk stratification and pulse oximeter readings to dictate nurse and clinician follow-up. We report raw data that compare surge levels in our community for the Alpha (B.1.1.7), Delta (B.1.617.2) and Omicron (B.1.1.529) surges. Methods From April 2020 to present, the CVH enrolled patients diagnosed with COVID-19 based on FDA approved PCR tests. For this abstract, we defined any surge as an outpatient CVH census of greater than 50 patients or an inpatient census of &amp;gt;10 patients. We defined the maximum intensity of the surge as &amp;gt;20% outpatient SARS CoV-2 positivity and a CVH census &amp;gt;100 patients or &amp;gt;20 inpatients with SARS CoV-2 infection. Results For the outpatient setting, days of surge and maximum intensity were 144 / 98 days for Alpha, 92 / 71 days for Delta, 74 / 47 days for Omicron, respectively. Average daily CVH admissions during surges were 17.7 for Alpha, 26.15 for Delta, and 27.15 for Omicron. Total emergency department (ED) and urgent care visits were 12,765 and 23,696 for Delta, and 9701 and 16102 for Omicron. In the inpatient setting, days of surge and maximum intensity days were 102/76 days for Delta and 78/48 days for Omicron. Our peak inpatient COVID-19 daily census was 51 and 50 patients for Delta and Omicron. Conclusion Our CVH has enrolled over 8700 patients, and our hospital has not been on diversion during the COVID-19 pandemic, unlike many surrounding hospital systems of similar size. More importantly, the CVH has helped create a sustainable model that gathers local data to aid predictive algorithms and facilitate proactive rather than reactive resource allocations. This virtual model can be adapted for multiple other health conditions in the outpatient setting to improve patient safety and quality care. Disclosures All Authors: No reported disclosures.

Impact of Nail Polish Colour on the Accuracy of Pulse Oximeter Reading in Healthy Individuals

Objective: To assess the effect of single-layered common nail polish colour on change in pulse oximeter reading.&#x0D; Study Design: Cross-sectional analytical study.&#x0D; Place and Duration of the Study: Combined Military Hospital, Peshawar, Pakistan, from Sep 2021 to Apr 2022.&#x0D; Methodology: Four hundred healthy females were included in the study that was normothermic, had an Oxygen saturation (SpO2) reading of 95% or more and do not have associated comorbidities, nailbed abnormalities or any history of trauma to limb. Individuals having any previous factors were excluded from the study. After informed consent, SpO2 was recorded using a portable infrared pulse oximeter in all four fingernails of the subjects at room temperature and then rechecked after the single-layered common nail polish was applied and dried. Red, green, black and purple were assigned to the index finger,middle finger, ring finger and little finger, respectively. In addition to oxygen saturation, other parameters, including age,gender, educational status, residence etc., were also recorded.&#x0D; Results: There was a statistically significant difference in oxygen saturation readings via portable infrared pulse oximeter in all four fingernails after applying single-layered common nail polish colours (p-value&lt;0.0001). However, there was no clinically significant difference in oxygen saturation reading recorded in any individual.&#x0D; Conclusion: A single layer of common nail polish affected the SpO2 reading measured through a portable pulse oximeter. This should be kept in mind when evaluating such patients in emergency reception.

RACIAL BIAS IN PULSE OXIMETRY IN ACUTE HYPOXEMIC RESPIRATORY FAILURE

RACIAL BIAS IN PULSE OXIMETRY IN ACUTE HYPOXEMIC RESPIRATORY FAILURE

Effects of High-Intensity Aerobic Interval Training on Cardiopulmonary Function in Patients With Chronic Heart Failure at The University Teaching Hospital, Lusaka, Zambia

Chronic heart failure patients present with a wide variety of symptoms such as, fatigue and dyspnea, which adversely affect their quality of life. Heart failure is a complex disease and a major cause of morbidity and mortality in developed and developing countries including Zambia. Through studies undertaken, high intensity aerobic interval training has been recommended in patients with chronic heart failure, to help improve symptoms and consequently the quality of life. Minimal research pertaining to effectiveness of aerobic exercise on various physiological parameters such as peripheral oxygen saturation, cardiopulmonary capacity and quality of life have been done in Africa and Zambia. Methods: This study evaluated the physiological effects of high intensity aerobic interval training on the cardiopulmonary function in New York Heart Association (NYHA) Class II and III chronic heart failure patients with a focus on peripheral oxygen delivery/saturation, cardiopulmonary capacity and the quality of life. This study utilised the Randomised Clinical Trial (RCT) study design and the study population was selected from the University Teaching Hospital-Heart clinic in Lusaka, Zambia. Results: A total number of 42 patients participated, and were randomly assigned to the two arms of the study. Twenty-one (21) were assigned to the interventional group (IG) and 21 to the control group (CG) respectively. The IG underwent a 12 week aerobic HIIT exercise-training program, while the CG was subjected to 30 minutes’ walk on a treadmill for the same period of 12 weeks. The expected primary outcomes were the baseline to endline differences in oxygen delivery/saturation readings, cardiopulmonary capacity test readings and the quality of life (measured using the Minnesota questionnaire) for both groups. The results obtained from the pulse oximeter readings, showed an increase in the oxygen saturation readings (97.90 to 98.62%), 6-minute walk distance readings (360.05 m to 429 m) and the questionnaire score totals of the different dimensions (physical, emotional/mental and socio-psychological factors) of the questionnaire (p-value ;0.0001) of the IG. The CG oxygen saturation readings (97.38 % to 97.90%) and 6-minute walk tests scores (359.14 to 370.9 m) showed minimal change. While, the questionnaire scores showed a statistical difference in the emotional/mental (p-value &lt; 0.0001), physical (p=0.005) and socio-psychological factors (p- value &lt; 0.0001). Conclusion: High intensity aerobic interval training has shown to improve the peripheral oxygen delivery, cardiopulmonary capacity and quality of life in chronic heart failure patients hence, must be considered as an adjunct therapy aside pharmacological management in stable chronic heart failure patients in Zambia.

Remote Patient Monitoring System For Covid-19 Patient Using Wi-Fi-Based Pulse Oximeter Reading Sensor

Continuous Heart disease and blood pressure are diseases that demand immediate care. Heart disease is currently one of the world's most fatal illnesses, as it always results in death. Pulse Oximeter Reading must be continuously measured, analyzed, and monitored in real-time to ensure that relevant measures may be taken when necessary. In this paper, we present a model that employs IoT to inform users about the incidence of heart disease and high blood pressure in their daily health. The Remote Patient Monitoring System for Covid-19 Patients Based on Oximeter Reading Sensor uses the Web Server ESP32 MAX30100 to replace the present Oximeter Reading monitoring and public broadcasting approaches. In addition, the NodeMCU ESP8266 Wi-Fi module allows the devices to save data in the cloud when connected to the Internet. Also, it is possible to construct effective real-time Heart Rate and Oxygen Level (IoT) monitoring. The findings indicated that users might access and monitor Heart rate and oxygen level via the Web Server regardless of their location in the monitoring region. Furthermore, providing an LCD is incredibly beneficial as it can show readings and ensure the users receive Pulse Oximeter Reading monitoring information when the device is in operation.

Differential pulse oximetry readings between ethnic groups and delayed transfer to intensive care units.

Pulse oximeters are widely used to monitor blood oxygen saturations, although concerns exist that they are less accurate in individuals with pigmented skin. This study aimed to determine if patients with pigmented skin were more severely unwell at the period of transfer to intensive care units (ICUs) than individuals with White skin. Using data from a large teaching hospital, measures of clinical severity at the time of transfer of patients with COVID-19 infection to ICUs were assessed, and how this varied by ethnic group. Data were available on 748 adults. Median pulse oximetry demonstrated similar oxygen saturations at the time of transfer to ICUs (Kruskal-Wallis test, P = 0.51), although median oxygen saturation measurements from arterial blood gases at this time demonstrated lower oxygen saturations in patients classified as Indian/Pakistani ethnicity (91.6%) and Black/Mixed ethnicity (93.0%), compared to those classified as a White ethnicity (94.4%, Kruskal-Wallis test, P = 0.005). There were significant differences in mean respiratory rates in these patients (P < 0.0001), ranging from 26 breaths/min in individuals with White ethnicity to 30 breaths/min for those classified as Indian/Pakistani ethnicity and 31 for those who were classified as Black/Mixed ethnicity. These data are consistent with the hypothesis that differential measurement error for pulse oximeter readings negatively impact on the escalation of clinical care in individuals from other than White ethnic groups. This has implications for healthcare in Africa and South-East Asia and may contribute to differences in health outcomes across ethnic groups globally.

Study of complications of congenital heart diseases with special reference to pulse oximetry and anthropometry

Background: This study was done to determine prevalence of congenital heart disease (CHD), its complications especially effect on growth parameter and role of pulse oximeter as a diagnostic modality.Methods: This study was a hospital based prospective observational study conducted on hospitalized children in paediatric wards and PICU of Civil hospital, B. J. medical college Ahmedabad, for one year which is a tertiary care teaching hospital.Results: Prevalence of CHD in our institute was 1.2% during the period of one year. Signs of failure (tachycardia, tachypnoea, pallor and hepatomegaly) were seen in more than 50% of patients. Nearly 29.5% patients had hypoxia on arrival on pulse oximeter reading while 74% patients had normal saturation. Complications commonly found in CHD are congestive heart failure and growth failure.Conclusions: CHD is a chronic disease and has all its consequences; complications are commonly found in congenital heart diseases are congestive heart failure and growth failure. Pulse oximeter can be used as screening test but not as the reliable diagnostic method.

Effect of wearing latex gloves on the accuracy of pulse oximeter readings to prevent cross-contamination

Background: Pulse oximeter is a painless and non-invasive device used to measure oxygen saturation level. In December 2019, an outbreak of coronavirus disease was caused by a novel severe acute respiratory syndrome coronavirus-2 (SARS-2). They are a large family of viruses that causes illness ranging from the common cold to the most severe disease such as MERS (Middle East Respiratory Syndrome) and SARS (severe acute respiratory syndrome). Since it affects the respiratory system, the use of a Pulse oximeter has increased significantly to measure oxygen saturation level.Objective: The objective of the study is to analyze any discrepancy in the accuracy of pulse oximeter readings when taken with or without latex gloves. Method: A total of 100 individuals were selected who satisfied the inclusion and exclusion criteria. The pulse oximeter was placed on the right middle finger and a reading for oxygen saturation level in arterial blood was obtained after 3-5seconds. Two parameters such as reading with latex gloves and without latex gloves pulse oximeter reading were measured. The data obtained were statistically analyzed.Result: Upon statistical analysis no significant difference was found between the value on the patient wearing gloves or without wearing gloves.

The feasibility, safety, and efficacy of upper limb garment-integrated blood flow restriction training in healthy adults

BackgroundBlood flow restriction training (BFR) has been demonstrated to increase muscle hypertrophy and strength, but has logistical and cost barriers. Garment-integrated BFR has the potential to reduce these barriers by lowering equipment demands and cost. The primary aim of the study was to explore the feasibility of garment-integrated BFR in the upper limb of healthy adults, with a secondary aim of exploring safety and efficacy.MethodsPhysically active and otherwise healthy participants with no previous experience with BFR were sought. Eligible participants completed a five-week garment-integrated BFR programme that involved completing two sessions per week. Feasibility was determined by a priori defined thresholds for recruitment, adherence to the garment-integrated BFR programme, and data collection. Safety was determined by recording adverse events and by monitoring for total arterial occlusion pressure using a fingertip pulse oximeter. Efficacy was determined by measuring push-ups to volitional failure, arm girth, and number of prescribed repetitions completed. Feasibility and safety outcomes were reported descriptively or as a proportion with associated 95% confidence intervals (95% CI). Mean change, 95% CIs, and associated effect sizes were calculated for efficacy outcomes.ResultsTwenty-eight participants were included (15 men, 13 women; mean age 31.6 years [±9.1]) and 27 successfully completed the study. Participants were successfully recruited within three months and 278/280 sessions were successfully completed (adherence=99.3%, 95% CI 97.4%, 99.9%). Minimal adverse events were reported; one incident of localised bruising (0.36%, 95% CI 0.06%, 2.0%) and three incidences of excessive pain during or post-exercise from two separate participants (1.07%, 95% CI 0.03%, 3.1%). 82/2240 pulse oximeter readings were not recorded (3.7%, 95% CI 2.9%, 4.5%). Mean push-ups to volitional failure increased by 40% (mean change=8.0, 95% CI 6, 10, d=1.40). Mean arm girth and number of prescribed repetitions completed were unchanged.ConclusionsGarment-integrated BFR is feasible and has no signal of important harm in the upper limb of healthy adults, and could proceed to a future trial with stop/go criteria for randomisation. Further work is required to investigate the efficacy of garment-integrated BFR and determine its equivalence or superiority compared to existing BFR methods.

Performance of popular pulse oximeters compared with simultaneous arterial oxygen saturation or clinical-grade pulse oximetry: a cross-sectional validation study in intensive care patients

ObjectivesTo evaluate the performance of direct-to-consumer pulse oximeters under clinical conditions, with arterial blood gas measurement (SaO2) as reference standard.DesignCross-sectional, validation study.SettingIntensive care.ParticipantsAdult patients requiring SaO2-monitoring.InterventionsThe studied oximeters are top-selling...

Case Report: Severe COVID-19 in a Kidney Transplant Recipient Without Humoral Response to SARS-CoV-2 mRNA Vaccine Series.

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Happy hypoxia in COVID-19: pathophysiology and pulse oximetry accuracy

Many patients with COVID-19 have presented to emergency departments with arterial hypoxaemia but without breathlessness; this is called ‘happy hypoxia’ or, more accurately, ‘silent hypoxaemia’. Hypoxaemia needs to be identified correctly in patients with COVID-19 as it is associated with in-hospital mortality. The aetiology of silent hypoxia is unclear, and the pathophysiological processes involved in the relationship between the response to hypoxaemia and the sensation of dyspnoea may explain its clinical presentation. Pulse oximetry is used routinely to measure oxygen saturation. However, recent literature has questioned its accuracy in patients with COVID-19. Inaccuracies in readings, which arise for several reasons, could in part explain silent hypoxaemia. Caution should be taken when interpreting pulse oximeter readings or patients could be given a higher inspired oxygen fraction than necessary. Silent hypoxaemia may also mask disease severity in patients with COVID-19.