Oxygen Saturation in Hospitalized COVID-19 Patients and Its Relation to Colchicine Treatment: A Retrospective Cohort Study with an Updated Systematic Review.

Background: Colchicine has been proposed as a cytokine storm-blocking agent for COVID-19 due to its efficacy as an anti-inflammatory drug. The findings of the studies were contentious on the role of colchicine in preventing deterioration in COVID-19 patients. We aimed to evaluate the efficacy of colchicine in COVID-19-hospitalized patients. Design: A retrospective observational cohort study was carried out at three major isolation hospitals in Alexandria (Egypt), covering multiple centers. In addition, a systematic review was conducted by searching six different databases for published studies on the utilization of colchicine in patients with COVID-19 until March 2023. The primary outcome measure was to determine whether colchicine could decrease the number of days that the patient needed supplemental oxygen. The secondary outcomes were to evaluate whether colchicine could reduce the number of hospitalization days and mortality rate in these patients. Results: Out of 515 hospitalized COVID-19 patients, 411 were included in the survival analysis. After adjusting for the patients' characteristics, patients not receiving colchicine had a shorter length of stay (median: 7.0 vs. 6.0 days) and fewer days of supplemental oxygen treatment (median: 6.0 vs. 5.0 days), p < 0.05, but there was no significant difference in mortality rate. In a subgroup analysis based on oxygen equipment at admission, patients admitted on nasal cannula/face masks who did not receive colchicine had a shorter duration on oxygen supply than those who did [Hazard Ratio (HR) = 0.76 (CI 0.59-0.97)]. Using cox-regression analysis, clarithromycin compared to azithromycin in colchicine-treated patients was associated with a higher risk of longer duration on oxygen supply [HR = 1.77 (CI 1.04-2.99)]. Furthermore, we summarized 36 published colchicine studies, including 114,878 COVID-19 patients. Conclusions: COVID-19-hospitalized patients who were given colchicine had poorer outcomes in terms of the duration of supplemental oxygen use and the length of their hospital stay. Therefore, based on these findings, the use of colchicine is not recommended for COVID-19-hospitalized adults.

Ratio of Oxygen Saturation to Inspired Oxygen, ROX Index, Modified ROX Index to Predict High Flow Cannula Success in COVID-19 Patients: Multicenter Validation Study.

INTRODUCTION: High-flow nasal cannula (HFNC) is a respiratory support measure for coronavirus 2019 (COVID-19) patients that has been increasingly used in the emergency department (ED). Although the respiratory rate oxygenation (ROX) index can predict HFNC success, its utility in emergency COVID-19 patients has not been well-established. Also, no studies have compared it to its simpler component, the oxygen saturation to fraction of inspired oxygen (SpO2/FiO2 [SF]) ratio, or its modified version incorporating heart rate. Therefore, we aimed to compare the utility of the SF ratio, the ROX index (SF ratio/respiratory rate), and the modified ROX index (ROX index/heart rate) in predicting HFNC success in emergency COVID-19 patients. METHODS: We conducted this multicenter retrospective study at five EDs in Thailand between January-December 2021. Adult patients with COVID-19 treated with HFNC in the ED were included. The three study parameters were recorded at 0 and 2 hours. The primary outcome was HFNC success, defined as no requirement of mechanical ventilation at HFNC termination. RESULTS: A total of 173 patients were recruited; 55 (31.8%) had successful treatment. The two-hour SF ratio yielded the highest discrimination capacity (AUROC 0.651, 95% CI 0.558-0.744), followed by two-hour ROX and modified ROX indices (AUROC 0.612 and 0.606, respectively). The two-hour SF ratio also had the best calibration and overall model performance. At its optimal cut-point of 128.19, it gave a balanced sensitivity (65.3%) and specificity (61.8%). The two-hour SF≥128.19 was also significantly and independently associated with HFNC failure (adjusted odds ratio 0.29, 95% CI 0.13-0.65; P=0.003). CONCLUSION: The SF ratio predicted HFNC success better than the ROX and modified ROX indices in ED patients with COVID-19. With its simplicity and efficiency, it may be the appropriate tool to guide management and ED disposition for COVID-19 patients receiving HFNC in the ED.

Overestimation of Oxygen Saturation Measured by Pulse Oximetry in Hypoxemia. Part 1: Effect of Optical Pathlengths-Ratio Increase.

On average, arterial oxygen saturation measured by pulse oximetry (SpO2) is higher in hypoxemia than the true oxygen saturation measured invasively (SaO2), thereby increasing the risk of occult hypoxemia. In the current article, measurements of SpO2 on 17 cyanotic newborns were performed by means of a Nellcor pulse oximeter (POx), based on light with two wavelengths in the red and infrared regions (660 and 900 nm), and by means of a novel POx, based on two wavelengths in the infrared region (761 and 820 nm). The SpO2 readings from the two POxs showed higher values than the invasive SaO2 readings, and the disparity increased with decreasing SaO2. SpO2 measured using the two infrared wavelengths showed better correlation with SaO2 than SpO2 measured using the red and infrared wavelengths. After appropriate calibration, the standard deviation of the individual SpO2-SaO2 differences for the two-infrared POx was smaller (3.6%) than that for the red and infrared POx (6.5%, p < 0.05). The overestimation of SpO2 readings in hypoxemia was explained by the increase in hypoxemia of the optical pathlengths-ratio between the two wavelengths. The two-infrared POx can reduce the overestimation of SpO2 measurement in hypoxemia and the consequent risk of occult hypoxemia, owing to its smaller increase in pathlengths-ratio in hypoxemia.

Clinical determinants of oxygen saturation and length of hospitalisation of COVID-19 patients: A cross-sectional study in Indonesia.

Aims: Indonesia was one of the countries with the highest COVID-19 positive cases. Understanding the length of hospitalisation is critical for anticipating bed demand and resource allocation, such as oxygen. This study aims to examine the determinants of oxygen saturation and the length of hospitalisation in Hermina Mekarsari Hospital, West Java, Indonesia. Methods: This cross-sectional study uses medical records from June to August 2021. The inclusion criteria were: COVID-19 patients aged between18 and 65, fully conscious, and not using mechanical ventilation. Participants who passed away during hospital stay were excluded. We used demographic information, laboratory data, and the clinician's assessments of the patients admitted to the hospital. Linear regression was performed for oxygen saturation on day seven, while logistic regression analysis was conducted to predict the length of hospital stay. Results: In total, 371 participants with an average age of 47.2 (standard deviation 15.8) years were included. Most participants were female (57.7%) and smoking (78.4%). The results indicated that decreasing oxygen saturation was reported in vomiting patients (ß = 1.63, p-value = .001), hypertensive patients (ß 1.18 with, p-value = .034), and patients with the increased respiratory rate (ß = 0.28, p-value = .000). In the logistic regression, we found that respondents who experienced dyspnoea, headache, fever, an increasing number of D-Dimer and blood glucose, and those with diabetes mellitus were more likely to stay more than 14 days. Conclusions: Oxygen saturation was influenced by vomiting, hypertension, and increasing respiratory rate. Length of hospitalisation of more than 14 days was influenced by dyspnoea, headache, fever, increased number of D-Dimer, blood glucose, and diabetes mellitus. Identifying the determinants of oxygen saturation and length of stay can inform health professionals in designing a suitable intervention to reduce mortality and length of stay among COVID-19 patients in Indonesia.

Correlation between oxygen saturation of patient and severity index of Covid 19 pneumonia on CT.

OBJECTIVE: To investigate the correlation between capillary blood oxygen saturation and computerised tomography severity index in patients with coronavirus disease-2019 pneumonia. METHODS: The cross-sectional analytical study was conducted at the coronavirus disease-2019 ward of Nishtar Medical University and Hospital, Multan, Pakistan, June 1, 2020, to June 1, 2021. At the time of admission, capillary oxygen saturation of all patients was measured. Pulmonary computerised tomography scans were then performed, and computerised tomography severity index was calculated. Data was analysed using SPSS 18. Results: Of the 170 patients, 90 (52.9%) were males and 80(47%) were females. The overall mean age of the sample was 56.32±12.45 years. At the time of admission, the mean oxygen saturation was 88.9±6.53% and the mean severity index was 15.01±7.79. Overall, 22(12.9%) patients had hypoxia and the severity index reading was significantly high in these patients (p=0.001). Chronic obstructive pulmonary disease, hypertension and diabetes were significantly related to reduced blood oxygen saturation (p<0.05). Patients with hypertension had significantly raised computerised tomography scores. A significant inverse correlation was found between capillary oxygen saturation and computerised tomography severity index (p<0.01). CONCLUSIONS: A significant inverse correlation was found between capillary oxygen saturation and computerised tomography severity index. Underlying comorbidities also affected the severity index.

Epidemiological profile of death resulting from Covid-19 in a municipality in southwest of Paraná / Perfil epidemiológico de óbitos decorrentes da Covid-19 em um município do sudoeste do Paraná / Perfil epidemiológico de las muertes por Covid-19 en un municipio del suroeste de Paraná

Introdução: No final do ano de 2019 surgiu na China uma doença infectocontagiosa de característica respiratória e alto grau de disseminação até então desconhecida. No Brasil o primeiro caso de Covid-19 foi confirmado no final de fevereiro de 2020 e a primeira morte em meados de março. Segundo dados da plataforma Coronavírus Brasil, em 17 de março de 2021, houve registro de 11.603.535 casos confirmados e 282.127 óbitos. Objetivo: Descrever o perfil de pessoas que morreram tendo como causa básica do óbito a Covid-19, em um município do Sudoeste do Paraná, entre os anos de 2020 e 2021. Metodologia: Trata-se de um estudo transversal, descritivo, documental de caráter quantitativo que foi realizado na prefeitura municipal de Francisco Beltrão. Resultados: Houve prevalência de óbitos em pacientes do sexo masculino, idosos, com presença de alguma comorbidade associada, sendo hipertensão a mais citada (50,8%). Os sintomas mais prevalentes foram tosse (74,4%), dispneia (56,3%) e saturação < 95% (48,3%), necessitando ainda de hospitalização em algum período da doença (94,1%), sendo os leitos de Sistema Único de Saúde os mais procurados (74,4%). Quanto à taxa de ocupação 49,6% dos casos necessitou apenas de leitos de enfermaria e 42% unidades de terapia intensiva. Discussão: Diversas pesquisas apontam que o sexo masculino é o mais acometido por condições graves de saúde, devido à demora na busca de assistência médica. No que se refere à idade, neste estudo, a prevalência de óbitos se deu entre 71 e 75 anos (15,1%) o que justifica que o envelhecimento é um fator de risco elevado para complicações da doença. Durante a análise dos dados, notou- se que grande parte dos pacientes que tiveram como desfecho o óbito, possuíam algum fator associado, dentre os mais citados, verificou-se a Hipertensão Arterial Sistêmica (50,8%) Diabetes Mellitus (24,8%), doenças cardiovasculares (23,9%) e obesidade (14,7%). No que diz respeito à hospitalização, nesse estudo notou-se que 74,4% da amostra foram hospitalizadas em leitos de SUS, 18,5% em hospitais particulares e 7,1% não possuíam essa informação. Conclusão: É possível observar a importância do estudo epidemiológico para identificar o perfil da população em risco, podendo auxiliar no planejamento do atendimento, rastreamento e controle da doença, além de conhecer a evolução da patologia, a fim de buscar ações adequadas para seu enfrentamento.

Introduction: At the end of 2019, a previously unknown infectious disease with respiratory characteristics and a high degree of dissemination emerged in China. In Brazil the first case of Covid-19 was confirmed in late February 2020 and the first death in mid-March. According to data from the Coronavirus Brazil platform, as of March 17, 2021, 11,603,535 confirmed cases and 282,127 deaths were recorded. Objective: To describe the profile of people who died with Covid-19 as the underlying cause of death in a city in southwestern Paraná between the years 2020 and 2021. Methodology: This is a cross-sectional, descriptive, documental, quantitative study carried out at the Francisco Beltrão City Hall. Results: There was a prevalence of deaths in male patients, elderly, with the presence of some associated comorbidity, hypertension being the most cited (50.8%). The most prevalent symptoms were cough (74.4%), dyspnea (56.3%) and saturation < 95% (48.3%), requiring hospitalization in some period of the disease (94.1%), and the Unified Health System beds were the most sought (74.4%). As for the occupancy rate, 49.6% of the cases required only ward beds and 42% intensive care units. Discussion: Several studies show that men are the most affected by serious health conditions, due to the delay in seeking medical assistance. Regarding age, in this study, the prevalence of deaths was between 71 and 75 years (15.1%), which justifies that aging is a high risk factor for disease complications. During data analysis, it was noted that most patients who died had some associated factor, among the most cited were systemic arterial hypertension (50.8%), diabetes mellitus (24.8%), cardiovascular diseases (23.9%) and obesity (14.7%). Regarding hospitalization, in this study it was noted that 74.4% of the sample were hospitalized in SUS beds, 18.5% in private hospitals, and 7.1% did not have this information. Conclusion: It is possible to observe the importance of the epidemiological study to identify the profile of the population at risk, which can help in planning care, tracking and control of the disease, besides knowing the evolution of the pathology in order to seek appropriate actions for its confrontation

Introducción: A finales del año 2019 apareció en China una enfermedad infecto- contagiosa de característica respiratoria y alto grado de diseminación desconocida hasta entonces. En Brasil se confirmó el primer caso de Covid-19 a finales de febrero de 2020 y la primera muerte a mediados de marzo. Según los datos de la plataforma Coronavirus Brasil, hasta el 17 de marzo de 2021, había 11.603.535 casos confirmados y 282.127 muertes. Objetivo: Describir el perfil de las personas fallecidas con Covid-19 como causa subyacente de muerte en una ciudad del sudoeste de Paraná entre los años 2020 y 2021. Metodología: Se trata de un estudio transversal, descriptivo, documental de carácter cuantitativo que se realizó en la prefectura municipal de Francisco Beltrão. Resultados: Hubo una prevalencia de muertes en pacientes masculinos, de edad avanzada, con presencia de alguna comorbilidad asociada, siendo la hipertensión la más citada (50,8%). Los síntomas más prevalentes fueron la tos (74,4%), la disnea (56,3%) y la saturación < 95% (48,3%), requiriendo hospitalización en algún periodo de la enfermedad (94,1%), siendo las camas del Sistema Único de Salud las más solicitadas (74,4%). En cuanto a la tasa de ocupación, el 49,6% de los casos sólo necesitaban camas de sala y el 42% unidades de cuidados intensivos. Discusión: Varias investigaciones señalan que el género masculino es el más afectado por las condiciones de salud graves, debido al retraso en la búsqueda de asistencia médica. En cuanto a la edad, en este estudio, la prevalencia de muertes se produjo entre los 71 y los 75 años (15,1%), lo que justifica que el envejecimiento sea un factor de riesgo elevado para las complicaciones de la enfermedad. Durante el análisis de los datos, se observó que la mayoría de los pacientes que fallecieron tenían algún factor asociado, entre los más citados estaban la Hipertensión Arterial Sistémica (50,8%), la Diabetes Mellitus (24,8%), las enfermedades cardiovasculares (23,9%) y la obesidad (14,7%). En lo que respecta a la hospitalización, en este estudio se observó que el 74,4% de la muestra estaba hospitalizada en camas del SUS, el 18,5% en hospitales privados y el 7,1% no tenía esta información. Conclusión: Es posible observar la importancia del estudio epidemiológico para identificar el perfil de la población en riesgo, pudiendo ayudar en la planificación de la atención, el rastreo y el control de la enfermedad, además de conocer la evolución de la patología, con el fin de buscar las acciones adecuadas para su enfrentamiento.

Effects of oxygen saturation on the hypoxia-inducible factor-1α, subfatin, asprosin, irisin, c-reactive protein, maresin-1, and diamine oxidase in diabetic patients with COVID-19.

OBJECTIVE: Oxygen is essential for living organisms that perform aerobic respiration since cells begin to die when humans and animals are deprived of oxygen. Oxygen saturation decreases and shortness of breath occurs in coronavirus (COVID-19) disease. Therefore, in this study, we aimed to determine the changes in hypoxia-inducible factor-1α (HIF-1α), subfatin, asprosin, irisin, C-reactive protein (C-RP), Maresin-1 (MaR-1), and diamine oxidase (DAO) molecules in diabetic patients with coronavirus according to their oxygen saturations. PATIENTS AND METHODS: Participants were classified into 4 Groups of 22, including patients with oxygen saturation between 95% and 100% (Group I, control), between 80% and 85% (Group II), between 75% and 79% (Group III), and between 70% and 74% (Group IV). COVID-19 was diagnosed with PCR testing and 5 mL of blood was taken following the diagnosis. HIF-1α, subfatin, asprosin, irisin, MaR-1, and DAO values of the participants were measured with ELISA. Other parameters used in the study were obtained from the records of the patients. RESULTS: When Group I was compared to Groups II, there was no significant change in Group II while HIF-1α, subfatin, asprosin, irisin, C-RP, and DAO counts had increased significantly in Groups III and IV. When the MaR-1 values were examined, they were reported to have decreased significantly in Groups III and IV (p < 0.05). Similarly, when Group II and Group IV were compared, HIF-1α, subfatin, asprosin, irisin, C-RP, and DAO values of the participants in Group IV had significantly increased while MaR-1 values had significantly decreased (p < 0.05). In the case of oxygen saturation decreasing below the critical value (70-74%) in patients with coronavirus, the release of HIF-1HIF-1α, subfatin, asprosin, irisin, C-RP, and DAO increased while the MaR-1 values decreased (p < 0.05). CONCLUSIONS: Changes in these molecules in patients with coronavirus and diabetes according to their oxygen saturation suggested that they functioned as the "metabolic oxygen sensors" of the metabolism. Therefore, according to these data, it was predicted that these molecules had the potential to be used in the diagnosis and follow-up of diseases related to oxygen (such as asthma, and critical intensive care patients) in clinics in the future.

Prediction of low pulse oxygen saturation in COVID-19 using remote monitoring post hospital discharge.

BACKGROUND: Monitoring systems have been developed during the COVID-19 pandemic enabling clinicians to remotely monitor physiological measures including pulse oxygen saturation (SpO2), heart rate (HR), and breathlessness in patients after discharge from hospital. These data may be leveraged to understand how symptoms vary over time in COVID-19 patients. There is also potential to use remote monitoring systems to predict clinical deterioration allowing early identification of patients in need of intervention. METHODS: A remote monitoring system was used to monitor 209 patients diagnosed with COVID-19 in the period following hospital discharge. This system consisted of a patient-facing app paired with a Bluetooth-enabled pulse oximeter (measuring SpO2 and HR) linked to a secure portal where data were available for clinical review. Breathlessness score was entered manually to the app. Clinical teams were alerted automatically when SpO2 < 94 %. In this study, data recorded during the initial ten days of monitoring were retrospectively examined, and a random forest model was developed to predict SpO2 < 94 % on a given day using SpO2 and HR data from the two previous days and day of discharge. RESULTS: Over the 10-day monitoring period, mean SpO2 and HR increased significantly, while breathlessness decreased. The coefficient of variation in SpO2, HR and breathlessness also decreased over the monitoring period. The model predicted SpO2 alerts (SpO2 < 94 %) with a mean cross-validated. sensitivity of 66 ± 18.57 %, specificity of 88.31 ± 10.97 % and area under the receiver operating characteristic of 0.80 ± 0.11. Patient age and sex were not significantly associated with the occurrence of asymptomatic SpO2 alerts. CONCLUSION: Results indicate that SpO2 alerts (SpO2 < 94 %) on a given day can be predicted using SpO2 and heart rate data captured on the two preceding days via remote monitoring. The methods presented may help early identification of patients with COVID-19 at risk of clinical deterioration using remote monitoring.

Pulse Rate Guided Oxygen Saturation Monitoring Using a Wearable Armband Sensor.

Continuous clinical grade measurement of SpO2 in out-of-hospital settings remains a challenge despite the widespread use of photoplethysmography (PPG) based wearable devices for health and wellness applications. This article presents two SpO2 algorithms: PRR (pulse rate derived ratio-of-ratios) and GPDR (green-assisted peak detection ratio-of-ratios), that utilize unique pulse rate frequency estimations to isolate the pulsatile (AC) component of red and infrared PPG signals and derive SpO2 measurements. The performance of the proposed SpO2 algorithms are evaluated using an upper-arm wearable device derived green, red, and infrared PPG signals, recorded in both controlled laboratory settings involving healthy subjects (n=36) and an uncontrolled clinic application involving COVID-19 patients (n=52). GPDR exhibits the lowest root mean square error (RMSE) of 1.6±0.6% for a respiratory exercise test, 3.6 ±1.0% for a standard hypoxia test, and 2.2±1.3% for an uncontrolled clinic use-case. In contrast, PRR provides relatively higher error but with greater coverage overall. Mean error across all combined datasets were 0.2±2.8% and 0.3±2.4% for PRR and GPDR respectively. Both SpO2 algorithms achieve great performance of low error with high coverage on both uncontrolled clinic and controlled laboratory conditions.

The accuracy of pulse oximetry in measuring oxygen saturation by levels of skin pigmentation: a systematic review and meta-analysis.

BACKGROUND: During the COVID-19 pandemic, there have been concerns regarding potential bias in pulse oximetry measurements for people with high levels of skin pigmentation. We systematically reviewed the effects of skin pigmentation on the accuracy of oxygen saturation measurement by pulse oximetry (SpO2) compared with the gold standard SaO2 measured by CO-oximetry. METHODS: We searched Ovid MEDLINE, Ovid Embase, EBSCO CINAHL, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform (up to December 2021) for studies with SpO2-SaO2 comparisons and measuring the impact of skin pigmentation or ethnicity on pulse oximetry accuracy. We performed meta-analyses for mean bias (the primary outcome in this review) and its standard deviations (SDs) across studies included for each subgroup of skin pigmentation and ethnicity and used these pooled mean biases and SDs to calculate accuracy root-mean-square (Arms) and 95% limits of agreement. The review was registered with the Open Science Framework ( https://osf.io/gm7ty ). RESULTS: We included 32 studies (6505 participants): 15 measured skin pigmentation and 22 referred to ethnicity. Compared with standard SaO2 measurement, pulse oximetry probably overestimates oxygen saturation in people with the high level of skin pigmentation (pooled mean bias 1.11%; 95% confidence interval 0.29 to 1.93%) and people described as Black/African American (1.52%; 0.95 to 2.09%) (moderate- and low-certainty evidence). The bias of pulse oximetry measurements for people with other levels of skin pigmentation or those from other ethnic groups is either more uncertain or suggests no overestimation. Whilst the extent of mean bias is small or negligible for all subgroups evaluated, the associated imprecision is unacceptably large (pooled SDs > 1%). When the extent of measurement bias and precision is considered jointly, pulse oximetry measurements for all the subgroups appear acceptably accurate (with Arms < 4%). CONCLUSIONS: Pulse oximetry may overestimate oxygen saturation in people with high levels of skin pigmentation and people whose ethnicity is reported as Black/African American, compared with SaO2. The extent of overestimation may be small in hospital settings but unknown in community settings. REVIEW PROTOCOL REGISTRATION: https://osf.io/gm7ty.

Viruses and Mycoplasma pneumoniae are the main etiological agents of community-acquired pneumonia in hospitalized pediatric patients in Spain.

OBJECTIVES: To describe the etiology of community-acquired pneumonia (CAP) in hospitalized children in Spain and analyze the predictors of the etiology. HYPOTHESIS: The different etiological groups of pediatric CAP are associated with different clinical, radiographic, and analytical data. DESIGN: Observational, multicenter, and prospective study. PATIENT SELECTION: This study included children aged 1 month to 17 years with CAP, who were hospitalized between April 2012 and May 2019. METHODS: An extensive microbiological workup was performed. The clinical, radiographic, and analytical parameters were analyzed for three etiological groups. RESULTS: Among the 495 children included, at least one causative pathogen was identified in 262 (52.9%): pathogenic viruses in 155/262 (59.2%); atypical bacteria (AB), mainly Mycoplasma pneumonia, in 84/262 (32.1%); and typical bacteria (TyB) in 40/262 (15.3%). Consolidation was observed in 89/138 (64.5%) patients with viral CAP, 74/84 (88.1%) with CAP caused by AB, and 40/40 (100%) with CAP caused by TyB. Para-pneumonic pleural effusion (PPE) was observed in 112/495 (22.6%) patients, of which 61/112 (54.5%) presented a likely causative pathogen: viruses in 12/61 (19.7%); AB in 23/61 (37.7%); and TyB in 26/61 (42.6%). Viral etiology was significantly frequent in young patients and in those with low oxygen saturation, wheezing, no consolidation, and high lymphocyte counts. CAP patients with AB as the etiological agent had a significantly longer and less serious course as compared to those with other causative pathogens. CONCLUSIONS: Viruses and M. pneumoniae are the main causes of pediatric CAP in Spain. Wheezing, young age, and no consolidation on radiographs are indicative of viral etiology. Viruses and AB can also cause PPE. Since only a few cases can be directly attributed to TyB, the indications for antibiotics must be carefully considered in each patient.

Rationale and limitations of the SpO2/FiO2 as a possible substitute for PaO2/FiO2 in different preclinical and clinical scenarios. / Justificativa e limitações da SpO2/FiO2 como possível substituta da PaO2/FiO2 em diferentes cenários pré-clínicos e clínicos.

Although the PaO 2/FiO 2 derived from arterial blood gas analysis remains the gold standard for the diagnosis of acute respiratory failure, the SpO2/FiO2 has been investigated as a potential substitute. The current narrative review presents the state of the preclinical and clinical literature on the SpO2/FiO2 as a possible substitute for PaO2/FiO2 and for use as a diagnostic and prognostic marker; provides an overview of pulse oximetry and its limitations, and assesses the utility of SpO2/ FiO2 as a surrogate for PaO2/FiO2 in COVID-19 patients. Overall, 49 studies comparing SpO2/FiO2 and PaO2/FiO2 were found according to a minimal search strategy. Most were conducted on neonates, some were conducted on adults with acute respiratory distress syndrome, and a few were conducted in other clinical scenarios (including a very few on COVID-19 patients). There is some evidence that the SpO2/ FiO2 criteria can be a surrogate for PaO2/FiO2 in different clinical scenarios. This is reinforced by the fact that unnecessary invasive procedures should be avoided in patients with acute respiratory failure. It is undeniable that pulse oximeters are becoming increasingly widespread and can provide costless monitoring. Hence, replacing PaO2/FiO2 with SpO2/FiO2may allow resourcelimited facilities to objectively diagnose acute respiratory failure.

Embora a PaO2/FiO2 derivada da gasometria arterial continue sendo o padrão-ouro do diagnóstico de insuficiência respiratória aguda, a SpO2/FiO2 tem sido investigada como potencial substituta. Esta revisão narrativa apresenta o estado da literatura pré-clínica e clínica sobre a SpO2/FiO2 como possível substituta da PaO2/FiO2 e para uso como marcador diagnóstico e prognóstico; ainda, é fornecida uma visão geral da oximetria de pulso e suas limitações, além da avaliação da utilidade da SpO2/ FiO2 como substituta da PaO2/FiO2 em pacientes com COVID-19. Ao todo, foram encontrados 49 estudos comparando SpO2/FiO2 e PaO2/ FiO2 com base em uma estratégia de pesquisa mínima. A maioria dos estudos foi realizada em recémnascidos, alguns foram realizados em adultos com síndrome do desconforto respiratório agudo, e outros foram realizados em outros cenários clínicos (incluindo poucos em pacientes com COVID-19). Há certa evidência de que os critérios de SpO2/FiO2 podem substituir a PaO2/FiO2 em diferentes cenários clínicos. Isso é reforçado pelo fato de que devem ser evitados procedimentos invasivos desnecessários em pacientes com insuficiência respiratória aguda. É inegável que os oxímetros de pulso estão cada vez mais difundidos e podem proporcionar um monitoramento sem custos. Portanto, substituir a PaO2/FiO2 pela SpO2/FiO2 pode permitir que instalações com recursos limitados diagnostiquem a insuficiência respiratória aguda de maneira objetiva.

Remote investigation and assessment of vital signs (RIA-VS)-proof of concept for contactless estimation of blood pressure, pulse, respiratory rate, and oxygen saturation in patients with suspicion of COVID-19.

BACKGROUND: Vital signs are critical in assessing the severity and prognosis of infections, for example, COVID-19, influenza, sepsis, and pneumonia. This study aimed to evaluate a new method for rapid camera-based non-contact measurement of heart rate, blood oxygen saturation, respiratory rate, and blood pressure. METHODS: Consecutive adult patients attending a hospital emergency department for suspected COVID-19 infection were invited to participate. Vital signs measured with a new camera-based method were compared to the corresponding standard reference methods. The camera device observed the patient's face for 30 s from ∼1 m. RESULTS: Between 1 April and 1 October 2020, 214 subjects were included in the trial, 131 female (61%) and 83 male (39%). The mean age was 44 years (range 18-81 years). The new camera-based device's vital signs measurements were, on average, very close to the gold standard but the random variation was larger than the reference methods. CONCLUSIONS: The principle of contactless measurement of blood pressure, pulse, respiratory rate, and oxygen saturation works, which is very promising. However, technical improvements to the equipment used in this study to reduce its random variability is required before clinical implementation. This will likely be a game changer once this is sorted out. CLINICAL TRIAL REGISTRATION: Universal Trial Number (UTN) U1111-1251-4114 and the ClinicalTrials.gov Identifier NCT04383457.

ROX index and SpO2/FiO2 ratio for predicting high-flow nasal cannula failure in hypoxemic COVID-19 patients: A multicenter retrospective study.

BACKGROUND: The ratio of oxygen saturation (ROX) index, defined as the ratio of oxygen saturation (SpO2)/fraction of inspired oxygen (FiO2) to respiratory rate, can help identify patients with hypoxemic respiratory failure at high risk for intubation following high-flow nasal cannula (HFNC) initiation; however, whether it is effective for predicting intubation in coronavirus disease 2019 (COVID-19) patients receiving HFNC remains unknown. Moreover, the SpO2/FiO2 ratio has been assessed as a prognostic marker for acute hypoxemic respiratory failure. This study aimed to determine the utility of the ROX index and the SpO2/FiO2 ratio as predictors of failure in COVID-19 patients who received HFNC. METHODS: This multicenter study was conducted in seven university-affiliated hospitals in Korea. Data of consecutive hospitalized patients diagnosed with COVID-19 between February 10, 2020 and February 28, 2021 were retrospectively reviewed. We calculated the ROX index and the SpO2/FiO2 ratio at 1 h, 4 h, and 12 h after HFNC initiation. The primary outcome was HFNC failure defined as the need for subsequent intubation despite HFNC application. The receiver operating characteristic curve analysis was used to evaluate discrimination of prediction models for HFNC failure. RESULTS: Of 1,565 hospitalized COVID-19 patients, 133 who received HFNC were analyzed. Among them, 63 patients (47.4%) were successfully weaned from HFNC, and 70 (52.6%) were intubated. Among patients with HFNC failure, 32 (45.7%) died. The SpO2/FiO2 ratio at 1 h after HFNC initiation was an important predictor of HFNC failure (AUC 0.762 [0.679-0.846]). The AUCs of SpO2/FiO2 ratio at 4 h and ROX indices at 1 h and 4 h were 0.733 (0.640-0.826), 0.697 (0.597-0.798), and 0.682 (0.583-0.781), respectively. Multivariable analysis showed that the patients aged ≥70 years are 3.4 times more likely to experience HFNC failure than those aged <70 years (HR 3.367 [1.358-8.349], p = 0.009). The SpO2/FiO2 ratio (HR 0.983 [0.972-0.994], p = 0.003) at 1 h was significantly associated with HFNC failure. CONCLUSIONS: The SpO2/FiO2 ratio following HFNC initiation was an acceptable predictor of HFNC failure. The SpO2/FiO2 ratio may be a good prognostic marker for predicting intubation in COVID-9 patients receiving HFNC.

The role of a noninvasive index 'Spo2/ Fio2' in predicting mortality among patients with COVID-19 pneumonia.

INTRODUCTION: Noninvasive risk assessment is crucial in patients with COVID-19 in emergency department. Since limited data is known about the role of noninvasive parameters, we aimed to evaluate the role of a noninvasive parameter 'SpO2/FiO2' in independently predicting 30-day mortality in patients with COVID-19 and its prognostic utility in combination with a noninvasive score 'CRB-65'. METHODS: A retrospective study was performed in a tertiary training and research hospital, which included 272 patients with COVID-19 pneumonia diagnosed with polymerase chain reaction in emergency department. Data on characteristics, vital signs, and laboratory parameters were recorded from electronic medical records. The primary outcome of the study was 30-day mortality, and we assessed the discriminative ability of SpO2/FiO2 in predicting mortality in patients with COVID-19 pneumonia and its prognostic utility in combination with conventional pneumonia risk assessment scores. RESULTS: Multivariate analysis revealed that only SpO2/FiO2 level was found to be an independent parameter associated with 30-day mortality (OR:0.98, 95% CI: 0.98-0.99, p = 0.003). PSI and CURB-65 were found to be better scores than CRB-65 in predicting 30-day mortality (AUC: 0.79 vs 0.72, p = 0.04; AUC: 0.76 vs 0.72, p = 0.01 respectively). Both SpO2/FiO2 combined with CRB-65 and SpO2/FiO2 combined with CURB-65 have good discriminative ability and seemed to be more favorable than PSI in predicting 30-days mortality (AUC: 0.83 vs 0.75; AUC: 0.84 vs 0.75), however no significant difference was found (p = 0.21 and p = 0.06, respectively). CONCLUSION: SpO2/FiO2 is a promising index in predicting mortality. Addition of SpO2/FiO2 to CRB-65 improved the role of CRB-65 alone, however it performed similar to PSI. The combined noninvasive model of SpO2/FiO2 and CRB-65 may help physicians quickly stratify COVID-19 patients on admission, which is expected to be particularly important in hospitals still stressed by pandemic volumes.