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1.
Sensors (Basel) ; 22(1)2022 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-35009870

RESUMO

Oxyhemoglobin saturation by pulse oximetry (SpO2) has always played an important role in the diagnosis of symptoms. Considering that the traditional SpO2 measurement has a certain error due to the number of wavelengths and the algorithm and the wider application of machine learning and spectrum combination, we propose to use 12-wavelength spectral absorption measurement to improve the accuracy of SpO2 measurement. To investigate the multiple spectral regions for deep learning for SpO2 measurement, three datasets for training and verification were built, which were constructed over the spectra of first region, second region, and full region and their sub-regions, respectively. For each region under the procedures of optimization of our model, a thorough of investigation of hyperparameters is proceeded. Additionally, data augmentation is preformed to expand dataset with added noise randomly, increasing the diversity of data and improving the generalization of the neural network. After that, the established dataset is input to a one dimensional convolution neural network (1D-CNN) to obtain a measurement model of SpO2. In order to enhance the model accuracy, GridSearchCV and Bayesian optimization are applied to optimize the hyperparameters. The optimal accuracies of proposed model optimized by GridSearchCV and Bayesian Optimization is 89.3% and 99.4%, respectively, and trained with the dataset at the spectral region of six wavelengths including 650 nm, 680 nm, 730 nm, 760 nm, 810 nm, 860 nm. The total relative error of the best model is only 0.46%, optimized by Bayesian optimization. Although the spectral measurement with more features can improve the resolution ability of the neural network, the results reveal that the training with the dataset of the shorter six wavelength is redundant. This analysis shows that it is very important to construct an effective 1D-CNN model area for spectral measurement using the appropriate spectral ranges and number of wavelengths. It shows that our proposed 1D-CNN model gives a new and feasible approach to measure SpO2 based on multi-wavelength.


Assuntos
Aprendizado Profundo , Teorema de Bayes , Aprendizado de Máquina , Redes Neurais de Computação , Oximetria
2.
Methods Mol Biol ; 2393: 179-206, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34837180

RESUMO

Tumor development can be indirectly evaluated using features of the tumor microenvironment (TME), such as hemoglobin saturation (HbSat), blood vessel dilation, and formation of new vessels. High values of HbSat and other features of the TME could indicate high metabolic activity and could precede the formation of angiogenic tumors; therefore, changes in HbSat profile can be used as a biomarker for tumor progression. One methodology to evaluate HbSat profile over time, and correlate it with tumor development in vivo in a preclinical model, is through a dorsal skin-fold window chamber. In this chapter, we provide a detailed description of this methodology to evaluate hemoglobin saturation profile and to predict tumor development. We will cover the surgical preparation of the mouse, the installation/maintenance of the dorsal window chamber, and the imaging processing and evaluation to the HbSat profile to predict new development of new tumor areas over time. We included, in this chapter, step by step examples of the imaging processing method to obtain pixel level HbSat values from raw pixels data, the computational method to determine the HbSat profile, and the steps for the classification of the areas into tumor and no-tumor.


Assuntos
Neoplasias , Animais , Diagnóstico por Imagem , Hemoglobinas , Camundongos , Oximetria , Roedores , Microambiente Tumoral
3.
J Neurosurg Anesthesiol ; 34(1): 29-34, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32379101

RESUMO

BACKGROUND: The aim of this study was to assess the diagnostic ability of near-infrared spectroscopy-monitored regional cerebral oxygen saturation (rSO2) to detect cerebral hypoperfusion during internal carotid artery (ICA) clamping compared with motor and somatosensory evoked potential (EP) monitoring. METHODS: This prospective study recruited consecutive patients undergoing carotid endarterectomy under general anesthesia. Significant EP changes (defined as >50% decrease in ipsilateral somatosensory EP amplitude or disappearance of contralateral motor EP on >2 consecutive stimulations) during ICA clamping were considered a warning sign for cerebral hypoperfusion. If significant EP changes occurred, the amplitude of the EPs and simultaneous rSO2 values were recorded before therapeutic intervention. The relationship between reductions in rSO2 and EP amplitudes was analyzed using Spearman rank-correlation analysis. Receiver operating characteristic curve analysis was used to calculate the optimal cutoff value for the relative reduction in rSO2. False-positive rates were evaluated according to immediate postoperative motor outcomes. RESULTS: A total of 203 patients were included for analysis, of whom 23 developed significant EP changes during ICA clamping. There was a positive relationship between decreases in EP amplitude and rSO2 (R2=0.15, P=0.02). A rSO2 reduction ≥16% from baseline had the optimal diagnostic performance for the detection of cerebral hypoperfusion (area under the receiver operating characteristic curve=0.82; 95% confidence interval: 0.76-0.87). The false-positive rate was 8.9%. CONCLUSIONS: Decreases in rSO2 correlated with decreases in EP amplitude during ICA clamping. A relative reduction in rSO2 ≥16% could serve as a warning for clamping-associated cerebral hypoperfusion. The 8.9% false-positive rate is a potential clinical limitation of the use of rSO2 to predict postoperative neurological deficits.


Assuntos
Isquemia Encefálica , Endarterectomia das Carótidas , Isquemia Encefálica/diagnóstico , Circulação Cerebrovascular , Humanos , Oximetria , Oxigênio , Estudos Prospectivos
4.
Pediatr Pulmonol ; 57(1): 209-216, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34633759

RESUMO

INTRODUCTION: Pulse oximetry monitoring is prescribed to children receiving home oxygen for chronic medical conditions associated with hypoxemia. Although home pediatric pulse oximetry is supported by national organizations, there is a lack of guidelines outlining indications and prescribing parameters. METHODS: A mixed-methods analysis of pediatric home pulse oximetry orders prescribed through the institutional home healthcare provider at a large US children's hospital 6/2018-7/2019 was retrospectively reviewed to determine prescribed alarm parameter limits and recommended interventions. Semi-structured qualitative interviews with pediatric providers managing patients receiving home oxygen and pulse oximetry were conducted to identify opportunities to improve home pulse oximetry prescribing practices. Interviews were analyzed using a modified content analysis approach to identify recurring themes. RESULTS: A total of 368 children received home pulse oximetry orders. Orders were most frequently prescribed on noncardiac medical floors (32%). Attending physicians were the most frequent ordering providers (52%). Frequency of use was prescribed in 96% of orders, however, just 70% were provided with specific instructions for interventions when alarms occurred. Provider role and clinical setting were significantly associated with the presence of a care plan. Provider interviews identified opportunities for improvement with the device, management of alarm parameter limits, and access to home monitor data. DISCUSSION: This study demonstrated significant variability in home pulse oximetry prescribing practices. Provider interviews highlighted the importance of the provider-patient relationship and areas for improvement. There is an opportunity to create standardized guidelines that optimize the use of home monitoring devices for patients, families, and pulmonary providers.


Assuntos
Oximetria , Alta do Paciente , Criança , Hospitais Pediátricos , Humanos , Monitorização Fisiológica , Estudos Retrospectivos
5.
J Cyst Fibros ; 20 Suppl 3: 57-63, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34930544

RESUMO

BACKGROUND: Cystic fibrosis (CF) programs and people with CF (PwCF) employed various monitoring methods for virtual care during the COVID-19 pandemic. This paper characterizes experiences with remote monitoring across the U.S. CF community. METHODS: The CF Foundation (CFF) sponsored distribution of home spirometers (April 2020 to May 2021), surveys to PwCF and CF programs (July to September 2020), and a second program survey (April to May 2021). We used mixed methods to explore access, use, and perspectives regarding the use of remote monitoring in future care. RESULTS: By October 2020, 13,345 spirometers had been distributed, and 19,271 spirometers by May 2021. Programs (n=286) estimated proportions of PwCF with home devices increased over seven months: spirometers (30% to 70%), scales (50% to 70%), oximeters (5% to 10%) with higher estimates in adult programs for spirometers and oximeters. PwCF (n=378) had access to scales (89%), followed by oximeters (48%) and spirometers (47%), often using scales and oximeters weekly, and spirometers monthly. Over both surveys, some programs had no method to collect respiratory specimens for cultures associated with telehealth visits (47%, n=132; 41%, n=118). Most programs (81%) had a process for phlebotomy associated with a telehealth visit, primarily through off-site labs. Both PwCF and programs felt future care should advance remote monitoring and recommended improvements for access, training, and data collection systems. CONCLUSIONS: PwCF and programs experienced unprecedented access to remote monitoring and raised its importance for future care. Improvements to current systems may leverage these shared experiences to augment future care models.


Assuntos
COVID-19 , Fibrose Cística , Equipamentos e Provisões/provisão & distribuição , Serviços de Assistência Domiciliar , Monitorização Fisiológica/métodos , Espirometria , Adulto , COVID-19/epidemiologia , COVID-19/prevenção & controle , Criança , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Fibrose Cística/terapia , Atenção à Saúde/organização & administração , Atenção à Saúde/tendências , Acesso aos Serviços de Saúde/organização & administração , Acesso aos Serviços de Saúde/normas , Serviços de Assistência Domiciliar/organização & administração , Serviços de Assistência Domiciliar/normas , Humanos , Modelos Organizacionais , Determinação de Necessidades de Cuidados de Saúde , Oximetria/instrumentação , Oximetria/métodos , Melhoria de Qualidade , SARS-CoV-2 , Espirometria/instrumentação , Espirometria/métodos , Telemedicina/métodos , Telemedicina/normas , Estados Unidos/epidemiologia
7.
S Afr Med J ; 111(10): 950-956, 2021 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-34949288

RESUMO

BACKGROUND: The phenomenon of silent hypoxaemia has been described in patients with COVID-19 pneumonia, which is characterised by low oxygen saturation levels of <90% in those who appear clinically well and do not show signs of significant respiratory distress. OBJECTIVES: To assess the impact on clinical outcomes for high-risk COVID-19 patients using a pulse oximeter to monitor oxygen saturation levels in a home setting. METHODS: We performed a retrospective cohort analysis using data from a large South African insurance administrator. Patients were categorised as high risk, based on age and specific underlying clinical conditions, or from predictive models derived from medical scheme administrative claims data. The impact of pulse oximetry home monitoring on COVID-19 clinical outcomes was investigated by the use of Cox proportional hazard models. RESULTS: Between 2 March 2020 and 31 October 2020, of 38 660 patients analysed, 8 115 were in the intervention group. The 60-day mortality rate for the evaluated high-risk population was 1.35%. After adjusting for age and comorbidity differences, the intervention group was found to have an adjusted hazard ratio of 0.52 (p<0.0001). No statistical significance was found between the intervened and control groups for admission to hospital, admission to intensive care unit (ICU) and use of mechanical ventilation. The intervention group had a lower median C-reactive protein (CRP) level on admission (p=0.03). After adjustment for admission CRP levels, elevated CRP was associated with an increased mortality (p<0.0001), while the statistical significance in mortality between the intervention and the control group was lost. CONCLUSIONS: High-risk COVID-19 patients who used a pulse oximeter to monitor oxygen saturation levels had significantly lower mortality rates compared with other high-risk patients. The mortality benefit may be explained by earlier presentation to hospital, as suggested by lower initial CRP levels.


Assuntos
COVID-19/fisiopatologia , Hospitalização/estatística & dados numéricos , Oximetria/métodos , Adulto , Proteína C-Reativa/metabolismo , COVID-19/mortalidade , Estudos de Coortes , Feminino , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Respiração Artificial/estatística & dados numéricos , Estudos Retrospectivos , Índice de Gravidade de Doença , África do Sul
8.
Sensors (Basel) ; 21(21)2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34770264

RESUMO

Despite the wide range of clinical and research applications, the reliability of the absolute oxygenation measurements of continuous wave near-infrared spectroscopy sensors is often questioned, partially due to issues of standardization. In this study, we have compared the performances of 13 units of a continuous wave near-infrared spectroscopy device (PortaMon, Artinis Medical Systems, NL) to test their suitability for being used in the HEMOCOVID-19 clinical trial in 10 medical centers around the world. Detailed phantom and in vivo tests were employed to measure the precision and reproducibility of measurements of local blood oxygen saturation and total hemoglobin concentration under different conditions: for different devices used, different operators, for probe repositioning over the same location, and over time (hours/days/months). We have detected systematic differences between devices when measuring phantoms (inter-device variability, <4%), which were larger than the intra-device variability (<1%). This intrinsic variability is in addition to the variability during in vivo measurements on the forearm muscle resulting from errors in probe positioning and intrinsic physiological noise (<9%), which was also larger than the inter-device differences (<3%) during the same test. Lastly, we have tested the reproducibility of the protocol of the HEMOCOVID-19 clinical trial; that is, forearm muscle oxygenation monitoring during vascular occlusion tests over days. Overall, our conclusion is that these devices can be used in multi-center trials but care must be taken to characterize, follow-up, and statistically account for inter-device variability.


Assuntos
Oximetria , Espectroscopia de Luz Próxima ao Infravermelho , Oxigênio , Consumo de Oxigênio , Reprodutibilidade dos Testes
9.
Clin Perinatol ; 48(4): 843-853, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34774212

RESUMO

Most extremely premature infants have respiratory instability that can manifest as frequent episodes of intermittent hypoxemia. Although caregivers target clinically recommended ranges of arterial oxygen saturation (oxygen saturation as measured by pulse oximetry [Spo2]), consistent maintenance of these ranges is not always achieved. Excessive administration of supplemental oxygen combined with limited staff resources increases exposure to extreme Spo2 levels. In this population, exposure to hyperoxemia and prolonged episodes of intermittent hypoxemia have been associated with damage to the eye and lung and impaired neurodevelopment. To improve Spo2 targeting, various systems for automated control of inspired oxygen have been developed recently.


Assuntos
Doenças do Prematuro , Humanos , Hipóxia , Lactente , Lactente Extremamente Prematuro , Recém-Nascido , Oximetria , Oxigênio
10.
Clin J Pain ; 37(12): 904-907, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34757342

RESUMO

OBJECTIVES: Evaluation of pain in critically ill intubated patients is difficult and subjective. This study aimed to evaluate the accuracy of oximetry-derived peripheral perfusion index (PPI) in pain assessment in critically ill intubated patients using the behavioral pain scale (BPS) as a reference. MATERIALS AND METHODS: This prospective observational study included 35 adult mechanically ventilated surgical patients during their first 2 postoperative days in the intensive care unit. Values of PPI, BPS, Richmond Agitation Sedation Scale (RASS), heart rate, and blood pressure were obtained before and after a standard painful stimulus (changing the patient position) and the ratio between the second and the first reading was calculated to determine the change (Δ) in all variables. The outcomes were the correlation between ΔBPS and ΔPPI as well as other hemodynamic parameters. The ability of the PPI to detect pain (defined as BPS ≥6) was analyzed using the area under receiver operating characteristic curve. RESULTS: Paired readings were obtained from 35 patients. After the standard painful stimulus, the PPI decreased while the BPS and the Richmond agitation sedation scale increased. The Spearman correlation coefficient (95% confidence interval) between Δ PPI and Δ BPS was 0.41 (0.09-0.65). PPI values showed poor accuracy in detecting pain with area under receiver operating characteristic curve (95% confidence interval): 0.65 (0.53-0.76), with best cutoff value of ≤2.7. CONCLUSION: The PPI decreased after application of a standard painful stimulus in critically ill intubated patients. ∆PPI showed a low correlation with ∆BPS, and a PPI of ≤2.7 showed a low ability to detect BPS ≥6. Therefore, PPI should not be used for pain evaluation in critically ill intubated surgical patients.


Assuntos
Estado Terminal , Índice de Perfusão , Adulto , Humanos , Oximetria , Dor , Medição da Dor
11.
Pan Afr Med J ; 39: 203, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34603584

RESUMO

Introduction: the COVID-19 pandemic has necessitated the prolonged use of facemasks by healthcare workers. Facemask non-compliance has been largely blamed on discomfort associated with the mask, and apprehension regarding potential health hazards such as asphyxia from mask usage. We sought to evaluate the impact of different respiratory mask types on the comfort of healthcare workers and their arterial oxygen saturation during periods of active clinical duty. Methods: we conducted a cross-sectional study on healthcare workers donning different types of facemasks in the normal course of duty. Objective non-invasive determination of arterial oxygen saturation of each participant was done using a portable pulse oximeter. Subjective self-assessment of global discomfort was scored by means of a 11-point numerical scale from 0 (no discomfort) to 10 (worst discomfort imaginable). The user's perceived elements of the discomfort were also evaluated. A statistical significance was accepted when P <0.05. Results: seventy-six healthcare workers completed the study, and wore the masks for periods ranging from 68-480 minutes. The discomfort experienced with the use of the N95 mask; 4.3 (2.0) was greater than the surgical mask; 2.7 (1.8); P=0.001. No significant change in arterial oxygen saturation was observed with the use of either of the mask types. The tight strapping of the N95 mask was perceived as a contributor to the discomfort experienced with mask usage; P=0.009. Conclusion: the N95 masks imposed greater discomfort than the surgical masks, but neither of the masks impacted on the arterial oxygen saturation of the healthcare workers.


Assuntos
COVID-19 , Pessoal de Saúde/psicologia , Máscaras/efeitos adversos , Oxigênio/metabolismo , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Respiradores N95/efeitos adversos , Oximetria , Fatores de Tempo
12.
BMJ Open ; 11(10): e051978, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625416

RESUMO

OBJECTIVE: Extraction and standardisation of pulse oximetry and supplemental oxygen data from electronic health records has the potential to improve risk-adjustment, quality assessment and prognostication. We develop an approach to standardisation and report on its use for benchmarking purposes. MATERIALS AND METHODS: Using electronic health record data from the nationwide Veteran's Affairs healthcare system (2013-2017), we extracted, standardised and validated pulse oximetry and supplemental oxygen data for 2 765 446 hospitalisations in the Veteran's Affairs Patient Database (VAPD) cohort study. We assessed face, concurrent and predictive validities using the following approaches, respectively: (1) evaluating the stability of patients' pulse oximetry values during a 24-hour period, (2) testing for greater amounts of supplemental oxygen use in patients likely to need oxygen therapy and (3) examining the association between supplemental oxygen and subsequent mortality. RESULTS: We found that 2 700 922 (98%) hospitalisations had at least one pulse oximetry reading, and 864 605 (31%) hospitalisations received oxygen therapy. Patients monitored by pulse oximetry had a reading on average every 6 hours (median 4; IQR 3-7). Patients on supplemental oxygen were older, white and male compared with patients not receiving oxygen therapy (p<0.001) and were more likely to have diagnoses of heart failure and chronic pulmonary diseases (p<0.001). The amount of supplemental oxygen for patients with at least three consecutive values recorded during a 24-hour period fluctuated by median 2 L/min (IQR: 2-3), and 81% of such triplets showed the same level of oxygen receipt. CONCLUSION: Our approach to standardising pulse oximetry and supplemental oxygen data shows face, concurrent and predictive validities as the following: supplemental oxygen clusters in the range consistent with hospital wall-dispensed oxygen supplies (face validity); there are greater amounts of supplemental oxygen for certain clinical conditions (concurrent validity) and there is an association of supplemental oxygen with in-hospital and postdischarge mortality (predictive validity).


Assuntos
Assistência ao Convalescente , Veteranos , Estudos de Coortes , Hospitais , Humanos , Masculino , Oximetria , Oxigênio , Alta do Paciente , Saúde dos Veteranos
13.
Aerosp Med Hum Perform ; 92(10): 780-785, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34641998

RESUMO

BACKGROUND: A growing number of symptom reports suggestive of acceleration atelectasis in fast jet aircrew have raised the question as to whether traditional guidelines on inspired gas composition remain valid. The aim of this study was to assess the effects of inspired O2 concentration on the development of acceleration atelectasis when wearing modern anti-G garments. METHODS: There were 14 nonaircrew subjects who completed 5 centrifuge exposures to +5 Gz lasting 90 s. During exposures subjects breathed a gas mixture containing 21, 35, 45, 60, or 75% O2. To assess the extent of atelectasis post-Gz, forced inspiratory vital capacity (FIVC), regional FIVC (EITFIVC), shunt, respiratory resistance, reactance, and compliance and peripheral O2 saturation during a hypoxic exposure were measured. RESULTS: Compared with baseline, FIVC was not statistically significantly altered. EITFIVC was 14.4% lower after the 75% O2 exposure only with a greater symptom reporting with higher FIO2 in some individuals. A significantly greater shunt (3>6%) followed the 60 and 75% O2 exposures. O2 concentration during Gz had no effect on respiratory resistance, reactance, compliance, or hypoxemia. DISCUSSION: There is evidence of mild acceleration atelectasis present when breathing 60% O2, particularly in susceptible individuals, with 75% O2 causing more obvious physiological compromise. An inspired oxygen concentration of <60% will prevent the majority of individuals from developing acceleration atelectasis. Pollock RD, Gates SD, Radcliffe JJ, Stevenson AT. Indirect measurements of acceleration atelectasis and the role of inspired oxygen concentrations. Aerosp Med Hum Perform. 2021; 92(10):780785.


Assuntos
Oxigênio , Atelectasia Pulmonar , Aceleração , Humanos , Hipóxia , Oximetria
14.
Clinics (Sao Paulo) ; 76: e3056, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34614114

RESUMO

OBJECTIVES: Owing to the fact that obstructive sleep apnea (OSA) is an underreported disease, the strategy used for the diagnosis of OSA has been extensively dissected to devise a simplified process that can be accessed by the public health services. Polysomnography (PSG) type I, the gold standard for the diagnosis of OSA, is expensive and difficult to access by low-income populations. In this study, we aimed to verify the accuracy of the oxyhemoglobin desaturation index (ODI) in comparison to the apnea-hypopnea index (AHI) using a portable monitor. METHODS: We evaluated 94 type III PSG home test results of 65 elderly patients (69.21±6.94 years old), along with information, such as the body mass index (BMI) and sex, using data obtained from a clinical trial database. RESULTS: A significant linear positive correlation (r=0.93, p<0.05) was observed between ODI and AHI, without any interference from sex, BMI, and positional component. The sensitivity of ODI compared to that of AHI increased with an increase in the severity of OSA, while the specificity of ODI in comparison to that of AHI was high for all degrees of severity. The accuracy of ODI was 80.7% for distinguishing between patients with mild and moderate apnea and 84.4% for distinguishing between patients with moderate and severe apnea. CONCLUSION: The ODI values obtained in uncontrolled conditions exhibited high sensitivity for identifying severe apnea compared to the AHI values, and correctly identified the severity of OSA in more than 80% of the cases. Thus, oximetry is promising strategy for diagnosing OSA.


Assuntos
Apneia Obstrutiva do Sono , Idoso , Índice de Massa Corporal , Humanos , Pessoa de Meia-Idade , Oximetria , Polissonografia , Apneia Obstrutiva do Sono/diagnóstico
15.
Medicine (Baltimore) ; 100(40): e27422, 2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34622851

RESUMO

ABSTRACT: As severe acute respiratory syndrome coronavirus 2 continues to spread, easy-to-use risk models that predict hospital mortality can assist in clinical decision making and triage. We aimed to develop a risk score model for in-hospital mortality in patients hospitalized with 2019 novel coronavirus (COVID-19) that was robust across hospitals and used clinical factors that are readily available and measured standardly across hospitals.In this retrospective observational study, we developed a risk score model using data collected by trained abstractors for patients in 20 diverse hospitals across the state of Michigan (Mi-COVID19) who were discharged between March 5, 2020 and August 14, 2020. Patients who tested positive for severe acute respiratory syndrome coronavirus 2 during hospitalization or were discharged with an ICD-10 code for COVID-19 (U07.1) were included. We employed an iterative forward selection approach to consider the inclusion of 145 potential risk factors available at hospital presentation. Model performance was externally validated with patients from 19 hospitals in the Mi-COVID19 registry not used in model development. We shared the model in an easy-to-use online application that allows the user to predict in-hospital mortality risk for a patient if they have any subset of the variables in the final model.Two thousand one hundred and ninety-three patients in the Mi-COVID19 registry met our inclusion criteria. The derivation and validation sets ultimately included 1690 and 398 patients, respectively, with mortality rates of 19.6% and 18.6%, respectively. The average age of participants in the study after exclusions was 64 years old, and the participants were 48% female, 49% Black, and 87% non-Hispanic. Our final model includes the patient's age, first recorded respiratory rate, first recorded pulse oximetry, highest creatinine level on day of presentation, and hospital's COVID-19 mortality rate. No other factors showed sufficient incremental model improvement to warrant inclusion. The area under the receiver operating characteristics curve for the derivation and validation sets were .796 (95% confidence interval, .767-.826) and .829 (95% confidence interval, .782-.876) respectively.We conclude that the risk of in-hospital mortality in COVID-19 patients can be reliably estimated using a few factors, which are standardly measured and available to physicians very early in a hospital encounter.


Assuntos
COVID-19/mortalidade , Mortalidade Hospitalar/tendências , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Comorbidade , Creatinina/sangue , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Modelos Logísticos , Masculino , Michigan/epidemiologia , Pessoa de Meia-Idade , Oximetria , Prognóstico , Curva ROC , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , SARS-CoV-2 , Índice de Gravidade de Doença , Fatores Sexuais , Fatores Socioeconômicos
17.
Resuscitation ; 168: 110-118, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34600027

RESUMO

AIM: Evaluate cerebrovascular autoregulation (CAR) using near-infrared spectroscopy (NIRS) after pediatric cardiac arrest and determine if deviations from CAR-derived optimal mean arterial pressure (MAPopt) are associated with outcomes. METHODS: CAR was quantified by a moving, linear correlation between time-synchronized mean arterial pressure (MAP) and regional cerebral oxygenation, called cerebral oximetry index (COx). MAPopt was calculated using a multi-window weighted algorithm. We calculated burden (magnitude and duration) of MAP less than 5 mmHg below MAPopt (MAPopt - 5), as the area between MAP and MAPopt - 5 curves using numerical integration and normalized as percentage of monitoring duration. Unfavorable outcome was defined as death or pediatric cerebral performance category (PCPC) at hospital discharge ≥3 with ≥1 change from baseline. Univariate logistic regression tested association between burden of MAP less than MAPopt - 5 and outcome. RESULTS: Thirty-four children (median age 2.9 [IQR 1.5,13.4] years) were evaluated. Median COx in the first 24 h post-cardiac arrest was 0.06 [0,0.20]; patients spent 27% [19,43] of monitored time with COx ≥ 0.3. Patients with an unfavorable outcome (n = 24) had a greater difference between MAP and MAPopt - 5 (13 [11,19] vs. 9 [8,10] mmHg, p = 0.01) and spent more time with MAP below MAPopt - 5 (38% [26,61] vs. 24% [14,28], p = 0.03). Patients with unfavorable outcome had a higher burden of MAP less than MAPopt - 5 than patients with favorable outcome in the first 24 h post-arrest (187 [107,316] vs. 62 [43,102] mmHg × Min/Hr; OR 4.93 [95% CI 1.16-51.78]). CONCLUSIONS: Greater burden of MAP below NIRS-derived MAPopt - 5 during the first 24 h after cardiac arrest was associated with unfavorable outcomes.


Assuntos
Circulação Cerebrovascular , Parada Cardíaca , Pressão Arterial , Pressão Sanguínea , Criança , Pré-Escolar , Parada Cardíaca/terapia , Humanos , Oximetria
18.
Med Sci Monit ; 27: e930776, 2021 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-34635632

RESUMO

During the coronavirus disease 2019 (COVID-19) pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, patients presented with COVID-19 pneumonia of varying severity. The phenomenon of severe hypoxemia without signs of respiratory distress is also known as silent or hidden hypoxemia. Although silent hypoxemia is not unique to pneumonia due to SARS-CoV-2 infection, this phenomenon is now recognized to be associated with severe COVID-19 pneumonia. Proper management of critically ill patients is the key to reducing mortality. Herein, we summarize the possible and rare factors contributing to silent hypoxemia in patients with COVID-19. Microvascular thrombosis causes dead space ventilation in the lungs, and the flow of pulmonary capillaries is reduced, which leads to an imbalance in the V/Q ratio. The dissociation curve of oxyhemoglobin shifts to the left and limits the release of oxygen to the tissue. SARS-CoV-2 interferes with the synthesis of hemoglobin and reduces the ability to carry oxygen. The accumulation of endogenous carbon monoxide and carboxyhemoglobin will reduce the total oxygen carrying capacity and interfere with pulse oxygen saturation readings. There are also some non-specific factors that cause the difference between pulse oximetry and oxygen partial pressure. We propose some potentially more effective clinical alternatives and recommendations for optimizing the clinical management processes of patients with COVID-19. This review aims to describe the prevalence of silent hypoxemia in COVID-19 pneumonia, to provide an update on what is known of the pathophysiology, and to highlight the importance of diagnosing silent hypoxemia in patients with COVID-19 pneumonia.


Assuntos
COVID-19/metabolismo , Hipóxia/virologia , Pneumonia Viral/virologia , Doenças Assintomáticas/epidemiologia , COVID-19/epidemiologia , COVID-19/virologia , Humanos , Hipóxia/epidemiologia , Hipóxia/metabolismo , Pulmão/citologia , Pulmão/metabolismo , Pulmão/virologia , Microvasos/metabolismo , Oximetria , Oxigênio/metabolismo , Pneumonia Viral/metabolismo , Prevalência , SARS-CoV-2/isolamento & purificação , Trombose/metabolismo , Trombose/virologia
19.
Medicina (Kaunas) ; 57(10)2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34684147

RESUMO

Background and objectives: Exertional desaturation (ED) is often overlooked in chronic obstructive pulmonary disease (COPD). We aim to investigate the impact of ED on mortality and the predictors of ED in COPD. Materials andmethods: A cohort of COPD patients with clinically stable, widely ranging severities were enrolled. ED is defined as oxyhemoglobin saturation by pulse oximetry (SpO2) < 90% or a drop of ΔSpO2 ≥ 4% during a six-minute walk test (6MWT). Cox regression analysis is used to estimate the hazard ratio (HR) for three-year mortality. Results: A total of 113 patients were studied, including ED (N = 34) and non-ED (N = 79) groups. FVC (% of predicted value), FEV1/FVC (%), FEV1 (% of predicted value), DLCO (%), maximal inspiratory pressure, SpO2 during the 6MWT, GOLD stage, and COPD severity were significantly different between the ED and non-ED groups in univariate analysis. Low minimal SpO2 (p < 0.001) and high maximal heart rate (p = 0.04) during the 6MWT were significantly related to ED in multivariate analysis. After adjusting for age, gender, body mass index, 6MWD, FEV1, mMRC, GOLD staging, exacerbation, hs-CRP, and fibrinogen, the mortality rate of the ED group was higher than that of the non-ED group (p = 0.012; HR = 4.12; 95% CI 1.37-12.39). For deaths, the average survival time of ED was shorter than that of the non-ED group (856.4 days vs. 933.8 days, p = 0.033). Conclusions: ED has higher mortality than non-ED in COPD. COPD should be assessed for ED, especially in patients with low minimal SpO2 and high maximal HR during the 6MWT.


Assuntos
Doença Pulmonar Obstrutiva Crônica , Caminhada , Humanos , Oximetria , Testes de Função Respiratória , Teste de Caminhada
20.
Sleep Med Clin ; 16(4): 567-574, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34711382

RESUMO

Sleep studies have typically followed criteria established many decades ago, but emerging technologies allow signal analyses that go far beyond the scoring rules for manual analysis of sleep recordings. These technologies may apply to the analysis of signals obtained in standard polysomnography in addition to novel signals more recently developed that provide both direct and indirect measures of sleep and breathing in the ambulatory setting. Automated analysis of signals such as electroencephalogram and oxygen saturation, in addition to heart rate and rhythm, provides a wealth of additional information on sleep and breathing disturbances and their potential for comorbidity.


Assuntos
Síndromes da Apneia do Sono , Apneia Obstrutiva do Sono , Humanos , Oximetria , Polissonografia , Sono , Síndromes da Apneia do Sono/diagnóstico , Síndromes da Apneia do Sono/terapia
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