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1.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33563754

RESUMO

COVID-19 transmits by droplets generated from surfaces of airway mucus during processes of respiration within hosts infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. We studied respiratory droplet generation and exhalation in human and nonhuman primate subjects with and without COVID-19 infection to explore whether SARS-CoV-2 infection, and other changes in physiological state, translate into observable evolution of numbers and sizes of exhaled respiratory droplets in healthy and diseased subjects. In our observational cohort study of the exhaled breath particles of 194 healthy human subjects, and in our experimental infection study of eight nonhuman primates infected, by aerosol, with SARS-CoV-2, we found that exhaled aerosol particles vary between subjects by three orders of magnitude, with exhaled respiratory droplet number increasing with degree of COVID-19 infection and elevated BMI-years. We observed that 18% of human subjects (35) accounted for 80% of the exhaled bioaerosol of the group (194), reflecting a superspreader distribution of bioaerosol analogous to a classical 20:80 superspreader of infection distribution. These findings suggest that quantitative assessment and control of exhaled aerosol may be critical to slowing the airborne spread of COVID-19 in the absence of an effective and widely disseminated vaccine.


Assuntos
/fisiopatologia , Expiração/fisiologia , Obesidade/fisiopatologia , Aerossóis , Fatores Etários , Animais , Índice de Massa Corporal , /virologia , Estudos de Coortes , Humanos , Muco/química , Muco/virologia , Obesidade/epidemiologia , Obesidade/virologia , Tamanho da Partícula , Primatas , Sistema Respiratório/metabolismo , Carga Viral
2.
Medicine (Baltimore) ; 100(6): e23570, 2021 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-33578509

RESUMO

ABSTRACT: The Gas Man simulation software provides an opportunity to teach, understand and examine the pharmacokinetics of volatile anesthetics. The primary aim of this study was to investigate the accuracy of a cardiac output and alveolar ventilation matched Gas Man model and to compare its predictive performance with the standard pharmacokinetic model using patient data.Therefore, patient data from volatile anesthesia were successively compared to simulated administration of desflurane and sevoflurane for the standard and a parameter-matched simulation model with modified alveolar ventilation and cardiac output. We calculated the root-mean-square deviation (RMSD) between measured and calculated induction, maintenance and elimination and the expiratory decrement times during emergence and recovery for the standard and the parameter-matched model.During induction, RMSDs for the standard Gas Man simulation model were higher than for the parameter-matched Gas Man simulation model [induction (desflurane), standard: 1.8 (0.4) % Atm, parameter-matched: 0.9 (0.5) % Atm., P = .001; induction (sevoflurane), standard: 1.2 (0.9) % Atm, parameter-matched: 0.4 (0.4) % Atm, P = .029]. During elimination, RMSDs for the standard Gas Man simulation model were higher than for the parameter-matched Gas Man simulation model [elimination (desflurane), standard: 0.7 (0.6) % Atm, parameter-matched: 0.2 (0.2) % Atm, P = .001; elimination (sevoflurane), standard: 0.7 (0.5) % Atm, parameter-matched: 0.2 (0.2) % Atm, P = .008]. The RMSDs during the maintenance of anesthesia and the expiratory decrement times during emergence and recovery showed no significant differences between the patient and simulated data for both simulation models.Gas Man simulation software predicts expiratory concentrations of desflurane and sevoflurane in humans with good accuracy, especially when compared to models for intravenous anesthetics. Enhancing the standard model by ventilation and hemodynamic input variables increases the predictive performance of the simulation model. In most patients and clinical scenarios, the predictive performance of the standard Gas Man simulation model will be high enough to estimate pharmacokinetics of desflurane and sevoflurane with appropriate accuracy.


Assuntos
Débito Cardíaco/efeitos dos fármacos , Desflurano/farmacocinética , Expiração/fisiologia , Ventilação Pulmonar/fisiologia , Sevoflurano/farmacocinética , Adulto , Idoso , Algoritmos , Anestésicos Inalatórios/administração & dosagem , Anestésicos Inalatórios/farmacocinética , Débito Cardíaco/fisiologia , Ensaios Clínicos como Assunto , Simulação por Computador/estatística & dados numéricos , Desflurano/administração & dosagem , Quimioterapia Combinada , Feminino , Humanos , Pulmão/metabolismo , Pulmão/fisiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/metabolismo , Alvéolos Pulmonares/fisiologia , Sevoflurano/administração & dosagem
3.
PLoS One ; 15(12): e0243971, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33332454

RESUMO

BACKGROUND: Expiratory flow-initiated pressure-controlled inverse ratio ventilation (EF-initiated PC-IRV) reduces physiological dead space. We hypothesised that EF-initiated PC-IRV would be lung protective compared with volume-controlled ventilation (VCV). METHODS: Twenty-eight men undergoing robot-assisted laparoscopic radical prostatectomy were enrolled in this randomised controlled trial. The EF-initiated PC-IRV group (n = 14) used pressure-controlled ventilation with the volume guaranteed mode. The inspiratory to expiratory (I:E) ratio was individually adjusted by observing the expiratory flow-time wave. The VCV group (n = 14) used the volume control mode with a 1:2 I:E ratio. The Mann-Whitney U test was used to compare differences in the serum cytokine levels. RESULTS: There were no significant differences in serum IL-6 between the EF-initiated PC-IRV (median 34 pg ml-1 (IQR 20.5 to 63.5)) and VCV (31 pg ml-1 (24.5 to 59)) groups (P = 0.84). The physiological dead space rate (physiological dead space/expired tidal volume) was significantly reduced in the EF-initiated PC-IRV group as compared with that in the VCV group (0.31 ± 0.06 vs 0.4 ± 0.07; P<0.001). The physiological dead space rate was negatively correlated with the forced vital capacity (% predicted) in the VCV group (r = -0.85, P<0.001), but not in the EF-initiated PC-IRV group (r = 0.15, P = 0.62). Two patients in the VCV group had permissive hypercapnia with low forced vital capacity (% predicted). CONCLUSIONS: There were no differences in the lung-protective properties between the two ventilatory strategies. However, EF-initiated PC-IRV reduced physiological dead space rate; thus, it may be useful for reducing the ventilatory volume that is necessary to maintain normocapnia in patients with low forced vital capacity (% predicted) during robot-assisted laparoscopic radical prostatectomy.


Assuntos
Expiração/fisiologia , Pulmão/fisiologia , Respiração com Pressão Positiva , Respiração Artificial/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Ventilação com Pressão Positiva Intermitente , Masculino , Pessoa de Meia-Idade , Troca Gasosa Pulmonar/fisiologia , Volume de Ventilação Pulmonar/fisiologia , Adulto Jovem
4.
J Acoust Soc Am ; 148(6): 3385, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33379875

RESUMO

Forced expiratory (FE) noise is a powerful bioacoustic signal containing information on human lung biomechanics. FE noise is attributed to a broadband part and narrowband components-forced expiratory wheezes (FEWs). FE respiratory noise is composed by acoustic and hydrodynamic mechanisms. An origin of the most powerful mid-frequency FEWs (400-600 Hz) is associated with the 0th-3rd levels of bronchial tree in terms of Weibel [(2009). Swiss Med. Wkly. 139(27-28), 375-386], whereas high-frequency FEWs (above 600 Hz) are attributed to the 2nd-6th levels of bronchial tree. The laboratory prototype of the apparatus is developed, which includes the electret microphone sensor with stethoscope head, a laptop with external sound card, and specially developed software. An analysis of signals by the new method, including FE time in the range from 200 to 2000 Hz and band-pass durations and energies in the 200-Hz bands evaluation, is applied instead of FEWs direct measures. It is demonstrated experimentally that developed FE acoustic parameters correspond to basic indices of lung function evaluated by spirometry and body plethysmography and may be even more sensitive to some respiratory deviations. According to preliminary experimental results, the developed technique may be considered as a promising instrument for acoustic monitoring human lung function in extreme conditions, including diving and space flights. The developed technique eliminates the contact of the sensor with the human oral cavity, which is characteristic for spirometry and body plethysmography. It reduces the risk of respiratory cross-contamination, especially during outpatient and field examinations, and may be especially relevant in the context of the COVID-19 pandemic.


Assuntos
Acústica/instrumentação , Expiração/fisiologia , Sons Respiratórios/diagnóstico , Humanos , Ruído
6.
JAMA Netw Open ; 3(7): e2013807, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32716517

RESUMO

Importance: Individuals with asymptomatic or mild coronavirus disease 2019 (COVID-19) have been reported to frequently transmit the disease even without direct contact. The severe acute respiratory syndrome coronavirus 2 has been found at very high concentrations in swab and sputum samples from such individuals. Objective: To estimate the virus levels released from individuals with asymptomatic to moderate COVID-19 into different aerosol sizes by normal breathing and coughing, and to determine what exposure could result from this in a room shared with such individuals. Design, Setting, and Participants: This mathematical modeling study combined the size-distribution of exhaled breath microdroplets for coughing and normal breathing with viral swab and sputum concentrations as approximation for lung lining liquid to obtain an estimate of emitted virus levels. Viral data were obtained from studies published as of May 20, 2020. The resulting emission data fed a single-compartment model of airborne concentrations in a room of 50 m3, the size of a small office or medical examination room. Main Outcomes and Measures: Modeling was used to estimate the viral load emitted by individuals breathing normally or coughing, and the concentrations expected in the simulated room at different ventilation rates. Results: The mean estimated viral load in microdroplets emitted by simulated individuals while breathing regularly was 0.0000049 copies/cm3, with a range of 0.0000000049 to 0.637 copies/cm3. The corresponding estimates for simulated coughing individuals were a mean of 0.277 copies/cm3 per cough, with a range of 0.000277 to 36 030 copies/cm3 per cough. The estimated concentrations in a room with an individual who was coughing frequently were very high, with a maximum of 7.44 million copies/m3 from an individual who was a high emitter. However, regular breathing from an individual who was a high emitter was modeled to result in lower room concentrations of up to 1248 copies/m3. Conclusions and Relevance: In this modeling study, breathing and coughing were estimated to release large numbers of viruses, ranging from thousands to millions of virus copies per cubic meter in a room with an individual with COVID-19 with a high viral load, depending on ventilation and microdroplet formation process. The estimated infectious risk posed by a person with typical viral load who breathes normally was low. The results suggest that only few people with very high viral load pose an infection risk in poorly ventilated closed environments. These findings suggest that strict respiratory protection may be needed when there is a chance to be in the same small room with an individual, whether symptomatic or not, especially for a prolonged period.


Assuntos
Doenças Assintomáticas , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Tosse/virologia , Expiração/fisiologia , Modelos Estatísticos , Pneumonia Viral/transmissão , Pneumonia Viral/virologia , Carga Viral , Betacoronavirus , Infecções por Coronavirus/epidemiologia , Meio Ambiente , Humanos , Pandemias , Pneumonia Viral/epidemiologia , Ventilação
7.
Arch Dis Child Fetal Neonatal Ed ; 105(6): 669-671, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32669360

RESUMO

BACKGROUND: The COVID-19 pandemic has raised concern for healthcare workers getting infected via aerosol from non-invasive respiratory support of infants. Attaching filters that remove viral particles in air from the expiratory limb of continuous positive airway pressure (CPAP) devices should theoretically decrease the risk. However, adding filters to the expiratory limb could add to expiratory resistance and thereby increase the imposed work of breathing (WOB). OBJECTIVE: To evaluate the effects on imposed WOB when attaching filters to the expiratory limb of CPAP devices. METHODS: Two filters were tested on three CPAP systems at two levels of CPAP in a mechanical lung model. Main outcome was imposed WOB. RESULTS: There was a minor increase in imposed WOB when attaching the filters. The differences between the two filters were small. CONCLUSION: To minimise contaminated aerosol generation during CPAP treatment, filters can be attached to expiratory tubing with only a minimal increase in imposed WOB in a non-humidified environment. Care has to be taken to avoid filter obstruction and replace filters as recommended.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Infecções por Coronavirus/prevenção & controle , Filtração/instrumentação , Controle de Infecções/instrumentação , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Betacoronavirus , Expiração/fisiologia , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Modelos Anatômicos , Trabalho Respiratório/fisiologia
8.
Rev. int. med. cienc. act. fis. deporte ; 20(78): 197-210, jun. 2020. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-194777

RESUMO

OBJETIVO: determinar el efecto de una prueba aeróbica de natación en piscina clorada indoor sobre la concentración de NO2-, H2O2 y el pH en el condensado del aire espirado. MÉTODO: diez nadadores aficionados nadaron 2,5 km en piscina clorada. Se obtuvieron muestras antes y en cuatro oportunidades durante las ocho horas posteriores a la prueba. El análisis estadístico usó modelos mixtos y la prueba de Spearman RESULTADOS: la prueba se realizó a 74,99 ± 10,10 % de la reserva cardíaca y duró 50,80 ± 8,98 minutos. Posterior a la prueba disminuyó el NO2- (p = 0,04) y el pH (p = 0,02) en el condensado del aire espirado. Los valores pre-ejercicio se relacionaron con los cambios absolutos p = 0,0002, p = 0,047 y con el volumen de entrenamiento p = 0,017, p = 0,077 para NO2- y H2O2 respectivamente. CONCLUSIONES: la natación en piscina clorada disminuye la concentración de NO2- y el pH en el condensado del aire espirado


OBJECTIVE: to determine the effect of an aerobic swimming test in chlorinated indoor swimming pool on the concentration of NO2-, H2O2 and the pH in the exhaled breath condensate. METHODS: ten amateur swimmers swam 2,5 km in a chlorinated pool. Samples were obtained before and four times in the eight hours after the test. The statistical analysis used mixed models and the Spearman test. RESULTS: the test was performed at 74,99 ± 10,10 % of the cardiac reserve and lasted 50,80 ± 8,98 minutes. After the test the NO2- (p = 0,04) and the pH (p = 0,02) in the exhaled air condensate decreased. The pre-exercise values were related to the absolute changes p = 0,0002, p = 0.047 and with the training volume p = 0,017, p = 0.077 for NO2- and H2O2 respectively. CONCLUSIONS: Swimming in a chlorinated pool decreases the NO2-concentration and the pH in the exhaled breath condensate


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , Natação/fisiologia , Expiração/fisiologia , Exercício Físico/fisiologia , Testes Respiratórios/métodos , Concentração de Íons de Hidrogênio , Nitritos , Piscinas , Pulmão/metabolismo , Oxidantes/metabolismo , Consumo de Oxigênio/fisiologia
9.
Apunts, Med. esport (Internet) ; 55(206): 81-85, abr.-jun. 2020. tab, graf
Artigo em Inglês | IBECS | ID: ibc-189898

RESUMO

The spread of CoV-2 occurs mainly by respiratory droplets. Its dispersion depends on several factors: viscoelasticity of fluid, ventilation, evaporation rate, exhalations, sneeze or cough. At moment, the preventive distance to avoid the contamination has been established in 1-2 m. We believe that it is necessary to review this aspect, because the respiratory flows change with the intensity of physical activity. The ventilatory response can be evaluated in terms of ventilatory demand or ventilatory efficiency. During maximal effort tests, athletes mobilize an extraordinary amount of air arriving to 150/200 L/min. The respiratory volume follows increase in linear progression during the test in function of power developed. When the air volume is increased 10 times, we think that the distance should be around 6-7 m


No disponible


Assuntos
Humanos , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Expiração/fisiologia , Atividade Motora , Esforço Físico , Sistema Respiratório/fisiopatologia , Ventilação , Espirro , Tosse , Distância Social
10.
Nat Med ; 26(5): 676-680, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32371934

RESUMO

We identified seasonal human coronaviruses, influenza viruses and rhinoviruses in exhaled breath and coughs of children and adults with acute respiratory illness. Surgical face masks significantly reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols, with a trend toward reduced detection of coronavirus RNA in respiratory droplets. Our results indicate that surgical face masks could prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.


Assuntos
Infecções por Coronavirus/transmissão , Máscaras/virologia , Pneumonia Viral/transmissão , Infecções Respiratórias/transmissão , Aerossóis/isolamento & purificação , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Expiração/fisiologia , Humanos , Orthomyxoviridae/isolamento & purificação , Orthomyxoviridae/patogenicidade , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , RNA Viral/isolamento & purificação , Infecções Respiratórias/patologia , Infecções Respiratórias/virologia , Eliminação de Partículas Virais
11.
Rev Mal Respir ; 37(5): 355-363, 2020 May.
Artigo em Francês | MEDLINE | ID: mdl-32334966

RESUMO

INTRODUCTION: Chest computed tomography (CT) is essential to monitor lung disease in children with cystic fibrosis, but it involves recurrent exposure to ionizing radiation. The aim of this study was to compare the current complete CT protocol (volumetric end-inspiratory plus sequential expiratory acquisition) to a sequential expiratory acquisition protocol alone in terms of image analysis and ionizing radiation dose. METHODS: Seventy-eight CT scans from 57 children aged 5 to 18 years old were scored on the complete protocol images and on the expiratory sequential images only. Each CT protocol was scored independently, using the Brody scoring system, by two paediatric radiologists. RESULTS: Correlations between the Brody global scores of the two different CT protocols were very good (r=0.90 for both observers), for the bronchiectasis score (r=0.72 and 0.86), mucus plugging score (r=0.87 and 0.83), and expiratory trapped air (r=0.96 and 0.92). Total ionizing radiation dose was reduced, with the measured dose length product (DLP) reduced from 103.31mGy.cm (complete protocol) to 3.06mGy.cm (expiratory protocol) (P<0.001). CONCLUSION: An expiratory chest CT protocol was accurate in diagnosing early signs of CF disease and permitted significant reduction of radiation dose. This protocol would allow spacing out of complete CT scanning with its higher radiation dose and should be considered for the monitoring of lung disease severity in children with CF.


Assuntos
Fibrose Cística/diagnóstico , Expiração/fisiologia , Monitorização Fisiológica/métodos , Exposição Ocupacional/prevenção & controle , Doses de Radiação , Tomografia Computadorizada por Raios X , Adolescente , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Fibrose Cística/fisiopatologia , Feminino , Humanos , Masculino , Exposição Ocupacional/efeitos adversos , Prognóstico , Radiografia Torácica/efeitos adversos , Radiografia Torácica/métodos , Respiração , Testes de Função Respiratória , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/efeitos adversos , Tomografia Computadorizada por Raios X/métodos
13.
Anaesthesia ; 75(8): 1086-1095, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32311771

RESUMO

Healthcare workers are at risk of infection during the severe acute respiratory syndrome coronavirus-2 pandemic. International guidance suggests direct droplet transmission is likely and airborne transmission occurs only with aerosol-generating procedures. Recommendations determining infection control measures to ensure healthcare worker safety follow these presumptions. Three mechanisms have been described for the production of smaller sized respiratory particles ('aerosols') that, if inhaled, can deposit in the distal airways. These include: laryngeal activity such as talking and coughing; high velocity gas flow; and cyclical opening and closure of terminal airways. Sneezing and coughing are effective aerosol generators, but all forms of expiration produce particles across a range of sizes. The 5-µm diameter threshold used to differentiate droplet from airborne is an over-simplification of multiple complex, poorly understood biological and physical variables. The evidence defining aerosol-generating procedures comes largely from low-quality case and cohort studies where the exact mode of transmission is unknown as aerosol production was never quantified. We propose that transmission is associated with time in proximity to severe acute respiratory syndrome coronavirus-1 patients with respiratory symptoms, rather than the procedures per se. There is no proven relation between any aerosol-generating procedure with airborne viral content with the exception of bronchoscopy and suctioning. The mechanism for severe acute respiratory syndrome coronavirus-2 transmission is unknown but the evidence suggestive of airborne spread is growing. We speculate that infected patients who cough, have high work of breathing, increased closing capacity and altered respiratory tract lining fluid will be significant producers of pathogenic aerosols. We suggest several aerosol-generating procedures may in fact result in less pathogen aerosolisation than a dyspnoeic and coughing patient. Healthcare workers should appraise the current evidence regarding transmission and apply this to the local infection prevalence. Measures to mitigate airborne transmission should be employed at times of risk. However, the mechanisms and risk factors for transmission are largely unconfirmed. Whilst awaiting robust evidence, a precautionary approach should be considered to assure healthcare worker safety.


Assuntos
Betacoronavirus , Infecções por Coronavirus/transmissão , Pessoal de Saúde , Transmissão de Doença Infecciosa do Paciente para o Profissional , Pneumonia Viral/transmissão , Aerossóis , Microbiologia do Ar , Reanimação Cardiopulmonar/efeitos adversos , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/prevenção & controle , Expiração/fisiologia , Humanos , Controle de Infecções/métodos , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Máscaras , Nebulizadores e Vaporizadores , Pandemias/prevenção & controle , Tamanho da Partícula , Pneumonia Viral/fisiopatologia , Pneumonia Viral/prevenção & controle , Fenômenos Fisiológicos Respiratórios
14.
Int J Sports Med ; 41(7): 484-491, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32252100

RESUMO

This prospective experimental study aimed to compare effects of 3 different home-based postoperative respiratory muscle training protocols - inspiratory, expiratory and combined, in the patients' postoperative recovery, regarding safety and respiratory muscle function, pulmonary function, physical fitness, physical activity (PA), dyspnoea and quality of life (QoL). Patients were divided in four groups Usual Care (UCare), inspiratory (IMT), expiratory (EMT) or combined muscle training (CombT) according to group allocation. Significant treatment*time interactions were found for maximal inspiratory pressure (MIP) (p=0.014), sedentary PA (SEDPA) (p=0.003), light PA (LIGPA) (p=0.045) and total PA (p=0.035). Improvements were observed for MIP in CombT (p=0.001), IMT (p=0.001), EMT (p=0.050). SEDPA reduced in EMT (p=0.001) and IMT (p=0.006), while LIGPA increased in both groups (p=0.001), as well as Total PA (p=0.005 and p=0.001, respectively). In UCare, CombT, and EMT, QoL improved only for Usual Activities. In conclusion, the addition of respiratory muscle training to physiotherapy usual care is safe and effective to increase MIP and contribute to improve physical activity. The CombT showed greater improvement on MIP, while IMT compared to EMT, was more effective to improve physical activity.


Assuntos
Exercícios Respiratórios/métodos , Neoplasias Pulmonares/cirurgia , Toracotomia/reabilitação , Idoso , Aptidão Cardiorrespiratória , Exercício Físico , Expiração/fisiologia , Feminino , Humanos , Inalação/fisiologia , Masculino , Pessoa de Meia-Idade , Cuidados Pós-Operatórios/métodos , Estudos Prospectivos , Qualidade de Vida
15.
Biomed Res Int ; 2020: 7530498, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32185217

RESUMO

Objective: To investigate the pulmonary function responses to respiratory muscle training (RMT) in individuals with tetraplegia and provide a systematic review of the included studies. Methods: Computerized retrieval of randomized controlled trials (RCT) in PubMed, Embase, and the Cochrane Library on the improvement of respiratory function in patients with spinal cord injury by RMT was conducted until May 2019. Two researchers independently screened the literature, extracted the data, and evaluated the risk of bias in the included studies. Articles were scored for their methodological quality using the Cochrane Collaboration risk of bias assessment tool. Results: Sixteen studies were identified. A significant benefit of RMT was revealed for five outcomes: force vital capacity (FVC, WMD: -0.43, 95% CI -0.84 to -0.03, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12, P = 0.037), vital capacity (VC, WMD: -0.40, 95% CI -0.69 to -0.12. Conclusion: Our findings demonstrate that RMT can effectively improve spinal cord injury pulmonary function of the patient, which is marked by increasing respiratory strength, function, and endurance. Limited by the quantity and quality of the included studies, the above conclusion needs to be verified by more high-quality studies.


Assuntos
Exercícios Respiratórios , Músculos Respiratórios/fisiopatologia , Traumatismos da Medula Espinal/fisiopatologia , Expiração/fisiologia , Humanos , Inalação/fisiologia , Pulmão/fisiopatologia , Força Muscular/fisiologia , Capacidade Vital/fisiologia
16.
Am J Respir Crit Care Med ; 201(10): 1218-1229, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32150440

RESUMO

Rationale: Tidal expiratory flow limitation (tidal-EFL) is not completely avoidable by applying positive end-expiratory pressure and may cause respiratory and hemodynamic complications in ventilated patients with lungs prone to collapse. During spontaneous breathing, expiratory diaphragmatic contraction counteracts tidal-EFL. We hypothesized that during both spontaneous breathing and controlled mechanical ventilation, external expiratory resistances reduce tidal-EFL.Objectives: To assess whether external expiratory resistances 1) affect expiratory diaphragmatic contraction during spontaneous breathing, 2) reduce expiratory flow and make lung compartments more homogeneous with more similar expiratory time constants, and 3) reduce tidal atelectasis, preventing hyperinflation.Methods: Three positive end-expiratory pressure levels and four external expiratory resistances were tested in 10 pigs after lung lavage. We analyzed expiratory diaphragmatic electric activity and respiratory mechanics. On the basis of computed tomography scans, four lung compartments-not inflated (atelectasis), poorly inflated, normally inflated, and hyperinflated-were defined.Measurements and Main Results: Consequently to additional external expiratory resistances, and mainly in lungs prone to collapse (at low positive end-expiratory pressure), 1) the expiratory transdiaphragmatic pressure decreased during spontaneous breathing by >10%, 2) expiratory flow was reduced and the expiratory time constants became more homogeneous, and 3) the amount of atelectasis at end-expiration decreased from 24% to 16% during spontaneous breathing and from 32% to 18% during controlled mechanical ventilation, without increasing hyperinflation.Conclusions: The expiratory modulation induced by external expiratory resistances preserves the positive effects of the expiratory brake while minimizing expiratory diaphragmatic contraction. External expiratory resistances optimize lung mechanics and limit tidal-EFL and tidal atelectasis, without increasing hyperinflation.


Assuntos
Diafragma/fisiologia , Expiração/fisiologia , Contração Muscular/fisiologia , Respiração com Pressão Positiva/métodos , /terapia , Animais , Diafragma/fisiopatologia , Modelos Animais de Doenças , Pulmão/diagnóstico por imagem , Respiração com Pressão Positiva/efeitos adversos , Atelectasia Pulmonar/diagnóstico por imagem , Ventilação Pulmonar , Respiração Artificial/métodos , Mecânica Respiratória/fisiologia , Suínos , Tomografia Computadorizada por Raios X
17.
Artigo em Inglês | MEDLINE | ID: mdl-32050421

RESUMO

The purpose of this study was to evaluate the inspiratory and expiratory muscle strength of individuals affected by stroke and to compare it with the predicted values in the literature considering their corresponding age. Respiratory muscle strength was evaluated in 22 elderly people who had sequels of stroke, four with right hemiparesis, 16 with left hemiparesis and two with bilateral, of ages ranging from 34 to 82 years. The collected data were submitted to statistical analysis using a Mann-Whitney test to evaluate if there was a significant difference in the average data collected when compared with a mean of the predicted data in the literature. Fourteen men and eight women were evaluated, who obtained mean values of 71.85 cmH2O and 57.75 cmH2O, respectively, for a maximal inspiratory pressure (MIP), and when compared to the predicted values for men and women, 105.41 cmH2O (p-value 0.0019) and 80.57 cmH2O (p-value 0.00464) were significantly lower. For a maximal expiratory pressure (MEP), the mean value obtained for men was 62.28 cmH2O and 49.5 cmH2O for women, whereas the predicted values in the literature were 114.79 cmH2O (p-value < 0.0001) and 78, 46 cmH2O (p-value 0.0059), respectively. In the statistical analysis, it was possible to notice that the studied population did not reach the predicted age indexes and that there was a significant difference between the median columns. In conclusion, there is a weakness in the respiratory muscles of hemiparetic men and women due to stroke.


Assuntos
Força Muscular/fisiologia , Músculos Respiratórios/fisiopatologia , Acidente Vascular Cerebral/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Expiração/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Acidente Vascular Cerebral/complicações
18.
Mikrochim Acta ; 187(3): 186, 2020 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-32088793

RESUMO

A colorimetric nanoprobe was developed for the quantification of tobramycin in exhaled breath condensate (EBC). The nanoprobe consists of silver nanoparticles (Ag NPs) modified with sodium dodecyl sulfate (SDS), which is applied in the presence of sodium metaborate. Characterization of the synthesized SDS-capped Ag NPs by transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX) showed that the nanoparticles were well synthesized with nearly uniform size and an average diameter of < 30 nm. Interaction of sodium metaborate with the SDS-capped Ag NPs and tobramycin results in aggregation of the nanoparticles and consequently decreases the absorbance intensity, leading to the production of a new absorbance peak and a color change from yellow to purple. The absorbance intensity was recorded at λmax = 400 nm and 522 nm and λ522/λ400 was used as the analytical signal. The experimental parameters were investigated and optimized using a multivariate optimization method (central composite design). The current nanoprobe gives a linear response for tobramycin from 1.0 to 50.0 ng mL-1 with a detection limit of 0.5 ng mL-1. The intra- and inter-day relative standard deviations for five replicated analyses of 10.0 ng mL-1 tobramycin are 2.8% and 4.2%, respectively. Graphical abstractSchematic representation of SDS-capped silver nanoparticles's response to tobramycin in the presence of sodium metaborate.


Assuntos
Testes Respiratórios/métodos , Colorimetria/métodos , Expiração/fisiologia , Nanopartículas Metálicas/química , Tobramicina/química , Humanos
19.
Can J Vet Res ; 84(1): 24-32, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31949326

RESUMO

The objective of this study was to document tidal variations in tracheal height during normal respiration in 19 healthy adult (> 1 y old) small-breed dogs (< 10 kg) using fluoroscopy and radiography. Each dog underwent tracheal fluoroscopic examination on inspiration and expiration while in a standing position (F-S) and in right lateral recumbency (F-RL), followed by radiographic projections obtained in right lateral recumbency. The percent variation in tracheal height during maximal inspiration and expiration was determined at 3 different locations [cervical region (CR), thoracic inlet (TI), and intrathoracic (IT) region]. When all imaging procedures and sites of measurement were considered, tracheal height varied during physiologic inspiration and expiration from 0% to 21.1%, with a mean of 4.5%. The mean percent variation in tracheal height was not significantly different among imaging modalities (F-S versus F-RL versus radiography) (P = 0.16) or measurement sites (CR versus TI versus IT) (P = 0.89). The body condition score (BCS) (P = 0.96), age (P = 0.95), and breed (P = 0.19) did not significantly influence the mean percent variation in tracheal height. The average variation in tracheal height during maximal physiological inspiration and expiration is small (< 6%) in most healthy adult small-breed dogs as assessed by fluoroscopy and radiography, although tracheal height may vary by as much as 21.1% in some healthy individuals. Inspiratory and expiratory radiographs acquired in right lateral recumbency provide an accurate assessment of tracheal height as an alternative to fluoroscopy.


Assuntos
Cães/anatomia & histologia , Expiração/fisiologia , Inalação/fisiologia , Traqueia/anatomia & histologia , Traqueia/diagnóstico por imagem , Animais , Tamanho Corporal , Cães/classificação , Cães/fisiologia , Feminino , Fluoroscopia/veterinária , Masculino , Radiografia Torácica/veterinária , Traqueia/fisiologia
20.
Database (Oxford) ; 20202020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31976536

RESUMO

Breathomics is a special branch of metabolomics that quantifies volatile organic compounds (VOCs) from collected exhaled breath samples. Understanding how breath molecules are related to diseases, mechanisms and pathways identified from experimental analytical measurements is challenging due to the lack of an organized resource describing breath molecules, related references and biomedical information embedded in the literature. To provide breath VOCs, related references and biomedical information, we aim to organize a database composed of manually curated information and automatically extracted biomedical information. First, VOCs-related disease information was manually organized from 207 literature linked to 99 VOCs and known Medical Subject Headings (MeSH) terms. Then an automated text mining algorithm was used to extract biomedical information from this literature. In the end, the manually curated information and auto-extracted biomedical information was combined to form a breath molecule database-the Human Breathomics Database (HBDB). We first manually curated and organized disease information including MeSH term from 207 literatures associated with 99 VOCs. Then, an automatic pipeline of text mining approach was used to collect 2766 literatures and extract biomedical information from breath researches. We combined curated information with automatically extracted biomedical information to assemble a breath molecule database, the HBDB. The HBDB is a database that includes references, VOCs and diseases associated with human breathomics. Most of these VOCs were detected in human breath samples or exhaled breath condensate samples. So far, the database contains a total of 913 VOCs in relation to human exhaled breath researches reported in 2766 publications. The HBDB is the most comprehensive HBDB of VOCs in human exhaled breath to date. It is a useful and organized resource for researchers and clinicians to identify and further investigate potential biomarkers from the breath of patients. Database URL: https://hbdb.cmdm.tw.


Assuntos
Sistemas de Gerenciamento de Base de Dados , Expiração/fisiologia , Metaboloma/fisiologia , Metabolômica/métodos , Compostos Orgânicos Voláteis , Testes Respiratórios , Mineração de Dados , Humanos , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química
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