ABSTRACT
La hipoxemia ocurre producto de una inadecuada captación de oxígeno a nivel pulmonar y se manifiesta como presión arterial de oxígeno menor a 60 mmHg o saturación arterial de oxígeno menor de 90%. Los mecanismos fisiopatológicos por los cuales se puede producir hipoxemia son hipoventilación, alteración del equilibrio ventilación perfusión, shunt cardiaco, alteración de la difusión y disminución de la presión inspirada de oxígeno. La comprensión de estos mecanismos es fundamental para entender su presentación clínica en distintas enfermedades.
Hypoxemia is the name given to inadequate uptake in the lung and is defined as an arterial oxygen pressure less than 60 mmHg or arterial oxygen saturation less than 90%. The pathophysiological mechanisms that can produce hypoxemia are: hypoventilation, ventilation perfusion mismatch, cardiac shunt, diffusion impairment and decreased inspired oxygen pressure. Full comprehension of these mechanism facilitates the understanding of hypoxemia among different diseases.
Subject(s)
Humans , Hypoxia/etiology , Hypoxia/physiopathology , Ventilation-Perfusion Ratio , Hypoventilation/complicationsABSTRACT
O diabetes melito é o maior fator de risco para doença arterial coronariana. Além da longa duração de diabetes, outros fatores, como presença de doença arterial periférica e tabagismo são fortes preditores para anormalidades na cintilografia de perfusão do miocárdio. O objetivo deste estudo foi avaliar o impacto dos fatores de risco de pacientes diabéticos nos resultados da cintilografia de perfusão do miocárdio e comparar com os resultados de pacientes não diabéticos em uma clínica de medicina nuclear. Foi realizado um estudo transversal retrospectivo por meio da análise de prontuários de pacientes que realizaram cintilografia miocárdica no período de 2010 a 2019. Foram avaliados 34.736 prontuários. Analisando a fase de estresse da cintilografia de perfusão do miocárdio, os portadores de diabetes melito precisaram receber estímulo farmacológico duas vezes mais que os não diabéticos para sua realização. Também foram avaliados fatores que tivessem impacto negativo no resultado da cintilografia de perfusão do miocárdio, e foi visto que o diabetes melito (33,6%), a insulinoterapia (18,1%), a hipertensão arterial sistêmica (69,9%), a dislipidemia (53%), o sedentarismo (83,1%), o uso de estresse farmacológico (50,6%), a dor torácica típica (8,5%) e a angina limitante durante o teste (1,7%) estiveram associados significativamente (p<0,001) a anormalidades neste exame. (AU)
Diabetes mellitus (DM) is the greatest risk factor for coronary artery disease. In addition to a long duration of diabetes, the presence of peripheral arterial disease and smoking are strong predictors of abnormalities on myocardial perfusion scintigraphy (MPS). This study aimed to assess the impact of risk factors in diabetic patients on MPS results and compare them with those of non-diabetic patients in a nuclear medicine clinic. A retrospective cross-sectional study was performed through the analysis of the medical records of patients who underwent MPS in 20102019. A total of 34,736 medical records were evaluated. Analyzing the stress phase of MPS, DM patients required two-fold more pharmacological stimulation than non-diabetic patients for MPS. Factors that negatively impact the MPS results were also evaluated, and DM (33.6%), insulin therapy (18.1%), systemic arterial hypertension (69.9%), dyslipidemia (53%), sedentary lifestyle (83.1%), use of pharmacological stress (50.6%), typical chest pain (8.5%), and limiting angina during the test (1.7%) were significantly associated (p < 0.001) with test abnormalities. (AU)
Subject(s)
Humans , Male , Middle Aged , Tobacco Use Disorder/complications , Diabetes Mellitus, Type 2/pathology , Peripheral Arterial Disease/complications , Ventilation-Perfusion Scan/methods , Myocardium/pathology , Tomography, Emission-Computed, Single-Photon/methods , Risk Factors , Myocardial Ischemia/diagnosis , Convulsive Therapy/methods , Dyslipidemias/complications , Sedentary Behavior , Hypertension/complications , Nuclear Medicine Department, HospitalABSTRACT
Las alteraciones de la relación entre la ventilación y el flujo sanguíneo (V/Q) en diversas regiones del pulmón alteran el aporte de oxígeno (O2) y remoción del dióxido de carbono (CO2) al organismo. Fisiológicamente existen diferencias regionales en la relación V/Q. Determinadas patologías pueden alterar esta relación, produciendo tres escenarios distintos: Cortocircuito (Shunt), Alteración V/Q y aumento del espacio muerto. Para evaluar estos escenarios y realizar una aproximación diagnostica son de utilidad el estudio de los gases arteriales y venosos, la diferencia alveolo arterial y la respuesta al suministrar O2
Alterations in the ventilation perfusion relationship (V/Q) in various lung regions alter the supply of oxygen (O2) and the removal of carbon dioxide (CO2) in the body. Physiologically, there are regional differences in the V/Q ratio. Certain pathologies can alter this relationship, producing three different scenarios: Shunt, V/Q mismach and dead space increased. To evaluate these scenarios and carry out a diagnostic approach, it is useful to study arterial and venous gasometry, the alveolar arterial difference and the response to oxygen supplying.
Subject(s)
Humans , Respiratory Physiological Phenomena , Ventilation-Perfusion Ratio/physiology , Blood Gas AnalysisABSTRACT
@#Background: The role of nuclear medicine in diagnosing pulmonary embolism (PE) is continuously evolving owing to advancements in imaging methods. In recent years, ventilation/perfusion single photon emission computed tomography-computed tomography (V/Q SPECT/CT) has established a synergistic role over conventional V/Q planar scintigraphy and V/Q SPECT in diagnosing pulmonary embolism. Objectives: In this study, we aimed to assess the incremental value of V/Q SPECT/CT over conventional V/Q planar scintigraphy and V/Q SPECT, and to determine if Q only-SPECT/CT without the conventional ventilation component could replace the current imaging protocol in diagnosing pulmonary embolism. Methods: We retrospectively assessed 73 patients with suspicion of pulmonary embolism who had undergone/Q planar scintigraphy, V/Q SPECT and V/Q SPECT/CT consecutively. Combination of clinical follow-up, laboratory test results and correlative imaging were used as reference standard. Q-only SPECT/CT datasets were then analysed separately without the V-planar, V-SPECT and V-SPECT/CT datasets. Results: A total of 66 patients fulfilled our initial inclusion and exclusion criteria, with 23 patients as positive for PE and 43 patients ruled out of having PE based on the reference standard. Sensitivity and specificity for V/P planar scintigraphy, V/Q SPECT, and V/Q SPECT-CT were 86.9% and 39.5%, 91.3% and 55.8%, and 100% and 97.6% respectively. Overall, SPECT/CT resulted in significantly higher diagnostic accuracy than planar and SPECT imaging respectively (p<0.05). Q-only SPECT/CT significantly over diagnosed pulmonary embolism in 12 patients (p<0.05). Conclusion: Adding V/Q SPECT/CT to the algorithm of PE significantly improves the sensitivity and specificity. However, by eliminating the ventilation component, the diagnostic accuracy is significantly reduced.
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This paper is about the Guideline for Ventilation / Perfusion Scintigraphy. It has been developed by the Brazilian Society of Nuclear Medicine to be a best practices guide used in Nuclear Medicine. Its function is to be an educational tool to help the Nuclear Medicine Services in Brazil to guarantee a quality care to the patients
Subject(s)
Humans , Male , Female , Ventilation-Perfusion Ratio , Guidelines as Topic/standards , Pulmonary Artery/pathology , Pulmonary Embolism/complications , Pulmonary Embolism/diagnostic imaging , Diagnostic Imaging/methods , Radionuclide Imaging/methods , Nuclear Medicine/standardsABSTRACT
Objective@#To explore the clinical effect of mometasone furoate nasal spray combined with montelukast in the treatment of children with obstructive sleep apnea hypopnea syndrome (OSAHS), and to analyze its feasibility and clinical application value.@*Methods@#From August 2017 to March 2019, 64 children with OSAHS who were treated in the People's Hospital of Jinhua were selected in the study.According to the random number table method, they were divided into the observation group and the control group, with 32 cases in each group.The observation group was treated with mometasone furoate nasal spray combined with montelukast for 12 weeks.The control group was treated with surgical treatment to remove hypertrophic tonsils and/or adenoids.The clinical symptom scores, polysomnography(PSG) monitoring index, adenoid and tonsil size index, and the efficacy after 12 weeks of treatment were compared between the two groups.@*Results@#There were no statistically significant differences in symptom scores and minimum arterial oxygen saturation(LSaO2) between the two groups before treatment(all P>0.05). After treatment, the symptom scores and LSaO2 of the control group were (1.90±0.53)points and (94.74±1.54)%, respectively, which of the observation group were (4.00±1.50)points and (85.34±10.57)%, respectively, the differences between the two groups were statistically significant(t=-7.416, 4.972, all P<0.05). There were statistically significant differences in the apnea hypopnea index(AHI) and obstructive apnea index(OAI) between the two groups(all P<0.05). After treatment, the A/N of the adenoids in the observation group was significantly decreased, and the difference in the tonsil classification was statistically significant(Z=-2.602, P<0.05). The effective rate of the observation group was 56.25%(18/32), which was significantly lower than that of the control group [100.00%(32/32)], the difference was statistically significant(χ2=17.920, P<0.05).@*Conclusion@#In summary, non-surgical treatment can alleviate OSAHS-related symptoms, reduce the size of tonsils and adenoids, and achieve the purpose of remission or cure.Non-surgical treatment can be selected when patients' families are reluctant to choose surgical treatment.
ABSTRACT
Lung ventilation/perfusion ( V/Q) imaging is the recommended diagnostic technique for pulmonary embolism. With the development of imaging equipments, radiopharmaceuticals and new quantita-tive techniques, lung V/Q imaging has been increasingly used in other lung diseases. This article reviews the clinical application of lung V/Q imaging in non-pulmonary embolic diseases.
ABSTRACT
Lung ventilation/perfusion (V/Q) imaging is the recommended diagnostic technique for pulmonary embolism. With the development of imaging equipments, radiopharmaceuticals and new quantitative techniques, lung V/Q imaging has been increasingly used in other lung diseases. This article reviews the clinical application of lung V/Q imaging in non-pulmonary embolic diseases.
ABSTRACT
Abstract The accurate diagnosis of pulmonary thromboembolism is essential to reducing the morbidity and mortality associated with the disease. The diagnosis of pulmonary thromboembolism is challenging because of the nonspecific nature of the clinical profile and the risk factors. Imaging methods provide the definitive diagnosis. Currently, the imaging method most commonly used in the evaluation of pulmonary thromboembolism is computed tomography. The recent development of dual-energy computed tomography has provided a promising tool for the evaluation of pulmonary perfusion through iodine mapping. In this article, we will review the importance of diagnosing pulmonary thromboembolism, as well as the imaging methods employed, primarily dual-energy computed tomography.
Resumo A acurácia no diagnóstico de tromboembolismo pulmonar é essencial para reduzir a morbimortalidade causada por esta enfermidade. Devido ao quadro clínico e fatores de risco inespecíficos, o diagnóstico de tromboembolismo pulmonar torna-se um desafio. Os métodos de imagem fornecem o diagnóstico definitivo, sendo a tomografia computadorizada o método mais utilizado atualmente. Nos últimos anos, houve o desenvolvimento da tomografia computadorizada com dupla energia e essa ferramenta tem se mostrado promissora para avaliação da perfusão pulmonar por meio do mapa de iodo. Neste artigo é feita revisão acerca da importância do diagnóstico de tromboembolismo pulmonar, bem como os métodos de imagem disponíveis, com ênfase na tomografia computadorizada com dupla energia.
ABSTRACT
Objective To evaluate the clinical value of CTPA combined with V/Q imaging to guide the end point of anticoagulant therapy in reducing the recurrence rate of pulmonary embolism. Methods A total of 159 cases of pulmonary embolism diagnosed by CTPA were randomly divided into experimental group(n=80)and control group(n = 79). After the regular low molecular weight heparin and warfarin anticoagulation therapy ,the experimental group used the CTPA combined with V/Q imaging to evaluate the pulmonary embolism absorption ,to guide the end point of anticoagulant therapy and to evaluate the recurrence rate of pulmonary embolism at the end of 1-year treatment. But in control group ,only CTPA was used to guide the treatment and then the recurrence rate in 2 groups was compared. Results The anticoagulant treatment course of experimental group was(5.90 ± 1.80) months,which was significantly longer than that of control group(3.57 ± 1.09)months(P0.05).Conclusions CTPA combined with V/Q imaging to guide the end point of anticoagulant therapy for pulmonary embolismhas important clinical value in reducing the recurrence rate of pulmonary embolism.
ABSTRACT
El objetivo del estudio fue evaluar el intercambio gaseoso y el comportamiento funcional cardiorrespiratorio en pacientes con hipertensión pulmonar (HTP) antes, durante y después del cambio de posición a decúbito prono. Treinta pacientes con HTP y alteraciones en el intercambio gaseoso fueron incluidos en el estudio. Las variables de intercambio gaseoso se evaluaron en decúbito supino para obtener los valores basales y en decúbito prono a los 30, 120 y 240 min. Así mismo, se sometieron al test marcha 6 minutos (6MWT) previo y posterior a 30 días de sueño nocturno en prono. Después de cuatro horas, todos los pacientes presentaron un incremento de la PaO2 y en la saturación arterial de oxígeno (SaO2), con disminución en los cortocircuitos intrapulmonares, mejorando el intercambio gaseoso y por consiguiente de la demanda fisiológica impuesta por el ejercicio en pacientes con HTP.
The objective of this investigation was to evaluate gas exchange and cardiopulmonary functional behavior in patients with pulmonary hypertension (PH) before, during and after the change to a prone position. Thirty patients with PH and alterations in gas exchange were included in the study. Gas exchange measurements were performed in four stages: at the baseline supine position and after 30, 120 and 240 minutes in prone position. Also, the patients were evaluated by the six minutes walking test (6MWT) after 30 days in prone position during night’s sleep. After four hours in prone position, all patients showed an increase of PaO2 and arterial saturation of oxygen (SaO2), with a decrease of intrapulmonary shunts, improving the gas exchange and therefore the physiological demand imposed by exercise in patients with PH.
Subject(s)
Female , Humans , Male , Young Adult , Pulmonary Gas Exchange , Prone Position , Exercise Tolerance , Hypertension, Pulmonary/physiopathology , Hypertension, Pulmonary/metabolism , Prospective Studies , Longitudinal StudiesABSTRACT
INTRODUÇÃO E OBJETIVOS: A Circulação extracorpórea (CEC) é associada a ativação leucocitária, resposta inflamatória e disfunção pulmonar. Objetivou-se avaliar os efeitos da filtragem leucocitária sobre a resposta inflamatória e a função pulmonar em indivíduos submetidos à revascularização do miocárdio (RM) com CEC. MÉTODO: Após aprovação pelo Comitê de Ética Institucional e obtenção do consentimento informado dos indivíduos, foi realizado estudo prospectivo randomizado, para comparar indivíduos adultos submetidos à RM com CEC, utilizando-se filtragem leucocitária (n=09) ou filtro standard (n=11) durante a CEC. Tomografia computadorizada (CT) de tórax, espirometria, análise da oxigenação e hemograma foram realizados antes da cirurgia. A anestesia foi induzida por via venosa com etomidato (0,3 mg.kg-1), sufentanil (0,3 ug.kg-1), pancurônio (0,08 mg.kg-1) e mantida com isoflurano (0,5 - 1,0 CAM) e sufentanil (0,5 ug.kg-1.h-1). A ventilação mecânica utilizou volume corrente de 8 mL.kg-1, com FiO2 de 0,6 e PEEP de 5 cm H2O, exceto durante a CEC. No grupo Filtragem, durante a CEC, foi inserido um filtro de leucócitos na linha arterial do circuito (LG-6, Pall Biomedical Products) e, no grupo Controle, foi utilizado o filtro Standard. Contagem leucocitária foi realizada após a indução, aos 5, 25 e 50 min de CEC, ao final da cirurgia, com 12 e 24 h PO. Dados hemodinâmicos, PaO2/FiO2, fração de Shunt, interleucinas, elastase e mieloperoxidase foram colhidos antes e após a CEC, no final da cirurgia, com 6,12 e 24 h PO. Trinta minutos depois da indução, e trinta após a CEC, três amostras sequenciais de ar exalado foram colhidas para análise de óxido nítrico (NO), por quimiluminescência. Espirometria e CT de tórax foram realizadas no primeiro dia pós-operatório. Os dados foram analisados por meio de ANOVA de duplo fator para medidas repetidas. RESULTADOS: O tempo de CEC foi similar entre os grupos controle e filtragem (86,78 ± 19,58 versus 104,64 ± 27,76 min, p=0,161)...
BACKGROUND AND OBJECTIVE: The Cardiopulmonary bypass (CPB) is related to leukocyte activation, inflammatory response and lung dysfunction. The aim of this study was to evaluate the effects of CPB-leukocyte filtration on the inflammatory response and lung function after coronary artery bypass grafting (CABG). METHODS: After approval by the institutional ethics committee and informed consent, a prospective randomized study was performed to compare CABG-patients undergoing CPB-leukocyte filtration (n=9) or standard CPB (n=11). Espirometry, chest computed tomography (CT), oxygenation analysis and leukocyte count were performed before surgery. Anesthesia induction was performed intravenously with etomidate (0,3 mg.kg-1), sufentanil (0,3 ug.kg-1), pancuronium bromide (0,08 mg.kg-1) e sustained with isoflurano (0,5 - 1,0 CAM) and sufentanil (0,5 ug.kg-1.h-1). The tidal volume used during mechanical ventilation was 8 mL.kg-1, the FiO2 0.6 and PEEP 5 cm H2O, except during CPB. In Filtered group, during CPB, was inserted a leukocyte filter in the arterial line of CPB circuit (LG-6, Pall Biomedical Products) and, in Control group, the Standard arterial line filter was utilized. Hemodynamic data, PaO2/FiO2, shunt fraction, interleukins, elastase and myeloperoxidase were evaluated before and after CPB, at the end of surgery, and 6, 12 and 24 h PO. Thirty minutes after induction, and Thirty after CPB, three sequential exhaled air samples were collected to perform analysis of nitric oxide (NO), by chemiluminescence technique. Espirometry and chest CT were performed on first PO. Data were analyzed using two-factor ANOVA for repeated measurements. RESULTS: Length of CPB was similar in the filtered and control groups (86.78 ± 19.58 versus 104.64 ± 27.76 min, p = 0.161). The filtered group showed lower neutrophil counts than the control group up to 50 minutes of CPB (3384 ± 2025 versus 6478 ± 3582 U/mm-3, p = 0.036), lower shunt fraction up to 6 hours after surgery (10 ± 2%)...
Subject(s)
Humans , Male , Female , Extracorporeal Circulation , Endothelium/abnormalities , Myocardial Revascularization , Respiration, Artificial , Thoracic Surgery , Ventilation-Perfusion RatioABSTRACT
O presente estudo teve por objetivo investigar a estabilidade do ponto ótimo cardiorrespiratório (POC) em dois testes cardiopulmonares de exercício máximos (TCPEs), realizados em cicloergômetro de membros inferiores. Para tanto, foram analisados retrospectivamente os dados de 1334 indivíduos avaliados por no mínimo duas vezes entre 1995 e 2013, sendo identificados, a partir de rígidos critérios de inclusão, 222 pacientes (159 homens) com a idade de 55±11,6 anos. Logo, foram verificados os dados do POC obtidos a partir da análise da ventilação e do consumo de oxigênio em cada minuto do TCPE, o VO2 máximo, e as curvas de eficiência do consumo de oxigênio (OUES) e do equivalente ventilatório de dióxido de carbono (VE/VCO2 slope), sendo a estabilidade avaliada pelos coeficientes de correlação intraclasse. A mediana do intervalo de tempo entre os dois TCPEs foi de 1,6 anos. Os valores de cada uma das variáveis obtidas nos dois TCPEs apresentaram altas e significativas associações (p <0,01), sendo: VO2max ri = 0,93 (IC95% = 0,91 a 0,94); POC ri = 0,87; (IC95% = 0,82 a 0,90); OUES ri = 0,90 (IC95% = 0,87 a 0,93) e VE/VCO2 slope ri = 0,74 (IC95% = 0,67 a 0,80). Concluímos que, em condições controladas, o POC é um índice ventilatório bastante estável em TCPEs realizadas em indivíduos adultos, com níveis de estabilidade similar ou superior de outras variáveis ou índices consagrados na literatura, corroborando, dessa forma, seu potencial de utilização em pesquisas fisiológicas e na prática clínica.
The present study aimed to assess the stability of the cardiorespiratory optimum point (COP) in two maximum cardiopulmonary exercise testing (CPET), performed in a lower limbs cycling ergometer. Therefore, we retrospectively analyzed data from 1334 subjects that were evaluated by at least twice between 1995 and 2013, and identified after rigid inclusion criteria, 222 subjects (159 men) aged 55 ± 11.6 years. COP results were obtained from the ventilation and oxygen consumption data averaged at each minute during CPET as well as maximum oxygen uptake, efficiency curves of oxygen consumption (OUES) and ventilatory equivalent for carbon dioxide (VE/VCO2 slope), and their stability assessed by intraclass correlation coefficients. The median time interval between two CPETs was 1.6 years. The values of the variables obtained in the two CPETs showed high and significant associations (p <0.01), being: VO2max ri = 0.93 (CI95% = 0.91 a 0.94); COP ri = 0.87; (CI95% = 0.82 a 0.90); OUES ri = 0.90 (CI95% = 0.87 a 0.93) and VE/VCO2 slope ri = 0.74 (CI95% = 0.67 a 0.80). We conclude that, under controlled conditions, COP is a very stable ventilatory index in CPET performed in adults, with stability levels similar or higher than other variables well-established in the literature, confirming thus its potential for use in physiological research and clinical practice.
Subject(s)
Humans , Male , Female , Middle Aged , Exercise , Exercise Test , Oxygen Consumption , Ventilation-Perfusion RatioABSTRACT
Introducción: los avances en la conducta anestésica, técnicas quirúrgicas y cuidados perioperatorios han posibilitado expandir la población que ahora puede ser considerada «operable¼ para la resección pulmonar. La fisiología de la ventilación pulmonar selectiva está conectada íntimamente a sus efectos en la relación ventilación/perfusión pulmonar. Varios factores afectan esta relación debido principalmente a sus efectos en la complacencia pulmonar. El aislamiento pulmonar desacopla el binomio ventilación/perfusión en el pulmón operado y puede producir hipoxemia significativa si no se trata apropiadamente. Objetivo: identificar la administración, basada en evidencias, de la ventilación durante la ventilación pulmonar selectiva enfocada a evitar la hipoxemia y el daño pulmonar posoperatorio. Métodos: revisión exhaustiva de la literatura disponible de las estrategias, basadas en evidencias, de la ventilación durante la ventilación pulmonar selectiva. Conclusiones: para un mejor tratamiento de los disturbios en la relación ventilación /perfusión que se producen en la ventilación pulmonar selectiva es necesario estar familiarizados con los principios básicos que gobiernan la ventilación y la perfusión pulmonar, así como aplicar los métodos para mejorar la oxigenación durante la ventilación pulmonar selectiva y las estrategias ventilatorias protectoras para disminuir la incidencia o severidad del daño pulmonar postoracotomía.
Background: The advances in anaesthetic behaviour, technical techniques and preoperative care have made it possible to expand the population that can now be considered as "operable" for lung resection. The physiology of selective lung ventilation is closely connected to its effects on the pulmonary ventilation-perfusion relation. Several factors affect this relation because of its effects in the lung satisfaction. The lung isolation uncouples the ventilation-perfusion binomial in the operated lung and can produce a significant hypoxemia if it is not treated properly. Objectives: To identify the evidence-based administration of the ventilation during the selective lung ventilation focused to avoid hypoxemia and postoperative lung injury. Methods: A detailed review of the available literature about evidence-based ventilation strategies during the selective lung ventilation was made. Conclusions: To follow a better treatment of the disturbances in relation to the ventilation-perfusion that occur in the selective lung ventilation it is necessary to become familiar with the basic principles that govern pulmonary ventilation-perfusion and apply methods to improve oxygenation during the selective lung ventilation and protective ventilation strategies to diminish the incidence or severity of lung injury after thoracotomy.
ABSTRACT
Introducción. El tromboembolismo pulmonar (TEP) es una patología frecuente con una incidencia real no bien conocida por su variabilidad clínica y dificultades para el diagnóstico. Varios estudios demostraron la utilidad clínica del dímero D (DD), pero su valor predictivo positivo es bajo, lo que obliga a realizar otras técnicas diagnósticas para confirmarlo. Objetivos. Determinar la utilidad del DD positivo, evaluar la correlación de signos clínicos y analizar el uso de tratamiento anticoagulante oral (ACO) ante el diagnóstico de TEP. Material y métodos. Se analizaron 58 pacientes internados con sospecha clínica de TEP y DD positivo desde Junio de 2009 a Febrero de 2012, a los que se les realizaron gammagrafía pulmonar ventilación/perfusión (GG V/Q). Se valoraron: factores de riesgo (FR), características clínicas y tratamiento con ACO al alta. Resultados. Del total de pacientes, el 60% eran mujeres y el 74% eran >65 años. Treinta y seis pacientes (62%) tenían GG V/Q positiva y las siguientes características clínicas: 23 (64%) FR positivos, 21 (58%) signos de trombosis venosa profunda (TVP), 22 (61%) disnea, 6 (16%) dolor torácico, 11 (30%) taquicardia y 4 (11%) tos. El resto de los pacientes (n=22, 38%) presentaban: 15 (68%) FR positivos, 10 (45%) signos de TVP, 15 (68%) disnea, 2 (9%) dolor torácico, 5 (23%) taquicardia y 5 (23%) tos; sin diferencias significativas entre los dos grupos. Todos los pacientes con GG V/Q positiva recibieron tratamiento con ACO al alta y sólo 11 (50%) pacientes presentaron GG V/Q negativa, con diferencias significativas. Conclusión. El DD positivo no predijo el diagnóstico de TEP, lo que demuestra la importancia de realizar una GG V/Q para confirmar el diagnóstico. No se observaron diferencias significativas en cuanto a edad, sexo, factores de riesgo y cuadro clínico. El tratamiento ambulatorio con ACO tuvo relación significativa con el diagnóstico por GG V/Q y no por la presencia de DD positivo.
Background. Pulmonary embolism (PE) is a common condition with a real impact not well known for its clinical variability and diagnostic difficulties. Several studies have demonstrated the clinical utility of D-dimer (DD), but its positive predictive value is low, forcing to perform other diagnostic techniques to confirm. Objectives. To determine the usefulness of positive DD; assess the correlation of clinical signs, and analyze the use of oral anticoagulation (OAC) to the diagnosis of PE. Methods and material. There were evaluated 58 patients admitted with clinical suspicion of PE and positive DD from June 2009 to February 2012, which was performed lung scan ventilation/perfusion (V/Q scan). We evaluated risk factors (RF), clinical features and OAC therapy at discharge. Results. Of all patients, 60% were female and 74% were >65 years. Thirty-six (62%) had V/Q scan positive and the following clinical features: 23 (64%) RF positive, 21 (58%) signs of deep vein thrombosis (DVT), 22 (61%) dyspnea, 6 (16%) chest pain, 11 (30%) tachycardia and 4 (11%) cough. The remaining patients (n=22, 38%) were: 15 (68%) RF positive, 10 (45%) signs of DVT, 15 (68%) dyspnea, 2 (9%) chest pain, 5 (23 %) tachycardia and 5 (23%) cough, without significant differences between the two groups. All patients with V/Q scan positive received OAC therapy at discharge and only 11 (50%) patients had negative V/Q scan, with significant differences. Conclusion. The positive DD did not predict the diagnosis of PE, demonstrating the importance of GG V/Q to confirm the diagnosis. There were no significant differences in age, sex, risk factors and clinical presentation. Outpatient treatment with ACO was significantly associated with the diagnosis by GG V/Q and not by the presence of positive DD.
Introdução. A embolia pulmonar (EP) é uma condição comum, com um impacto real não é bem conhecida pela sua variabilidade clínica e dificuldades diagnósticas. Vários estudos têm demonstrado a utilidade clínica do dímero-D (DD), mas seu valor preditivo positivo é baixo, forçando a realizar outras técnicas de diagnóstico para confirmar. Objetivos. Determinar a utilidade de DD positivo; avaliar a correlação de sinais clínicos, e analisar o uso de anticoagulação oral (ACO) para o diagnóstico de EP. Material e métodos. Foram analisados 58 pacientes internados com suspeita clínica de PE e DD positivo a partir de Junho de 2009 a Fevereiro de 2012, as quais foram realizadas cintilografia pulmonar de ventilação/perfusão varredura (CP V/Q). Foram avaliados fatores de risco (FR), características clínicas e terapia OAC na alta. Resultados. Do total de pacientes, 60% eram do sexo feminino e 74% tinham >65 anos. 36 (62%) apresentaram CP V/Q positiva e as seguintes características clínicas: 23 (64%) FR positivos, 21 (58%) sinais de trombose venosa profunda (TVP), 22 (61%) dispnéia, seis (16% ) dor torácica, 11 (30%) taquicardia e 4 (11%) tosse. O resto dos pacientes (n=22, 38%) apresentaram: 15 (68%) FR positivo, 10 (45%) sinais de TVP, 15 (68%) dispnéia, 2 (9%), dor torácico, 5 (23 %) taquicardia e 5 (23%) tosse, sem diferenças significativas entre os dois grupos. Todos os pacientes com CP V/Q positivo foram tratados com ACO na alta e apenas 11 (50%) dos pacientes tiveram CP V/Q negativo, com diferenças significativas. Conclusão. O DD positivo não prever o diagnóstico de EP, demonstrando a importância da CP V/Q para confirmar o diagnóstico. Não houve diferenças significativas na idade, sexo, fatores de risco e quadro clínico. Tratamento ambulatorial com ACO foi significativamente associado com o diagnóstico por CP V/Q e não pela presença de DD positivo.
ABSTRACT
FUNDAMENTO: No Teste Cardiopulmonar de Exercício (TCPE) máximo são analisadas diversas variáveis ventilatórias, incluindo o equivalente ventilatório de oxigênio (VE/VO2). O valor mínimo do VE/VO2 reflete a melhor integração entre os sistemas respiratório e cardiovascular, podendo ser denominado Ponto Ótimo Cardiorrespiratório (POC). OBJETIVO: Determinar o comportamento do POC em função do gênero e da idade em adultos saudáveis e verificar a associação com outras variáveis do TCPE. MÉTODOS: De 2.237 indivíduos, foram selecionados 624 (62% homens e 48 ± 12 anos de idade), não atletas, saudáveis, submetidos ao TCPE máximo. O POC ou VE/VO2 mínimo foi obtido a partir da análise da ventilação e do consumo de oxigênio em cada minuto do TCPE. Foi verificada a relação entre idade e POC para os dois gêneros, assim como as associações com: VO2máx, VO2 no limiar anaeróbico (VO2LA), eficiência da inclinação de consumo de oxigênio (OUES) e com VE máxima. Comparou-se ainda a intensidade do esforço (MET) no POC, LA e VO2máx. RESULTADOS: O POC aumenta com a idade, sendo 23,2 ± 4,48 e 25,0 ± 5,14, respectivamente, em homens e mulheres (p < 0,001). Há associações moderadas e inversas com VO2máx (r = -0,47; p < 0,001), com VO2LA (r = -0,42; p < 0,001) e com o OUES (r = -0,34; p < 0,001). O POC ocorreu, em média, a (44% do VO2máx) e antes do LA (67% do VO2máx) (p < 0,001). CONCLUSÃO: POC, uma variável submáxima, aumenta com a idade e é discretamente mais alto em mulheres. Sendo modestamente associado a outras medidas ventilatórias, parece haver uma contribuição independente na interpretação da resposta cardiorrespiratória ao TCPE.
BACKGROUND: At the maximal Cardiopulmonary Exercise Testing (CPET), several ventilatory variables are analyzed, including the ventilatory equivalent for oxygen (VE/VO2). The minimum VE/VO2 value reflects the best integration between the respiratory and cardiovascular systems and may be called "Cardiorespiratory Optimal Point (COP)". OBJECTIVE: To determine the behavior of the COP according to gender and age in healthy adults and verify its association with other CPET variables. METHODS: Of 2,237 individuals, 624 were selected (62% men and 48 ± 12 years), non- athletes, healthy, who were submitted to maximal CPET. COP or minimum VE/VO2 was obtained from the analysis of ventilation and oxygen consumption in every minute of CPET. We investigated the association between age and COP for both genders, as well as associations with: VO2max, VO2 at anaerobic threshold (VO2AT), oxygen uptake efficiency slope (OUES) and with maximum VE. We also compared the intensity of exertion (MET) at the COP, AT and VO2max. RESULTS: COP increases with age, being 23.2 ± 4.48 and 25.0 ± 5.14, respectively, in men and women = (p < 0.001). There are moderate and inverse associations with VO2max (r = -0.47; p < 0.001), with VO2AT (r = -0.42; p < 0.001) and with OUES (r = -0.34; p < 0.001). COP occurred, on average, at 44% do VO2max and before AT (67% of VO2max) (p < 0.001). CONCLUSION: COP, a submaximal variable, increases with age and is slightly higher in women. Being modestly associated with other ventilation measures, there seems to be an independent contribution to the interpretation of the cardiorespiratory response to CPET.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Exercise Test/methods , Oxygen Consumption/physiology , Pulmonary Ventilation/physiology , Ventilation-Perfusion Ratio/physiology , Age Factors , Reference Values , Retrospective Studies , Sex Factors , Spirometry , Statistics, Nonparametric , Time FactorsABSTRACT
Objective To investigate the relationship between end-tidal carbon dioxide with its related indicators and ventilation/perfusion of the acute respiratory distress syndrome (ARDS) lung,and to explore a feasible way to titrate positive end-expiratory pressure (PEEP) in clinical practice.Methods Five mixed-breed dogs with oleic acid lung injury model were mechanically ventilated at a serial PEEP trial including a recruitment maneuver (RM) before each PEEP level changed.The value of blood dynamics,end-tidal carbon dioxide partial pressure ( PetCO2 ) and arterial carbon dioxide pressure under different PEEP levels were recorded.Arterial end-tidal carbon dioxide gradient (Pa-etCO2) and dead space fraction (Vd/Vt％) were calculated.All dogs received CT scan.Lung volume under different pressure levels,and ratio and volume of alveolar closing pressure,collapsed alveoli,sufficiently and insufficiently ventilated alveoli were obtained.Alveolar opening and closing analysis were performed by non-liner regression equation.Results The mean pressure when Vd/Vt％ obtained lowest level were ( 11.2 ± 4.4 ) cm H2O(1 em H2 O =0.098 kPa),which had no significant difference when compared to alveolar closing pressure[ ( 11.5 ± 3.2 ) cm H2O ]( P ＞ 0.05 ).The fraction of insufficiently ventilated and collapsed alveoli showed a significant linear correlation with the Vd/Vt％ when PEEP was lower than Pmin ( r =0.632,P =0.004 ).There was a linear correlation between the Vd/Vt％ and the fraction of over-distended alveoli when PEEP was higher than Pmin ( r =0.770,P =0.001 ).Conclusions Closing pressure is in accordance with PEEP level after RM having reached the best ventilation/circulation ratio.The characteristics of lung collapse can be revealed by Vd/Vt％ changes after RM.To titrate PEEP for the lowest Vd/Vt％ after RM may be a feasible way to match the best ventilation and circulation effects of PEEP.
ABSTRACT
BACKGROUND: Body posture, as a gravitational factor, has a clear impact on pulmonary ventilation and perfusion. In lung units with mismatched ventilation and perfusion, gas exchange and/or elimination of carbon dioxide can be impaired. In this situation, differences in the value of arterial and end-tidal carbon dioxide tension [Delta(PaCO2 - PETCO2)] are expected to increase. This study was conducted to observe how Delta(PaCO2 - PETCO2) changed according to the 3 different surgical positions, and to determine whether Delta(PaCO2 - PETCO2) is a reliable predictor of ventilation/perfusion mismatch when a patient is in different postural positions. METHODS: Fifty-nine patients were divided into either the chronic obstructive pulmonary disease (COPD) group (n = 29) or the non-COPD group (n = 30). PaCO2 and PETCO2 were measured during surgery in the supine, prone, and lateral decubitus positions after a 10 minute stabilization period. The Delta(PaCO2 - PETCO2) were calculated and compared among positions. RESULTS: The Delta(PaCO2 - PETCO2) decreased slightly in the prone position and increased significantly in the lateral decubitus position compared with the supine position in both groups. These patterns almost corresponded with the degree of ventilation/perfusion mismatch from the results of the radiological studies. The Delta(PaCO2 - PETCO2) in the COPD group was significantly greater than that in the non-COPD group at all surgical positions. CONCLUSIONS: Lateral decubitus position is associated with marked increase in Delta(PaCO2 - PETCO2), especially in patients with COPD. The Delta(PaCO2 - PETCO2) is a simple and reliable indicator to predict ventilation/perfusion mismatch at different surgical positions in patients with or without COPD.
Subject(s)
Humans , Benzeneacetamides , Carbon , Carbon Dioxide , Lung , Perfusion , Piperidones , Posture , Prone Position , Pulmonary Disease, Chronic Obstructive , Pulmonary Ventilation , Supine Position , Ventilation , Ventilation-Perfusion RatioABSTRACT
Aging generates four important changes in the structure and function of the respiratory system. There is a reduction in the elastic recoil of the lung causing "senile emphysema", a condition characterized by reduction in the alveolar surface area without alveolar destruction, which is associated with hyperinflation, increased lung compliance and reduction in alveolar-capillary diffusing capacity. There is a decrease in the compliance of the chest watt, due to calcification of its articulations, dorsal kyphosis and "barrel chest". There is a decrease in the strength of respiratory muscles which correlates with cardiac Index, nutritional status and hyperinflation, and there is a reduction in the ventilatory response to hypoxia and hypercapnia as well as in the perception of increased airway resistance. The increased static lung compliance combined with the decreased chest watt compliance leads to an increase in the functional residual capacity with aging. On the other hand, the loss of alveolar and airways elastic recoil combined with the reduction in the strength of the expiratory muscles, leads to an increase in residual volume and decreased maximal expiratory airflow rates and vital capacity. Despite these changes, the respiratory system maintains an adequate gas exchange at rest and during exercise during the whole life span, showing a normal PaCO2 and a slight decline in PaO2 (-0,3 mmHg per year) which is attenuated to become almost undetectable over the age of 70.