Cardiopulmonary effects of prolonged surgical abdominal retractors application during general anesthesia: a prospective observational comparative study

Abstract Introduction: Increasing abdominal pressures could affect pulmonary compliance and cardiac performance, a fact based on which the aim of the present study to detect the cardiopulmonary burden of multiple retractors application during supine versus lateral abdominal surgeries. We hypothesized that surgical ring multiple retractors application would affect the pulmonary and cardiac functions during both lateral and supine abdominal surgeries. Methods: Prospective observational comparative study on forty surgical patients subdivided into two groups twenty each, comparing pulmonary compliance and cardiac performance before, during and after retractors application, group (S) supine position cystectomy surgery, and group (L) lateral position nephrectomy surgery under general anesthesia, Composite 1ry outcome; dynamic compliance C-dyn and cardiac index CI and Other outcome variables ICON cardio-meter were also recorded. Results: C-dyn and C-stat were significantly decreased late during retractor application in lateral compared to supine surgery with significant decrease compared to basal values all over the surgical time. CI was significantly increased after retractor removal in both of the study groups compared to basal values. PAW P was significantly increased in -lateral compared to supine surgery -with significant increase compared to basal value all over the surgical time in both of the study groups. significant increase in DO2I compared to basal value during both supine and lateral positions. Conclusion: Surgical retraction results in a short-lived significant decreases in lung compliance and cardiac output particularly during the lateral-kidney position than the supine position compliance.

Agreement analysis of stroke volume and cardiac output measurement between a oscillometric device and transthoracic echocardiogram in normotensive individuals: a preliminary report

Abstract Introduction The evaluation of stroke volume (SV) is useful in research and patient care. To accomplish this, an ideal device should be noninvasive, continuous, reliable, and reproducible. The Mobil-O-Graph (MOG) is a noninvasive oscillometric matrix validated for measuring aortic and peripheral blood pressure, which through conversion algorithms can estimate hemodynamic parameters. Objectives To compare the MOG measurement of stroke volume, cardiac output, and cardiac index with the transthoracic echocardiogram (TTE). Methods Healthy volunteers aged 18 years or older were included. Two-dimensional TTEs were performed by a single operator. Subsequently, the measurement of noninvasive hemodynamics with MOG was performed with the operator blind to the results of the echocardiogram. Correlation analyses between stroke volume, cardiac output, and cardiac index parameters were performed. The degree of agreement between the methods was verified using the Bland-Altman method. Results A total of 38 volunteers were enrolled with a mean age of 27.6 ± 3.8 years; 21 (55%) were male The SV by TTE was 76.8 ± 19.5 mL and 75.7 ± 19.3 mL by MOG, Rho = 0.726, p< 0.0001. The CO by TTE was 5.04 ± 0.8 mL.min-1 and 5.1 ± 0.8 mL.min-1 by MOG Rho = 0.510, p= 0.001. Bland-Altman plots showed a good concordance between the two techniques. Conclusions Our study shows that the measurement of SV and CO by noninvasive hemodynamics with the MOG device offers a good concordance with the TTE with very few values beyond the confidence limits.

Comparative study between suprasternal and apical windows: a user-friendly cardiac output measurement for the anesthesiologist

Abstract Introduction Transthoracic echocardiography is a safe and readily available tool for noninvasive monitoring of Cardiac Output (CO). The use of the suprasternal window situated at the sternal notch can be an alternative approach for estimating blood flow. The present study aimed to compare two methods of CO calculation. We compared the descending aorta Velocity-Time Integral (VTI) measurement from the suprasternal window view with the standard technique to determine CO that uses VTI measurements from the LVOT (Left Ventricular Outflow Tract) view. We also aimed to find out whether after basic training a non-echocardiographer operator can obtain reproducible measurements of VTI using this approach. Methods In the first part of the study, 26 patients without known cardiovascular diseases were evaluated and VTI data were acquired from the suprasternal window by a non-echocardiographer and an echocardiographer. Next, 17 patients were evaluated by an echocardiographer only and VTI and CO measurements were obtained from suprasternal and apical windows. Data were analyzed using the Bland and Altman method (BA), correlation and regression. Results We found a strong correlation between measurements obtained by a non-expert and an expert echocardiographer and detected that an inexperienced trainee can acquire VTI measurements from the suprasternal window view. Regarding agreement between CO measurements, data obtained showed a positive correlation and the Bland and Altman analysis presented a total variation of 38.9%. Conclusion Regarding accuracy, it is likely that TTE (Transthoracic Echocardiogram) measurements of CO from the suprasternal window view are comparable to other minimally invasive techniques currently available. Due to its user-friendliness and low cost, it can be a convenient technique for obtaining perioperative hemodynamic measurements, even by inexperienced operators.

Hemodynamic effects of different fluid volumes for a fluid challenge in septic shock patients / 中华医学杂志(英文版)

BACKGROUND@#It is still unclear what the minimal infusion volume is to effectively predict fluid responsiveness. This study was designed to explore the minimal infusion volume to effectively predict fluid responsiveness in septic shock patients. Hemodynamic effects of fluid administration on arterial load were observed and added values of effective arterial elastance (Ea) in fluid resuscitation were assessed.@*METHODS@#Intensive care unit septic shock patients with indwelling pulmonary artery catheter (PAC) received five sequential intravenous boluses of 100 mL 4% gelatin. Cardiac output (CO) was measured with PAC before and after each bolus. Fluid responsiveness was defined as an increase in CO >10% after 500 mL fluid infusion.@*RESULTS@#Forty-seven patients were included and 35 (74.5%) patients were fluid responders. CO increasing >5.2% after a 200 mL fluid challenge (FC) provided an improved detection of fluid responsiveness, with a specificity of 80.0% and a sensitivity of 91.7%. The area under the ROC curve (AUC) was 0.93 (95% CI: 0.84-1.00, P  < 0.001). Fluid administration induced a decrease in Ea from 2.23 (1.46-2.78) mmHg/mL to 1.83 (1.34-2.44) mmHg/mL (P = 0.002), especially for fluid responders in whom arterial pressure did not increase. Notably, the baseline Ea was able to detect the fluid responsiveness with an AUC of 0.74 (95% CI: 0.59-0.86, P < 0.001), whereas Ea failed to predict the pressure response to FC with an AUC of 0.50 (95% CI: 0.33-0.67, P = 0.086).@*CONCLUSION@#In septic shock patients, a minimal volume of 200 mL 4% gelatin could reliably detect fluid responders. Fluid administration reduced Ea even when CO increased. The loss of arterial load might be the reason for patients who increased their CO without pressure responsiveness. Moreover, a high level of Ea before FC was able to predict fluid responsiveness rather than to detect the pressure responsiveness.@*TRIAL REGISTRATION@#ClinicalTrials.gov, NCT04515511.

Diagnóstico de Enfermagem em pacientes com infarto do miocárdio: estudo longitudinal / Nursing diagnoses in patients whit myocardial infarction: follow up study / Diagnósticos de Eanfermería em pacientes com infarto de miocardio: estudio longitudinal

Objetivo: Identificar o diagnóstico de enfermagem prioritário no paciente pós-infarto do miocárdio com supradesnivelamento do segmento ST. Métodos: Estudo observacional, longitudinal, prospectivo, realizado com 54 pacientes de ambos os sexos, admitidos na fase aguda do infarto durante os primeiros cinco dias pós-infarto (D1 a D5), em um hospital de ensino. Amostragem foi não probabilística. Para a coleta de dados, utilizou-se um instrumento estruturado a partir do modelo teórico conceitual das Necessidades Humanas Básicas. Empregaram-se análises descritivas e bivariadas. Resultados: O diagnóstico de enfermagem de maior incidência no D1 pós-infarto foi Debito cardíaco diminuído, seguido por padrão respiratório ineficaz e dor aguda. O diagnóstico de enfermagem Débito Cardíaco Diminuído foi associado aos indivíduos não brancos (p<0,05). Conclusão: Observou-se a prevalência do diagnóstico de enfermagem prioritário de débito cardíaco diminuído nos cinco primeiros dias pós-infarto. (AU)

Objective: Identify the priority nursing diagnosis in the post-myocardial infarction patient with ST segment elevation. Methods: Observational, longitudinal, prospective study conducted with 54 patients of both sexes, admitted in the acute phase of infarction during the first five days post-infarction (D1 to D5), in a teaching hospital. Sampling was non-probabilistic. To collect data, we used a structured instrument from the conceptual theoretical model of Human Basic Needs. We used descriptive and bivariate analysis. Results: The nursing diagnosis with the highest incidence in post-infarction D1 was a decrease in cardiac output, followed by an ineffective breathing pattern and acute pain. The nursing diagnosis Decreased Cardiac Output was associated with non-white individuals (p <0.05). Conclusion: The prevalence of the priority nursing diagnosis of decreased cardiac output was observed in the first five days after infarction. (AU)

Objetivo: Identificar el diagnóstico de enfermería prioritario en el paciente con infarto de miocardio con elevación del segmento ST. Métodos: Estudio observacional, longitudinal, prospectivo, realizado con 54 pacientes de ambos sexos, ingresados en la fase aguda del infarto durante los primeros cinco días posteriores al infarto (D1 a D5), en un hospital universitario. El muestreo no fue probabilístico. Para la recolección de datos, se utilizó un instrumento estructurado a partir del modelo teórico conceptual de las necesidades humanas básicas. Se utilizaron análisis descriptivos y bivariados. Resultados: El diagnóstico de enfermería con la mayor incidencia en el post-infarto D1 fue disminución del gasto cardíaco, seguido de un patrón de respiración ineficaz y dolor agudo. El diagnóstico de enfermería Disminución del gasto cardíaco se asoció con individuos no blancos (p <0.05). Conclusión: La prevalencia del diagnóstico de enfermería prioritario de disminución del gasto cardíaco se observó en los primeros cinco días después del infarto. (AU)

Impact of mild hypothermia therapy on hemodynamics during the induction stage in neonates with moderate to severe hypoxic-ischemic encephalopathy / 中国当代儿科杂志

OBJECTIVE@#To study the changes in hemodynamics during the induction stage of systemic mild hypothermia therapy in neonates with moderate to severe hypoxic-ischemic encephalopathy (HIE).@*METHODS@#A total of 21 neonates with HIE who underwent systemic mild hypothermia therapy in the Department of Neonatology, Dongguan Children's Hospital Affiliated to Guangdong Medical University, from July 2017 to April 2020 were enrolled. The rectal temperature of the neonates was lowered to 34℃ after 1-2 hours of induction and maintained at this level for 72 hours using a hypothermia blanket. The impedance method was used for noninvasive hemodynamic monitoring, and the changes in heart rate (HR), mean arterial pressure (MAP), stroke volume (SV), cardiac output (CO), cardiac index (CI), and total peripheral resistance (TPR) from the start of hypothermia induction to the achievement of target rectal temperature (34℃). Blood lactic acid (LAC) and resistance index (RI) of the middle cerebral artery were recorded simultaneously.@*RESULTS@#The 21 neonates with HIE had a mean gestational age of (39.6±1.1) weeks, a mean birth weight of (3 439±517) g, and a mean 5-minute Apgar score of 6.8±2.0. From the start of hypothermia induction to the achievement of target rectal temperature (34℃), there were significant reductions in HR, CO, and CI (@*CONCLUSIONS@#The systemic mild hypothermia therapy may have a significant impact on hemodynamics in neonates with moderate to severe HIE, and continuous hemodynamic monitoring is required during the treatment.

Cardiac output values and correlation of renal injury with neutrophil gelatinase-associated lipocalin levels in off-pump coronary artery bypass patients

Abstract Objective: To investigate the correlation between cardiac output values and renal neutrophil gelatinase-associated lipocalin (NGAL) levels as a biomarker of renal ischemia. Methods: Forty patients, who underwent off-pump coronary artery bypass (OPCAB) surgery and in whom the positioning of the heart was fixed with simple suspension sutures without a mechanical stabilizer, were included in the study. Continuous cardiac output (CO) measurements were recorded using the arterial pressure waveform analysis method (FloTrac sensor system) in the perioperative period. CO was recorded every minute during non-anatomical cardiac positioning for left anterior descending artery (LAD), diagonal artery (D), circumflex artery (Cx), and right coronary artery (RCA) bypasses. Serum NGAL samples were analyzed in the preoperative, perioperative, and postoperative periods. Results: The CO values measured at various non-anatomical cardiac positions during distal anastomosis for LAD, D, Cx, and RCA were significantly lower than pre- and postoperative values measured with the heart in normal anatomical position (3.45±0.78, 2.9±0.71, 3.11±0.56, 3.19±0.81, 5.03±1.4, and 4.85±0.78, respectively, P=0.008). There was no significant difference between CO values measured at various non-anatomical cardiac positions during distal anastomosis. Although there was no significant correlation between NGAL levels and age, duration of surgery, preoperative CO, D-CO, RCA-CO, and postoperative CO measurements, there was a significant correlation between NGAL levels and LAD-CO (P=0.044) and Cx-CO (P=0.018) at the postoperative 12th hour. Conclusion: Full revascularization may be achieved by employing the OPCAB technique while using simple suspension sutures without a mechanical stabilizer and by providing safe CO levels and low risk of renal ischemia.

Serum elabela level significantly increased in patients with complete heart block

Abstract Objective: To investigate the change in serum Elabela level, a new apelinergic system peptide, in patients with complete atrioventricular (AV) block and healthy controls. Methods: The study included 50 patients with planned cardiac pacemaker (PM) implantation due to complete AV block and 50 healthy controls with similar age and gender. Elabela level was measured in addition to routine anamnesis, physical examination, and laboratory tests. Patients were divided into two groups, with and without AV block, and then compared. Results: In patients with AV block, serum Elabela level was significantly higher and heart rate and cardiac output were significantly lower than in healthy controls. Serum Elabela level was found to be positively correlated with high-sensitive C-reactive protein and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, but negatively correlated with heart rate, high-density lipoprotein cholesterol, and cardiac output. In linear regression analysis, it was found that these parameters were only closely related to heart rate and NT-proBNP. Serum Elabela level was determined in the patients with AV block independently; an Elabela level > 9.5 ng/ml determined the risk of complete AV-block with 90.2% sensitivity and 88.0% specificity. Conclusion: In patients with complete AV block, the serum Elabela level increases significantly before the PM implantation procedure. According to the results of our study, it was concluded that serum Elabela level could be used in the early determination of patients with complete AV block.

Monitorizacion del gasto cardiaco con ecocardiografia transtoracica y cateter de Swan Ganz. Estudio comparativo en pacientes en ventilacion mecanica con presión positiva espiratoria final elevada / Cardiac output measured by transthoracic echocardiography and Swan-Ganz catheter. A comparative study in mechanically ventilated patients with high positive end-expiratory pressure

RESUMEN Objetivo: Comparar las medidas de gasto cardiaco por ecocardiografía transtorácica y por catéter arterial pulmonar en pacientes en ventilación mecánica con presión positiva al final de la espiración elevada. Evaluar el efecto de la insuficiencia tricúspide. Métodos: Se estudiaron 16 pacientes en ventilación mecánica. El gasto cardiaco se midió con el catéter arterial pulmonar y por ecocardiografía transtorácica. Las medidas se realizaron en diferentes niveles de presión positiva al final de la espiración (10cmH2O, 15cmH2O, y 20cmH2O). Se evalúo el efecto de la insuficiencia tricúspide sobre la medida de gasto cardiaco. Se estudió el coeficiente de correlación intraclase; el error medio y los límites de concordancia se estudiaron con el diagrama de Bland-Altman. Se calculó el porcentaje de error. Resultados: Se obtuvieron 44 pares de medidas de gasto cardiaco. Se obtuvo un coeficiente de correlación intraclase de 0,908, p < 0,001; el error medio fue 0,44L/min para valores de gasto cardíaco entre 5 a 13L/min. Los límites de concordancia se encontraron entre 3,25L/min y -2,37L/min. Con insuficiencia tricúspide el coeficiente de correlación intraclase fue 0,791, sin insuficiencia tricúspide el coeficiente de correlación intraclase fue 0,935. La presencia de insuficiencia tricúspide aumentó el porcentaje de error de 32 % a 52%. Conclusiones: En pacientes con presión positiva al final de la espiración elevada la medida de gasto cardiaco por ecocardiografía transtorácica es comparable con catéter arterial pulmonar. La presencia de insuficiencia tricúspide influye en el coeficiente de correlación intraclase. En pacientes con presión positiva al final de la espiración elevada, el uso de ecocardiografía transtorácica para medir gasto cardiaco es comparable con las medidas invasivas.

ABSTRACT Objective: To compare cardiac output measurements by transthoracic echocardiography and a pulmonary artery catheter in mechanically ventilated patients with high positive end-expiratory pressure. To evaluate the effect of tricuspid regurgitation. Methods: Sixteen mechanically ventilated patients were studied. Cardiac output was measured by pulmonary artery catheterization and transthoracic echocardiography. Measurements were performed at different levels of positive end-expiratory pressure (10cmH2O, 15cmH2O, and 20cmH2O). The effect of tricuspid regurgitation on cardiac output measurement was evaluated. The intraclass correlation coefficient was studied; the mean error and limits of agreement were studied with the Bland-Altman plot. The error rate was calculated. Results: Forty-four pairs of cardiac output measurements were obtained. An intraclass correlation coefficient of 0.908 was found (p < 0.001). The mean error was 0.44L/min for cardiac output values between 5 and 13L/min. The limits of agreement were 3.25L/min and -2.37L/min. With tricuspid insufficiency, the intraclass correlation coefficient was 0.791, and without tricuspid insufficiency, 0.935. Tricuspid insufficiency increased the error rate from 32% to 52%. Conclusions: In patients with high positive end-expiratory pressure, cardiac output measurement by transthoracic echocardiography is comparable to that with a pulmonary artery catheter. Tricuspid regurgitation influences the intraclass correlation coefficient. In patients with high positive end-expiratory pressure, the use of transthoracic echocardiography to measure cardiac output is comparable to invasive measures.

Exercício físico e pressão arterial: efeitos, mecanismos, influências e implicações na hipertensão arterial / Physical exercise and blood pressure: effects, mechanisms, influences and impacts on hypertension

O exercício físico é recomendado no tratamento da hipertensão arterial. Agudamente, a execução do exercício promove aumento da pressão arterial (PA), mas, no período de recuperação pós-exercício, é possível evidenciar redução da PA e, principalmente, após um período de treinamento físico crônico, pode haver diminuição da PA clínica e de 24 horas dos hipertensos. Apesar desses efeitos serem conhecidos, sua magnitude e mecanismos dependem do tipo de exercício executado e de suas características. Este artigo revê os efeitos agudos e crônicos clássicos do exercício aeróbico e os efeitos mais recentemente estudados dos exercícios resistidos isométrico e dinâmico na PA, seus mecanismos e fatores de influência, ressaltando os pontos que embasam as recomendações atuais sobre o uso do exercício na hipertensão arterial. O conhecimento atual demonstra que: 1) o exercício aeróbico promove aumento da PA sistólica durante sua execução, gera hipotensão pós-exercício clinicamente relevante e reduz a PA clínica e de 24 horas após o treinamento; 2) o exercício resistido isométrico promove aumento progressivo da PA sistólica e diastólica durante sua execução, não produz hipotensão pós-exercício consistente e reduz a PA clínica após o treinamento, mas esse efeito hipotensor ocorre com um protocolo específico de exercício de handgrip; e 3) o exercício resistido dinâmico promove grande aumento da PA sistólica e diastólica durante sua execução, gera hipotensão pós-exercício cuja relevância clínica ainda precisa ser comprovada e parece diminuir a PA clínica, mas não a ambulatorial, após o treinamento. Face a esses conhecimentos, o treinamento aeróbico complementado pelo resistido dinâmico é recomendado na hipertensão

Physical exercise is recommended for hypertension treatment. Acutely, exercise execution increases blood pressure (BP), but, during the recovery period, BP decreases, and after a chronic training period, clinic and ambulatory BP may decrease in hypertensives. Despite these known effects of exercise, their magnitude and mechanisms depend on the type of exercise and its characteristics. This article reviews the classical acute and chronic effects of aerobic exercise and the more recent knowledge about isometric and dynamic resistance exercises on BP, its mechanisms and factors of influence, highlighting the aspects underlying exercise recommendations for hypertension. Current scientific knowledge shows that: 1) aerobic exercise increases systolic BP during its execution, produces a clinically significant post-exercise hypotension, and chronically decreases clinic and 24-hour BP; 2) isometric resistance exercise produces a progressive increase in systolic and diastolic BP during its execution, does not promote consistent post-exercise hypotension, and decreases clinic BP after training, but this hypotensive effect results from a specific protocol of isometric handgrip; and 3) dynamic resistance exercise produces a huge progressive increase in systolic and diastolic BP during its execution, promotes post-exercise hypotension with questionable clinical relevance, and seems to decrease clinic but not ambulatory BP after training. Based on this current knowledge, regular aerobic exercise complemented by dynamic resistance exercise is recommended for hypertension

Measuring Heart Rate During Exercise: From Artery Palpation to Monitors and Apps

The use of technology has increased tremendously, by means of more reliable, smaller, more accessible and specially more user-friendly devices, which provide a wider range of features, and promote significant benefits for the population and health professionals. It is in this context that monitors and apps for heart rate (HR) measurement have emerged. HR is a clinical vital sign of diagnostic and prognostic importance. In response to body movement, HR tends to increase, in a direct relationship with the intensity of exercise. HR was primarily measured by the count of arterial pulse, and recently, HR can be precisely measured by monitors, bracelets and smartphone apps capable to perform real-time measurements and storage of data. This paper aimed to make a brief and updated review on the theme, providing a broader view of advantages and limitations of these resources for HR measurement in exercise. HR monitors and apps use basically two types of technology, optical sensor (photoplethysmography) and electrical signal from the heart. In general, these devices have shown good accuracy in measuring HR and HR variability at rest, but there are differences between brands and models considering the type, mode and intensity of exercise. HR measurements by monitors and smartphone apps are simple, accessible and may help cardiologists in the monitoring of the intensity of aerobic exercise, focusing on health promotion and on primary and secondary prevention of cardiovascular diseases

Test-Retest Reliability of Non-Invasive Cardiac Output Measurement during Exercise in Healthy Volunteers in Daily Clinical Routine / Confiabilidade Teste-Reteste de Medição Não-Invasiva de Débito Cardíaco durante Exercício em Voluntários Saudáveis sob Condições Clínicas de Rotina

Abstract Background: Thoracic bioreactance (TB), a noninvasive method for the measurement of cardiac output (CO), shows good test-retest reliability in healthy adults examined under research and resting conditions. Objective: In this study, we evaluate the test-retest reliability of CO and cardiac power (CPO) output assessment during exercise assessed by TB in healthy adults under routine clinical conditions. Methods: 25 test persons performed a symptom-limited graded cycling test in an outpatient office on two different days separated by one week. Cardiorespiratory (power output, VO2peak) and hemodynamic parameters (heart rate, stroke volume, CO, mean arterial pressure, CPO) were measured at rest and continuously under exercise using a spiroergometric system and bioreactance cardiograph (NICOM, Cheetah Medical). Results: After 8 participants were excluded due to measurement errors (outliers), there was no systematic bias in all parameters under all conditions (effect size: 0.2-0.6). We found that all noninvasively measured CO showed acceptable test-retest-reliability (intraclass correlation coefficient: 0.59-0.98; typical error: 0.3-1.8). Moreover, peak CPO showed better reliability (intraclass correlation coefficient: 0.80-0.85; effect size: 0.9-1.1) then the TB CO, thanks only to the superior reliability of MAP (intraclass correlation coefficient: 0.59-0.98; effect size: 0.3-1.8). Conclusion: Our findings preclude the clinical use of TB in healthy subject population when outliers are not identified.

Resumo Fundamento: A biorreatância torácica (BT), um método não invasivo destinado à medição do débito cardíaco (DC), mostra boa confiabilidade teste-reteste em adultos saudáveis examinados em condições de pesquisa e repouso. Objetivo: No presente estudo, avaliamos a confiabilidade teste-reteste da avaliação do DC e trabalho cardíaco (TC) durante exercício, avaliado por BT em adultos saudáveis sob condições clínicas de rotina. Métodos: 25 indivíduos realizaram teste ergométrico gradual sintoma-limitante em ambiente ambulatorial em dois dias diferentes, com intervalo de uma semana. Parâmetros cardiorrespiratórios (trabalho cardíaco, VO2máx) e hemodinâmicos (frequência cardíaca, volume sistólico, DC, pressão arterial média, TC) foram medidos em repouso e continuamente sob exercício utilizando sistema espiroergométrico e cardiógrafo de biorreatância (NICOM, Cheetah Medical). Resultados: Após 8 participantes terem sido excluídos devido a erros de medição (outliers), não houve viés sistemático em nenhum dos parâmetros em todas as condições (tamanho do efeito: 0,2-0,6). Observamos que todos os débitos cardíacos medidos de forma não invasiva apresentaram níveis aceitáveis de confiabilidade teste-reteste (coeficiente de correlação intraclasse: 0,59-0,98; erro típico: 0,3-1,8). Além disso, TC máximo apresentou melhor confiabilidade (coeficiente de correlação intraclasse: 0,80-0,85; tamanho do efeito: 0,9-1,1), seguido do DC pela BT, graças apenas à confiabilidade superior da PAM (coeficiente de correlação intraclasse: 0,59-0,98; tamanho do efeito: 0,3-1,8). Conclusão: Nossos achados impedem o uso clínico da BT em indivíduos saudáveis quando outliers não forem identificados.

Transthoracic echocardiographic assessment of cardiac output in mechanically ventilated critically ill patients by intensive care unit physicians / Avaliação ecocardiográfica transtorácica do débito cardíaco feita por médicos da unidade de terapia intensiva em pacientes críticos sob ventilação mecânica

Abstract Background and objectives: Transthoracic echocardiography may potentially be useful to obtain a prompt, accurate and non-invasive estimation of cardiac output. We evaluated whether non-cardiologist intensivists may obtain accurate and reproducible cardiac output determination in hemodynamically unstable mechanically ventilated patients. Methods: We studied 25 hemodynamically unstable mechanically ventilated intensive care unit patients with a pulmonary artery catheter in place. Cardiac output was calculated using the pulsed Doppler transthoracic echocardiography technique applied to the left ventricular outflow tract in apical 5 chamber view by two intensive care unit physicians who had received a basic Transthoracic Echocardiography training plus a specific training focused on Doppler, left ventricular outflow tract and velocity-time integral determination. Results: Cardiac output assessment by transthoracic echocardiography was feasible in 20 out of 25 enrolled patients (80%) and showed an excellent inter-operator reproducibility (Pearson correlation test r = 0.987; Cohen's K = 0.840). Overall, the mean bias was 0.03 L.min-1, with limits of agreement -0.52 and +0.57 L.min-1. The concordance correlation coefficient (ρc) was 0.986 (95% IC 0.966-0.995) and 0.995 (95% IC 0.986-0.998) for physician 1 and 2, respectively. The value of accuracy (Cb) of COTTE measurement was 0.999 for both observers. The value of precision (ρ) of COTTE measurement was 0.986 and 0.995 for observer 1 and 2, respectively. Conclusions: A specific training focused on Doppler and VTI determination added to the standard basic transthoracic echocardiography training allowed non-cardiologist intensive care unit physicians to achieve a quick, reproducible and accurate snapshot cardiac output assessment in the majority of mechanically ventilated intensive care unit patients.

Resumo Justificativa e objetivos: A ecocardiografia transtorácica pode ser potencialmente útil para obter uma estimativa rápida, precisa e não invasiva do débito cardíaco. Avaliamos se os intensivistas não cardiologistas podem obter uma determinação precisa e reprodutível do débito cardíaco em pacientes mecanicamente ventilados e hemodinamicamente instáveis. Métodos: Avaliamos 25 pacientes em unidade de terapia intensiva, mecanicamente ventilados, hemodinamicamente instáveis, com cateteres de artéria pulmonar posicionados. O débito cardíaco foi calculado com a técnica de ecocardiografia transtorácica com Doppler pulsátil aplicada à via de saída do ventrículo esquerdo no corte apical (5-câmaras) por dois médicos intensivistas que receberam treinamento básico em ecocardiografia transtorácica e treinamento específico focado em Doppler, via de saída do ventrículo esquerdo e determinação da integral de tempo-velocidade. Resultados: A avaliação do débito cardíaco pelo ecocardiograma transtorácico foi factível em 20 dos 25 pacientes inscritos (80%) e mostrou excelente reprodutibilidade entre operadores (teste de correlação de Pearson r = 0,987; K de Cohen = 0,840). No geral, o viés médio foi de 0,03 L.min-1, com limites de concordância de -0,52 e +0,57 L.min-1. O coeficiente de correlação de concordância (ρc) foi 0,986 (95% IC 0,966-0,995) e 0,995 (95% IC 0,986-0,998) para os médicos 1 e 2, respectivamente. O valor de precisão (Cb) da mensuração de COTTE foi de 0,999 para ambos os observadores. O valor de precisão (ρ) da mensuração de COTTE foi de 0,986 e 0,995 para os observadores 1 e 2, respectivamente. Conclusões: Um treinamento específico focado na determinação do Doppler e VTI, adicionado ao treinamento padrão em ecocardiografia transtorácica básica, permitiu que médicos não cardiologistas da unidade de terapia intensiva obtivessem uma avaliação rápida, reprodutível e precisa do débito cardíaco instantâneo na maioria dos pacientes mecanicamente ventilados em unidade de terapia intensiva.

Magnetic Resonance Imaging Assessment of Blood Flow Distribution in Fenestrated and Completed Fontan Circulation with Special Emphasis on Abdominal Blood Flow

OBJECTIVE: To investigate the regional flow distribution in patients with Fontan circulation by using magnetic resonance imaging (MRI). MATERIALS AND METHODS: We identified 39 children (18 females and 21 males; mean age, 9.3 years; age range, 3.3–17.0 years) with Fontan circulation in whom flow volumes across the thoracic and abdominal arteries and veins were measured by using MRI. The patients were divided into three groups: fenestrated Fontan circulation group with MRI performed under general anesthesia (GA) (Group 1, 15 patients; average age, 5.9 years), completed Fontan circulation group with MRI performed under GA (Group 2, 6 patients; average age, 8.7 years), and completed Fontan circulation group with MRI performed without GA (Group 3, 18 patients; average age, 12.5 years). The patient data were compared with the reference ranges in healthy controls. RESULTS: In comparison with the controls, Group 1 showed normal cardiac output (3.92 ± 0.40 vs. 3.72 ± 0.69 L/min/m2, p = 0.30), while Group 3 showed decreased cardiac output (3.24 ± 0.71 vs. 3.96 ± 0.64 L/min/m2, p = 0.003). Groups 1 and 3 showed reduced abdominal flow (1.21 ± 0.28 vs. 2.37 ± 0.45 L/min/m2, p < 0.001 and 1.89 ± 0.39 vs. 2.64 ± 0.38 L/min/m2, p < 0.001, respectively), which was mainly due to the diversion of the cardiac output to the aortopulmonary collaterals in Group 1 and the reduced cardiac output in Group 3. Superior mesenteric and portal venous flows were more severely reduced in Group 3 than in Group 1 (ratios between the flow volumes of the patients and healthy controls was 0.26 and 0.37 in Group 3 and 0.63 and 0.53 in Group 1, respectively). Hepatic arterial flow was decreased in Group 1 (0.11 ± 0.22 vs. 0.34 ± 0.38 L/min/m2, p = 0.04) and markedly increased in Group 3 (0.38 ± 0.22 vs. −0.08 ± 0.29 L/min/m2, p < 0.0001). Group 2 showed a mixture of the patterns seen in Groups 1 and 3. CONCLUSION: Fontan circulation is associated with reduced abdominal flow, which can be attributed to reduced cardiac output and portal venous return in completed Fontan circulation, and diversion of the cardiac output to the aortopulmonary collaterals in fenestrated Fontan circulation.

Fluid responsiveness in the pediatric population / 대한마취과학회지

It is challenging to predict fluid responsiveness, that is, whether the cardiac index or stroke volume index would be increased by fluid administration, in the pediatric population. Previous studies on fluid responsiveness have assessed several variables derived from pressure wave measurements, plethysmography (pulse oximeter plethysmograph amplitude variation), ultrasonography, bioreactance data, and various combined methods. However, only the respiratory variation of aortic blood flow peak velocity has consistently shown a predictive ability in pediatric patients. For the prediction of fluid responsiveness in children, flow- or volume-dependent, noninvasive variables are more promising than pressure-dependent, invasive variables. This article reviews various potential variables for the prediction of fluid responsiveness in the pediatric population. Differences in anatomic and physiologic characteristics between the pediatric and adult populations are covered. In addition, some important considerations are discussed for future studies on fluid responsiveness in the pediatric population.

Comparison of pulse pressure variation and pleth variability index in the prone position in pediatric patients under 2 years old / 대한마취과학회지

BACKGROUND: The assessment of intravascular volume status is very important especially in children during anesthesia. Pulse pressure variation (PPV) and pleth variability index (PVI) are well known parameters for assessing intravascular volume status and fluid responsiveness. We compared PPV and PVI for children aged less than two years who underwent surgery in the prone position. METHODS: A total of 27 children were enrolled. We measured PPV and PVI at the same limb during surgery before and after changing the patients’ position from supine to prone. We then compared PPV and PVI at each period using Bland-Altman plot for bias between the two parameters and for any correlation. We also examined the difference between before and after the position change for each parameter, along with peak inspiratory pressure, heart rate and mean blood pressure. RESULTS: The bias between PPV and PVI was −2.2% with a 95% limits of agreement of −18.8% to 14.5%, not showing significant correlation at any period. Both PPV and PVI showed no significant difference before and after the position change. CONCLUSIONS: No significant correlation between PVI and PPV was observed in children undergoing surgery in the prone position. Further studies relating PVI, PPV, and fluid responsiveness via adequate cardiac output estimation in children aged less than 2 years are required.

Pediatric Ventricular Assist Device

There have been great advances in ventricular assist device (VAD) treatment for pediatric patients with advanced heart failure. VAD support provides more time for the patient in the heart transplant waiting list. Augmented cardiac output improves heart failure symptoms, end-organ function, and general condition, and consequently provides beneficial effects on post-transplant outcomes. Miniaturized continuous flow devices are more widely adopted for pediatric patient with promising results. For infants and small children, still paracorporeal pulsatile device is the only option for long-term support. Younger age, congenital heart disease, biventricular support, patient's status and end-organ dysfunction at the time of implantation are risks for poor outcomes. Patient selection, timing of implantation, and selection of device for each patient are critical for optimal clinical outcomes.

Correlation between NT-proBNP and lipase levels according to the severity of chronic mitral valve disease in dogs

Chronic mitral valve disease (CMVD) is the most common cardiovascular disease in dogs, causing decreased cardiac output that results in poor tissue perfusion and tissue damage to kidneys, pancreas, and other organs. The purpose of this study was to evaluate the relationships between heart disease severity and N-terminal pro B-type natriuretic peptide (NT-proBNP) and lipase in dogs with CMVD, as well as to evaluate longitudinal changes in these values. A total of 84 dogs participated in this 2015 to 2017 study. Serum values of NT-proBNP and lipase were analyzed; radiography was used to measure the vertebral heart score and assess various echocardiographic values. NT-proBNP showed a strong positive correlation with increasing stage of heart disease; lipase showed a mild positive correlation with heart disease stage. When the three values (NT-proBNP, lipase and month) were continuously measured at 6-month intervals, all showed a correlation with the increasing length of the disease.

Comparison of the immediate hemodynamic changes induced by unilateral and bilateral spinal anesthesia in hypertensive elderly patients

BACKGROUND: The objective of this study was to compare the frequency of hypotension and immediate hemodynamic changes induced by unilateral and bilateral spinal anesthesia in hypertensive elderly patients. METHODS: Forty hypertensive elderly patients undergoing lower leg surgery were randomly allocated into unilateral (group US) and bilateral spinal anesthesia (group BS). After intrathecal bupivacaine injection, patients in group US were kept in the lateral position for 10 min while patients in group BS were immediately placed in the supine position. Hemodynamic parameters were measured for 20 min by non-invasive cardiac output monitor based on bioreactance. RESULTS: In both groups, mean arterial pressure was significantly decreased after spinal anesthesia compared to the baseline value. However, frequency of hypotension requiring vasoactive drug was significantly lower in group US (5%) than in group BS (35%) (P = 0.044). The dermatom of sensory block on the operated limb was significantly lower in group US [T10 (10–10)] than in group BS [T8 (7.5–10)] (P = 0.013). In comparison within the group, changes of cardiac index were similar as the baseline value in both groups, although total peripheral resistance index was constant in group US but significantly decreased in group BS. CONCLUSIONS: Unilateral spinal anesthesia effectively reduced the frequency of hypotension requiring vasoactive drug and affected hemodynamic performance less than bilateral spinal anesthesia.