Caracterização do comprometimento pulmonar associado à COVID-19 em pacientes com necessidade de ventilação mecânica / Characterization of pulmonary impairment associated with COVID-19 in patients requiring mechanical ventilation

RESUMO Objetivo: Detectar precocemente a instabilidade respiratória e hemodinâmica para caracterizar o comprometimento pulmonar em pacientes com COVID-19 grave. Métodos: Analisamos retrospectivamente os dados colhidos de pacientes com COVID-19 que apresentaram insuficiência respiratória aguda com necessidade de intubação e ventilação mecânica. Utilizamos a avaliação da termodiluição transpulmonar por meio do dispositivo PiCCO™. Foram coletados os dados demográficos, respiratórios, hemodinâmicos e ecocardiográficos dentro das primeiras 48 horas após a admissão. Para resumir os dados, utilizamos estatística descritiva. Resultados: Entre 22 de março e 7 de abril de 2020, foram admitidos 23 pacientes com COVID-19 grave. Foram monitorados com o dispositivo PiCCO™ 12 (22,6%) deles. Quando da admissão, o volume diastólico final global indexado era normal (média de 738,8mL ± 209,2) e, na hora 48, encontrava-se moderadamente aumentado (879mL ± 179), enquanto o índice cardíaco se achava abaixo do normal (2,84 ± 0,65). Todos os pacientes revelaram a presença de água extravascular pulmonar acima de 8mL/kg na admissão (17,9 ± 8,9). Não identificamos qualquer evidência de origem cardiogênica. Conclusão: No caso de pneumonia grave por COVID-19, o quadro hemodinâmico e respiratório é compatível com edema pulmonar sem evidência de origem cardiogênica, o que favorece o diagnóstico de síndrome do desconforto respiratório agudo.

ABSTRACT Objective: To detect early respiratory and hemodynamic instability to characterize pulmonary impairment in patients with severe COVID-19. Methods: We retrospectively analyzed data collected from COVID-19 patients suffering from acute respiratory failure requiring intubation and mechanical ventilation. We used transpulmonary thermodilution assessment with a PiCCO™ device. We collected demographic, respiratory, hemodynamic and echocardiographic data within the first 48 hours after admission. Descriptive statistics were used to summarize the data. Results: Fifty-three patients with severe COVID-19 were admitted between March 22nd and April 7th. Twelve of them (22.6%) were monitored with a PiCCO™ device. Upon admission, the global-end diastolic volume indexed was normal (mean 738.8mL ± 209.2) and moderately increased at H48 (879mL ± 179), and the cardiac index was subnormal (2.84 ± 0.65). All patients showed extravascular lung water over 8mL/kg on admission (17.9 ± 8.9). We did not identify any argument for cardiogenic failure. Conclusion: In the case of severe COVID-19 pneumonia, hemodynamic and respiratory presentation is consistent with pulmonary edema without evidence of cardiogenic origin, favoring the diagnosis of acute respiratory distress syndrome.

Accuracy and Efficacy of Impedance Cardiography as a Non-Invasive Cardiac Function Monitor

PURPOSE: The most common method of monitoring cardiac output (CO) is thermodilution using pulmonary artery catheter (PAC), but this method is associated with complications. Impedance cardiography (ICG) is a non-invasive CO monitoring technique. This study compared the accuracy and efficacy of ICG as a non-invasive cardiac function monitoring technique to those of thermodilution and arterial pressure contour. MATERIALS AND METHODS: Sixteen patients undergoing liver transplantation were included. Cardiac index (CI) was measured by thermodilution using PAC, arterial waveform analysis, and ICG simultaneously in each patient. Statistical analysis was performed using intraclass correlation coefficient (ICC) and Bland-Altman analysis to assess the degree of agreement. RESULTS: The difference by thermodilution and ICG was 1.13 L/min/m², and the limits of agreement were −0.93 and 3.20 L/min/m². The difference by thermodilution and arterial pressure contour was 0.62 L/min/m², and the limits of agreement were −1.43 and 2.67 L/min/m². The difference by arterial pressure contour and ICG was 0.50 L/min/m², and the limits of agreement were −1.32 and 2.32 L/min/m². All three percentage errors exceeded the 30% limit of acceptance. Substantial agreement was observed between CI of thermodilution with PAC and ICG at preanhepatic and anhepatic phases, as well as between CI of thermodilution and arterial waveform analysis at preanhepatic phase. Others showed moderate agreement. CONCLUSION: Although neither method was clinically equivalent to thermodilution, ICG showed more substantial correlation with thermodilution method than with arterial waveform analysis. As a non-invasive cardiac function monitor, ICG would likely require further studies in other settings.

Pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus ® ) for the perioperative management of a caesarean section in a patient with severe cardiomyopathy / Análise do contorno do pulso calibrado por termodiluição transpulmonar (Picco Plus ® ) para o manejo perioperatório de cesariana em paciente com miocardiopatia grave

ABSTRACT BACKGROUND: The delivery of cardiac patients is a challenge for the anaesthesiologist, to whom the welfare of both the mother and the foetus is a main issue. In case of caesarean section, advanced monitoring allows to optimize haemodynamic condition and to improve morbidity and mortality. OBJECTIVE: To describe the use of pulse contour analysis calibrated by Trans-pulmonar thermodilution (Picco Plus® for the perioperative management of a caesarean section in a patient with severe cardiomyopathy. CASE REPORT: We describe the case of a 28-year-old woman with a congenital heart disease who was submitted to a caesarean section under general anaesthesia for maternal pathology and foetal breech presentation. Intra- and post-operative management was optimized by advanced haemodynamic monitorization obtained by pulse contour wave analysis and thermodilution calibration (Picco Plus® monitor). The information about preload, myocardial contractility and postcharge was useful in guiding the fluid therapy and the use of vasoactive drugs. CONCLUSION: This case report illustrates the importance of advanced haemodynamic monitoring with an acceptably invasive device in obstetric patients with high cardiac risk. The increasing experience in advanced haemodynamic management will probably permit to decrease morbidity and mortality of obstetric patients in the future.

RESUMO JUSTIFICATIVA: O parto em pacientes cardíacas é um desafio para o anestesiologista, para o qual o bem-estar tanto da mãe quanto do feto é a questão principal. Em caso de cesariana, o monitoramento avançado permite melhorar a condição hemodinâmica e diminuir a morbidade e mortalidade. OBJETIVO: Descrever o uso da análise do contorno do pulso calibrado por termodiluição transpulmonar (Picco Plus®) para o manejo perioperatório de cesariana em paciente com miocardiopatia grave. RELATO DE CASO: Descrevemos o caso de uma paciente de 28 anos com uma doença cardíaca congênita, submetida a uma cesariana sob anestesia geral devido a afecção materna e apresentação fetal pélvica. O manejo nos períodos intraoperatório e pós-operatório foi aprimorado por monitoração hemodinâmica avançada obtida pela análise do contorno da onda de pulso e calibração por termodiluição (monitor Picco Plus®). As informações sobre pré-carga, pós-carga e contratilidade miocárdica foram úteis para orientar a reposição hídrica e o uso de medicamentos vasoativos. CONCLUSÃO: Este relato de caso ilustra a importância da monitoração hemodinâmica avançada com dispositivo aceitavelmente invasivo em pacientes obstétricas com alto risco cardíaco. O aumento do conhecimento no manejo hemodinâmico avançado provavelmente possibilitará a redução da morbidade e mortalidade de pacientes obstétricas no futuro.

Effect of Paroxysmal Atrial Fibrillation on Parameters Monitored by Transpulmonary Thermodilution Method / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of atrial fibrillation on the accuracy of parameters monitored by transpulmonary thermodilution method.</p><p><b>METHODS</b>Totally 12 patients from emergency intensive care unit with paroxysmal atrial fibrillation were enrolled. The hemodynamic parameters such as heart rate, mean arterial pressure, cardiac index, systemic vascular resistance index, intrathoracic blood volume index, and extravascular lung water index were monitored by transpulmonary thermodilution method before paroxysmal atrial fibrillation and during atrial fibrillation, the number of B-lines was detected by lung ultrasonography before and during paroxysmal atrial fibrillation. The changes of all the parameters were analyzed.</p><p><b>RESULTS</b>When the paroxysmal atrial fibrillation happened, the heart rate increased significantly [(123.3±20.0) beat/min vs. (98.9±12.3) beat/min, P=0.006]; the mean arterial pressure [(86.9±10.2) mmHg vs. (93.0±12.5) mmHg, P=0.058], cardiac index [(2.82±0.62) L/(min·m(2)) vs. (3.31±1.02) L/(min·m(2)), P=0.058] and systemic vascular resistance index [(2254±947) dyn·s·cm(-5)·m(2) vs. (2302±828) dyn·s·cm(-5)·m(2), P=0.351] had no obvious change; however, the intrathoracic blood volume index significantly increased [(1333±90) ml/m(2) vs. (937±111) ml/m(2), P<0.001]; extravascular lung water index also increased significantly [(16.1±1.1) ml/kg vs. (6.5±1.9) ml/kg, P<0.001]. No significant difference was found in the number of B-lines detected by lung ultrasonography before and during atrial fibrillation (10.0±4.2 vs. 9.4±4.4, P=0.180).</p><p><b>CONCLUSION</b>Both intrathoracic blood volume and extravascular lung water monitored by transpulmonary thermodilution method were overvalued during paroxysmal atrial fibrillation, which may mislead the clinical judgment and decision-making.</p>

Produção científica da Enfermagem sobre promoção de saúde, condição crônica e envelhecimento / Producción científica de Enfermería de promoción de la salud, condición crónica y envejecimiento / Nursing scientific production on health promotion, chronic condition, and aging

RESUMOObjetivo:caracterizar a produção científica dos Programas de Pós-Graduação em Enfermagem do Brasil, sobre promoção da saúde com enfoque nas pessoas idosas em condição crônica, no período de 2006 a 2010.Método:pesquisa integrativa, realizada através da busca de dissertações e teses da base de dados do Centro de Estudos e Pesquisas em Enfermagem da Associação Brasileira de Enfermagem, publicados no período de 2006 a 2010, que focassem a promoção de saúde de idosos em condição crônica.Resultados:emergiram cinco categorias temáticas: "Convívio com a doença"; "Tecnologias de cuidado"; "Potencialidades para o autocuidado" "Dimensão psicoespiritual" e "Família cuidadora".Conclusão:pôde-se identificar a assistência de enfermagem como elemento fundamental para promover a saúde do indivíduo idoso e torná-lo mais independente de cuidados para conviver com suas limitações ou incapacidades, mesmo acometido por doenças crônicas.

RESUMENObjetivo:caracterizar la producción científica de la Postgraduate Nursing Brasil, en la promoción de la salud con especial atención a las personas mayores con enfermedades crónicas en el período 2006-2010.Método:la investigación integral realizada mediante la búsqueda de disertaciones y tesis en la base de datos del Centro de Estudios e Investigación en Enfermería Asociación Brasileña de Enfermería, publicada en el período 2006-2010, que se centrará en la promoción de la salud para las personas mayores con enfermedades crónicas.Resultados:cinco temas emergieron: "La convivencia con la enfermedad", "cuidado Technologies", "potencial para el propio cuidado" "dimensión psico-espiritual" y "cuidador familiar".Conclusión:se pudo identificar el cuidado de enfermería como un elemento clave para promover la salud de las personas mayores y que sea una atención más independiente que vivir con limitaciones o incapacidades, aún afectados por enfermedades crónicas.

ABSTRACTObjective:to characterize the scientific production of Postgraduate Programs Nursing in Brazil on health promotion with a focus on elderly people with chronic conditions in the period from 2006 to 2010.Method:integrative research developed by searching for dissertations and theses in the database of the Center for Nursing Studies and Research of the Brazilian Nursing Association published in the period from 2006 to 2010 and which focused on health promotion for elderly people with chronic conditions.Results:five themes emerged: "Living with the disease"; "Technologies of care", "Potential for self-care" "Psycho-spiritual dimension", and "Family caregiver".Conclusion:it was possible to identify nursing care as a key element to promote the health of elderly people and make them more independent in their care so as to live with their limitations or disabilities, even when affected by chronic diseases.

The effect of blood volume change on the accuracy of pulse contour cardiac output / 中华外科杂志

<p><b>OBJECTIVE</b>To study the accuracy of pulse contour cardiac output (PCCO) during blood volume change.</p><p><b>METHODS</b>Hemorrhagic shock model was made in twenty dogs followed by volume resuscitation. Two PiCCO catheters were placed into each model to monitor the cardiac output (CO). One of catheters was used to calibrate CO by transpulmonary thermodilution technique (COTP) (calibration group), and the other one was used to calibrate PCCO (none-calibration group). In the hemorrhage phase, calibration was carried out each time when the blood volume dropped by 5 percents in the calibration group until the hemorrhage volume reached to 40 percent of the basic blood volume. Continuous monitor was done in the none-calibration group.Volume resuscitation phase started after re-calibration in the two groups. Calibration was carried out each time when the blood equivalent rose by 5 percents in calibration group until the percentage of blood equivalent volume returned back to 100. Continuous monitor was done in none-calibration group. COTP, PCCO, mean arterial pressure (MAP), systemic circulation resistance (SVR), global enddiastolic volume (GEDV) were recorded respectively in each time point.</p><p><b>RESULTS</b>(1) At the baseline, COTP in calibration group showed no statistic difference compared with PCCO in none-calibration group (P >0.05). (2) In the hemorrhage phase, COTP and GEDV in calibration group decreased gradually, and reached to the minimum value (1.06 ± 0.57) L/min, (238 ± 93) ml respectively at TH8. SVR in calibration group increased gradually, and reached to the maximum value (5 074 ± 2 342) dyn · s · cm⁻⁵ at TH6. However, PCCO and SVR in none-calibration group decreased in a fluctuating manner, and reached to the minimum value (2.42 ± 1.37) L/min, (2 285 ± 1 033) dyn · s · cm⁻⁵ respectively at TH8. COTP in the calibration group showed a significant statistic difference compared with PCCO in the none-calibration group at each time point (At TH1-8, t values were respectively -5.218, -5.495, -4.639, -6.588, -6.029, -5.510, -5.763 and -5.755, all P < 0.01). From TH1 to TH8, the difference in percentage increased gradually. There were statistic differences in SVR at each time point between the two groups (At TH1 and TH4, t values were respectively 2.866 and 2.429, both P < 0.05, at TH2 - TH3 and TH5 - TH8, t values were respectively 3.073, 3.590, 6.847, 8.425, 6.910 and 8.799, all P < 0.01). There was no statistic difference in MAP between the two groups (P > 0.05). (3) In the volume resuscitation phase, COTP and GEDV in the calibration group increased gradually. GEDV reached to the maximum value ((394±133) ml) at TR7, and COTP reached to the maximum value (3.15 ± 1.42) L/min at TR8. SVR in the calibration group decreased gradually, and reached to the minimum value (3 284 ± 1 271) dyn · s · cm⁻⁵ at TR8. However, PCCO and SVR in the none-calibration group increased in a fluctuating manner. SVR reached to the maximum value (8 589 ± 4 771) dyn · s · cm⁻⁵ at TR7, and PCCO reached to the maximum value (1.35 ± 0.70) L/min at TR8. COTP in the calibration group showed a significant statistic difference compared with PCCO in the none-calibration group at each time point (At TR1-8, t values were respectively 8.195, 8.703, 7.903, 8.266, 9.600, 8.340, 8.938, 8.332, all P < 0.01). From TR1 to TR8, the difference in percentage increased gradually. There were statistic differences in SVR at each time point between the two groups (At TR1, t value was -2.810, P < 0.05, at TR2-8, t values were respectively -6.026, -6.026, -5.375, -6.008, -5.406, -5.613 and -5.609, all P < 0.05). There was no statistic difference in MAP between the two groups (P > 0.05).</p><p><b>CONCLUSION</b>PCCO could not reflect the real CO in case of rapid blood volume change, which resulting in the misjudgment of patient's condition. In clinical practice, more frequent calibrations should be done to maintain the accuracy of PCCO in rapid blood volume change cases.</p>

Advances in the research of extravascular lung water after severe burn / 中华烧伤杂志

Pulmonary edema frequently occurs after severe burn. It not only impairs pulmonary function directly, but also can induce or exacerbate other pulmonary complications such as lung infection, acute lung injury ( ALI), and ARDS. Extravascular lung water (EVLW) is closely related to the pulmonary edema. Dynamical monitor of EVLW has been used to predict and quantify the degree of pulmonary edema clinically. This review focuses on the recent progresses at home and abroad on the formation mechanism, monitoring approach, and prevention and treatment of EVLW after severe burn injury.

Comparison between continuous non-invasive estimated cardiac output by pulse wave transit time and thermodilution method.

Aims and Objectives: Cardiac output (CO) measurement is essential for many therapeutic decisions in anesthesia and critical care. Most available non‑invasive CO measuring methods have an invasive component. We investigate “pulse wave transit time” (estimated continuous cardiac output [esCCO]) a method of CO measurement that has no invasive component to its use. Materials and Methods: After institutional ethical committee approval, 14 adult (21–85 years) patients undergoing surgery and requiring pulmonary artery catheter (PAC) for measuring CO, were included. Postoperatively CO readings were taken simultaneously with thermodilution (TD) via PAC and esCCO, whenever a change in CO was expected due to therapeutic interventions. Both monitoring methods were continued until patients’ discharge from the Intensive Care Unit and observer recording values using TD method was blinded to values measured by esCCO system. Results: Three hundred and one readings were obtained simultaneously from both methods. Correlation and concordance between the two methods was derived using Bland‑Altman analysis. Measured values showed significant correlation between esCCO and TD (r = 0.6, P < 0.001, 95% confidence limits of 0.51-0.68). Mean and (standard deviation) for bias and precision were 0.13 (2.27) L/min and 6.56 (2.19) L/min, respectively. The 95% confidence interval for bias was ‑ 4.32 to 4.58 L/min and for precision 2.27 to10.85 L/min. Conclusions: Although, esCCO is the only true non‑invasive continuous CO monitor available and even though its values change proportionately to TD method (gold standard) with the present degree of error its utility for clinical/therapeutic decision‑making is questionable.

Development of cardiac output monitoring system based on thermodilution method / 中国医疗器械杂志

Cardiac output (CO) monitoring is a crucial part of the hemodynamic status monitoring. So far, thermodilution method, which is clinically recognized as the gold standard method to monitor cardiac output, still has irreplaceable advantages. This paper mainly introduces the use of platform for cardiac output measurement based on thermodilution method, mainly including three parts: the hardware platform, software design and algorithm process. A large amount of test data of this system has been got by CO simulator testing in the laboratory and preliminary clinical tests in the hospital. The testing result showed that using the proposed system can achieve good accuracy and repeatability.

Assessment of cardiac output and volume load by transpulmonary thermodilution technique in immature pigs / 中国医学科学院学报

<p><b>OBJECTIVE</b>To assess the accuracy of cardiac output (CO) measured by transpulmonary thermodilution technique (TPTD)and explore the validity of intrathoracic blood volume index (ITBVI) for assessment of circulatory volume status.</p><p><b>METHODS</b>Ten immature pigs with a mean weight of (20.6±1.9)kg were studied during the conditions including normovolemia, hypervolemia, and hypovolemia. Simultaneous CO was measured in each condition using pulmonary artery thermodilution (PATD) method and TPTD. More specifically, CO (COPA) was determined with PATD, while CO (COTP) and ITBVI were determined with TPTD. All measurements were repeated 3 times. Central venous pressure (CVP) and heart rate were measured at the same time. The potential correlations of CVP and ITBVI with cardiac index (CI) and stroke volume index (SVI) in each blood volume status were analyzed.</p><p><b>RESULTS</b>A total of 90 simultaneous measurements of COPA and COTP in 3 different blood volume conditions were made. The correlation coefficient between the two measurements was 0.977 (P<0.001) and the mean difference was (0.25±0.26)L/min (95%CI:0.20-0.30 L/min, P<0.001). The coefficient of variation of COTP was 3.7%, while COPA was 5.4%. Compared with those in normovolemia, CVP and ITBVI in hypervolemia significantly increased (P=0.002, 0.019), ITBVI in hypovolemia decreased significantly (P<0.001), and CVP in hypovolemia decreased insignificantly (P=0.05). Correlation analysis revealed a significant correlation between ITBVI with CI and SVI in normovolemia (r=0.741, P=0.014; r=0.885, P=0.001). In contrast, correlations between CVP with CI and SVI were poor.</p><p><b>CONCLUSIONS</b>TPTD can accurately and precisely measure CO in different blood volume conditions. ITBVI measured by TPTD has better validity for the assessment of circulatory volume status than CVP.</p>

Association between Cardiac Troponin Level and Coronary Flow Reserve in Patients without Coronary Artery Disease: Insight from a Thermodilution Technique Using an Intracoronary Pressure Wire

BACKGROUND AND OBJECTIVES: Cardiac troponins are associated with increased mortality, even among patients with no coronary artery disease. Elevated cardiac troponin levels are frequently observed in patients without significant coronary lesions, although the mechanism underlying this finding is unclear. The aim of our study was to evaluate the association between the levels of cardiac troponin and coronary flow reserve (CFR). SUBJECTS AND METHODS: We evaluated serum cardiac troponin-I in 19 patients (9 female; age 61.9+/-10.9 year-old). All patients had an ejection fraction >40% and angiographically normal coronary arteries. Simultaneous measurements of fractional flow reserve (FFR), the index of microcirculatory resistance (IMR), and CFR measurements using an intracoronary temperature- and pressure-sensing guidewire under basal conditions and during maximal hyperemia were performed in three vessels: the left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA). RESULTS: All patients were followed for a median of 13 months. FFR, IMR, and CFR measurements were performed successfully in all subjects. Mean CFRs of LAD, LCX, and RCA were 1.98+/-1.20, 2.75+/-2.11, and 4.44+/-2.51, respectively. Mean IMRs of LAD, LCX and RCA were 33.28+/-18.78, 29.11+/-26.70, and 30.55+/-23.65, respectively. There was a poor correlation between CFR and troponin-I values in each vessel. In selecting the lowest value of CFR in each patient as the corresponding value, the lowest CFR was not associated with troponin-I levels (r=-0.219, p=0.367). CONCLUSION: In patients without significant coronary lesions, the correlation between CFR and troponin-I level was not significant using a thermodilution technique. Further study of a larger population with longer-term follow-up may be needed to more fully understand microvascular dysfunction.

Diferencia veno-arterial de dióxido de carbono como predictor de gasto cardiaco disminuido en modelo pediátrico experimental / Veno-arterial difference of carbondioxide as a predictor of low cardiac output in an experimental pediatric model

Background: Cardiac output (CO) measurement is not a standard of care for critically ill children, but it can be estimated by indirect methods such as veno-arterial pCO2 difference (ΔVACO2). Aim: To determine the correlation between CO and ΔVACO2 and evaluate the usefulness of ΔVACO2 in the diagnosis of low CO in an experimental pediatric model. Materials and Methods: Thirty piglets weighing 4.8 ± 0.35 kg were anesthetized and monitored with transpulmonary thermodilution. Lung injury was induced with tracheal instillation of Tween 20®. Serial measurements of central venous and arterial blood gases, as well as CO, were obtained at baseline, 1, 2 and 4 h after lung injury induction. Low cardiac output (LCO) was defined as CO lower than 2.5 Llminlm². Results: There was an inverse correlation between CO and ΔVACO2 (r = -0.36, p < 0.01). ΔVACO2 was 14 ± 8 mmHg in LCO state and 8 ± 6 mmHg when this condition was not present (p < 0.01). Area under the receiver operating characteristic (ROC) curves of ΔVACO2 and LCO state was 0.78 (0.68-0.86). The best cut-point was 8.9 mmHg to determine LCO with a sensibility 0.78, specificity 0.7, positive predictive value 0.27 and negative predictive value 0.96. Conclusions: In this model there was an inverse correlation between ΔVACO2 and CO. The best cutoff value to discard LCO was ΔVACO2 of 8.9 mmHg, indicating that under this value the presence of LCO is very unlikely.

Sildenafil prevents the increase of extravascular lung water and pulmonary hypertension after meconium aspiration in newborn piglets

Meconium aspiration syndrome causes respiratory failure after birth and in vivo monitoring of pulmonary edema is difficult. The objective of the present study was to assess hemodynamic changes and edema measured by transcardiopulmonary thermodilution in low weight newborn piglets. Additionally, the effect of early administration of sildenafil (2 mg/kg vo, 30 min after meconium aspiration) on this critical parameter was determined in the meconium aspiration syndrome model. Thirty-eight mechanically ventilated anesthetized male piglets (Sus scrofa domestica) aged 12 to 72 h (1660 ± 192 g) received diluted fresh human meconium in the airway in order to evoke pulmonary hypertension (PHT). Extravascular lung water was measured in vivo with a PiCCO monitor and ex vivo by the gravimetric method, resulting in an overestimate of 3.5 ± 2.3 mL compared to the first measurement. A significant PHT of 15 Torr above basal pressure was observed, similar to that of severely affected humans, leading to an increase in ventilatory support. The vascular permeability index increased 57 percent, suggesting altered alveolocapillary membrane permeability. Histology revealed tissue vessel congestion and nonspecific chemical pneumonitis. A group of animals received sildenafil, which prevented the development of PHT and lung edema, as evaluated by in vivo monitoring. In summary, the transcardiopulmonary thermodilution method is a reliable tool for monitoring critical newborn changes, offering the opportunity to experimentally explore putative therapeutics in vivo. Sildenafil could be employed to prevent PHT and edema if used in the first stages of development of the disease.

Comparison of transthoracic electrical bioimpedance cardiac output measurement with thermodilution method in post coronary artery bypass graft patients.

Transthoracic electrical bioimpedance (TEB) has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO) measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India) and compared it with thermodilution (TD) method in patients after off-pump coronary artery bypass (OPCAB) graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous) on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min), while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min). The average correlation (r) was 0.548 (P = 0.0002), accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min), while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min). Their average correlation was relatively poor (r = 0.469, P= 0.002), accompanied by a bias of −0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation) and 17.4% (during spontaneous breathing), respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.

Como determinar a volemia em pacientes com lesão pulmonar aguda/síndrome do desconforto respiratório agudo / Determining blood volume in patients with acute lung injury/acute respiratory distress syndrome

A morbidade e a mortalidade de pacientes com lesão pulmonar aguda (LPA) ou síndrome do desconforto respiratório agudo (SDRA) permanecem elevadas. Devido às alterações na membrana alvéolo-capilar, assim como uma possível elevação da pressão hidrostática, a reposição volêmica passa a ter extrema importância. Para tal, são necessárias avaliações precisas do estado volêmico e da predição da resposta hemodinâmica.Estudos recentes enfatizam a indução de um balanço negativo em pacientes com LPA que não se encontram em choque circulatório. Novos estudos têm focado em alternativas menos invasivas e mais precisas na abordagem de fluidos em pacientes com LPA/SDRA. Nesse contexto, recentes estudos têm demonstrado a superioridade de parâmetros dinâmicos sobre parâmetros estáticos na responsividade de fluidos. Além disso, parâmetros que forneçam informações importantes de pré-carga cardíaca e do grau de edema pulmonar têm sido enfatizados por alguns ensaios clínicos de pequeno porte.Indica-se a restrição de fluidos em pacientes com LPA/SDRA desde que não haja choque circulatório. Nessa situação, considera-se o uso de parâmetros dinâmicos para determinar a quantidade e o tipo de fluido administrados. Para a determinação de edema pulmonar, lança-se mão da medida da água extravascular pulmonar, sabendo de suas potencialidades e limitações.

The morbidity and mortality remain elevated in patients with acute lung injury/acute respiratory distress syndrome (ALI/ARDS). Hemodynamic stabilization in such patients may require fluid resuscitation, but the increase in hydrostatic pressure may worsen lung edema in presence of increased permeability of the alveolar-capillary membrane. Therefore, accurate evaluation of the fluid state and prediction of the hemodynamic response are essential. Recent studies have focused on the induction of a negative fluid balance in ALI patients who are not in circulatory shock. Other studies of ALI/ARDS patients have focused on fluid management strategies that are less invasive and more accurate. In this context, recent studies have demonstrated the superiority of dynamic parameters over static parameters in determining the hemodynamic response. In addition, parameters that furnish useful data regarding cardiac preload and the degree of pulmonary edema have been emphasized in recent small clinical trials. In ALI/ARDS patients, fluid restriction is indicated if there are no clinical signs of circulatory shock. In such cases, the nature and quantity of fluid administered should be determined on the basis of the dynamic parameters. To screen for pulmonary edema, extravascular lung water can be measured, assuming that its potential and limitations are borne in mind.

Noninvasive measurement of cardiac performance in recovery from exercise in heart failure patients

OBJECTIVE: To examine the association between cardiac performance during recovery and the severity of heart failure, as determined by clinical and cardiopulmonary exercise test responses. METHODS: As part of a retrospective cohort study, 46 heart failure patients and 13 normal subjects underwent cardiopulmonary exercise testing while cardiac output was measured using a noninvasive device. Cardiac output in recovery was expressed as the slope of a single exponential relationship between cardiac output and time; the recovery-time constant was assessed in relation to indices of cardiac function, along with clinical, functional, and cardiopulmonary exercise responses. RESULTS: The recovery time constant was delayed in patients with heart failure compared with normal subjects (296.7 + 238 vs. 110.1 +27 seconds, p <0.01), and the slope of the decline of cardiac output in recovery was steeper in normal subjects compared with heart failure patients (p,0.001). The slope of the decline in cardiac output recovery was inversely related to peak VO2 (r = -0.72, p<0.001) and directly related to the VE/VCO2 slope (r = 0.57, p,0.001). Heart failure patients with abnormal recovery time constants had lower peak VO2, lower VO2 at the ventilatory threshold, lower peak cardiac output, and a heightened VE/VCO2 slope during exercise. CONCLUSIONS: Impaired cardiac output recovery kinetics can identify heart failure patients with more severe disease, lower exercise capacity, and inefficient ventilation. Estimating cardiac output in recovery from exercise may provide added insight into the cardiovascular status of patients with heart failure.

Correlação entre gasometria atrial direita e índice cardíaco no pós-operatório de cirurgia cardíaca / Correlation between right atrial venous blood gasometry and cardiac index in cardiac surgery postoperative period

OBJETIVO: Determinar a confiabilidade em se correlacionar o índice cardíaco com os dados fornecidos pela gasometria do sangue venoso atrial direito em pacientes submetidos à cirurgia cardíaca, durante o período pós-operatório. MÉTODOS: A partir das amostras de sangue arterial e venoso do átrio direito, colhidas no pós-operatório de cirurgia cardíaca, foram determinados os parâmetros de oxigênio do sangue venoso do átrio direito. Estes parâmetros foram então comparados com o índice cardíaco determinado pela termodiluição. RESULTADOS: Houve boa correlação entre a saturação de oxigênio do sangue venoso do átrio direito (SvO2), diferença artério-venosa do conteúdo de oxigênio do sangue colhido no átrio direito e o índice cardíaco aferido pela termodiluição, com boa sensibilidade e especificidade e alto valor preditivo positivo e negativo. A pressão do sangue do átrio direito (PvO2) apresentou baixa sensibilidade na estimativa de baixo débito cardíaco. CONCLUSÃO: No pós-operatório de cirurgia cardíaca, a SvO2e a diferença artério-venosa do conteúdo de oxigênio (C(av)O2) apresentaram-se como parâmetros confiáveis correlacionados a baixo débito cardíaco. A PvO2 foi pouco sensível no diagnóstico de baixo débito no pós-operatório de cirurgia cardíaca.

OBJECTIVE: To determine, even during postoperative period, the confiability of the cardiac index correlate with the data data given by a central atrial venous blood gasometry in patients who underwent cardiac surgery. METHODS: From the sample of arterial and venous blood of right atrium gathered in postoperative of cardiac surgery, it was determinated the hemoglobin concentration and the gasometric study through what was observed of the venous oxygen saturation (SvO2) and the partial pressure of oxygen from venous blood gathered in right atrium (PvO2), add to the calculation of artery-venous difference of the oxygen content - radial artery / right atrium (C( a-v )O2). Afterwards, these parameters were compared with the cardiac index determined by thermodilution. RESULTS: There was good correlation between SvO2, C(av)O2 of the venous right atrial blood and cardiac index meansured by termodiluition method, with sensibility and especificity good and high positive predict value and negative predict value. The PvO2 demonstrated poor sensibility in the estimative of low output. CONCLUSION: In cardiac surgery postoperative, the SvO2and the C(a-v)O2 were safe parameters correlated with low cardiac output. The PvO2 demonstrated poor sensibility in the estimative of low output in postoperative cardiac surgery.

Accuracy of perioperative cardiac preload monitoring by global end-diastolic volume and intrathoracic blood volume in orthotopic liver transplantation / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the clinical value of global end-diastolic volume (GEDV) and intrathoracic blood volume (ITBV) in perioperative monitoring of the cardiac preload in patients undergoing orthotopic liver transplantations (OLT).</p><p><b>METHODS</b>Eight ASA III or IV patients aged 42-50 years undergoing OLT without venovenous bypass under general anesthesia were enrolled in this study. Before the induction, a thermodilution femoral artery catheter was inserted into the femoral artery under local anesthesia and connected to a PiCCOplus system to monitor ITBV and GEDV. A CCO catheter was inserted into the right internal jugular vein to monitor the pulmonary artery obstruction pressure (PAOP), central venous press (CVP) and stroke volume (SVPAC). Anesthesia was induced with a combination of midazolam (0.1 mg/kg), propofol (1 mg/kg) and fentanyl (3 microg/kg). Pipecuronium (0.1 mg/kg) was given to facilitate naso-endotracheal intubation. Before anesthesia (T0) and at 10 min before the anhepatic phase (T1), 10 min after anhepatic phase (T2), 10 min after neohepatic phase (T3) and at the end of surgery (T4), all the TPTD and CCO parameters were measured by injecting 10 ml cold saline solution (below 8 degrees celsius;) via the distal port of the central venous catheter.</p><p><b>RESULTS</b>ITBV and GEDV at T2 were significantly lower than those at T0, T1, T3 and T4 (P<0.05). SVPAC at T2 was dramatically decreased compared with that at T0 and T1 (P<0.05). The changes in the pressure preload parameters of the pulmonary artery catheter (PAOP and CVP) did not correlate to the changes in SVPAC, whereas the changes in the volume preload parameters (ITBV and GEDV) of the TPTD was significantly correlated to the changes in SVPAC (P<0.01). PAOP and CVP did not correlate to the changes in ITBV and GEDV.</p><p><b>CONCLUSION</b>ITBV and GEDV are more reliable than PAOP and CVP in perioperative monitoring of the cardiac preload in patients undergoing OLT.</p>

The effect of milrinone infusion on right ventricular function during coronary anastomosis and early outcomes in patients undergoing off-pump coronary artery bypass surgery / 대한마취과학회지

BACKGROUND: During coronary anastomosis in off-pump coronary artery bypass surgery (OPCAB), hemodynamic alternations can be induced by impaired diastolic function of the right ventricle. This study was designed to examine the effect of milrinone on right ventricular function and early outcomes in patients undergoing OPCAB. METHODS: Forty patients undergoing OPCAB were randomly assigned in a double-blind manner to receive either milrinone (milrinone group, n = 20) or normal saline (control group, n = 20). Hemodynamic variables were measured after pericardiotomy (T1), 5 min after stabilizer application for anastomosis of the left anterior descending coronary artery (LAD, T2), the obtuse marginalis branch (OM, T3), the right coronary artery (RCA, T4), 5 min after sternal closure (T5), and after ICU arrival. The right ventricular ejection fraction (RVEF) and right ventricular volumetric parameters were also measured using the thermodilution technique. For evaluation of early outcomes, the 30-day operative mortality and morbidity risk models were used. RESULTS: There was no significant difference in hemodynamic variables, including mean arterial pressure, between the 2 groups, except for the cardiac index and RVEF. The cardiac index and RVEF were significantly greater at T3 in the milrinone group than in the control group. CONCLUSIONS: Continuous infusion of milrinone demonstrated a beneficial effect on cardiac output and right ventricular function in patients undergoing OPCAB, especially during anastomosis of the graft to the OM artery, and it had no adverse effect on early outcomes.