Cardiac Output Values Research Articles

Comparison between invasive cardiac output and left ventricular assist device flow parameter.

Evaluate the correlation between left ventricular assist device flow parameter and invasive cardiac output measurements. We retrospectively evaluated right heart catheterization examinations performed in left ventricular assist device patients from 2 tertiary medical centers. We evaluated the correlation between cardiac output measurement methods (indirect Fick and thermodilution) and pump flow parameter using linear regression, agreement was graphically displayed using Bland-Altman plot technique. Clinical, echocardiographic, pump and haemodynamic parameters were compared between patients with and without discordance, defined as at least 20% difference between measurements. The study population consisted of 102 patients (median age 58 [51-64], 86% males, 17 ± 12 months post left ventricular assist device implantation) with a total of 544 measurement compared. Discordance between measurements were present in 102 of 226 (45%) comparisons between indirect Fick and pump flow and in 72 of 161 (48%) between thermodilution and pump flow. A comparison of indirect Fick and left ventricular assist device exhibited a statistical correlation of R = 0.751, and that of thermodilution and left ventricular assist device of R = 0.789. Parameters associated with the presence of discordance between cardiac output measurements included a higher rate of aortic valve opening, lower indirect Fick and higher thermodilution cardiac output. After excluding the lowest tertile of indirect Fick cardiac output values, the correlation between measurements improved (thermodilution: R = 0.879 and indirect Fick: R = 0.843, p < 0.001). The current left ventricular assist device flow parameter provides an estimation of cardiac output that correlates well with indirect Fick and exhibits the strongest correlation with thermodilution. This correlation was stronger after excluding lower cardiac output values.

Impact of arterial system alterations due to amputation on arterial stiffness and hemodynamics: a numerical study

Subjects with amputation of the lower limbs are at increased risk of cardiovascular mortality and morbidity. We hypothesize that amputation-induced alterations in the arterial tree negatively impact arterial biomechanics, blood pressure and flow behavior. These changes may interact with other biological factors, potentially increasing cardiovascular risk. To evaluate this hypothesis regarding the purely mechanical impact of amputation on the arterial tree, we used a simulation computer model including a detailed one-dimensional (1D) arterial network model (143 arterial segments) coupled with a zero-dimensional (0D) model of the left ventricle. Our simulations included five settings of the arterial network: (1) 4-limbs control, (2) unilateral amputee (right lower limb), (3) bilateral amputee (both lower limbs), (4) trilateral amputee (lower-limbs and right upper-limb), and (5) quadrilateral amputee (lower and upper limbs). Analysis of regional stiffness, as calculated by pulse wave velocity (PWV) for large-, medium- and small-sized arteries, showed that, while aortic stiffness did not change with increasing degree of amputation, stiffness of medium and smaller-sized arteries increased with greater amputation severity. Despite a staged decrease in cardiac output, the systolic and diastolic blood pressure values increased, resulting in an increase in both central and peripheral pulse pressures but with an attenuation of pulse pressure amplification. The most significant increase in peak systolic pressure and decrease in peak systolic blood flow was observed at the site of the abdominal aorta. Wave separation analysis indicated no changes in the shape of the forward and backward wave components. However, the results from wave intensity analysis showed that with extended amputation, there was an increase in peak forward wave intensity and a rise in the inverse peak of the backward wave intensity, suggesting potential alterations in cardiac hemodynamic load. In conclusion, this simulation study showed that biomechanical and hemodynamic changes in the arterial network geometry could interact with additional risk factors to increase the cardiovascular risk in patients with amputations.

Ultrasound-Based Cardiac Output Monitoring During Pediatric Open-Heart Surgery in Children

Aim of the study. To evaluate the feasibility of using non-invasive hemodynamic monitoring technology based on Doppler ultrasound during open-heart surgery in children.Material and methods. Prospective, observational, single-center cohort study included 20 patients aged 10 to 34 months undergoing surgery for congenital heart defects. Ten patients underwent atrial septal defect closure (ASD group), other 10 patients had ventricular septal defect closure (VSD group). Cardiac output (CO) was measured in all patients to guide inotropic and infusion therapy adjustments at three control time points: (1) after intubation and before skin incision, (2) during the immediate post-bypass period with the chest open after weaning from cardiopulmonary bypass (CPB), and (3) after sternal closure and before transfer to the intensive care unit (ICU).Results. At time point 1, the CO values for both the ASD and VSD groups were within the normal reference range: 5.2 L/min [4.7; 5.5] and 5.1 L/min [4.6; 5.6], respectively. At time point 2, CO was measured in 15 of 20 patients, including 8 patients in the ASD group and 7 in the VSD group. Coverage was 75% because of the challenges of measuring 5 patients on the operating table. In the immediate post-bypass period, two patients with VSD (25%) developed hypotension with CO reduced to 3.6 L/min, which is lower than the age-related hemodynamic reference value (5.1 L/min). Inotropic support in these two patients was increased by switching from dopamine, 7 mcg/kg/min, to adrenaline at a dose of 0.05 mcg/kg/min, resulting in improvement of hemodynamic parameters and an increase in CO to 5.2 L/min and 5.0 L/min, respectively, compared to normal agerelated reference values (4.1; 6.1 L/min). After sternal closure, CO values in both groups did not differ significantly from age-related reference values.Conclusion. The USCOM cardiac output monitoring device can be used to manage intraoperative hemodynamics and adjust inotropic therapy even during open chest surgery. However, its routine use in all stages of surgery with median sternotomy is difficult because it requires more time to align the aortic valve projection.

P072 VALIDATION OF A NOVEL METHOD FOR NONINVASIVE ESTIMATION OF CARDIAC OUTPUT USING BRACHIAL OSCILLOMETRIC BLOOD PRESSURE MEASUREMENTS IN PATIENTS WITH VARIOUS CLINICAL CONDITIONS

Background and Objective: Estimating cardiac output (CO) and other hemodynamic parameters from blood pressure (BP) measurements could aid in selecting appropriate antihypertensive treatments in clinical settings. Our research group has developed a non-invasive method to estimate CO based on total arterial compliance (Ct). However, its validity in populations with various cardio-metabolic chronic diseases remains uncertain. The objective of this study is to assess the validity of our CO estimation method across different patient with varied clinical conditions. Methods: A cross-sectional study was conducted involving 217 adult patients who underwent ambulatory transthoracic Doppler echocardiograms, irrespective of valvular or cardiac pathology, or medication use, provided they had normal aortic valvular anatomy. Stroke volume was calculated as the product of the cross-sectional area of the aortic annulus and the average velocity of the left ventricular outflow tract. Simultaneously, oscillometric BP measurements were obtained. Subsequently, the CO values obtained via Doppler echocardiography and those estimated based on Ct were compared to determine validity. Ct was estimated as: Ct/BSA= 38/PPth + 4/5 × Td/T - 3/7, where BSA denotes body surface area, Td signifies diastolic time, T represents the cardiac period, and PPth refers to the theoretical pulse pressure. Results: Of the participants, 49.7% were men, with an average age of 54.0±14.0 years. Among them, three had a history of acute myocardial infarction, one had a pacemaker, nineteen were diabetic, and one hundred thirty-six were hypertensive. CO by echocardiography averaged 4.9±1.0 L/min, ranging from 2.0 to 8.5 L/min. The agreement of CO between the new method and Doppler echocardiography was good. Bland-Altman plots showed that the differences between the methods were randomly distributed along the mean difference line (Figure). Conclusions: The novel method for noninvasive estimation of CO based on Ct with brachial oscillometric BP measurements in patients with various clinical conditions is deemed valid. Its implementation in clinical practice has the potential to transform patient assessment.

A comparison of hemodynamic measurement methods during orthotopic liver transplantation: evaluating agreement and trending ability of PiCCO versus pulmonary artery catheter techniques

BackgroundSignificant hemodynamic changes occur during liver transplantation, emphasizing the importance of precious and continuous monitoring of cardiac output, cardiac index, and other parameters. Although the monitoring of cardiac output by pulse indicator continuous cardiac output (PiCCO) was statistically homogeneous compared to the clinical gold standard pulmonary artery catheterization (PAC) in previous studies of liver transplantation, there are fewer statistical methods for the assessment of its conclusions, and a lack of comparisons of other hemodynamic parameters (e.g., SVRI, systemic vascular resistance index). Some studies have also concluded that the agreement between PiCCO and PAC is not good enough. Overall, there are no uniform conclusions regarding the agreement between PiCCO and PAC in previous studies. This study evaluates the agreement and trending ability of relevant hemodynamic parameters obtained with PiCCO compared to the clinical gold standard PAC from multiple perspectives, employing various statistical methods.MethodsFifty-two liver transplantation patients were included. Cardiac output (CO), cardiac index (CI), SVRI and stroke volume index (SVI) values were monitored at eight time points using both PiCCO and PAC. The results were analyzed by Bland-Altman analysis, Passing-bablok regression, intra-class correlation coefficient (ICC), 4-quadrant plot, polar plot, and trend interchangeability method (TIM).ResultsThe Bland-Altman analysis revealed high percentage errors for PiCCO: 54.06% for CO, 52.70% for CI, 62.18% for SVRI, and 51.97% for SVI, indicating poor accuracy. While Passing-Bablok plots showed favorable agreement for SVRI overall and during various phases, the agreement for other parameters was less satisfactory. The ICC results confirmed good overall agreement between the two devices across most parameters, except for SVRI during the new liver phase, which showed poor agreement. Additionally, four-quadrant and polar plot analyses indicated that all agreement rate values fell below the clinically acceptable threshold of over 90%, and all angular deviation values exceeded ± 5°, demonstrating that PiCCO is unable to meet the acceptable trends. Using the TIM, the interchangeability rates were found to be quite low: 20% for CO and CI, 16% for SVRI, and 13% for SVI.ConclusionsOur study revealed notable disparities in absolute values of CO, CI, SVRI and SVI between PiCCO and PAC in intraoperative liver transplant settings, notably during the neohepatic phase where errors were particularly pronounced. Consequently, these findings highlight the need for careful consideration of PiCCO’s advantages and disadvantages in liver transplantation scenarios, including its multiple parameters (such as the encompassing extravascular lung water index), against its limited correlation with PAC.

Bioreactance assessment of cardiac output lacks reliability for the follow-up of patients with pulmonary hypertension.

Cardiac output (CO) is one of the primary prognostic factors evaluated during the follow-up of patients treated for pulmonary hypertension (PH). It is recommended that it be measured using the thermodilution technique during right heart catheterization. The difficulty to perform iterative invasive measurements on the same individual led us to consider a non-invasive option. The aims of the present study were to assess the agreement between CO values obtained using bioreactance (Starling™ SV) and thermodilution, and to evaluate the ability of the bioreactance monitor to detect patients whose CO decreased by more than 15% during follow-up and, accordingly, its usefulness for patient monitoring. A prospective cohort study evaluating the performance of the Starling™ SV monitor was conducted in patients with clinically stable PH. Sixty patients referred for hemodynamic assessment were included. CO was measured using both the thermodilution technique and bioreactance during two follow-up visits. A total of 60 PH patients were included. All datasets were available at the baseline visit (V0) and 50 of them were usable during the follow-up visit (V1). Median [IQR] CO was 4.20 l/min [3.60-4.70] when assessed by bioreactance, and 5.30 l/min [4.57-6.20] by thermodilution (p<0.001). The Spearman correlation coefficient was 0.51 [0.36-0.64], and the average deviation on Bland-Altman plot was -1.25 l/min (95% CI [-1.48-1.01], p<0.001). The ability of the monitor to detect a variation in CO of more than 15% between two follow-up measurements, when such variation existed using thermodilution, was insufficient for clinical practice (AUC = 0.54, 95% CI [0.33-0.75]).

Evaluation of the Effect of Conversion of Nonvalvular Atrial Fibrillation to Sinus Rhythm on Cardiac Remodeling.

Atrial fibrillation (AF)represents the most prevalent cardiac arrhythmia globally, with a significant burden on mortality and morbidity. While rhythm control strategies, particularly electrical cardioversion (EC), have gained traction in recent years, the precise impact of sinus rhythm (SR) restoration on cardiac reverse remodeling remains a subject of debate. In this study, 23 AF patients underwent elective EC. AF diagnosis was made via ECG by a cardiologist, and candidates for cardioversion were selected by an electrophysiologist. Transthoracic echocardiography (TTE) by utilizing two-dimensional, three-dimensional, and tissue Doppler imaging modalities was performed before cardioversion. Patients who maintained SR after six months underwent a second TTE evaluation. SR was restored successfully in all 23 patients and 15 patients (65.2%) maintained SR after six months. SR group had significantly lower baseline cardiac output (CO)and indexed left ventricular end-systolic volume (LVESVi), and better European Heart Rhythm Association (EHRA) scores after six months. Within the SR group, patients exhibited significant changes in mitral regurgitation, tricuspid regurgitation, EHRA score, LVESVi, stroke volume, left ventricle ejection fraction, left ventricle global longitudinal strain, indexed minimum left atrial volume, left atrial emptying fraction, and left and right atrial diameters. Reduced CO was associated with AF recurrence. Receiver operating curve analysis revealed that CO value can predict six-month AF recurrence with a cut-off point of 2.3. Our study underscores the beneficial effects of SR restoration on cardiac parameters in AF patients post EC. Notably, CO value emerged as a predictor of AF recurrence, emphasizing the importance of comprehensive assessments for predicting long-term outcomes.

Cardiac output calculation using the Liljestrand and Zander formula: is this method applicable during immediate transition after birth? — A post hoc analysis

The transition from intrauterine to extrauterine life is a critical period for neonates. Assessing the cardiovascular transition during this period immediately after birth is crucial but challenging. The present study compares adjusted estimated cardiac output values calculated by the Liljestrand and Zander formula (COest/adj LaZ) with non-invasively measured cardiac output values (CO-bioimpedance) during immediate transition after birth. We performed a secondary outcome analysis of a prospective observational study in preterm and term neonates. Ten and 15 min after birth, arterial blood pressure and heart rate were assessed, and CO-bioimpedance was measured using electrical bioimpedance method (Aesculon monitor, Osypka, Germany). We calculated COest/adj LaZ and compared it to CO-bioimpedance. Further, we performed a correlation analysis. Thirty-two neonates with a median (IQR) gestational age of 37.0 (32.0–39.4) weeks were included. Mean ± SD CO-bioimpedance was 0.62 ± 0.15 l/min, and COest/adj LaZ was calculated to be 0.64 ± 0.10 l/min, whereby both correlated significantly (p = 0.025, r = 0.359) with each other. Conclusion: The present study demonstrates high comparability of COest/adj LaZ and CO-bioimpedance in neonates during immediate transition after birth, suggesting that cardiac output can be derived in a cost-effective and feasible manner if other methods are not available.What is Known:• Echocardiography is considered the gold standard for non-invasive CO evaluation, but its feasibility during the immediate transition period is limited.What is New:• Non-invasive methods such as CO-bioimpedance for cardiac output (CO) measurement and the Liljestrand and Zander (LaZ) formula for estimating CO offer promising alternatives during the immediate transition period.

Evaluating the intraoperative changes in several hemodynamic parameters using uscom method in severe burn patients undergoing burn necrotomy, skin grafting

Objective: To evaluate the intraoperative changes in some hemodynamic parameters by the USCOM method in severe burn patients undergoing burn necrotomy, skin grafting.Subjects and methods: 30 severe burn patients, aged 16-60, treated at the Emergency Department, National Burn Hospital, were scheduled for necrosis and skin grafting from May 2023 to December 2023. Cross-sectional, clinical descriptive study.Results: CO and CI values at all study times were within normal limits (3.5-8 l/min and 2.4-4.2 l/min/m2). CO and CI were highest at the time of pre-medication (6.93 and 4.24) and lowest at the time of skin grafting (5.87 and 3.61). SVR values at all times were within normal limits (800 - 1600 d.s.cm-5). SVR was highest at the time the patient was awake (1278.33) and lowest at the time immediately after induction of anesthesia (976.93). SVRI values at 3 times after induction of anesthesia, before necrotomy, and at the time of necrotomy were lower than normal values (1800-3200 d.s.cm-5.m2). SVI at the remaining time points was within normal limits. SV values at all times were within normal ranges (50-110 cm3). SVI values at most times were smaller than normal values (35 - 65 ml/m2), except for at the time of necrotomy (35.03). SVV values at all times were higher than normal (&lt; 20%).Conclusion: Stroke volume variation (SVV) parameters at all study times were higher than normal values corresponding to the age range. The stroke volume index parameter SVI at most times was lower than the normal value, and SVRI at all times was not higher than the normal value. However, the parameters cardiac output (CO), cardiac index (CI), stroke volume (SV), and systemic vascular resistance (SVR) were all within the range of normal values corresponding to the age range at the research time points.

Assessing cardiac power output values in a healthy adult population.

Cardiac power output (CPO), which combines pressure and flow capacities, directly measures the heart's pumping capability. It is proposed as a superior alternative to ejection fraction in assessing cardiac function. However, there is a lack of data on CPO in healthy individuals, prompting a study to determine the cardiac power output in healthy adults in the Iranian population.This cross-sectional descriptive study investigated cardiac power in a sample of healthy individuals. Participants were recruited from healthy individuals referred to the Echocardiography department using convenience sampling.In this study, we examined the echocardiographic parameters in 173 individuals, of which 52% were men. Men exhibited significantly higher values for stroke volume, cardiac output, and cardiac power output (CPO) in both ventricles, as well as larger body surface area (BSA) and systemic mean arterial pressure (MAP), compared to women. Individuals under the age of 40 had significantly higher BSA and right ventricular cardiac output compared to those aged 40 or above. Multivariate analysis revealed that MAP, left ventricular (LV) cardiac output, LVCPO, pulmonary MAP, right ventricular (RV) CPO, and RV cardiac power index (CPI) were significant predictors of LVCPI changes.Our findings emphasize the importance of cardiac power output as a comprehensive measure of cardiac function, complementing the traditional use of ejection fraction. Further research is warranted to validate these results, establish accurate reference ranges, and explore the clinical implications of cardiac power output in various patient populations.

Relationship between cardiac output, heart rate and microcirculation in patients with multiorgan dysfunction syndrome

Multiple organ dysfunction syndrome (MODS) is one of the main causes of death in intensive care units. There is evidence that microcirculation in sepsis and coronary shock is regulated separately from hemodynamics. This study investigates the relationship between heart rate (HR), cardiac output (CO) and microcirculation in patients with MODS. This is apartial analysis of the "MODIFY study" (Reducing Elevated Heart Rate in Patients With Multiple Organ Dysfunction Syndrome [MODS] by Ivabradine). During the period 05/2010-09/2011, the microcirculation of 46patients with septic and coronary MODS was measured using the sidestream dark field technique on the day of inclusion and 96 h later. Patients were randomized into acontrol and ivabradine treatment group. Overall, there is arelevant improvement in microcirculation over time small perfused vessels, SPV [%] on day0, d0:56.5 ± 34.2/d4:73.2 ± 22.1 (p = 0.03); perfused vessel density, PVDsmall [1/mm2] d0:7.5 ± 5.0/d4:9.8 ± 3.4 (p = 0.04); proportion of perfused vessels, PPVsmall [%] d0:51.6 ± 31.6/d4:66.7 ± 21.8 (p = 0.04); microcirculatory flow index, MFI d0:1.7 ± 1.0/d4:2.2 ± 0.7 (p = 0.05). Administration of ivabradine shows no effect. In patients with coronary MODS, there is arelevant correlation between microcirculatory parameters and cardiac output (SPV [%]: r = 0.98, p = 0.004). Patients with coronary MODS show better microcirculation values at high heart rates (> 100 bpm), while patients with septic MODS show an opposite relationship. The results indicate that in critically ill patients, depending on the genesis of the MODS, there are different relationships between HF or CO values, on the one hand, and the parameters of the microcirculation, on the other.

Agreement between direct Fick and bolus thermodilution measurements of cardiac output during right heart catheterisation and the impact on haemodynamic classifications

Abstract Background/Introduction When measuring cardiac output (CO) during right heart catheterisation (RHC), both direct Fick (DF) and bolus thermodilution (TD) methods are endorsed by pulmonary hypertension (PH) guidelines (1). Agreement between these techniques in contemporary practice is not well understood, nor are the diagnostic consequences of disagreement. Purpose To investigate the real-world agreement between DF and TD techniques for measuring CO during contemporary RHC, and evaluate the impact of disagreement on patients’ haemodynamic classification. Methods This was a single-centre study including 182 patients who had CO measured simultaneously by DF and TD methods during RHC. Oxygen consumption (VO2) was measured with an indirect calorimeter. The primary outcome was the agreement between DF and TD derived CO using Bland-Altman analysis. Secondary outcomes included the impact of specific clinical variables on CO agreement, and the frequency of disagreement in determining patients’ haemodynamic classification. Results Disagreement between DF and TD measures of CO was noted, with the DF technique tending to overestimate CO relative to the TD measurement (median DF-CO 5.42 L/min [interquartile range (IQR) 3.90 – 7.41] vs median TD-CO 4.10 L/min [IQR 3.47 – 5.10], p&amp;lt;0.001). For CO values between 3-7 L/min, the error between DF and TD measurements ranged from -4.75% to +44.5%, and limits of agreement were between -69.9% and +101% (Figure 1). Disagreement was increased by 19.2% in patients with at least moderate-to-severe tricuspid regurgitation, and by 16.0% in those with irregular heart rhythms (Table1). The agreement between DF and TD derived pulmonary vascular resistance (PVR) was equally poor. Nonetheless, in 86.3% of patients, the techniques agreed in classifying the PVR as abnormally elevated (&amp;gt; 2 Wood Units), with disagreement occurring more frequently in patients with less severe PH. Conclusions In this real-world study there was poor agreement between DF and TD derived CO, resulting in more than 10% of patients having discrepant haemodynamic classifications. This data highlight that both methods should be utilised in clinical practice, particularly in borderline cases or when the haemodynamic assessment influences treatment eligibility or operative risk assessment. The two techniques should not be used interchangeably for serial surveillance, and the impact of our findings on invasive assessments of valvular pathologies needs further investigation.

Abstract 17947: Mathematical Model of Cheyne-Stokes Respirations as an Educational Tool for Understanding Cardiorespiratory Interactions in Heart Failure

Background: Patients with heart failure often develop Cheyne-Stokes Respirations (CSR): a breathing pattern characterized by alternating periods of hyperventilation and apnea. The cardio-respiratory interactions that result in CSR are complex and often difficult to understand for students learning cardiovascular physiology. Aims: We developed a mathematical model of CSR where cardiac output (CO), respiratory rate (RR) and arterial CO 2 (pCO 2 ) can be manipulated to evaluate how periodic fluctuations in different physiological variables develop, thus providing a deeper understanding of cardiorespiratory interactions in heart failure. Methods: Our model consisted of 3 coupled differential equations. (1) pCO 2 is directly proportional to metabolic CO 2 production and inversely proportional to alveolar ventilation (V A ). V A depends on RR, alveolar volume, and CO, with the interaction between CO and ventilation calculated by combining Fick’s principle and the Alveolar Gas Equation. (2) Changes in RR are modeled as a Hill function dependent on pCO 2 . (3) Finally, CO depends on pCO 2 , arterial O 2, and RR. The model was propagated forward in time using Euler’s method. A graphical user interface allows users to easily manipulate variables and observe heart lung interactions. Results: Initial values for RR, CO, and PCO 2 resulting in stable, aperiodic breathing were 10 breaths/min, 6 L/Min, and 40 mmHg, respectively. Perturbing any of these values resulted in periodic fluctuations in RR, CO, and pCO 2 (Figure 1). A key insight of the model is that progressive decreases in CO induce more prominent oscillations in RR and pCO 2 and that pCO 2 directly influences CO. Conclusions: Our mathematical model of cardio-respiratory interactions allows users to easily manipulate physiological variables to graphically visualize how changes in CO and respiratory function give rise to CSR. This may enable students to obtain a deeper understanding of cardiovascular physiology.

Effect of sleeping position on cardiac output, pulmonary pressure, and superior vena cava flow in healthy term infants

Although the mechanism of action in newborns is unknown, sleep positioning is associated with many pathophysiological events. This study aimed to compare the effects of supine and prone sleeping positions on cardiac output (CO), systolic pulmonary arterial pressure (SPAP), and superior vena cava (SVC) flow in healthy newborns. In the first 24-72h of life, 40 healthy term newborns born in the same hospital were included in this prospective, cross-sectional, observational study. CO, SVC flow, and SPAP values of newborns in the supine and prone sleeping positions were calculated using echocardiographic examination. The measurements were statistically compared. In the supine sleeping position, CO, SVC flow, and SPAP were 235.00 (193.07-283.30) ml/kg/min, 92.80 (77.82-121.87) ml/kg/min, and 27.85 (24.70-30.48) mmHg. In the prone sleeping position, CO, SVC flow, and SPAP were measured as 195.35 (166.00-229.40) ml/kg/min, 67.25 (51.82-96.66) ml/kg/min, 31.60 (28.45-37.20) mmHg, respectively. Depending on sleeping position, these variables were significantly different between the groups. SVC flow and CO decreased in the prone sleeping position compared to the supine sleeping position in healthy newborns, whereas SPAP increased. The different hemodynamic effects of sleeping position on the cardiac, pulmonary, and nervous systems should be considered as flow and pressure changes are important in newborns.

Reference ranges for third-trimester maternal cardiovascular function parameters measured in normotensive pregnant women using a non-invasive cardiac output monitor: A study based on data from the prospective PEACH cohort study.

We defined reference ranges for maternal cardiac output, systemic vascular resistance, and stroke volume measured in the third trimester of pregnancy using the Ultrasound Cardiac Output Monitor 1A. Based on data from the prospective PEACH (PreEclampsia, Angiogenesis, Cardiac dysfunction and Hypertension) cohort study. Rigshospitalet and Hvidovre Hospital, Denmark. Normotensive pregnant women aged 18-45 years with singleton pregnancies, enrolled in the PEACH study in 2016-2018. We modelled cardiac output, systemic vascular resistance and stroke volume as a function of gestational age using multilevel linear models with fractional polynomials. Unconditional and conditional reference ranges for cardiovascular parameters measured in gestational weeks 28-40. Our study cohort included 405 healthy pregnant women who contributed 1210 cardiovascular function measurements for analysis. Maximum cardiac output and stroke volume values were measured in gestational weeks 30-32 and decreased over the third trimester, whereas systemic vascular resistance increased during the same period. We created reference ranges for eight combinations of maternal height, age and parity. We also created a simple calculator to allow for implementation of the reference ranges in clinical practice. Our reference ranges allow the use of a bedside ultrasound device to non-invasively assess cardiac function in pregnancy and identify women at risk of complications. The unconditional ranges allow clinicians to evaluate isolated measurements and identify women needing follow-up. The conditional ranges incorporate information from previous measurements and improve monitoring over time.

Gut Dysbiosis and Hemodynamic Changes as Links of the Pathogenesis of Complications of Cirrhosis.

The aim was to evaluate the relationship between gut dysbiosis and hemodynamic changes (hyperdynamic circulation) in cirrhosis, and between hemodynamic changes and complications of this disease. This study included 47 patients with cirrhosis. Stool microbiome was assessed using 16S rRNA gene sequencing. Echocardiography with a simultaneous assessment of blood pressure and heart rate was performed to assess systemic hemodynamics. Patients with hyperdynamic circulation had more severe cirrhosis, lower albumin, sodium and prothrombin levels, higher C-reactive protein, aspartate aminotransferase and total bilirubin levels, and higher incidences of portopulmonary hypertension, ascites, overt hepatic encephalopathy, hypoalbuminemia, hypoprothrombinemia, systemic inflammation, and severe hyperbilirubinemia than patients with normodynamic circulation. Patients with hyperdynamic circulation compared with those with normodynamic circulation had increased abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Fusobacteria, Micrococcaceae, Intestinobacter, Clostridium sensu stricto, Proteus and Rumicoccus, and decreased abundance of Bacteroidetes, Bacteroidaceae, Holdemanella, and Butyrivibrio. The systemic vascular resistance and cardiac output values correlated with the abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcaceae, Lactobacillaceae, Micrococcaceae, and Fusobacteria. Heart rate and cardiac output value were negatively correlated with the abundance of Bacteroidetes. The mean pulmonary artery pressure value was positively correlated with the abundance of Proteobacteria and Micrococcaceae, and negatively with the abundance of Holdemanella.

Evaluation of Fetal Cardiac Output and Modified Myocardial Performance Index in Pregnant Women with Idiopathic Polyhydramnios: A Case Control Study from a Tertiary Hospital.

This study aimed to investigate fetal cardiac output and myocardial performance index in pregnant women with idiopathic polyhydramnios and compare them to healthy pregnant women. Thirty patients admitted to Ankara City Hospital at 24-39 weeks of gestation with idiopathic polyhydramnios were included as the study group. Clinical characteristics, fetal cardiac output, and fetal modified myocardial performance index (Mod-MPI) were compared between the groups. The combined cardiac output (CCO), left cardiac output (LCO), right cardiac output (RCO), pulmonary artery velocity time integral (PA-VTI), and aortic VTI were statistically significantly higher in the study group (p=0.003, p=0.028, p=0.002, p=0.000, and p=0.017, respectively).The idiopathic polyhydramnios group had a significantly higher Mod-MPI and isovolumetric contraction time (ICT) and a significantly lower ejection time (ET) compared to the controls (p=000, p=0.003, and p=0.023, respectively). In the idiopathic polyhydramnios group, the aortic max (p=0.009) and aortic VTI (p=0.047) values were significantly lower and the left ventricular outflow tract isovolumetric relaxation time (LVOT-IRT) (p=0.021) was significantly higher in cases where the NICU was required. According to the ROC analysis performed in the idiopathic polyhydramnios group, the optimal cut-off values of aortic max, aortic VTI, and LVOT-IRT in the prediction of the NICU requirement were (57.5, 0.089 and 41.5, respective cut-off value) (p=0.010, p=0.048, p=0.021, respectively). Both fetal cardiac output and Mod-MPI values were altered in fetuses with idiopathic polyhydramnios.

Comparison of the effectiveness of USCOM and echocardiography in assessing cardiac output on pediatric patients with shock

BackgroundShock is a circulatory failure, and its clinical manifestations result in decreased cardiac output. Hemodynamic monitoring is important in shock patients to determine further management. Demand for noninvasive examination methods, such as ultrasound cardiac output monitoring (USCOM) and echocardiography, is increasing because of their practicality and lower risks. ObjectivesThe aim of this study is to compare cardiac output determined using USCOM and echocardiography in pediatric patients with shock. MethodsThis prospective observational study used a cross-sectional data collection approach. It collected data on 48 pediatric shock patients in the Pediatric Intensive Care Unit at Kandou General Hospital (Manado, Indonesia) between March and June 2022. The instruments used were USCOM and echocardiography. The regression analysis results are presented as odds ratios (ORs) with 95 % confidence intervals and p < 0.05. ResultsThe mean cardiac output of pediatric patients with shock was 2.50 (standard deviation [SD] = 2.28) with USCOM and 2.45 (SD = 0.77) with echocardiography. Echocardiographic and USCOM cardiac output values were significantly correlated, with a coefficient of determination (R2) of 0.832 (83.2 %), indicating a near-perfect linear correlation. ConclusionThis study's results show that USCOM is as effective as echocardiography in assessing cardiac output in children with shock.

“The peripheral perfusion index discriminates haemodynamic responses to induction of general anaesthesia”

Induction of general anaesthesia is often accompanied by hypotension. Standard haemodynamic monitoring during anaesthesia relies on intermittent blood pressure and heart rate. Continuous monitoring systemic blood pressure requires invasive or advanced modalities creating a barrier for obtaining important information of the circulation. The Peripheral Perfusion Index (PPI) is obtained non-invasively and continuously by standard photoplethysmography. We hypothesized that different patterns of changes in systemic haemodynamics during induction of general anaesthesia would be reflected in the PPI. Continuous values of PPI, stroke volume (SV), cardiac output (CO), and mean arterial pressure (MAP) were evaluated in 107 patients by either minimally invasive or non-invasive means in a mixed population of surgical patients. 2 min after induction of general anaesthesia relative changes of SV, CO, and MAP was compared to the relative changes of PPI. After induction total cohort mean(± st.dev.) MAP, SV, and CO decreased to 65(± 16)%, 74(± 18)%, and 63(± 16)% of baseline values. In the 38 patients where PPI decreased MAP was 57(± 14)%, SV was 63(± 18)%, and CO was 55(± 18)% of baseline values 2 min after induction. In the 69 patients where PPI increased the corresponding values were MAP 70(± 15)%, SV 80(± 16)%, and CO 68(± 17)% (all differences: p < 0,001). During induction of general anaesthesia changes in PPI discriminated between the degrees of reduction in blood pressure and algorithm derived cardiac stroke volume and -output. As such, the PPI has potential to be a simple and non-invasive indicator of the degree of post-induction haemodynamic changes.

The clinical application of ultrasound for acute kidney injury during sepsis-from macroscopic to microscopic renal perfusion perspectives

The aim was to quantify macroscopic renal blood flow and renal cortical microcirculation in patients with septic acute kidney injury (AKI) using ultrasound and contrast-enhanced ultrasound. In this case-control study, patients in the intensive care unit diagnosed with septic AKI were divided into stages 1-3 based on the 2012 KDIGO (Kidney Disease: Improving Global Outcomes) AKI diagnostic criteria. The patients were categorized into mild (stage 1) and severe (stages 2 and 3) groups, while septic patients without AKI served as the control group. Ultrasound parameters such as macrovascular renal blood flow and time-averaged velocity, as well as cardiac function parameters such as cardiac output and cardiac index, were measured. The time-intensity curve in the microcirculation was analyzed through contrast-enhanced ultrasound imaging software to calculate imaging parameters such as peak time, rise time, fall half-time and mean transit time of the interlobar arteries in the renal cortex. In terms of macrocirculation, renal blood flow and time-averaged velocity decreased gradually with the progression of septic acute renal injury (p=0.004, p < 0.001). There was no difference in cardiac output and cardiac index values among the three groups (p=0.17 and p=0.12). In terms of microcirculation, ultrasonic Doppler parameters of the renal cortical interlobular artery, such as peak intensity, risk index and ratio of peak systolic velocity to end-diastolic velocity, gradually increased (all p values <0.05). The temporal contrast-enhanced ultrasound parameters-time to peak, rise time, fall half-time and mean transit time-were prolonged in AKI groups when compared with the control group (p < 0.001, p=0.003, p=0.004 and p=0.009, respectively). In patients with septic AKI, the renal blood flow and time average velocity of macrocirculation in the kidneys are reduced, while the time parameters of microcirculation such as time to peak, rise time, fall half-time and mean transit time are prolonged, especially in patients with severe AKI. These changes are not related to changes in cardiac output or cardiac index.