Noninvasive Cardiac Output Research Articles

Agreement of Bioreactance Cardiac Output Monitoring With Thermodilution in Healthy Standing Horses.

Bioreactance is the continuous analysis of transthoracic voltage variation in response to an applied high frequency transthoracic current and was recently introduced for non-invasive cardiac output measurement (NICOM). We evaluated NICOM compared to thermodilution (TD) in adult horses. Six healthy horses were used for this prospective, blinded, experimental study. Cardiac output (CO) measurements were performed simultaneously using TD and the bioreactance method. Different cardiac output scenarios were established using xylazine (0.5 mg/kg IV) and dobutamine (1.5–3 mcg/kg/min). Statistical analysis was performed by calculating the concordance rate, performing a regression analysis, Pearson correlation, and Bland Altman. The TD-based CO and NICOM values were highly correlated for low, normal and high CO values with an overall correlation coefficient. A 4-quadrant plot showed an 89% rate of concordance. The linear regression calculated a relationship between NICOM and TDCO of Y = 0.4874 · X + 0.5936. For the corrected Bland Altman agreement, the mean bias and lower/upper limits of agreement were −0.26 and −3.88 to 3.41 L/min, respectively. Compared to TD, bioreactance- based NICOM showed good accuracy at induced low, normal, and high CO states in normal horses. Future studies performed under more clinical conditions will show if this monitor can help to assess hemodynamic status and guide therapy in horses in ICU settings and under general anesthesia.

Cardiac Output Measurement in Neonates and Children Using Noninvasive Electrical Bioimpedance Compared With Standard Methods: A Systematic Review and Meta-Analysis.

To systematically review and meta-analyze the validity of electrical bioimpedance-based noninvasive cardiac output monitoring in pediatrics compared with standard methods such as thermodilution and echocardiography. Systematic searches were conducted in MEDLINE and EMBASE (2000-2019). Method-comparison studies of transthoracic electrical velocimetry or whole body electrical bioimpedance versus standard cardiac output monitoring methods in children (0-18 yr old) were included. Two reviewers independently performed study selection, data extraction, and risk of bias assessment. Mean differences of cardiac output, stroke volume, or cardiac index measurements were pooled using a random-effects model (R Core Team, R Foundation for Statistical Computing, Vienna, Austria, 2019). Bland-Altman statistics assessing agreement between devices and author conclusions about inferiority/noninferiority were extracted. Twenty-nine of 649 identified studies were included in the qualitative analysis, and 25 studies in the meta-analyses. No significant difference was found between means of cardiac output, stroke volume, and cardiac index measurements, except in exclusively neonatal/infant studies reporting stroke volume (mean difference, 1.00 mL; 95% CI, 0.23-1.77). Median percentage error in child/adolescent studies approached acceptability (percentage error less than or equal to 30%) for cardiac output in L/min (31%; range, 13-158%) and stroke volume in mL (26%; range, 14-27%), but not in neonatal/infant studies (45%; range, 29-53% and 45%; range, 28-70%, respectively). Twenty of 29 studies concluded that transthoracic electrical velocimetry/whole body electrical bioimpedance was noninferior. Transthoracic electrical velocimetry was considered inferior in six of nine studies with heterogeneous congenital heart disease populations. The meta-analyses demonstrated no significant difference between means of compared devices (except in neonatal stroke volume studies). The wide range of percentage error reported may be due to heterogeneity of study designs, devices, and populations included. Transthoracic electrical velocimetry/whole body electrical bioimpedance may be acceptable for use in child/adolescent populations, but validity in neonates and congenital heart disease patients remains uncertain. Larger studies in specific clinical contexts with standardized methodologies are required.

Maternal cardiovascular function in the prediction of fetal distress in labor: a prospective cohort study

Objective To explore the strength of association and the diagnostic accuracy of maternal hemodynamic parameters detected noninvasively in predicting an adverse perinatal outcome in labor. Methods Prospective cohort study of singleton women undergoing antepartum care at 37–39 weeks of gestation. A noninvasive ultrasonic cardiac output monitor (USCOM®) was used for cardiovascular assessment. The study outcome was a composite score of adverse perinatal outcome, which included at least one of the following variables: Cesarean or instrumental delivery for abnormal fetal heart monitoring, umbilical artery pH <7.10 or admission to neonatal special care unit. Attending clinicians were blinded to maternal cardiovascular indices. Multivariate logistic regression and area under the curve (AUC) analyses were used to test the diagnostic accuracy of different maternal and ultrasound characteristics in predicting adverse perinatal outcome. Results A total of 133 women were recruited. The rate of adverse perinatal outcome was 25.6% (34/133). Women who delivered without abnormal perinatal outcome (controls) were more likely to be parous, compared to those who had an adverse perinatal outcome (44.4 vs. 73.5%; p = .005). Control women had significantly lower systemic vascular resistance (SVR) (median, 1166 vs. 1352 dynes × s/cm5, p = .023) and SVR index (SVRI) (median, 2168 vs. 2627 dynes × s/cm5/m2, p = .039) compared to women who had an adverse perinatal outcome. In this latter group the prevalence of SV <50 ml was significantly higher than in the control group (38.2% (13/34) vs. 11.1%, (11/99) p = .0012). At multivariable logistic regression analysis, SVR (aOR 1.307; 95% CI 1.112–2.23), SV <50 ml (aOR 4.70; 95% CI 1.336–12.006) and parity (3.90: 95% CI 1.545–10.334) were the only variables independently associated with adverse perinatal outcome. A model considering only SVR showed an AUC of 0.631. Integration of SVR with SV <50 ml and parity significantly improves the diagnostic performance of SVR alone to predict adverse outcome (AUC 0.732; p = .016). Conclusion Pre-labor modifications of maternal cardiovascular variables are associated with adverse perinatal outcome. However, their predictive accuracy for perinatal compromise is low, and thus their use as standalone screening test for adverse perinatal outcome in singleton pregnancies at term is not supported.

Non-invasive cardiac output measurement by electrical cardiometry and M-mode echocardiography in the neonate: a prospective observational study of 136 neonatal infants

BackgroundElectrical cardiometry (EC) is a continuous, non-invasive method for measuring cardiac output (CO). This study investigates the correlation and consistency of CO values in newborns obtained by using EC and M-mode echocardiography (Teichholz formula).MethodsIn this prospective observational study, simultaneous measurement of CO was implemented with EC (COec) and M-mode echocardiography (COm) in neonates. The absolute values of CO measured by the two methods were converted to Z-scores. Following that, Pears’s correlation analyses and the Bland–Altman index were employed to analyze the correlation and consistency of COec Z-scores and COm Z-scores.ResultsA total of 136 neonates (93 preterm infants) were enrolled in this study, and EC and M-mode echocardiography comparative studies were conducted 155 times. The mean value of COec and COm demonstrated significant statistical differences (P<0.001). A moderate correlation (r=0.601; P<0.001) was found between the two methods. The Bland-Altman index value was 3.2%, which remained less than 5% in the low birth weight (LBW) (2.1%), non-LBW (3.4%), spontaneous respiration (3.1%), nasal continuous positive airway pressure (nCPAP) (4.0%), mechanical ventilation (2.9%), hemodynamic significance of the patent ductus arteriosus (hsPDA) (4.3%), and non-hsPDA (3.7%) groups, respectively.ConclusionsAlthough the absolute values of CO measured by EC and M-mode echocardiography were not interchangeable, the distribution of CO in EC and M-mode echocardiography was similar.

Temporal haemodynamic changes after bisoprolol treatment in patients with uncontrolled hypertension.

BackgroundAnti-hypertensive drugs are widely used to control blood pressure, yet their effects on haemodynamics, especially in Chinese populations, and the potential for non-invasive methods to monitor these changes, are poorly understood. This study aimed to determine the early and late effects of bisoprolol treatment on blood pressure, cardiac output (CO), stroke volume (SV), heart rate (HR), systematic vascular resistance (SVR), and inotropy measured in Chinese patients with hypertension.MethodsTwelve Chinese subjects (median age: 55 years, interquartile range: 52–58 years; 33% male) with uncontrolled hypertension were recruited at the Prince of Wales Hospital in Hong Kong and haemodynamic measurements were assessed using a non-invasive Ultrasonic Cardiac Output Monitor (USCOM). Seven hourly measurements were taken before and after bisoprolol 2.5 mg on day 1 (T0 to T6), and in nine patients this was repeated six weeks later (TF0 to TF6). Any BP change of 5 mmHg was considered clinically significant and P<0.05 was considered statistically significant.ResultsOn day 1 (N=12), there was a significant drop in median CO [4.9 (4.7–5.6) vs. 3.8 (3.3–4.7) L/m2, P<0.0001] associated with a compensatory increase in SVR [1,698.1 (1,584.6–1,894.3) vs. 2,222.6 (1,777.4–2,712.5) d·s·cm−5, P<0.0001] at T2. The median dBP {92 [87–95] vs. 86 [79–89] mmHg, P=0.0002} and MAP {110 [104–114] vs. 104 [101–109] mmHg, P=0.038} reduced significantly 6 hours after bisoprolol treatment. Except for HR, all other measured haemodynamics returned to baseline at T6. On week 6 (N=9), SVR was generally reduced, but major parallel swings in CO and SVR were still evident. All patients showed a trend to lower blood pressure, SVR, and inotropy (P<0.05), but HR, SV, and CO returned to baseline values after 6 weeks treatment (P>0.05).ConclusionsThe acute haemodynamic changes between 6 hours of the first dose and the dose after 6 weeks of bisoprolol treatment are similar. Long-term therapy can effectively reduce blood pressure by reducing SVR.

Cardiac Output and Cerebral Oxygenation in Term Neonates during Neonatal Transition.

The immediate transition from foetus to neonate includes substantial changes, especially concerning the cardiovascular system. Furthermore, the brain is one of the most vulnerable organs to hypoxia during this period. According to current guidelines for postnatal stabilization, the recommended parameters for monitoring are heart rate (HR) and arterial oxygen saturation (SpO2). Recently, there is a growing interest in advanced monitoring of the cardio-circulatory system and the brain to get further objective information about the neonate’s condition during the immediate postnatal transition after birth. The aim of the present study was to combine cardiac output (CO) and brain oxygenation monitoring in term neonates after caesarean section in order to analyse the potential influence of CO on cerebral oxygenation during neonatal transition. This was a monocentric, prospective, observational study. For non-invasive cardiac output measurements, the electrical velocimetry (EV) method (Aesculon Monitor, Osypka Medical, CA, USA) was used. The pulse oximeter probe for SpO2 and HR measurements was placed on the right hand or wrist. The cerebral tissue oxygen index (cTOI) was measured using a NIRO-200NX monitor with the near-infrared spectroscopy (NIRS) transducer on the right frontoparietal head. Monitoring started at minute 1 and was continued until minute 15 after birth. At minutes 5, 10, and 15 after birth, mean CO was calculated from six 10 s periods (with beat-to-beat analysis). During the study period, 99 term neonates were enrolled. Data from neonates with uncomplicated transitions were analysed. CO showed a tendency to decrease until minute 10. During the complete observational period, there was no significant correlation between CO and cTOI. The present study was the first to investigate a possible correlation between CO and cerebral oxygenation in term infants during the immediate neonatal transition. In term infants with uncomplicated neonatal transition after caesarean section, CO did not correlate with cerebral oxygenation.

Bioreactance-derived haemodynamic parameters in the transitional phase in preterm neonates: a longitudinal study.

Bioreactance (BR) is a novel, non-invasive technology that is able to provide minute-to-minute monitoring of cardiac output and additional haemodynamic variables. This study aimed to determine the values for BR-derived haemodynamic variables in stable preterm neonates during the transitional period. A prospective observational study was performed in a group of stable preterm (< 37weeks) infants in the neonatal service of Tygerberg Children's Hospital, Cape Town, South Africa. All infants underwent continuous bioreactance (BR) monitoring until 72h of life. Sixty three preterm infants with a mean gestational age of 31weeks and mean birth weight of 1563g were enrolled. Summary data and time series graphs were drawn for BR-derived heart rate, non-invasive blood pressure, stroke volume, cardiac output and total peripheral resistance index. All haemodynamic parameters were significantly associated with postnatal age, after correction for clinical variables (gestational age, birth weight, respiratory support mode). To our knowledge, this is the first paper to present longitudinal BR-derived haemodynamic variable data in a cohort of stable preterm infants, not requiring invasive ventilation or inotropic support, during the first 72h of life. Bioreactance-derived haemodynamic monitoring is non-invasive and offers the ability to simultaneously monitor numerous haemodynamic parameters of global systemic blood flow. Moreover, it may provide insight into transitional physiology and its pathophysiology.

Maternal haemodynamics during labour epidural analgesia with and without adrenaline.

Labour is one of the most painful experiences in a woman's life. Epidural analgesia using low-concentration local anaesthetics and lipophilic opioids is the gold standard for pain relief during labour. Pregnancy in general, particularly labour, is associated with changes in maternal haemodynamic variables, such as cardiac output and heart rate, which increase and peak during uterine contractions. Adrenaline is added to labour epidural solutions to enhance efficacy by stimulating the α2-adrenoreceptor. The minimal effective concentration of adrenaline was found to be 2μgmL-1 for postoperative analgesia. The addition of adrenaline may also produce vasoconstriction, limiting the absorption of fentanyl into the systemic circulation, thereby reducing foetal exposure. However, adrenaline may influence the haemodynamic fluctuations, possibly adding to the strain on the circulatory system. The aim of this study was to compare the haemodynamic changes after application of labour epidural analgesia with or without adrenaline 2μgmL-1. This was a secondary analysis of a single-centre, randomised double-blind trial. Forty-one nulliparous women in labour requesting epidural analgesia were randomised to receive epidural solution of bupivacaine 1mgmL-1, fentanyl 2μgmL-1 with or without adrenaline 2μgmL-1. The participants were monitored using a Nexfin CC continuous non-invasive blood pressure and cardiac output monitor. The primary outcomes were changes in peak systolic blood pressure and cardiac output during uterine contraction within 30min after epidural activation. The effect of adrenaline was tested statistically using a linear mixed-effects model of the outcome variables' dependency on time, adrenaline, and their interaction. After excluding three patients due to poor data quality and two due to a malfunctioning epidural catheter, 36 patients (18 in each group) were analysed. The addition of adrenaline to the solution had no significant effect on the temporal changes in peak systolic blood pressure (p=0.26), peak cardiac output (0.84), or heart rate (p=0.91). Furthermore, no significant temporal changes in maternal haemodynamics (peak systolic blood pressure, p=0.54, peak cardiac output, p=0.59, or heart rate p=0.55) were associated with epidural analgesia during 30min after epidural activation in both groups despite good analgesia. The addition of 2μgmL-1 adrenaline to the epidural solution is not likely to change maternal haemodynamics during labour.

Comparing doppler-echocardiography and thermodilution for cardiac output measurements in resuscitated out-of-hospital cardiac arrest patients undergoing targeted temperature management

Abstract Funding Acknowledgements Type of funding sources: None. Background Cardiovascular dysfunction is common after out-of-hospital cardiac arrest (OHCA). Cardiac output measurements can be used to guide treatment during post-resuscitation care and echocardiography allows noninvasive cardiac output estimation. Purpose The aim of the present study was to compare Doppler echocardiography (doppler_CO) with thermodilution using pulmonary artery catheters (PAC_CO) for cardiac output estimation in a large and consecutively included cohort of comatose OHCA-patients undergoing targeted temperature management (TTM). Methods Single-center substudy of 171 patients included in the TTM-trial randomly assigned to 33 or 36 degrees C for 24 hours after OHCA. We measured PAC_CO and doppler_CO simultaneously shortly after admission and again after 24 hours. Measurements and Main Results We excluded 19 (11%) patients without PAC-measurement and 31 (18%) without doppler-measurements resulting in 120 paired measurements at admission. Patients were 61 (±11) years old, 86% were men and 91% had a witnessed OHCA. At ICU-admission, PAC_CO was 4.81 (±1.81) L/min. and doppler_CO was 3.74 (±1.38) L/min., with a mean bias of 1.07 (±1.65) L/min (with 95% limits of agreement of –2.16 to 4.04) L/min. Examining the Bland-Altman plot, precision fell with higher cardiac output (figure). A statistically significant, but moderate correlation was found between doppler_CO and PAC_CO at admission (r = 0.49), p &amp;lt; 0.0001). After 24 hours, PAC_CO was 4.63 (±1.38) L/min. and doppler_CO was 3.61 (±1.14) L/min, with a mean bias of 0.96 L/min. Assessing the change from admission to 24 hours, PAC_CO decreased averagely -0.12 (±2.22) L/min. and doppler_CO decreased -0.19 (±1.91) L/min. The changes from admission to 24 hours correlated between doppler_CO and PAC_CO (r = 0.55), p &amp;lt; 0.0001) with a mean bias of the changes of 0.07 L/min, with 95% limits of agreement of –3.76 to 3.91 L/min. Conclusions Changes in cardiac output during TTM may be evaluated with Doppler echocardiography with little mean bias compared to changes in CO measured with thermodilution, but relatively large changes are needed in the individual patient before it can be considered as real. Abstract Figure. Comparing Doppler vs. thermodilution

Non-invasive assessment of fluid responsiveness to guide fluid therapy in patients with sepsis in the emergency department: a prospective cohort study

BackgroundLittle is known about optimal fluid therapy for patients with sepsis without shock who present to the ED. In this study, we aimed to quantify the effect of a fluid...

Методика оценки количества жидкости в грудной клетке, основанная на антропометрических данных пациента и определении электрического импеданса грудной клетки

Актуальность. Определение в динамике объема жидкости в грудной клетке приобретает все более широкое распространение в клинических исследованиях и является перспективным методом мониторинга у пациентов отделений интенсивной терапии различного профиля. Наиболее доступными и экономичными методами мониторинга объема жидкости в грудной клетке в настоящее время являются методы, основанные на измерении электрического импеданса грудной клетки при сканировании ее высокочастотным током. Эти методики обеспечивают хорошую повторяемость результатов и практически не зависят от оператора. Цель работы: разработка собственной оригинальной методики определения содержания жидкости в грудной клетке. Материалы и методы. Электрический грудной импеданс измерялся при сканировании грудной клетки электрическим током частотой 32 КГц с наложением двух пар ленточных электродов по В. Кубичеку. Окружность основания шеи и грудной клетки в месте наложения электродов была тщательно измерена. Также опреде­лялось расстояние между измерительными электродами. Объем грудной клетки рассчитывался на основании модели усеченного конуса. Объем жидкости в грудной клетке рассчитывался по формуле V = γν/Z(R – r), где V — объем жидкости в грудной клетке; γ — усредненное значение электропроводности крови; ν — объем грудной клетки, рассчитанный на модели усеченного конуса; Z — величина электрического импеданса грудной клетки; R — радиус грудной клетки, а r — радиус основания шеи, внесение разницы между ними в формулу должно уменьшить ошибку, связанную с присутствием в грудной клетке соединительной ткани, обладающей электропроводностью, которая отличается от электропроводности крови. Исследования проведены как у практически здоровых добровольцев, так и у пациентов отделения политравмы с торакальной травмой и признаками дыхательной недостаточности. Результаты. Наши наблюдения показали, что величина объема жидкости в грудной клетке, вычисленная по предлагаемой нами методике, в норме приближается к 60 % — 59 ± 2 % объема грудной клетки, рассчитанного на основе модели усеченного конуса. В наиболее тяжелых случаях торакальной травмы относительное содержание жидкости в грудной клетке пострадавших достигало 75–80 %, а величина объема жидкости в грудной клетке, выраженная в условных единицах на 1/КΩ, находилась на уровне 45–50 условных 1/КΩ. Эти события были ассоциированы с наличием клинической картины острого респираторного дистресс-синдрома 2-й степени тяжести, и все пациенты находились на принудительной искусственной вентиляции легких (ИВЛ) с созданием постоянного положительного давления в дыхательных путях и респираторного плато на уровне 25–27 см Н2О. Положительная динамика процесса была ассоциирована с возрастанием величины индекса оксигенации, возможностью перевода пациентов на самостоятельное дыхание. При этом относительное содержание жидкости в грудной клетке пострадавших снижалось до 60–67 %, а у тех, кто нуждался в продолжении ИВЛ, — до 68–73 %. Величина объема жидкости в грудной клетке, выраженная в условных единицах на 1/КΩ, при быстром улучшении и возможности прекращения ИВЛ составляла 37–42 условных 1/КΩ, а при необходимости продол­жения ИВЛ — 43–46 условных 1/КΩ. Результаты определения объема жидкости в грудной клетке по методу авторов лучше соответствовали клинической картине торакальной травмы, тяжести проявлений синдрома острой дыхательной недостаточности, чем показатели методики NICOM. Выводы. Разработанная методика определения содержания жидкости в грудной клетке может быть применена в научных исследованиях и клинической практике в процессе проведения интенсивной терапии у пациентов с синдромом острой дыхательной недостаточности.

278 Assessing effects of lateral tilt on cardiac output using a Non-invasive technique

Aortocaval compression (ACC), or supine hypotension syndrome, may lead to adverse fetal outcomes secondary to changes in maternal hemodynamics. Lateral tilt has been advocated to address ACC. We aim to determine the maternal position with the least effect on maternal hemodynamics. Term pregnant women scheduled for induction of labor were first placed in semi-recumbent (baseline), followed by supine, 15o and 30 o left lateral tilt (LLT), each for 20 minutes period, after which hemodynamic parameters were measuring using non-invasive cardiac output monitor NICOM. Friedman ANOVA with Dunn’s test multiple comparison test were used for analysis. P<0.05 was considered statistically significant. Forty subjects were included (Table). Cardiac index (CI) significantly increased in the supine position compared with baseline (median [range]: 3.8 [2.8-5.2] vs 4.2 [2.9-5.9] L/min/m2). CI also increased in 15o and 30 o left lateral tilt but did not reach statistical significance (Figure). Compared with baseline, stroke volume index (SVI) significantly increased (baseline: 43.7 [31.0-65.0]; supine: 49.5 [34.0-77.0]; 15o LLT: 49.8 [34.0-70.0] and 30o LLT: 49.9 [32.0-66.0] ml/m2; P<0.05 for all; Figure) while maternal heart rate significantly decreased in all 3 positions (baseline: 88 [70-106], supine: 85[63-99], 15o LLT: 81 [61-98] and 30o LLT: 80.0 [61-96] bpm; P<0.05 for all). Stroke volume variation (SVV) significantly decreased in all 3 positions (baseline: 12.9 [8.0-18.0], supine: 11.6 [7.0-17.0], 15o LLT: 11.6 [6.0-20.0] and 30o LLT 11.5 [7.0-20.0] %; P<0.05 for all). Subgroup analysis for BMI above or below 30 Kg/m2 showed similar results. Compared to semi-recumbent position, supine followed by left tilt position led to improvements in maternal hemodynamic parameters. The improvement in SVV, a measure of hypovolemia, indicates an increase in venous return and upper-right shift in the Frank-Starling curve. It is best to avoid semi-recumbent position in term pregnancies.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Early hemodynamic assessment using NICOM in patients at risk of developing Sepsis immediately after emergency department triage

BackgroundOne factor leading to the high mortality rate seen in sepsis is the subtle, dynamic nature of the disease, which can lead to delayed detection and under-resuscitation. This study investigated whether serial hemodynamic parameters obtained from a non-invasive cardiac output monitor (NICOM) predicts disease severity in patients at risk for sepsis.MethodsProspective clinical trial of the NICOM device in a convenience sample of adult ED patients at risk for sepsis who did not have obvious organ dysfunction at the time of triage. Hemodynamic data were collected immediately following triage and 2 hours after initial measurement and compared in two outcome groupings: (1) admitted vs. dehydrated, febrile, hypovolemicdischarged patients; (2) infectious vs. non-infectious sources. Receiver operator characteristic (ROC) curves were calculated to determine whether the NICOM values predict hospital admission better than a serum lactate.Results50 patients were enrolled, 32 (64 %) were admitted to the hospital. Mean age was 49.5 (± 16.5) years and 62 % were female. There were no significant associations between changes in hemodynamic variables and patient disposition from the ED or diagnosis of infection. Lactate was significantly higher in admitted patients and those with infection (p = 0.01, p = 0.01 respectively). The area under the ROC [95 % Confidence Intervals] for lactate was 0.83 [0.64–0.92] compared to 0.59 [0.41–0.73] for cardiac output (CO), 0.68 [0.49–0.80] for cardiac index (CI), and 0.63 [0.36–0.80] for heart rate (HR) for predicting hospital admission.ConclusionsCO and CI, obtained at two separate time points, do not help with early disease severity differentiation of patients at risk for severe sepsis. Although mean HR was higher in those patients who were admitted, a serum lactate still served as a better predictor of patient admission from the ED.

Non-invasive Cardiac Output Monitoring in Neonates.

Circulatory monitoring is currently limited to heart rate and blood pressure assessment in the majority of neonatal units globally. Non-invasive cardiac output monitoring (NiCO) in term and preterm neonates is increasing, where it has the potential to enhance our understanding and management of overall circulatory status. In this narrative review, we summarized 33 studies including almost 2,000 term and preterm neonates. The majority of studies evaluated interchangeability with echocardiography. Studies were performed in various clinical settings including the delivery room, patent ductus arteriosus assessment, patient positioning, red blood cell transfusion, and therapeutic hypothermia for hypoxic ischemic encephalopathy. This review presents an overview of NiCO in neonatal care, focusing on technical and practical aspects as well as current available evidence. We discuss potential goals for future research.

Non-invasive electrical cardiometry cardiac output monitoring during prehospital helicopter emergency medical care: a feasibility study

PurposeIntroducing advanced hemodynamic monitoring might be beneficial during Helicopter Emergency Medical Service (HEMS) care. However, it should not increase the on-scene-time, it should be easy to use and should be non-invasive. The goal of this study was to investigate the feasibility of non-invasive cardiac output measurements by electrical cardiometry (EC) and the quality of the EC signal during pre-hospital care provided by our HEMS.MethodsA convenience sample of fifty patients who required HEMS assistance were included in this study. Problems with respect to connecting the patient, entering patient characteristics and measuring were inventoried. Quality of EC signal of the measurements was assessed during prehospital helicopter care. We recorded the number of measurements with a signal quality indicator (SQI) ≥ 80 and the number of patients having at least 1 measurement with a SQI ≥ 80. Furthermore, the SQI value distribution of the measurements within each patient was analysed.ResultsIn the experience of the attending HEMS caregivers application of the device was easy and did not result in increased duration of on-scene time. Patch adhesion was reported as a concern due to clammy skin in 22% of all cases. 684 measurements were recorded during HEMS care. In 47 (94%) patients at least 1 measurement with an SQI ≥ 80 was registered. Of all recorded measurements 5.8% had an SQI < 40, 11.4% had an SQI 40–59, 14.9% had a SQI between 60 and 79 and 67.8% had SQI ≥ 80.ConclusionCardiac output measurements are feasible during prehospital HEMS care with good quality of the EC signal. Monitoring was easy to use and quick to install. In our view it is an promising candidate for the prehospital setting. Further research is needed to determine its clinical value during clinical decision making.

Electrical velocimetry (ICON cardiometry) assessment of hemodynamic changes associated with different inflation pressures during pediatric thoracoscopic surgery: a pilot study

Background Advances in endoscopic equipment and techniques have led to the use of minimally invasive thoracic surgery in an increasing number of pediatric surgical procedures. Logically, thoracoscopic surgery and anesthesia can induce significant physiologic changes; here comes the importance of an accurate, noninvasive cardiac output (CO) monitor for early diagnosis and management for any significant complications.Aims This study aimed to assess the effect of different intrathoracic pressures (ITP; insufflation pressures 4, 5, and 6 mmHg) during thoracoscopic surgeries in neonates and infants on hemodynamics using electrical velocimetry (ICON) as a noninvasive monitoring technique.Patients and methods This prospective pilot study was conducted in Abu El-Reesh Children’s Hospital, Kasr Al-Ainy Hospital, Faculty of Medicine, Cairo University, from November 2019 to January 2020. After obtaining ethical committee approval (D-6-2019) and registering at www.clinicaltrials.gov with the number NCT04131699, and after obtaining the consent of parents/legal guardians, 12 neonates and infants who presented for thoracoscopic surgery and met our selection criteria were included in the study. After standard premedication, monitoring, and anesthesia induction, for electrical velocimetry, an ‘ICON CARDIOTRONIC, OSYPKA MEDICAL’ continuous noninvasive CO monitor was attached to the patients according to the manufacturer’s instructions in neonates and infants. All patients’ data, including sex, height, and weight, were entered into the device, which estimated cardiovascular parameters at a 20-beat moving average recorded every 10 s. Cardiac index, CO, stroke volume, noninvasive arterial blood pressure, and heart rate readings had been taken in every patient. Records were taken before inflation of the chest as a baseline reference, 1 min after inflation of the chest as the ITP reaches 4 mmHg, then the ITP was increased to 5 mmHg, and the readings were taken after an extra 1 min. Finally, the ITP was increased to 6 mmHg, and the readings were taken after an additional 1 min.Results A total of 14 patients were screened for eligibility; of them, two patients were excluded for not meeting the inclusion criteria, and 12 patients were included. The median (interquartile range) age of patients was 4.5 (3–28) days. Sex distribution was equal (six males and six females). The cardiac index showed no significant increase with raising the pleural pressure (PP) by CO2 insufflation and postdeflation in comparison with baseline (preinsufflation). The CO showed no significant increase with raising the PP by CO2 insufflation in comparison with baseline (preinsufflation). Mean arterial blood pressure showed no significant change with gradual increase in PP and after deflation in comparison with preinflation readings; however, heart rate showed significant decrease after deflation in comparison with baseline (preinsufflation).Conclusion Hemodynamic stability was maintained during thoracoscopic surgery in neonates as measured by ICON. Further studies including systemic vascular resistance need to be done to give more explanation about hemodynamic affection during positive PP inflation. Moreover, different age groups, different patients’ positions, and patients with cardiac and pulmonary lesions need to be included to assess the various effects of pleural insufflation on these populations.

Basic hemodynamics and noninvasive cardiac output (Bioimpedance ICON Cardiometer): A diagnostic reliability during percutaneous nephrolithotomy bleeding under spinal anesthesia

ABSTRACT Background: To investigate reliability of Bio-impedance Cardiometer parameters in comparison with basic non-invasive parameters for early detection of haemodynamic changes during percutaneous nephrolithotomy (PNL) under spinal anesthesia. Methods: Forty patients were enrolled. Basal and 10-min interval parameters were recorded, included systolic blood pressure, mean arterial blood pressure, heart rate, O2 saturation and bio-impedance parameters. According to blood loss as measured by haemoglobin HB level, patients were divided into two groups; significant blood loss group > 20% from basal HB were compared with non-significant loss group. Results: Significant blood loss included 14 (35%) patients while other group included 26 (65%) patients. No difference was detected in demographics, basic non-invasive and bio-impedance cardiometer parameters either at basal values or at minute-120. No difference was detected in recorded data per 10-min interval in both groups throughout procedure except for heart rate and systolic time ratio (STR). STR changes were noticed 20 minutes prior to HR changes (at 80 minutes and 100 min, respectively). Mean±SD of STR at minute-80 was higher in group of significant blood loss (0.44 ± 0.07 Vs 0.38 ± 0.05, P 0.018). HR started to be significantly higher at minute-100 (87.5 ± 13 Vs.78.6 ± 12, P 0.05). Conclusions: STR is a more reliable tool than MBP and HR for early detection of haemodynamic collapse in case of non-measurable bleeding during PNL. STR should be integrated as a routine monitoring tool during PNL.

Cardiopulmonary Response to Exercise at High Altitude in Adolescents with Congenital Heart Disease

Objective: To extend our knowledge on tolerance of acute high-altitude exposure and hemodynamic response to exercise in adolescents with congenital heart disease (AscCHD) without meaningful clinical or functional restriction. Methods: A symptom limited cardiopulmonary exercise stress test and a non-invasive cardiac output measurement during steady state exercise were performed at 540 m and at 3454 m a.s.l. Symptoms of acute mountain sickness were noted. Results: We recruited 21 healthy controls and 16 AscCHD (59% male, mean age 14.7 ± 1.1 years). Three subjects (2 controls, 1 AscCHD) presented light symptoms of acute mountain sickness (dizziness and headache). During the symptom limited exercise test at lowland, control subjects showed a significantly higher power to weight index (3.5 ± 0.6 W/kg vs. 3.0 ± 0.7 W/kg, p < 0.001), heart rate (188.8 ± 10.4 1/min vs. 179.4 ± 13.1 1/min, p < 0.050) and ventilation (92.8 ± 22.9 l/min vs. 75.4 ± 18.6 l/min,

Cardiopulmonary Hemodynamic Profile Predicts Mortality After Transcatheter Tricuspid Valve Repair in Chronic HeartFailure.

This study was designed to assess hemodynamic changes in response to transcatheter tricuspid valve edge-to-edge repair (TTVR) and to identify hemodynamic predictors associated with mortality. Severe tricuspid regurgitation (TR) is associated with high mortality. TTVR effectively alleviates heart failure symptoms, but comprehensive hemodynamic characterization of patients undergoing TTVR is currently lacking. This international, multicenter study included 236 patients undergoing TTVR. Data from clinical assessment, echocardiography, intraprocedural right heart catheterization, and noninvasive cardiac output measurement were analyzed. Hemodynamic predictors for mortality were identified using linear Cox regression analysis and were used for stratification of patients with subsequent analysis of survival time. Patients (median age 78 years, 53% women) were symptomatic (89% in New York Heart Association functional class III or IV) because of severe TR (grade≥3+ in 100%). TTVR significantly reduced TR at discharge (grade≥3+ in 16%; p<0.001), with a corresponding 19% reduction of the right atrial v wave (21mmHg vs. 16mmHg; p<0.001) and an improvement in cardiac output (from 3.5 to 4.0 l/min; p<0.01). Invasive mean pulmonary artery pressure, transpulmonary gradient, pulmonary vascular resistance, and right ventricular stroke work were significant predictors of 1-year mortality (p<0.05 for all). Hemodynamic stratification by mean pulmonary artery pressure and transpulmonary gradient best predicted 1-year survival (p<0.001). Although patients with pre-capillary dominant pulmonary hypertension showed an unfavorable prognosis (1-year survival 38%), patients without or with post-capillary pulmonary hypertension had favorable outcome (1-year survival 92% or 78%, respectively). Invasive assessment of cardiopulmonary hemodynamic status predicts survival after TTVR. Invasivehemodynamic characterization may help identify patients profiting most from TTVR.

Effect of Endovascular Treatment on Systemic Vascular Resistance in Patients with Lower-Limb Peripheral Artery Disease.

Objective: Endovascular treatment (EVT) for lower-limb peripheral artery disease patients reduces blood pressure (BP) and improves prognosis. This study retrospectively examined hemodynamics during EVT to clarify the mechanism.Materials and Methods: Systemic vascular resistance (SVR) was measured using a noninvasive continuous cardiac output monitoring system during EVT. Furthermore, ankle brachial index was measured before and after EVT.Results: The study included 88 lesions of 56 patients (hypertension in 98%). SVR significantly decreased from 2409.1±746.8 dynes·s·cm−5 to 2033.7±635.0 dynes·s·cm−5 (p<0.0001). The difference in SVR before and after EVT was significantly greater in the Fontaine IV group than in the Fontaine IIa group (554.7±406.6 dynes·s·cm−5 vs. 312.9±245.7 dynes·s·cm−5, p=0.0151). The change in SVR was correlated with a change in mean BP in the upper limb (p=0.0026). When the change in pressure gradient between the upper limb and the diseased lower limb was large, mean BP of the upper limb significantly decreased (p=0.0022).Conclusion: EVT can reduce SVR and BP by canceling the pressure gradient between central BP and diseased lower-limb BP.