Cardiometry Research Articles

Safety during interhospital helicopter transfer of ventilated COVID-19 patients. No clinical relevant changes in vital signs including non-invasive cardiac output

BackgroundDuring the COVID-19 pandemic in The Netherlands, critically ill ventilated COVID-19 patients were transferred not only between hospitals by ambulance but also by the Helicopter Emergency Medical Service (HEMS). To date, little is known about the physiological impact of helicopter transport on critically ill patients and COVID-19 patients in particular. This study was conducted to explore the impact of inter-hospital helicopter transfer on vital signs of mechanically ventilated patients with severe COVID-19, with special focus on take-off, midflight, and landing.MethodsAll ventilated critically ill COVID-19 patients who were transported between April 2020 and June 2021 by the Dutch ‘Lifeliner 5’ HEMS team and who were fully monitored, including noninvasive cardiac output, were included in this study. Three 10-min timeframes (take-off, midflight and landing) were defined for analysis. Continuous data on the vital parameters heart rate, peripheral oxygen saturation, arterial blood pressure, end-tidal CO2 and noninvasive cardiac output using electrical cardiometry were collected and stored at 1-min intervals. Data were analyzed for differences over time within the timeframes using one-way analysis of variance. Significant differences were checked for clinical relevance.ResultsNinety-eight patients were included in the analysis. During take-off, an increase was noticed in cardiac output (from 6.7 to 8.2 L min−1; P < 0.0001), which was determined by a decrease in systemic vascular resistance (from 1071 to 739 dyne·s·cm−5, P < 0.0001) accompanied by an increase in stroke volume (from 88.8 to 113.7 mL, P < 0.0001). Other parameters were unchanged during take-off and mid-flight. During landing, cardiac output and stroke volume slightly decreased (from 8.0 to 6.8 L min−1, P < 0.0001 and from 110.1 to 84.4 mL, P < 0.0001, respectively), and total systemic vascular resistance increased (P < 0.0001). Though statistically significant, the found changes were small and not clinically relevant to the medical status of the patients as judged by the attending physicians.ConclusionsInterhospital helicopter transfer of ventilated intensive care patients with COVID-19 can be performed safely and does not result in clinically relevant changes in vital signs.

The Role of Electrical Cardiometry in Paediatrics and Neonatal Anaesthesia and Intensive Care: A Narrative Review

The Role of Electrical Cardiometry in Paediatrics and Neonatal Anaesthesia and Intensive Care: A Narrative Review

Validation of stroke volume variation assessed by electrical cardiometry to predict fluid responsiveness in patients undergoing coronary artery bypass surgery after closure of the sternum: an observational study

Validation of stroke volume variation assessed by electrical cardiometry to predict fluid responsiveness in patients undergoing coronary artery bypass surgery after closure of the sternum: an observational study

In-Silico Evaluation of Anthropomorphic Measurement Variations on Electrical Cardiometry in Neonates.

Non-invasive cardiac output methods such as Electrical Cardiometry (EC) are relatively novel assessment tools for neonates and they enable continuous monitoring of stroke volume (SV). An in-silico comparison of differences in EC-derived SV in relation to preset length and weight was performed. EC (ICON, Osypka Medical) was simulated using the “demo” mode for various combinations of length and weight representative of term and preterm infants. One-centimetre length error resulted in a SV-change of 1.8–3.6% (preterm) or 1.6–2.0% (term) throughout the tested weight ranges. One-hundred gram error in weight measurement resulted in a SV-change of 5.0–7.1% (preterm) or 1.5–1.8% (term) throughout the tested length ranges. Algorithms to calculate EC-derived SV incorporate anthropomorphic measurements. Therefore, inaccuracy in physical measurement can impact absolute EC measurements. This should be considered in the interpretation of previous findings and the design of future clinical studies of EC-derived cardiac parameters in neonates, particularly in the preterm cohorts where a proportional change was noted to be greatest.

Signal Quality of Electrical Cardiometry and Perfusion Index in Very Preterm Infants

Objective: The use of noninvasive monitoring of neonatal hemodynamics is increasing in neonatal care. Methods include noninvasive cardiac output estimated by electrical cardiometry (EC) and peripheral perfusion as perfusion index (PI) using pulse oximetry. Our aim was to evaluate the feasibility to continuously monitor preterm infants with EC and PI during the first 2 postnatal days and the effects of averaging EC data in signal quality (SigQ) analysis. Design: Prospective observational study. Setting: Tertiary neonatal academic hospital. Patients: Preterm infants <32 weeks gestation from birth until 48 h. Main Outcome Measures: Continuous EC and PI measurements. Feasibility was quantified as the time with high SigQ, classified using SigQ index in EC and exception codes in PI. Our predefined threshold for good feasibility was minimum of 24 h with high SigQ for both. Results: Twenty-two preterm infants (median [IQR] gestational age 28 + 6 (26 + 0, 30 + 4) weeks + days, birth weight 960 [773, 1,500] g) were included. We recorded a minimum of 24 h with high SigQ in 14 infants for EC (unaveraged data) and 22 infants for PI measurements. The median (range) % of recording time with high SigQ was 74% (50%, 88%) for EC and 94% (82%, 96%) for PI. Using 1 minute averaging for EC data resulted in an increase of infants with minimum 24 h of high SigQ to 21 infants. Conclusions: EC and PI monitoring are feasible in preterm infants within the first 48 h, but SigQ remains problematic for EC. Signal dropout is masked in averaged EC values.

Prognostic value of baseline carotid blood flow in critically ill children with septic shock.

Hemodynamic monitoring and cardiac output (CO) assessment in the ICU have been trending toward less invasive methods. Carotid blood flow (CBF) was suggested as a candidate for CO assessment. The present study aimed to test the value of carotid artery ultrasound analysis in prediction of mortality in pediatric patients with septic shock. Forty children with septic shock were included in the study. Upon admission, patients were subjected to careful history taking and thorough clinical examination. The consciousness level was assessed by the Glasgow Coma Scale (GCS). Laboratory assessment included complete blood count, C-reactive protein, arterial blood gases, serum electrolytes, and liver and kidney function tests. Electrical cardiometry was used to evaluate hemodynamic parameters. Patients were also subjected to transthoracic 2-D echocardiography. CBF was evaluated using GE Vivid S5 ultrasound device through dedicated software. At the end of study, 14 patients (35.0%) died. It was found that survivors had significantly higher CBF when compared non-survivors [median (IQR): 166.0 (150.0-187.3) versus 141.0 (112.8-174.3), p = 0.033]. In addition, it was noted that survivors had longer ICU stay when compared with non-survivors [16.5 (9.8-31.5) versus 6.5 (3.0-19.5) days, p = 0.005]. ROC curve analysis showed that CBF could significantly distinguish survivors from non-survivors [AUC (95% CI): 0.3 (0.11-0.48), p = 0.035] (Fig 2). Univariate logistic regression analysis identified type of shock [OR (95% CI): 28.1 (4.9-162.4), p<0.001], CI [OR (95% CI): 0.6 (0.43-0.84), p = 0.003] and CBF [OR (95% CI): 0.98 (0.96-0.99), p = 0.031]. However, in multivariate analysis, only type of shock significantly predicted mortality. CBF assessment may be a useful prognostic marker in children with septic shock.

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.

Predictive and prognostic roles of electrical cardiometry in noninvasive assessments of community‐acquired pneumonia patients with dyspnoea

Background:Thoracic impedance monitoring able to detect pneumonia in the very early phase of emerging infiltration prior the patient developed remarkable clinical symptoms. However, no studies have yet been conducted on the usefulness of predicting pneumonia patient outcomes with parameters from electrical cardiometry.Objective:In the present study, we evaluated whether parameters measured by electrical cardiometry can predict clinical outcomes including mortality and length of hospital stay in patients with community‐acquired pneumonia in the emergency department.Methods:Demographic, clinical and laboratory data were collected from enrolled patient. Electrical cardiometry monitoring was done with a portable electrical cardiometry device connected to the body surface sensor. The continuous data from electrical cardiometry were recorded, and parameters were stored on the electrical cardiometry device automatically and then the data were downloaded for further analysis.Results:Thoracic fluid content has shown to be significantly higher in the intensive care unit admission group and in the death group. Expired patients had higher value of thoracic fluid content at emergency department admission. From a receiver operating characteristics curve analysis, thoracic fluid content presented fair AUC values of 0.72 (95% confidence interval, 0.71–0.74) and 0.73 (0.62–0.82) for prediction of 28‐day mortality and intensive care unit admission. Arterial partial pressure of oxygen (PaO2), the ratio of arterial partial pressure of oxygen to inspired oxygen fraction (PaO2/FiO2 ratio) also showed excellent AUC value for prediction of mortality and intensive care unit admission.Conclusion:Electrical cardiometry monitoring indicated new possibility to anticipate prognosis of community‐acquired pneumonia patient. Increased thoracic fluid content value would relate worse outcome of the patient like mortality and intensive care unit admission. Electrical cardiometry monitoring allows real‐time measurements of thoracic fluid content without restraining the patient or invasive catheters.

Plethysmography Variability Index and Stroke Volume Variation Changes in Relation to Central Venous Pressure Changes During Living Related Donor Right Hepatotomy: A Diagnostic Test Accuracy.

During donor hepatectomy, we investigated (1) the Electrical Cardiometry associations and agreements between noninvasive plethysmography variability index and noninvasive stroke volume variation, (2) their association with central venous pressure, and (3) their ability to monitor intraoperative changes and discriminate donors with increased blood loss. A diagnostic test accuracy was applied among donors (American Society of Anesthesiologists classification I). Data were recorded at 10 minutes after anesthesia induction, hourly during dissection, after resection, and at end of surgery. Crystalloids were restricted during resection to reduce central venous pressure but were otherwise infused to maintain mean invasive arterial blood pressure >60 mm Hg and urine output >0.5 mL/kg/h. All 34 donors were related. Sons or daughters represented 58.8% (median age 26.0 years [interquartile range, 21.0-34.0]). Median values (with interquartile ranges) were anesthesia time, 7.5 hours (7.0-8.0); blood loss, 400 mL (400.0-500.0); infused acetated Ringer solution, 4000.0 mL (3500.0-4500.0); colloids, 250.0 mL (0-500.0); and urine output, 1.4 mL/kg/h (1.30-1.7). No blood products were transfused. Central venous pressure showed negligible negative correlations for both plethysmography variability index and stroke volume variation. Plethysmography variability index showed negligible correlation and poor agreement with stroke volume variation (P < .001, with intraclass correlation = 0.213 and a relatively wide bias; 95% CI, 0.03-0.37). All 3 methods reflected a state of normovolemia despite fluid restriction during resection and were unable to discriminate donors with increased blood loss (>400 mL). Plethysmography variability index and stroke volume variation showed negligible correlation and poor agreement with central venous pressure. Transfusion-free dissection was possible despite normovolemia, with median values of 8 mm Hg central venous pressure, 10% stroke volume variation, and 12% plethysmography variability index. Plethysmography variability index and stroke volume variation were unable to discriminate donors with increased blood loss.

A pilot study of short-term hemodynamic effects of negative pressure ventilation in chronic obstructive pulmonary disease assessed using electrical cardiometry.

BackgroundPulmonary rehabilitation combined with negative pressure ventilation (NPV) demonstrated benefits in patients with chronic obstructive pulmonary disease (COPD). The effect of NPV remains unknown. This study aims to clarify the short‐term response of the hemodynamic outcome of NPV in patients with COPD undergoing pulmonary rehabilitation program by electrical cardiometry.MethodsThis is an observational retrospective study of COPD patients who had been treated in a pulmonary rehabilitation unit with NPV between January 2018 and December 2019 that were enrolled to analyze the hemodynamic outcomes.ResultsThirty patients with COPD that were undergoing a pulmonary rehabilitation program and were regularly receiving NPV were enrolled. Cardiac output (p < .001) and heart rate (p < .001) showed a significant decrease after NPV. Stroke volume did not demonstrate significant change (p = .15). There was a significant decrease in thoracic fluid content (p = .016) and a significant increase in stroke volume variation (p = .038) systemic vascular resistance (p < .001) and left ventricular ejection time (p < .001). Other hemodynamic parameters were all comparable before and after NPV.ConclusionsNegative pressure ventilation demonstrated an impact on hemodynamics in patients with chronic obstructive pulmonary disease undergoing pulmonary rehabilitation. Electrical cardiometry is a feasible method of determining the hemodynamic effects of negative pressure ventilation. Thoracic fluid content significantly decreased immediately after the NPV.

Electrical Cardiometry and Cardiac Biomarkers in 24-h and 48-h Ultramarathoners

Our study aimed to (i) utilize novel electrical cardiometry and observe acute changes in cardiac biomarkers among 24-h and 48-h ultra-marathoners, and (ii) examine whether alterations in cardiac responses were associated with the average running speed of these participants. Twenty-four 24-h and sixteen 48-h ultra-marathoners were recruited. Electrical cardiometry in the 2 groups showed significant post-race drops in systolic pressure (24-h: p=0.001; 48-h: p=0.016) and rapid increases in heart rate (24-h, p=0.004; 48-h, p=0.001). Cardiac output increased in 48-h runners (p=0.012) and stroke volume decreased in 24-h runners (p=0.009) at post-test. Six of 20 (30%) 24-h and 4 of 16 (25%) 48-h runners had high-sensitivity troponin T values above the reference interval after the races. N-terminal proB-type natriuretic peptide levels showed a 15-fold increase in 24-h runners and a 10-fold increase in 48-h runners at post-race. There was a positive correlation between delta N-terminal proB-type natriuretic peptide and running mileage (rs=0.629, p=0.003) in 24-h ultra-marathoners. In conclusion, stroke volume and cardiac output showed inconsistent changes between the 2 groups. Average running speed has a significant effect on post-exercise elevation in cardiac biomarkers.

Objective Assessment of Physiologic Alterations Associated With Hemodynamically Significant Patent Ductus Arteriosus in Extremely Premature Neonates.

Delay in closure of ductus arteriosus in postnatal life may lead to serious consequences and complications in an extremely premature neonate secondary to hemodynamic alterations in regional blood flow pattern in various organs. Despite the widespread recognition amongst neonatologists to identify a hemodynamically significant patent ductus arteriosus (hsPDA) early in the postnatal course, there is lack of consensus in its definition and thus the threshold to initiate treatment. Echocardiographic assessment of PDA shunt size and volume combined with neonatologists' impression of clinical significance is most frequently used to determine the need for treatment of PDA. Common clinical signs of hsPDA utilized as surrogate for decreased tissue perfusion may lag behind early echocardiographic signs. Although echocardiogram allows direct assessment of PDA shunt and hemodynamic alterations in the heart, it is limited by dependence on pediatric cardiologist availability, interobserver variation and isolated time point assessment. Electrical cardiometry (EC) is a non-invasive continuous real time measurement of cardiac output by applying changes in thoracic electrical impedance. EC has been validated in preterm newborns by concomitant transthoracic echocardiogram assessments and may be beneficial in studying changes in cardiac output in premature newborns with hsPDA. Alterations in perfusion index derived from continuous pulse oximetry monitoring has been used to study changes in cardiac performance and tissue perfusion in infants with PDA. Near infrared spectroscopy (NIRS) has been used to objectively and continuously assess variations in renal, mesenteric, and cerebral oxygen saturation and thus perfusion changes due to diastolic vascular steal from hsPDA in preterm neonates. Doppler ultrasound studies measuring resistive indices in cerebral circulation indicate disturbance in cerebral perfusion secondary to ductal steal. With recent trends of change in practice toward less intervention in care of preterm newborn, treatment strategy needs to be targeted for select preterm population most vulnerable to adverse hemodynamic effects of PDA. Integration of these novel ways of hemodynamic and tissue perfusion assessment in routine clinical care may help mitigate the challenges in defining and targeting treatment of hsPDA thereby improving outcomes in extremely premature neonates.

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.

Goal Directed Fluid Therapy based on Stroke Volume Variation and Oxygen Delivery Index using Electrical Cardiometry in patients undergoing Scoliosis Surgery

ABSTRACT Background: The primary outcome was to evaluate whether goal-directed fluid therapy (GDFT) protocol, established on stroke volume variation (SVV) and oxygen delivery index (DO2I) using electrical cardiometry (EC) monitor, would be effective in reducing perioperative packed red blood cells (RBCs) transfusion, whereas the secondary outcome was to compare the effects of GDFT with liberal fluid therapy (LFT) as regards total amount of fluids transfused, perioperative complications, and postoperative length of ICU and total hospital stay. Settings and Design: This study was a prospective randomized controlled clinical trial. Methods: The study was carried out on 48 patients scheduled for scoliosis surgery. Twenty-four patients, whose intraoperative fluid administration was managed with the GDFT protocol, were compared with 24 patients who received a liberal intraoperative fluid therapy. The proposal and raw data were registered on PACTR as PACTR202007901764021. Results: Patients in group II received less units of packed RBCs (P < 0.001) and a lower volume of intraoperative crystalloids (P < 0.001). They had significantly lower serum lactate levels 2 h after induction (P = 0.033), at the end of surgery (P = 0.001) and 2 h postoperatively (P < 0.001) with shorter ICU stay (P < 0.001), total hospital length of stay (P < 0.001), and faster return of bowel function (P = 0.005). Conclusion:: Application of a GDFT protocol, established o SVV and DO2I using EC monitor in patients undergoing scoliosis surgery, can lead to reduced packed RBCs transfusions, reduced total crystalloid volume infusions, less postoperative pulmonary complications, shorter ICU, and total hospital stay with faster return of gastrointestinal function. Abbreviations: GDFT: goal-directed fluid therapy; SVV: stroke volume variation; DO2I: oxygen delivery index; EC: electrical cardiometry; LFT: liberal fluid therapy; CI: cardiac index; RBCs: red blood cells; CO: cardiac output; IVC: inferior vena cava; CVP: central venous pressure; MAP: mean arterial pressure; CaO2: arterial oxygen content; UOP: urine output; ASA: American Society of Anesthesiologist; BMI: body mass index; ROC: receiver operating characteristic; AUC: area under the curve; FFP: fresh frozen plasma

Cerebral oxygenation and circulatory parameters during pressure-controlled vs volume-targeted mechanical ventilation in extremely preterm infants.

Respiratory distress syndrome (RDS) is the most common cause of respiratory failure of infants born prematurely with very low birth weight (VLBW). Essential elements of RDS management include ventilatory support and endotracheal administration of a surfactant. To assess the effect of volume-targeted compared to pressure-controlled mechanical ventilation (MV) on circulatory parameters and cerebral oxygenation StO2 in extremely preterm infants. This prospective, cross-over trial enrolled neonates born before 28 weeks of gestation. The patients were ventilated for 3 h in pressure-controlled assist-control (PC-AC) mode, followed by 3 h of volume-guarantee assist-control ventilation (VG-AC). Pulse oximetry (saturation (SpO2) and heart rate (HR)), near-infrared spectroscopy (NIRS), StO2, and electrical cardiometry (EC) were used in monitoring of the patients. Twenty preterm infants with a mean gestational age of 26 weeks were studied. The patients' mean postnatal age was 7.7 days. The SpO2 values and HR were comparable during PC-AC and VG-AC. The mean values of peak inspiratory pressure (PIP), mean airway pressure (MAP) and expiratory tidal volume (VTE) were lower, while the respiratory rate (RR) was higher during PC-VG. There were no significant differences in the mean values of StO2, but based on a comparison of the standard deviations (SD) the StO2 variability was significantly lower during VG-AC. The circulatory parameters were comparable. The StO2 is more stable during VG than PC ventilation. These findings support the use of VG mode in premature infants.

Noninvasive Cardiac Output Monitoring Using Electrical Cardiometry and Outcomes in Critically Ill Children.

Cardiac output (CO) measurement is an important element of hemodynamic assessment in critically ill children and existing methods are difficult and/or inaccurate. There is insufficient literature regarding CO as measured by noninvasive electrical cardiometry (EC) as a predictor of outcomes in critically ill children. We conducted a retrospective chart review in children <21 years, admitted to our pediatric intensive care unit (PICU) between July 2018 and November 2018 with acute respiratory failure and/or shock and who were monitored with EC (ICON monitor). We collected demographic information, data on CO measurements with EC and with transthoracic echocardiography (TTE), and data on ventilator days, PICU and hospital days, inotrope score, and mortality. We analyzed the data using Chi-square and multiple linear regression analysis. Among 327 recordings of CO as measured by EC in 61 critically ill children, the initial, nadir, and median CO (L/min; median [interquartile range (IQR)]) were 3.4 (1.15, 5.6), 2.39 (0.63, 4.4), and 2.74 (1.03, 5.2), respectively. Low CO as measured with EC did not correlate well with TTE ( p = 0.9). Both nadir and mean CO predicted ventilator days ( p = 0.05 and 0.01, respectively), and nadir CO was correlated with peak inotrope score (correlation coefficient of -0.3). In our cohort of critically ill children with respiratory failure and/or shock, CO measured with EC did not correlate with TTE. Both nadir and median CO measured with EC predicted outcomes in critically ill children.

Effect of etomidate on systemic and regional cerebral perfusion in neonates and infants with congenital heart disease: A prospective observational study.

Neonates and infants with congenital heart disease undergoing general anesthesia have an increased risk for critical cardiovascular events. Etomidate produces very minimal changes in hemodynamic parameters in older children with congenital heart disease. There is a lack of studies evaluating the effect of etomidate on systemic and regional cerebral perfusion in neonates and infants with congenital heart disease. The aim of this prospective observational study was to evaluate the effect of etomidate on systemic and regional cerebral perfusion in neonates and infants with congenital heart disease. In fifty infants aged 0-11months (24% neonates n=12) with congenital heart disease, mean arterial blood pressure, cardiac index using electrical cardiometry, and regional cerebral oxygen saturation using near-infrared spectroscopy were measured at baseline and 1, 3, 5, and 10minutes after induction by 0.4mgkg-1 etomidate. Hypotension was defined as a mean arterial blood pressure under 35mm Hg and cerebral desaturation as a regional cerebral oxygen saturation of less than 80% of baseline. Mean arterial blood pressure, cardiac index, and regional cerebral oxygen saturation remained stable above the predefined limits. Mean arterial blood pressure decreased slightly within a physiological range after 3minutes (P=.005, 95% CI:-5.9 to -1.0). No significant change in cardiac index could be observed. Etomidate 0.4mgkg-1 does not impair systemic or regional cerebral perfusion in neonates or infants with congenital heart disease.

Improved Exercise Tolerance, Oxygen Delivery, and Oxygen Utilization After Transcatheter Aortic Valve Implantation for Severe Aortic Stenosis

BackgroundTranscatheter aortic valve implantation (TAVI) represents an effective therapeutic procedure, particularly in patients with severe aortic stenosis. We hypothesized that the decreased afterload induced by TAVI would improve exercise capacity by enhancing oxygen uptake in working muscles. MethodsA standardized exercise test was performed in patients with severe aortic stenosis the day before TAVI and within 5 days thereafter. The main study endpoint was the workload achieved during a 5-minute standardized exercise test. Using electrical cardiometry and near-infrared spectroscopy, we explored and compared the changes in cardiac index (CI), as well as muscular and cerebral tissue oximetry, during the 2 exercise tests. ResultsThirty patients completed the study protocol. Compared with the pre-TAVI period, patients achieved a higher median workload after TAVI (316 Joules [interquartile range {IQR}: 169–494] vs 190 Joules [IQR: 131–301], P = 0.002). Baseline CI increased from 2.5 l/min per m2 (IQR: 2.1–2.9) to 2.9 l/min per m2 (IQR: 2.5–3.2; P = 0.009), whereas CI at the end of the exercise test increased from 4.5 l/min per m2 (IQR: 3.4–5.3) to 4.7 l/min per m2 (3.4–6.4; P = 0.019). At the end of the exercise test, cerebral tissue oximetry increased from 70% (IQR: 65–72) to 74% (IQR: 66–78), and muscle tissue oximetry increased from 62% (IQR: 58–65) to 71% (65–74; P = 0.046 and P < 0.001, respectively). ConclusionsEarly improvement of exercise capacity after TAVI is associated with increased CI and better oxygen utilization in the brain and skeletal muscles.

Appropriate delivery method for cardiac disease pregnancy based on noninvasive cardiac monitoring.

Background There are numerous significant physiological changes occurring in circulation during labor. To detect these rapid hemodynamic changes, invasive and intermittent measurement techniques are not reliable. To suggest a suitable delivery method for pregnancy with cardiac disease, this study analyzed how each delivery method influences cardiac function using a noninvasive and continuous measurement technique. Methods A prospective study was accomplished at the National Cerebral and Cardiovascular Center in Japan from October 1, 2014, to November 30, 2018. The classification of the healthy heart pregnant women was according to the delivery method: vaginal delivery (VD) without epidural anesthesia, VD with epidural anesthesia, and caesarean section (CS). The hemodynamic parameters cardiac index (CI), stroke volume index (SI), and heart rate (HR) were evaluated regularly throughout delivery by noninvasive electrical cardiometry monitor. Results Ten cases were examined for each group. CI and HR were significantly increased before VD, while the increase in CI and HR was mild in the epidural group in comparison to the nonepidural group. SI was increased toward the delivery in the epidural group, and it was constant in the nonepidural group. However, there was no alteration in the level of outcomes of the two groups. In CS, SI increased and HR decreased before delivery. After delivery, SI continued to increase, while HR did not change but CI increased. Conclusion In VD, the increase in venous circulation according to the autotransfusion is managed by increasing HR. By epidural anesthesia, the increase in HR was suppressed and SI was increased. However, as epidural anesthesia increases the vascular capacity, the level of SI outcome was comparable. In CS, the HR was decreased because of the spinal anesthesia and the SI was increased because of many factors like hydration. As there are many factors to control in CS, VD with epidural anesthesia will be the first preference for most cardiac patients.

Thoracic fluid content: a novel parameter for predicting failed weaning from mechanical ventilation

BackgroundWeaning of patients from the mechanical ventilation remains one of the critical decisions in intensive care unit. This study aimed to evaluate the accuracy of thoracic fluid content (TFC) as a predictor of weaning outcome.MethodsAn observational cohort study included 64 critically ill surgical patients who were eligible for extubation. Before initiating the spontaneous breathing trial, the TFC was measured using the electrical cardiometry technology. Patients were followed up after extubation and divided into successful weaning group and failed weaning group. Both groups were compared according to respiratory and cardiovascular parameters. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of TFC to predict weaning outcome.ResultsThe number of successfully weaned patients was 41/64 (64%). Twenty (31%) patients had impaired cardiac contractility, and of them, 13/20 (64%) patients were successfully extubated. Both groups, successful weaning group and failed weaning group, were comparable in most of baseline characteristics; however, the TFC was significantly higher in the failed weaning group compared to the successful weaning group. The area under the ROC curves (AUCs) showed moderate predictive ability for the TFC in predicting weaning failure (AUC [95% confidence interval] 0.69 [0.57–0.8], cutoff value > 50 kΩ−1), while the predictive ability of TFC was excellent in the subgroup of patients with ejection fraction < 40% (AUC [95% confidence interval 0.93 [0.72–1], cutoff value > 50 kΩ−1).ConclusionsThoracic fluid content showed moderate ability for predicting weaning outcome in surgical critically ill patients. However, in the subgroup of patients with ejection fraction less than 40%, TFC above 50 kΩ−1 has an excellent ability to predict weaning failure.