Non-invasive Cardiac Output Monitoring Research Articles

Value of carotid corrected flow time or changes value of FTc could be more useful in predicting fluid responsiveness in patients undergoing robot-assisted gynecologic surgery: a prospective observational study.

The aim of this study was to evaluate the ability of point-of-care Doppler ultrasound measurements of carotid corrected flow time and its changes induced by volume expansion to predict fluid responsiveness in patients undergoing robot-assisted gynecological surgery. In this prospective study, carotid corrected flow time was measured using Doppler images of the common carotid artery before and after volume expansion. The stroke volume index at each time point was recorded using noninvasive cardiac output monitoring with MostCare. Of the 52 patients enrolled, 26 responded. The areas under the receiver operating characteristic curves of the carotid corrected flow time and changes in carotid corrected flow time induced by volume expansion were 0.82 and 0.67, respectively. Their optimal cut-off values were 357 and 19.5 ms, respectively. Carotid corrected flow time was superior to changes in carotid corrected flow time induced by volume expansion for predicting fluid responsiveness in this population.

Noninvasive Cardiac Output Monitoring by Electrical Cardiometry with Transthoracic Echocardiography in Postoperative Paediatric Cardiac Surgical Patients: Comment.

Noninvasive Cardiac Output Monitoring by Electrical Cardiometry with Transthoracic Echocardiography in Postoperative Paediatric Cardiac Surgical Patients: Comment.

A comparative study between serum lactate level versus change in end tidal carbon dioxide level regarding assessment of hemodynamic instability in intensive care unit patients after cardiac surgeries

ABSTRACT Background After cardiac surgeries, elevated lactate level is used as a marker of tissue hypoperfusion. Still, there is a search for other helpful markers of hemodynamic instability. Exhaled carbon dioxide has been recently studied as marker of cardiac output and tissue perfusion and may be considered a reliable alternative which is more convenient and real time. Objectives The main aim is to correlate between end tidal carbon dioxide (ETCO2) and serum lactate level as indicators of hemodynamic instability in intensive care unit (ICU) patients after cardiac surgeries. The secondary objective is to correlate the measured parameters to the changes in the vital data and the resuscitation efforts. Methods A prospective cohort study that enrolled 51 adult patients admitted to ICU after cardiac surgeries. The serum lactate and ETCO2 values as well as vital data and vasopressor doses were recorded on admission to ICU, after 2 hours and after 6 hours. Results The study shows insignificant weak positive correlation between Lactate and ETCO2 levels at admission (r = 0.172, p value = 0.229), and insignificant negative weak correlation after 2 hours (r = -0.148, p value = 0.300) and after 6 hours (r = -0.235, p value = 0.096). Moreover, lactate level showed significant direct relation with the doses of vasopressors at admission, after 2 hours and after 6 hours postoperative (p value < 0.001 at all intervals). Whereas there was insignificant relation between ETCO2 and doses of vasopressors at all intervals (p value = 0.23, 0.4 and 0.18 respectively). Conclusion In post-cardiac surgery ICU patients we detected no statistically significant relation between serum lactate and ETCO2 as indicators of hemodynamic instability. The change in ETCO2 over a period of time has failed so far to be of a beneficial value as a non-invasive real-time cardiac output monitoring parameter. In addition, serum lactate had strong correlation with changes in vital signs and resuscitation efforts.

Validation of a noninvasive cardiac output monitor in maternal cardiac disease: comparison of NICOM and transthoracic echocardiogram

The physiological changes to the cardiovascular system during pregnancy are considerable and are more pronounced in those with cardiac disease. In the general population, noninvasive hemodynamic monitoring is a valid alternative to pulmonary artery catheterization, which poses risk in the pregnant population. There is limited data on noninvasive cardiac output monitoring in pregnancy as an alternative to pulmonary artery catheterization. We sought to compare transthoracic echocardiography with a noninvasive cardiac output monitor (NICOM, Cheetah Medical) in pregnant patients with and without cardiac disease. This was a prospective, open-label validation study that compared 2-dimensional transthoracic echocardiography with NICOM estimations of cardiac output in each trimester of pregnancy and the postpartum period. Participants with and without cardiac disease with a singleton gestation were included. NICOM estimations of cardiac output were derived from thoracic bioreactance and compared with 2-dimensional transthoracic echocardiography for both precision and accuracy. A mean percentage difference of ±30% between the 2 devices was considered acceptable agreement between the 2 measurement techniques. A total of 58 subjects were enrolled; 36 did not have cardiac disease and 22 had cardiac disease. Heart rate measurements between the 2 devices were strongly correlated in both groups, whereas stroke volume and cardiac output measurements showed weak correlation. When comparing the techniques, the NICOM device overestimated cardiac output in the control group in all trimesters and the postpartum period (mean percentage differences were 50.3%, 52.7%, 48.1%, and 51.0% in the first, second, and third trimesters and the postpartum period, respectively). In the group with cardiac disease, the mean percentage differences were 31.9%, 29.7%, 19.6%, and 35.2% for the respective timepoints. The NICOM device consistently overestimated cardiac output when compared with 2-dimensional transthoracic echocardiography at all timepoints in the control group and in the first trimester and postpartum period for the cardiovascular disease group. The physiological changes of pregnancy, specifically the mean chest circumference and total body water, may alter the accuracy of the cardiac output measurement by the NICOM device as they are currently estimated. Although NICOM has been validated for use in the critical care setting, there is insufficient data to support its use in pregnancy.

CAROTID ARTERY ULTRASOUND FOR ASSESSING FLUID RESPONSIVENESS IN PATIENTS UNDERGOING MECHANICAL VENTILATION WITH LOW TIDAL VOLUME AND PRESERVED SPONTANEOUS BREATHING.

Objective : This study aimed to investigate whether changes in carotid artery corrected flow time (ΔFTc bolus ) and carotid artery peak flow velocity respiratory variation (Δ V peak bolus ) induced by the fluid challenge could reliably predict fluid responsiveness in mechanically ventilated patients with a tidal volume < 8 mL/kg Predicted Body Weight while preserving spontaneous breathing. Methods : Carotid artery corrected flow time, Δ V peak, and hemodynamic data were measured before and after administration of 250 mL crystalloids. Fluid responsiveness was defined as a 10% or more increase in stroke volume index as assessed by noninvasive cardiac output monitoring after the fluid challenge. Results : A total of 43 patients with acute circulatory failure were enrolled in this study. Forty-three patients underwent a total of 60 fluid challenges. The ΔFTc bolus and Δ V peak bolus showed a significant difference between the fluid responsiveness positive group (n = 35) and the fluid responsiveness negative group (n = 25). Spearman correlation test showed that ΔFTc bolus and Δ V peak bolus with the relative increase in stroke volume index after fluid expansion ( r = 0.5296, P < 0.0001; r = 0.3175, P = 0.0135). Multiple logistic regression analysis demonstrated that ΔFTc bolus and Δ V peak bolus were significantly correlated with fluid responsiveness in patients with acute circulatory failure. The areas under the receiver operating characteristic curves of ΔFTc bolus and Δ V peak bolus for predicting fluid responsiveness were 0.935 and 0.750, respectively. The optimal cutoff values of ΔFTc bolus and Δ V peak bolus were 0.725 (sensitivity = 97.1%, specificity = 84%) and 4.21% (sensitivity = 65.7%, specificity = 80%), respectively. Conclusion : In mechanically ventilated patients with a tidal volume < 8 mL/kg while preserving spontaneous breathing, ΔFTc bolus and Δ V peak bolus could predict fluid responsiveness. The predictive performance of ΔFTc bolus was superior to Δ V peak bolus .

Comparison of parameter types for the calibration of noninvasive continuous cardiac output monitoring of patients undergoing lumbar spinal surgery in the prone position.

Cardiac output (CO) decreases on reversing the patient's position to the prone position. Estimated continuous cardiac output (esCCO) systems can noninvasively and continuously monitor CO calibrated by patient information or transesophageal echocardiogram (TEE). To compare the accuracy, precision, and trending ability of two calibration methods of CO estimation in patients in prone position. The CO estimates calibrated by TEE (esT) and patient information (esP) of 26 participants were included. CO was collected at four time points. The accuracy and precision of agreement were evaluated using the Bland-Altman method. A four-quadrant plot was used for trending ability analysis. The bias between esP and TEE and between esT and TEE was 0.2594 L/min (95% limits of agreement (LoA): -1.8374 L/min to 2.3562 L/min) and 0.0337 L/min (95% LoA: -0.7381 L/min to 0.8055 L/min), respectively. A strong correlation was found between ΔesP and ΔTEE (p< 0.001, CCC = 0.700) and between ΔesT and ΔTEE (p< 0.001, CCC = 0.794). The concordance rates between ΔesP and ΔTEE and between ΔesT and ΔTEE were 91.9% and 97.1%, respectively. Despite limited accuracy and precision, esP showed acceptable trending ability. The trending ability of esCCO calibrated by the reference TEE value was comparable with that of TEE.

Large animal ventilator-integrated volumetric capnography generates clinically acceptable values of physiologic dead space in anesthetized healthy adult horses.

To evaluate the agreement between the Tafonius large animal ventilator-integrated volumetric capnography (vCap) software and the Respironics NICO noninvasive cardiac output monitor reference system. Data were collected from 56 healthy adult horses undergoing general anesthesia. Animals were placed under general anesthesia and connected to the Tafonius large animal ventilator circle system. A flow partitioning device with CO2 and flow sensors was utilized to couple the endotracheal tube to the NICO monitor. Tafonius CO2 and flow sensors are incorporated into the Y-piece of the breathing circuit. Arterial blood samples were collected to determine the partial pressure of arterial carbon dioxide (PaCO2) immediately before data collection. The PaCO2 was input into the Tafonius and NICO monitor, and dead space ventilation (%Vd), end-tidal CO2 partial pressure (ETco2), mixed-expired CO2 partial pressure (Peco2), and expired tidal volume (Vt) were calculated over a single breath. Multiple measurements were completed for each patient, with a total of 200 paired data points collected for analysis. Data were assessed for normality, and Bland-Altman analysis was performed. Bias and 95% limits of agreement were calculated. The limits of agreement for %Vd of the ventilator-derived measurements fell within ± 10% of the NICO monitor reference method. Our results indicate that, when compared to the NICO monitor method, the Tafonius-integrated vCap software provides clinically acceptable values of Peco2, Vt, and %Vd in healthy adult horses.

Effects of CPAP and FiO2 on respiratory effort and lung stress in early COVID-19 pneumonia: a randomized, crossover study

Backgroundin COVID-19 acute respiratory failure, the effects of CPAP and FiO2 on respiratory effort and lung stress are unclear. We hypothesize that, in the compliant lungs of early Sars-CoV-2 pneumonia, the application of positive pressure through Helmet-CPAP may not decrease respiratory effort, and rather worsen lung stress and oxygenation when compared to higher FiO2 delivered via oxygen masks.MethodsIn this single-center (S.Luigi Gonzaga University-Hospital, Turin, Italy), randomized, crossover study, we included patients receiving Helmet-CPAP for early (< 48 h) COVID-19 pneumonia without additional cardiac or respiratory disease. Healthy subjects were included as controls. Participants were equipped with an esophageal catheter, a non-invasive cardiac output monitor, and an arterial catheter. The protocol consisted of a random sequence of non-rebreather mask (NRB), Helmet-CPAP (with variable positive pressure and FiO2) and Venturi mask (FiO2 0.5), each delivered for 20 min. Study outcomes were changes in respiratory effort (esophageal swing), total lung stress (dynamic + static transpulmonary pressure), gas-exchange and hemodynamics.ResultsWe enrolled 28 COVID-19 patients and 7 healthy controls. In all patients, respiratory effort increased from NRB to Helmet-CPAP (5.0 ± 3.7 vs 8.3 ± 3.9 cmH2O, p < 0.01). However, Helmet’s pressure decreased by a comparable amount during inspiration (− 3.1 ± 1.0 cmH2O, p = 0.16), therefore dynamic stress remained stable (p = 0.97). Changes in static and total lung stress from NRB to Helmet-CPAP were overall not significant (p = 0.07 and p = 0.09, respectively), but showed high interpatient variability, ranging from − 4.5 to + 6.1 cmH2O, and from − 5.8 to + 5.7 cmH2O, respectively. All findings were confirmed in healthy subjects, except for an increase in dynamic stress (p < 0.01). PaO2 decreased from NRB to Helmet-CPAP with FiO2 0.5 (107 ± 55 vs 86 ± 30 mmHg, p < 0.01), irrespective of positive pressure levels (p = 0.64). Conversely, with Helmet’s FiO2 0.9, PaO2 increased (p < 0.01), but oxygen delivery remained stable (p = 0.48) as cardiac output decreased (p = 0.02). When PaO2 fell below 60 mmHg with VM, respiratory effort increased proportionally (p < 0.01, r = 0.81).ConclusionsIn early COVID-19 pneumonia, Helmet-CPAP increases respiratory effort without altering dynamic stress, while the effects upon static and total stress are variable, requiring individual assessment. Oxygen masks with higher FiO2 provide better oxygenation with lower respiratory effort.Trial registration Retrospectively registered (13-May-2021): clinicaltrials.gov (NCT04885517), https://clinicaltrials.gov/ct2/show/NCT04885517.

Research Progress of Noninvasive Cardiac Output Monitor (NICOTM) and Hemodynamic Monitor in Neonates

Research Progress of Noninvasive Cardiac Output Monitor (NICOTM) and Hemodynamic Monitor in Neonates

The effect of prone positioning on maternal haemodynamics and fetal wellbeing in the third trimester-A primary cohort study with a scoping review.

Supine sleep position is associated with stillbirth, likely secondary to inferior vena cava compression, and a reduction in cardiac output (CO) and uteroplacental perfusion. Evidence for the effects of prone position in pregnancy is less clear. This study aimed to determine the effect maternal prone position on maternal haemodynamics and fetal heart rate, compared with left lateral position. Twenty-one women >28 weeks' gestation underwent non-invasive CO monitoring (Cheetah) every 5 minutes and continuous fetal heart rate monitoring (MONICA) in left lateral (20 minutes), prone (30 minutes), followed by left lateral (20 minutes). Anxiety and comfort were assessed by questionnaires. Regression analyses (adjusted for time) compared variables between positions. The information derived from the primary study was used in an existing mathematical model of maternal circulation in pregnancy, to determine whether occlusion of the inferior vena cava could account for the observed effects. In addition, a scoping review was performed to identify reported clinical, haemodynamic and fetal effects of maternal prone position; studies were included if they reported clinical outcomes or effects or maternal prone position in pregnancy. Study records were grouped by publication type for ease of data synthesis and critical analysis. Meta-analysis was performed where there were sufficient studies. Maternal blood pressure (BP) and total vascular resistance (TVR) were increased in prone (sBP 109 vs 104 mmHg, p = 0.03; dBP 74 vs 67 mmHg, p = 0.003; TVR 1302 vs 1075 dyne.s-1cm-5, p = 0.03). CO was reduced in prone (5.7 vs 7.1 mL/minute, p = 0.003). Fetal heart rate, variability and decelerations were unaltered. However, fetal accelerations were less common in prone position (86% vs 95%, p = 0.03). Anxiety was reduced after the procedure, compared to beforehand (p = 0.002), despite a marginal decline in comfort (p = 0.04).The model predicted that if occlusion of the inferior vena cava occurred, the sBP, dBP and CO would generally decrease. However, the TVR remained relatively consistent, which implies that the MAP and CO decrease at a similar rate when occlusion occurs. The scoping review found that maternal and fetal outcomes from 47 included case reports of prone positioning during pregnancy were generally favourable. Meta-analysis of three prospective studies investigating maternal haemodynamic effects of prone position found an increase in sBP and maternal heart rate, but no effect on respiratory rate, oxygen saturation or baseline fetal heart rate (though there was significant heterogeneity between studies). Prone position was associated with a reduction in CO but an uncertain effect on fetal wellbeing. The decline in CO may be due to caval compression, as supported by the computational model. Further work is needed to optimise the safety of prone positioning in pregnancy. This trial was registered at clinicaltrials.gov (NCT04586283).

Cardiac Output and Stroke Volume Assessments by Transthoracic Echocardiography and Pulse index Continuous Cardiac Output Monitor in Critically ill Adult Patients: A Comparative Study.

Bedside transthoracic echocardiography (TTEcho) is a noninvasive cardiac output (CO) monitoring method that has grown recently. However, there are questions regarding its accuracy compared to invasive methods. We aimed to evaluate the agreement and correlation of TTEcho and pulse index continuous CO (PiCCO) monitor measurements for CO and systolic volume (SV) in critically ill patients. This prospective experimental study included consecutive adult patients who required invasive hemodynamic monitoring admitted at an intensive care unit in the Federal District, Brazil, from January/2019 to January/2021. Correlation and agreement between SV and CO measurements by PiCCO and TTEcho were performed using the Spearman correlation and the Bland-Altman analysis. The study enrolled 29 patients, with adequate TTEcho evaluations in all patients. There were very strong correlations between CO-TTEcho and CO-PiCCO (r = 0.845, P < .001) and SV-TTEcho and SV-PiCCO (r = 0.800, P < .001). TTEcho estimations for CO and SV were feasible within the limits of agreement in 96.6% (28/29) compared to PiCCO. The mean difference between CO-PiCCO and CO-TTEcho was 0.250 L/min (limits of agreement: -1.083 to 1.583 L/min, percentage error: 21.0%), and between SV-PiCCO and SV-TTEcho was 2.000 mL (limits of agreement: -16.960 to 20.960, percentage error: 24.3%). The reduced cardiac index (CI) measurements by TTEcho showed an accuracy of 89.7% (95% IC: 72.6%-97.8%) and an F1 score of 92.7% (95% IC: 75.0%-98.0%), considering the CI-PiCCO as the gold standard. Echocardiographic measurements of CO and SV are comparable to measurements by PiCCO. These results reinforce echocardiography as a reliable tool to evaluate hemodynamics in critically ill patients.

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.

Diagnostic Adjunct Techniques in the Assessment of Hypovolemia: A Prospective Pilot Project

IntroductionMeasuring the hypovolemic resuscitation end point remains a critical care challenge. Our project compared clinical hypovolemia (CH) with three diagnostic adjuncts: 1) noninvasive cardiac output monitoring (NICOM), 2) ultrasound (US) static IVC collapsibility (US-IVC), and 3) US dynamic carotid upstroke velocity (US-C). We hypothesized US measures would correlate more closely to CH than NICOM. MethodsAdult trauma/surgical intensive care unit patients were prospectively screened for suspected hypovolemia after acute resuscitation, excluding patients with burns, known heart failure, or severe liver/kidney disease. Adjunct measurements were assessed up to twice a day until clinical improvement. Hypovolemia was defined as: 1) NICOM: ≥10% stroke volume variation with passive leg raise, 2) US-IVC: <2.1 cm and >50% collapsibility (nonventilated) or >18% collapsibility (ventilated), 3) US-C: peak systolic velocity increase 15 cm/s with passive leg raise. Previously unknown cardiac dysfunction seen on US was noted. Observation-level data were analyzed with a Cohen's kappa (κ). Results44 patients (62% male, median age 60) yielded 65 measures. Positive agreement with CH was 47% for NICOM, 37% for US-IVC and 10% for US-C. None of the three adjuncts correlated with CH (κ −0.045 to 0.029). After adjusting for previously unknown cardiac dysfunction present in 10 patients, no adjuncts correlated with CH (κ −0.036 to 0.031). No technique correlated with any other (κ −0.118 to 0.083). ConclusionsNone of the adjunct measurements correlated with CH or each other, highlighting that fluid status assessment remains challenging in critical care. US should assess for right ventricular dysfunction prior to resuscitation.

Abstract P419: First-Trimester Maternal Hemodynamics In Patients With Or Without Chronic Hypertension Using USCOM (ultrasound Cardiac Output Monitor), A Non-invasive And Quantitative Method.

Objective: We aim to investigate maternal hemodynamics at 10-14 weeks of gestation among patients with and without chronic hypertension, utilizing USCOM®, a non-invasive cardiac output monitor. Methods: A prospective pilot study was conducted for women with singleton pregnancies. Independent T, Mann-Whitney U, and Chi-square tests&amp;nbsp;were used to analyze cardiovascular parameters via Doppler waveform. Results: Thirteen pregnant women with preexisting hypertension and no other medical comorbidities were selected, and 26 controls were matched based on maternal age, ethnicity, and BMI in a ratio of 1:2. Six patients with chronic hypertension were on anti-hypertensive medications. Tables 1 and 2 present each respective group's basic demographic and hemodynamic characteristics. Conclusion: Despite no differences in BP, our study revealed significant hemodynamic changes in chronic hypertensive patients in the first trimester. Chronic hypertensive patients might have pre-existing pathological cardiovascular adaptation in early pregnancy, potentially compromising perinatal outcomes.

Assessing Fluid Responsiveness Using Noninvasive Hemodynamic Monitoring in Pediatric Shock: A Review

AbstractNoninvasive hemodynamic monitoring devices have been introduced to better quantify fluid responsiveness in pediatric shock; however, current evidence for their use is inconsistent. This review aims to examine available noninvasive hemodynamic monitoring techniques for assessing fluid responsiveness in children with shock. A comprehensive literature search was conducted using PubMed and Google Scholar, examining published studies until December 31, 2022. Articles were identified using initial keywords: [noninvasive] AND [fluid responsiveness]. Inclusion criteria included age 0 to 18, use of noninvasive techniques, and the emergency department (ED) or pediatric intensive care unit (PICU) settings. Abstracts, review papers, articles investigating intraoperative monitoring, and non-English studies were excluded. The methodological index for nonrandomized studies (MINORS) score was used to assess impact of study bias and all study components were aligned with Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Our review yielded 1,353 articles, 17 of which met our inclusion criteria, consisting of 618 patients. All were prospective observational studies performed in the ED (n = 3) and PICU (n = 14). Etiologies of shock were disclosed in 13/17 papers and consisted of patients in septic shock (38%), cardiogenic shock (29%), and hypovolemic shock (23%). Noninvasive hemodynamic monitors included transthoracic echocardiography (TTE) (n = 10), ultrasonic cardiac output monitor (USCOM) (n = 1), inferior vena cava ultrasonography (n = 2), noninvasive cardiac output monitoring (NICOM)/electrical cardiometry (n = 5), and &gt;2 modalities (n = 1). To evaluate fluid responsiveness, most commonly examined parameters included stroke volume variation (n = 6), cardiac index (CI) (n = 6), aortic blood flow peak velocity (∆V peak) (n = 3), and change in stroke volume index (n = 3). CI increase &gt;10% predicted fluid responsiveness by TTE in all ages; however, when using NICOM, this increase was only predictive in children &gt;5 years old. Additionally, ∆SV of 10 to 13% using TTE and USCOM was deemed predictive, while no studies concluded distensibility index by transabdominal ultrasound to be significantly predictive. Few articles explore implications of noninvasive hemodynamic monitors in evaluating fluid responsiveness in pediatric shock, especially in the ED setting. Consensus about their utility remains unclear, reiterating the need for further investigations of efficacy, accuracy, and applicability of these techniques.

Noninvasive Cardiac Output Monitoring (NICOM) in the Critically Ill Patient Undergoing Endotracheal Intubation: A Prospective Observational Study.

Background: Cardiovascular instability occurring during endotracheal intubation (ETI) in the critically ill is a commonly recognized phenomenon. However, this complication has not been evaluated in terms of the physiological cause (ie, decreased preload, contractility, or afterload) leading to the instability. Thus, the aim of the current investigation was to describe the hemodynamics occurring during ETI with noninvasive physiologic monitoring and to collect preliminary data on the hemodynamic effects of induction agents and positive pressure ventilation. Methods: A multicenter prospective study enrolling adult (≥18 years) critically ill patients undergoing ETI with noninvasive cardiac output monitoring in a medical/surgical intensive care unit from June 2018 to May 2019 was conducted. This study used the Cheetah Medical noninvasive cardiac output monitor to collect hemodynamic data during the peri-intubation period. Additional data collected included baseline characteristics such as illness severity, peri-intubation pharmacologic administration, and mechanical ventilation settings. Results: From the original 27 patients, only 19 (70%) patients had complete data and were included in the final analysis. Propofol was the most common sedative 8 (42%) followed by ketamine 6 (32%) and etomidate 5 (26%). Patients given propofol demonstrated a decrease in total peripheral resistance index (delta change [dynes × s/cm-5/m2]: -2.7 ± 778.2) but stabilization in cardiac index (delta change (L/min/m2]: 0.1 ± 1.5) while etomidate and ketamine demonstrated increases in total peripheral resistance index (etomidate delta change [dynes × s/cm-5/m2]: 302.1 ± 414.3; ketamine delta change [dynes × s/cm-5/m2]: 278.7 ± 418.9) but only etomidate resulted in a decrease in cardiac index (delta change [L/min/m2]: -0.3 ± 0.5). Positive pressure ventilation resulted in minimal changes to hemodynamics during ETI. Conclusions: The current study demonstrates that although propofol administration leads to a decrease in total peripheral resistance index, cardiac index is maintained while etomidate leads to a decrease in cardiac index with both etomidate and ketamine increasing total peripheral resistance index. These hemodynamic profiles are minimally affected by positive pressure ventilation. Study registration: ClinicalTrials.gov ID, NCT03525743.

Trainability for cardiopulmonary fitness is low in patients with peripheral artery disease.

In patients with peripheral arterial disease (PAD), exercise therapy is recommended to relieve leg symptoms, as noted in the 2016 AHA/ACC and 2017 ESC/ESVS guidelines. We assessed the trainability for cardiopulmonary fitness (CPF) and quality of life (QOL); three distinct patient types, namely, PAD, heart failure (HF), and stroke, were compared. This is a multicentre, retrospective analysis of prospectively collected data from three clinical studies. Data collected from 123 patients who completed 36 sessions of supervised aerobic training of moderate intensity were analysed, with 28 PAD, 55 HF, and 40 stroke patients totalling 123. Before and after training, cardiopulmonary exercise testing with non-invasive cardiac output monitoring and QOL evaluation using a 36-Item Short Form Survey (SF-36) were performed. Non-response was defined as a negative change in the post-training value compared with that in the pre-training value. The result showed an improvement in CPF in all three groups. However, cardiorespiratory fitness (CRF) increased by a lesser extent in the PAD group than in the HF and stroke groups; the physical and mental component scores (MCS) of SF-36 exhibited a similar pattern. Non-response rates of peak V˙O2, oxygen uptake efficiency slope, and MCS were higher in the PAD group. In the PAD group, non-responders regarding peak V˙O2 had a higher pulse wave velocity than responders. In patients with PAD following exercise therapy, CRF and QOL improved to a lesser extent on average; their non-response rate was also higher compared with that of HF or stroke patients. Therefore, a higher dose of exercise might be needed to elicit adaptation in PAD patients, especially those with high pulse wave velocity.

Advantages and limitations of noninvasive devices for cardiac output monitoring: a literature review.

Individualized hemodynamic optimization often requires cardiac output monitoring, mostly for goal-directed therapy in the operating room and fluid responsiveness assessment in the intensive care unit. Different technologies for noninvasive cardiac output determination have become available over the recent years. It is therefore crucial for care providers to be made aware of the advantages and limitations of those different devices for an appropriate use at the bedside. Nowadays, different noninvasive technologies exist, each with their advantages and limitations, but none are considered interchangeable with bolus thermodilution. Different clinical studies however, emphasize that the trending ability of such devices allows to guide decisions from care providers, and that their use may be associated with improved prognosis, especially in the operating room. Recent studies have also reported their potential use for hemodynamic optimization in specific populations. Noninvasive cardiac output monitoring may have a clinical impact on patient outcomes. Further studies are required to evaluate their clinical relevance, notably in the intensive care unit. Noninvasive monitoring opens up the possibility for hemodynamic optimization in specific or low-risk populations, the benefit of which remains to be assessed.

Capnodynamics - noninvasive cardiac output and mixed venous oxygen saturation monitoring in children.

Hemodynamic monitoring in children is challenging for many reasons. Technical limitations in combination with insufficient validation against reference methods, makes reliable monitoring systems difficult to establish. Since recent studies have highlighted perioperative cardiovascular stability as an important factor for patient outcome in pediatrics, the need for accurate hemodynamic monitoring methods in children is obvious. The development of mathematical processing of fast response mainstream capnography signals, has allowed for the development of capnodynamic hemodynamic monitoring. By inducing small changes in ventilation in intubated and mechanically ventilated patients, fluctuations in alveolar carbon dioxide are created. The subsequent changes in carbon dioxide elimination can be used to calculate the blood flow participating in gas exchange, i.e., effective pulmonary blood flow which equals the non-shunted pulmonary blood flow. Cardiac output can then be estimated and continuously monitored in a breath-by-breath fashion without the need for additional equipment, training, or calibration. In addition, the method allows for mixed venous oxygen saturation (SvO2) monitoring, without pulmonary artery catheterization. The current review will discuss the capnodyamic method and its application and limitation as well as future potential development and functions in pediatric patients.

Comparison of a noninvasive cardiac output monitor (NICOM) with simultaneous transthoracic echocardiography in pregnant women

Comparison of a noninvasive cardiac output monitor (NICOM) with simultaneous transthoracic echocardiography in pregnant women