Non-invasive Cardiac Output Monitoring Research Articles

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.

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.

Postoperative continuous non-invasive cardiac output monitoring on the ward: a feasibility study

Postoperative hypotension is common (occurring in one third of patients) and is associated with worse clinical outcomes. The LiDCO CNAP (continuous non-invasive arterial pressure) device measures haemodynamics but has not been widely adopted in ward environments. Improved early detection of hypotension by CNAP might guide interventions to improve clinical outcomes. We aimed to find the proportion of patients who tolerated LiDCO CNAP for 12 h postoperatively, to unmask episodes of hypotension detected by continuous monitoring and to characterise the haemodynamic profile at the time of hypotension. In this feasibility study, patients undergoing major elective surgery were continuously postoperatively monitored using CNAP. Haemodynamic data gathered from CNAP, including nSVRI (nominal systemic vascular resistance index), nSVI (nominal stroke volume index), SVV (stroke volume variation) and blood pressure, were analysed using Microsoft Excel and GraphPad Prism 8. 104 patients (age (mean ± sd): 68 ± 14, male (56%)) had CNAP sited postoperatively. 39% tolerated the CNAP device for at least 12 h. Within the 104 patients a mean of 81.2 min of hypotension detected by CNAP was not detected by usual care. The proportion of low/normal/high nSVI was 71%, 27% and 2%, nSVRI was 43%, 17% and 40%, respectively. CNAP monitoring was not tolerated for 12 h in the majority of patients. There were many episodes of hypotension unmasked through continuous monitoring. Based on the advanced haemodynamic data provided it is possible that the underlying cause of a third of postoperative hypotensive episodes is vasodilation rather than hypovolaemia.Trial registry number: NCT04010058 (ClinicalTrials.gov) Date of registration: 08/07/2019.

Observation of hemodynamic parameters using a non-invasive cardiac output monitor system to identify predictive indicators for post-spinal anesthesia hypotension in parturients undergoing cesarean section.

The administration of high-level spinal anesthesia for cesarean section may lead to significant hemodynamic changes. Bioreactance-based non-invasive cardiac output monitoring (NICOM™) provides an accurate monitoring system for parturients under spinal anesthesia. The present study hypothesized that baseline hemodynamic parameters obtained via the NICOM™ system could serve as predictive indicators for post-spinal anesthesia hypotension. Therefore, 80 full-term parturients with singleton pregnancies who underwent scheduled cesarean section were enrolled and allocated to either a supine position group or a 15˚ left tilt group. All parturients received standard pre-hydration with 750 ml of 0.9% saline. Baseline cardiac output index (CI), total peripheral resistance index (TPRI) and stroke volume (SV) were recorded using the NICOM™ system. Subsequently, spinal anesthesia with 2.4 ml of 0.5% hyperbaric bupivacaine, 10 µg of fentanyl and 0.2 mg of morphine was administered. Receiver operating characteristic (ROC) curves and multivariate logistic regression were used to analyze the data. A total of 40 parturients (51.9%) developed hypotension. The areas under the ROC curves were 0.666, 0.594 and 0.622 for the CI, TPRI and SV, respectively. The optimal cut-off value of the CI in predicting hypotension was 3.68 l/min/m2 (ROC, sensitivity=85.0%, specificity=48.6%). Furthermore, CI was considered as an independent factor for post-spinal anesthesia hypotension. In conclusion, the baseline CI obtained via the bioreactance-based NICOM™ system may serve as a predictor of post-spinal anesthesia hypotension in parturients regardless of patient position.

The Feasibility and Applications of Non-invasive Cardiac Monitoring in Obese Patients Undergoing Day-case Surgery: Results of a Prospective Observational Study

Aims: This prospective observational study evaluates the utility of non-invasive cardiac monitoring in obese patients in the day-surgery case, considering factors, such as Body Mass Index (BMI) and anaesthesia technique. Background: Obese patients are more likely to be admitted to hospital or to get hospitalized because they are more prone to concomitant diseases and obesity itself is not a contraindication to day surgery. Obese patients are a high-risk patient population that may particularly benefit from monitoring perioperative haemodynamic variations. Methods: In this observational study, we compared haemodynamic variations between overweight or obese and normal weight patients undergoing day-case surgery. We adopted NICOM® as a non-invasive cardiac output monitoring. Objective: The aim of the current study was to investigate the haemodynamic impact of BMI and anaesthesia technique during day-case surgery procedures. The other goal was to evaluate the feasibility and applications of non-invasive cardiac output monitoring among the obese population in day-surgery. Results: 74 patients were included in the study. 34 were overweight or obese (weight 84 ± 10 kg, height 160 ± 10 cm, BMI ≈ 30 kg/m2), 40 were normal weight (weight 63 ± 15 kg, height 160 ± 10 cm, BMI ≈ 22 kg/m2). Compared to normal-weight patients, obese patients show an increase in blood pressure with a return to baseline values at the end of surgery (p &lt; 0.05). The Cardiac Output (CO) shows a similar trend, whereas the heart rate is normal. A decrease in the Cardiac Index (CI) during the operation was noticed in both groups, the one in obese patients (p = 0.24) being greater. In the same way, the Stroke Volume Index (SVI) was lower in obese patients during surgery (p &lt; 0.05). In spinal anaesthesia, the Total Peripheral Resistance Index (TPRI) was not statistically different between the groups of study. As for the TPRI in obese patients, we reported values similar to the ones in non-obese patients in spinal anaesthesia. In local anesthesia, TPRI was higher in obese patients than in non-obese. Conclusion: Cardiovascular alterations in relation to obesity include an increase in blood pressure, CO and SV. An inadequate monitoring of haemodynamic parameters is a risk factor for perioperative complications. NICOM® provides a continuous, non-invasive haemodynamic measurement.

Bioreactance-Based Noninvasive Fluid Responsiveness and Cardiac Output Monitoring: A Pilot Study in Patients with Aneurysmal Subarachnoid Hemorrhage and Literature Review.

Management of volume status, arterial blood pressure, and cardiac output are core elements in approaching the patients with aneurysmal subarachnoid hemorrhage (SAH). For the prevention and treatment of delayed cerebral ischemia (DCI), euvolemia is advocated and caution is made towards the avoidance of hypervolemia. Induced hypertension and cardiac output augmentation are the mainstays of medical management during active DCI, whereas the older triple-H paradigm has fallen out of favor due to lack of demonstrable physiological or clinical benefits and serious concern for adverse effects such as pulmonary edema and multiorgan system dysfunction. Furthermore, insight into clinical hemodynamics of patients with SAH becomes salient when one considers the frequently associated cardiac and pulmonary manifestations of the disease such as SAH-associated cardiomyopathy and neurogenic pulmonary edema. In terms of fluid and volume targets, less attention has been paid to dynamic markers of fluid responsiveness despite the well-established, in the general critical care literature, superiority of these as compared to traditionally used static markers such as central venous pressure (CVP). Based on this literature and sound pathophysiologic reasoning, reliance on static markers (such as CVP) is unjustified when one attempts to assess strategies augmenting stroke volume (SV), arterial blood pressure, and oxygen delivery. There are several options for continuous bedside cardiorespiratory monitoring and optimization of SAH patients. We, here, review a noninvasive monitoring technique based on thoracic bioreactance and focusing on continuous cardiac output and fluid responsiveness markers.

Accuracy assessment of noninvasive cardiac output monitoring in the hemodynamic monitoring in critically ill patients.

The consistency of cardiac output (CO) measured by noninvasive cardiac output monitoring (NICOM), pulse index continuous cardiac output (PiCCO), and ultrasound in the hemodynamic monitoring of critically ill patients was studied. Using the NICOM built-in passive leg raising (PLR) test, stroke volume index variation (∆SVI) was calculated and was used to predict volume responsiveness in patients with circulatory shock (excluding cardiogenic shock). Critically ill patients requiring hemodynamic monitoring were admitted during the study period. The CO of each included patient under hemodynamic monitoring was measured by NICOM plus PiCCO or ultrasound, and the consistency of the measured COs was analyzed. By the NICOM built-in PLR test, ∆SVI was calculated and was used to predict volume responsiveness. The CO of 58 patients was measured by NICOM and ultrasound, and the COs measured by these two methods were consistent. The CO of 40 patients was measured by NICOM and PiCCO, and the COs measured by these two methods were consistent. The volume responsiveness of all 98 patients was assessed by the NICOM built-in PLR test. A total of 60 patients had ∆SVI >10%, so they underwent the fluid challenge. Among them, 43 patients were positive by both the NICOM built-in PLR and fluid challenge. When using ∆SVI to predict volume responsiveness in patients with circulatory shock (excluding cardiogenic shock), the area under the receiver operating characteristic curve was 0.754 (95% confidence interval, 0.626-0.856), and the cut-off value was 18% (sensitivity: 88.37%, specificity: 52.94%), indicating that ∆SVI has value in predicting the volume responsiveness of patients with noncardiogenic circulatory shock. NICOM had good consistency with ultrasound and PiCCO in the hemodynamic monitoring of critically ill patients and can be for hemodynamic monitoring and evaluation in critically ill patients. The ∆SVI obtained by the NICOM built-in PLR test has certain clinical value in predicting the volume responsiveness of patients with circulatory shock (excluding cardiac shock) and provides a method for evaluating the volume responsiveness of critically ill patients.

Technological Assessment and Objective Evaluation of Minimally Invasive and Noninvasive Cardiac Output Monitoring Systems.

The authors discuss minimally invasive and noninvasive cardiac output monitoring technologies available in the clinical practice and how to evaluate these systems objectively.

Prognostic Value of Maternal Cardiovascular Hemodynamics in Women With Gestational Hypertension and Chronic Hypertension in Pregnancy

This study aimed to assess the prognostic value of cardiovascular assessment in women with gestational hypertension or chronic hypertension for the risk of preeclampsia and need for closer antenatal surveillance. This was a prospective study of pregnancies complicated by gestational hypertension or chronic hypertension presenting to St George's Hospital, between January 2015 and May 2018. A noninvasive ultrasonic cardiac output monitor was used to obtain cardiovascular variables of cardiac output (CO) and systemic vascular resistance (SVR) and weight-adjusted indices. The primary outcome was the time to development of preeclampsia in women with gestational hypertension or chronic hypertension. In women with gestational hypertension or chronic hypertension (n=149), cox-proportional hazards analysis showed that mean arterial pressure (P=0.006), Afro-Caribbean ethnicity (P=0.045), and gestational age at the time of diagnosis above 34 weeks (P<0.001) were significantly associated with increased risk of earlier preeclampsia. Women with high SVR and normal CO (adjusted hazard ratio, 2.32 [95% CI, 1.06-5.08]; P=0.035) and high SVR and low CO (adjusted hazard ratio, 7.79 [95% CI, 1.94-31.24]; P=0.003) cardiovascular profiles had significantly higher risk of earlier preeclampsia compared with women with normal SVR and normal CO. The findings of this study demonstrate that hypertensive women with increased SVR and low CO had a higher risk of developing preeclampsia sooner.

Maternal haemodynamic function differs in pre‐eclampsia when it is associated with a small‐for‐gestational‐age newborn: a prospective cohort study

To describe maternal haemodynamic differences in gestational hypertension with small-for-gestational-age babies (HDP+SGA), gestational hypertension with appropriate-for-gestational-age babies (HDP-only) and control pregnancies. Prospective cohort study. Tertiary Hospital, UK. Women with gestational hypertension and healthy pregnant women. Maternal haemodynamic indices were measured using a non-invasive Ultrasound Cardiac Output Monitor (USCOM-1A® ) and corrected for gestational age and maternal characteristics using device-specific reference ranges. Maternal cardiac output, stroke volume, systemic vascular resistance. We included 114 HDP+SGA, 202 HDP-only and 401 control pregnancies at 26-41weeks of gestation. There was no significant difference in the mean arterial blood pressure (110 versus 107mmHg, P=0.445) between the two HDP groups at presentation. Pregnancies complicated by HDP+SGA had significantly lower median heart rate (76 versus 85bpm versus 83bpm), lower cardiac output (0.85 versus 0.98 versus 0.97MoM) and higher systemic vascular resistance (1.4 versus 1.0 versus 1.2MoM) compared with control and HDP-only pregnancies, respectively (all P<0.05). Women with HDP+SGA present with more severe haemodynamic dysfunction than HDP-only. Even HDP-only pregnancies exhibit impaired haemodynamic indices compared with normal pregnancies, supporting a role of the maternal cardiovascular system in gestational hypertension irrespective of fetal size. Central haemodynamic changes may play a role in the pathogenesis of pre-eclampsia and should be considered alongside placental aetiology. Hypertensive disorders of pregnancy are associated with worse maternal haemodynamic function when associated with small-for-gestational-age birth.

Usefulness of non-invasive cardiac output monitoring in elderly patients undergoing monopolar transurethral resection of the prostate: a pilot study.

ObjectiveTo assess the impact of irrigating fluid on hemodynamic profiles using real-time non-invasive cardiac output monitoring (NICOM) in elderly patients undergoing monopolar transurethral resection of the prostate (TURP).MethodsTwenty patients between 65 and 80 years of age who were scheduled for monopolar TURP and received spinal anesthesia up to T10 were enrolled. Irrigating fluid (2.7% sorbitol with 0.5% mannitol solution) was used. Hemodynamic profiles including cardiac index, and stroke volume variation (SVV) using NICOM were obtained. Estimated irrigating fluid absorption was indirectly calculated.ResultsThe median amount of irrigating fluid used was 6000 mL. The median SVV was 11%, which increased to 12% at 10 minutes after initiating surgery. No significant changes in the cardiac index were observed. The estimated absorption of irrigating fluid was almost zero.ConclusionsAlthough the estimated amount of irrigating fluid that was absorbed was negligible, the increase in SVV may indicate intravascular volume depletion with diuresis resulting from mannitol in the irrigating fluid early during irrigation. Therefore, even during short irrigating times, intensive hemodynamic monitoring should be performed to monitor the possibility of intravascular volume depletion as well as volume overload, especially immediately after large amounts of irrigating fluid are used.

Hemodynamic profiles with and without left uterine displacement: A randomized study in term pregnancies receiving subarachnoid blockade for cesarean delivery

Study objectiveThe aim of this study was to evaluate the effect of left uterine displacement (LUD) on maternal hemodynamic measures following subarachnoid blockade (SAB) for cesarean delivery (CD). The primary outcome was cardiac output (CO) differences between the LUD and non-LUD groups pre-delivery. DesignProspective, randomized, controlled study. SettingObstetric operating room. Materials and methodsWe studied hemodynamic profiles in sixty healthy women with term pregnancies who underwent elective CD with SAB. Hemodynamics were measured using a non-invasive CO monitor, the Nexfin™. All women received a crystalloid 10 mL/kg preload, and hypotension was treated with ephedrine boluses. InterventionsSixty women with term pregnancies were randomized into two groups: LUD group (received 15–30° LUD after SAB, n = 30) and non-LUD group (no LUD after SAB, n = 30). MeasurementsPatient's hemodynamic variables including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), CO, systemic vascular resistance (SVR), and left ventricular contractility index (dP/dT) were measured continuously from pre-SAB until end of surgery. Main resultsIn pre-delivery phase at 5 min after spinal anesthesia, the LUD group had significantly higher CO (7.20 ± 1.78 [95%CI 6.53–7.87] vs. 6.23 ± 1.44 L/min [95% CI 5.69–6.77]; p = 0.016) and higher dP/dT (784 ± 313 vs. 604 ± 241 mmHg/s; p = 0.020) than the non-LUD group. The LUD group had a lower incidence of maternal systolic hypotension at 5-min post-SAB (16.7% vs. 53.3% in non-LUD group, p = 0.003). ConclusionsThe study demonstrates modest hemodynamic advantages (higher CO, less hypotension, higher dP/dT) with pre-delivery LUD. The results support maternal hemodynamic benefits of LUD until delivery in women with term pregnancies undergoing CD with SAB.

Rescuer Exertion and Fatigue Using Two-Thumb vs. Two-Finger Method During Simulated Neonatal Cardiopulmonary Resuscitation.

Background: Rescuer fatigue during neonatal CPR can affect CPR quality leading to reduced cerebral and myocardial perfusion.Aim: To investigate rescuer fatigue during simulated neonatal CPR using both objective (heart rate and cardiac output) and subjective measures.Methods: A randomized crossover manikin study performed. Nineteen doctors working in neonatology were randomized to (a) two-thumb term, (b) two-finger term, (c) two-thumb preterm, or (d) two-finger preterm group. Cardiac output and heart rate were measured with a non-invasive cardiac output monitor. A Likert scale assessed participants' level of perceived exertion.Results: In the preterm group, the mean change in HR from rest to 5 min in the TT group was 11.58 bpm (SD 6.22) vs. 9.94 bpm (SD 8.48), (p-value 0.36). There was no difference in change in CO, 2.10 (SD 1.15) in the TT group vs. 1.39 (SD 1.63) in TF group (p value 0.23). There was no difference in BORG RPE rating. In the term group, the mean change in HR from rest to 5 min was 15 bpm (SD 8.40) in TT group and 13 bpm (SD 7.86) in TF group, (p-value 0.416). The median change in CO from rest to 5 min was 1.50 (0.78 to 2.42 IQR) in TT group vs. 1.60 (0.65 to 3.0 IQR) in TF group.Conclusion: Providing chest compressions is associated with an increase in both heart rate and cardiac output. We did not identify difference between objective and subjective measures of fatigue between either technique in a preterm or term model.

Delay optimization of multipoint pacing increases the cardiac index and narrows the QRS width

IntroductionThe benefits of MPP delay optimization on hemodynamics and ventricular contraction synchronicity can be quantified with cardiac index (CI) and QRS width. A delay with the maximum CI and minimum QRS width may be the optimized settings for multipoint pacing (MPP). MethodsTwelve patients with advanced heart failure who received cardiac resynchronization therapy defibrillation with MPP at the Third People's Hospital of Chengdu from March 2016 to April 2019 were included. Interventricular and intraventricular delays were optimized through noninvasive cardiac output monitoring and a 12 lead ECG. ResultsAccording to CI, the optimized left ventricular- left ventricular - right ventricular delay setting was mainly 25 ms–25 ms and 40 ms–40 ms. And the delay with the minimum QRS width was mainly in 5 ms–5 ms, 25 ms–25 ms, and 40 ms–25 ms. The optimal MPP configuration increased CI compared to the MPP setting that produced the minimum CI (4.5 ± 1.3 vs. 2.8 ± 1.0 L/min/m2, P < 0.001). The QRS width of the optimized MPP was narrower than the MPP setting that produced the maximum QRS width (127 ± 20 vs. 160 ± 29 ms, P < 0.001). ConclusionDelay optimization improves hemodynamic response and ventricular contraction synchronicity. The delay of 25 ms–25 ms may be the optimal setting for most MPP patients.

Goal-directed hemodynamic therapy in patients with colorectal cancer undergoing laparoscopic surgery

Introduction.The conductance of goal-directed hemodynamic therapy is controversial due to the difficulty in its implementation in routine practice despite the significant number of studies and meta-analyses.Objective.To estimate the efficacy of a modified algorithm of goal-directed hemodynamic management in patients with colorectal cancer who undergo laparoscopic surgery based on non-invasive monitoring of cardiac output.Subjects and methods.A single-centered, randomized trial was conducted. The control group included 75 patients, while the goal-directed therapy (GDT) group included 72 patients. In the control group, hemodynamic management was based on mean arterial pressure and intraabdominal perfusion pressure. In addition, results of fluid responsiveness tests were considered in the GDT group. The suggested protocol efficacy was evaluated on the basis of frequency of critical incidents, shifts in acid-base balance and lactate concentration, infusion volume, vasopressor doses, the incidence of acute kidney injury, and other complications.Results.After anesthesia induction and according to the results of a modified, passive leg raising test, 67.1% of patients were considered responders and received 1250 (1000; 1500) ml of balanced crystalloids before carboxyperitoneum. The infusion differentiation test of hypotension cause was performed in 47 patients of the GDT group, 37% were considered responders, and others received vasopressors and/or inotropes. The use of the GDT protocol led to a decrease in total infusion volume and vasopressor doses. A lower frequency of critical incidents was recorded when the GDT protocol was used. In the GDT group, there were no signs of ischemia and increased frequency of complications (including acute kidney injury).Conclusions.Testing of fluid responsiveness and non-invasive cardiac output monitoring allows for the correction of hemodynamics during surgery. Goal-directed therapy in the intraoperative period allows different approaches to maintaining systemic and intraabdominal perfusion pressure, thus decreasing the total volume of infusion without increasing hypoperfusion risk.

Emergency department non-invasive cardiac output study (EDNICO): an accuracy study

BackgroundThere is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assess here the accuracy of five non-invasive methods in detecting fluid responsiveness in the ED: (1) common carotid artery blood flow, (2) suprasternal aortic Doppler, (3) bioreactance, (4) plethysmography with digital vascular unloading method, and (5) inferior vena cava collapsibility index. Left ventricular outflow tract echocardiography derived velocity time integral is the reference standard. This follows an assessment of feasibility and repeatability of these methods in the same cohort of ED patients.MethodsThis is a prospective observational study of non-invasive methods for assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Sensitivity and specificity of each method in determining the fluid responsiveness status of participants is determined in comparison to the reference standard.ResultsThirty-three patient data sets were included for analysis. The specificity and sensitivity to detect fluid responders was 46.2 and 45% for common carotid artery blood flow (CCABF), 61.5 and 63.2% for suprasternal artery Doppler (SSAD), 46.2 and 50% for bioreactance, 50 and 41.2% for plethysmography vascular unloading technique (PVUT), and 63.6 and 47.4% for inferior vena cava collapsibility index (IVCCI), respectively. Analysis of agreement with Cohen’s Kappa − 0.08 for CCABF, 0.24 for SSAD, − 0.04 for bioreactance, − 0.08 for PVUT, and 0.1 for IVCCI.ConclusionIn this study, non-invasive methods were not found to reliably identify fluid responders. Non-invasive methods of identifying fluid responders are likely to play a key role in improving patient outcome in the ED in fluid depleted states such as sepsis. These results have implications for future studies assessing the accuracy of such methods.

Comparison of cardiac output, IVC diameters and lactate levels in prediction of mortality in patients in emergency department; An observational study.

Objective:Fluid overload is an independent marker for mortality in critically ill patients. Assessment of fluid status and fluid responsiveness is crucial for the management of these patients. In this study, we compared the lactate level, inferior vena cava (IVC) diameter and non-invasive cardiac output (CO) monitoring in prediction of mortality in emergency department.Methods:This was a cross sectional observational study which comprised of 68 patients and was performed in ED of Tabriz University of Medical Sciences, Iran, from Sept 2016 until Sept 2017. IVC diameter was measured before the P-wave on ECG to avoid interference with a-wave and v-wave on the venous pressure curve, and during maximal inspiration and expiration to avoid Valsalva-like maneuvers. An arterial lactate sample was taken from all patients before performing the initial resuscitation. All patients underwent non-invasive CO monitoring by CO2 rebreathing technique. Mortality was noted on day 28.Results:Deceased patients had a significantly low level of IVC diameters, less CO values and more lactate levels. However, based on ROC curve analysis, the prediction accuracy and validity of both CO values obtained by rebreathing CO2 and IVC diameter was poor and the highest accuracy was obtained by lactate level assessment.Conclusion:Initial lactate value is a reliable parameter for prediction of mortality in non-traumatic critically ill patients. IVC diameter changes during spontaneous ventilation and non-invasive CO monitoring does not possess acceptable accuracy for prediction of mortality in these patients.