Noninvasive Cardiac Output Research Articles

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.

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.

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.

Cerebrovascular responses to graded exercise in young healthy males and females.

Although systemic sex‐specific differences in cardiovascular responses to exercise are well established, the comparison of sex‐specific cerebrovascular responses to exercise has gone under‐investigated especially, during high intensity exercise. Therefore, our purpose was to compare cerebrovascular responses in males and females throughout a graded exercise test (GXT). Twenty‐six participants (13 Females and 13 Males, 24 ± 4 yrs.) completed a GXT on a recumbent cycle ergometer consisting of 3‐min stages. Each sex completed 50W, 75W, 100W stages. Thereafter, power output increased 30W/stage for females and 40W/stage for males until participants were unable to maintain 60‐80 RPM. The final stage completed by the participant was considered maximum workload(W max). Respiratory gases (End‐tidal CO2, EtCO2), middle cerebral artery blood velocity (MCAv), heart rate (HR), non‐invasive mean arterial pressure (MAP), cardiac output (CO), and stroke volume (SV) were continuously recorded on a breath‐by‐breath or beat‐by‐beat basis. Cerebral perfusion pressure, CPP = MAP (0. 7,355 distance from heart‐level to doppler probe) and cerebral vascular conductance index, CVCi = MCAv/CPP 100mmHg were calculated. The change from baseline (Δ) in MCAv was similar between the sexes during the GXT (p = .091, ω p 2 = 0.05). However, ΔCPP (p < .001, ω p 2 = 0.25) was greater in males at intensities ≥ 80% W max and ΔCVCi (p = .005, ω p 2 = 0.15) was greater in females at 100% W max. Δ End‐tidal CO2 (ΔEtCO2) was not different between the sexes during exercise (p = .606, ω p 2 = −0.03). These data suggest there are sex‐specific differences in cerebrovascular control, and these differences may only be identifiable at high and severe intensity exercise.

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.

Hemodynamic response in cirrhotic patients with transjugular intrahepatic portosystemic shunt

Objective: To discuss the effects of transjugular intrahepatic portosystemic shunt (TIPS) procedure on hemodynamics in cirrhotic patients. Methods: A total of 23 cirrhotic patients for TIPS insertion were enrolled from January 2018 to October 2018. Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP), transthoracic echocardiography and non-invasive cardiac output measurement based on impedance cardiogram were carried out before and 24h, 1 month, 6 months after TIPS in order to observe cardiac function and hemodynamic changes after TIPS. Results: Significant increases in right atrial area [(17.2±4.0) cm(2) vs. (15.0±3.4) cm(2), P<0.05], right ventricular area [(15.1±3.8) cm(2) vs. (13.7±3.5) cm(2), P<0.05] and left ventricular volume [(97.4±21.5) ml vs. (91.1±22.7) ml, P<0.05] were observed 24 h after TIPS. These changes were accompanied with significant reduction in collapsible index of inferior vena cava [(20.7± 8.1)% vs. (28.6±11.3)%, P<0.01] and elevation in pulmonary arterial systolic pressure [(36.0±8.4) mmHg (1 mmHg=0.133 kPa) vs. (31.8±5.4) mmHg, P<0.01]. There also existed significantly elevated serum NT-proBNP [(551.2±325.1) ng/L vs. (124.2±94.4) ng/L, P<0.01], cardiac output [(5.82±0.96) L/min vs. (5.12±1.28) L/min, P<0.01], cardiac index [(3.47±0.64) L·min(-1)·m(-2) vs. (3.05±0.78) L·min(-1)·m(-2), P<0.01], early diastolic filling rate [(59.0±14.3)% vs. (54.5±11.0)%, P<0.05], and reduced systemic vascular resistance index (SVRi) [(1 798.4±357.3) dyne·s·cm(-5)·m(-2) vs. (2 195.7±508.7) dyne·s·cm(-5)·m(-2), P<0.01] 24 h after TIPS. At the end of 6-month follow-up, all these parameters, but not SVRi, returned towards baseline values. Moreover, peak early to late diastolic tissue velocity ratio at the level of lateral mitral annulus (E'/A') was significantly higher at the end of 6-month follow-up than that at baseline (1.06±0.32 vs. 0.90±0.45, P<0.05). Neither the right ventricular fractional area changes nor the left ventricular ejection fractions during the follow-up period were different from those at baseline (P>0.05). Conclusion: Cirrhotic patients who had no cardiovascular pathologies had adequate adaptation and good compensation ability to reach a new hemodynamic homeostasis for the increased volume load after TIPS insertion.

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.

Low cardiac output measured by bioreactance and adverse outcome in preterm infants with birth weight less than 1250 g

BackgroundRecently a new continuous non-invasive cardiac output measurement, bioreactance, has become available. Bioreactance measurement of cardiac output has been shown to correlate with left ventricular output detected by echocardiography in healthy term and preterm neonates. AimsOur aim was to correlate cardiac output measurements by bioreactance in the first 48 h of life with adverse outcomes attributable to hypoperfusion (peri/intraventricular haemorrhage (PIVH) and/or necrotising enterocolitis (NEC)) in the cohort of extremely preterm infants. Study designA prospective observational cohort study. SubjectsPreterm infants with birth weight less than 1250 g. Outcome measuresCardiac output was measured between six and 48 h of age by bioreactance. Our primary outcome was a difference in cardiac output between infants with an adverse outcome attributable to hypoperfusion (Group 1), and infants without the predefined adverse outcome (Group 2). ResultsThere were 39 infants enrolled in the study. There were six infants in Group 1. These infants had a significantly lower minimal cardiac output measurement compared to Group 2 (mean 36.7 ml/kg/min vs 64.5 ml/kg/min, p = .0006). The mean cardiac output in Group 1 was significantly lower on day one of life, followed by a significant increase in cardiac output on day two of life compared to Group 2. ConclusionsInfants with birth weight less than 1250 g and PIVH and/or NEC had significantly lower cardiac output compared to infants without these complications on day one of life. This low cardiac output was then followed by a significant increase on day two of life.

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.

Are Noninvasive Continuous Cardiac Output Monitoring Interchangeable with Esophageal Doppler?

Objective: To compare the trending ability, accuracy, and precision of non-invasive stroke volume (SV) measurement based on a bioreactance technique and measurement of the pulse wave transit time (PWTT) versus the esophageal Doppler monitoring (EDM). Materials and Methods: Two hundred twenty-seven paired measurements from 10 patients who underwent abdominal surgery under general anesthesia were included for SV measurements. Pearson’s correlation coefficient was calculated, and Bland-Altman analysis was performed to evaluate the agreement between EDM and bioreactance (EDM-bioreactance) and between EDM and PWTT (EDM-PWTT). Results: EDM-bioreactance had a correlation coefficient of 0.75 (95% confidence interval [CI] 0.62 to 0.78; p&lt;0.001), bias of 0.28 ml (limits of agreement –30.92 to 31.38 ml), and percentage error of 46.82%. EDM-PWTT had a correlation coefficient of 0.48 (95% CI 0.44 to 0.72; p&lt;0.001), bias of –0.18 ml (limits of agreement –40.28 to 39.92 ml), and percentage error of 60.17%. A subgroup analysis of data from patients who underwent crystalloid loading was performed to detect the trending ability. The four-quadrant plot analysis between EDM-bioreactance and EDM-PWTT demonstrated concordance rates of 70.00% and 73.68%, respectively. Conclusion: SV measurement based on bioreactance technique and measurement of PWTT are not interchangeable with EDM. Trial registration: Thai Clinical Trials Registry, TCTR 20181217003 Keywords: Stroke volume, Cardiac output, Doppler, Perioperative care, Pulse, Time

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.

Accuracy of a multiparametric score based on pulse wave analysis for prediction of fluid responsiveness: ancillary analysis of an observational study.

PurposeThe pressure recording analytical method (PRAM) monitor is a non-invasive pulse contour cardiac output (CO) device that cannot be considered interchangeable with the gold standard for CO estimation. It, however, generates additional hemodynamic indices that need to be evaluated. Our objective was to investigate the performance of a multiparametric predictive score based on a combination of several parameters generated by the PRAM monitor to predict fluid responsiveness.MethodsSecondary analysis of a prospective observational study from April 2016 to December 2017 in two French teaching hospitals. We included critically ill patients who were monitored by esophageal Doppler monitoring and an invasive arterial line, and received a 250–500 mL crystalloid fluid challenge. The main outcome measure was the predictive score discrimination evaluated by the area under the receiver operating characteristics curve.ResultsThe three baseline PRAM-derived parameters associated with fluid responsiveness in univariate analysis were pulse pressure variation, cardiac cycle efficiency, and arterial elastance (P < 0.01, P = 0.03, and P < 0.01, respectively). The median [interquartile range] predictive score, calculated after discretization of these parameters according to their optimal threshold value was 3 [2–3] in fluid responders and 1 [1–2] in fluid non-responders, respectively (P < 0.001). The area under the curve of the predictive score was 0.807 (95% confidence interval, 0.662 to 0.909; P < 0.001).ConclusionA multiparametric score combining three parameters generated by the PRAM monitor can predict fluid responsiveness with good positive and negative predictive values in intensive care unit patients.Electronic supplementary materialThe online version of this article (10.1007/s12630-020-01736-y) contains supplementary material, which is available to authorized users.

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.

The Effect of Surgical Patient Positions on Plet Variability Index, Perfusion Index and Noninvasive Continuous Cardiac Output Measurement Method in Voluntary Breathing Volunteers

Amaç: Cerrahi prosedür için verilen farklı pozisyonlar doku perfüzyonunda ve kardiyak outputta değişikliklere neden olabilir. Bu çalışmada spontan solunuma sahip katılımcılarda plet değişkenlik indeksinin (PVI), perfüzyon indeks (PI) ve noninvaziv sürekli kardiyak output ölçüm yöntemi (EscCO) nin farklı cerrahi pozisyonlardaki değişimlerini araştırmayı amaçladık.Materyal ve Metod: 20 katılımcıdan oluşan bir sağlıklı birey grubu prospektif gözlemsel çalışmaya dahil edildi. Sırasıyla Supin, 30 derece baş yukarı, 45 derece baş yukarı, 20 derece Trendelenburg, 20 derece ters-Trendelenburg, ve pron pozisyonları uygulandı. Her pozisyon arası 10 ar dk olacak şekilde süre tutuldu. Her pozisyon değişikliğinden önce gönüllüler sırtüstü pozisyona alındı ve beş dakika dinlendikten sonra yeni pozisyon verildi. Pozisyon değişiminden sonraki 5. dakika PI, PVI, EscCO, SpO2 değerleri kayıt altına alındı.Bulgular: Katılımcıların farklı pozisyondayken ölçülen PI, PVI ile EscCO değerlerinde istatistiksel olarak anlamlı bir fark bulunamadı.Sonuç: Bu çalışma, PI, PVI ile EscCO nun tüm cerrahi pozisyonlarda herhangi bir değişikliğe uğramadığını ve her üç parametrenin de spontan solunumuna sahip genç sağlıklı bireylerde pozisyondan etkilenmediği ortaya koymuştur.

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.

Noninvasive cardiac output measurement based optimization in nonresponders of cardiac resynchronization therapy.

Cardiac resynchronization therapy (CRT) is an important and effective therapy for end-stage heart failure (HF). Nonresponse to CRT is one of the main obstacles to its application in clinical practice. Herein, we investigated the utilization of the optimization technique using noninvasive cardiac output measurement (NICOM) based Mobil-O-Graph device that measures several circulation parameters noninvasively. Seventy-five CRT nonresponder HF patients with an implanted CRT device were included. Patients were randomized equally to 3 groups: NICOM, echocardiographic, and empirical optimization groups. After 3 months of optimization, changes in six minutes walk test (6-MWT), cardiac output (CO), left ventricular ejection fraction (LVEF), and end-systolic volume (LVESV) were measured. New York Heart Association (NYHA) class and hospitalization for HF were also determined. There were no statistically significant differences among the three groups in terms of demographics, baseline characteristics. In the NICOM group, the 6-MWT, LVEF, CO, and LVESV measurements showed significant improvements compared to baseline values (P<.05). There was no significant improvement in 6-MWT, LVEF, CO, NYHA class, and LVESV in Echo and Empirical groups after 3 months (P>.05). 6-MWT, CO, LVESV percentages, and hospitalization for HF were significantly different between the groups (P<.05). In post hoc analyzes, the percentages of the change in 6-MWT, CO, LVESV, and hospitalization for HF were significantly higher in the NICOM group (P<.017). This study suggests that Mobil-O-Graph device optimization according to CO measures does appear to have potential hemodynamic and clinical benefits in nonresponder CRT patients. Use of Mobil-O-Graph device as an option for optimization of CRT devices can be an attractive method of improving CRT outcomes.