Non-invasive Cardiac Output Monitoring Research Articles

Effect of post-operative goal-directed fluid therapy (GDFT) on organ function after orthotopic liver transplantation: Secondary outcome analysis of the COLT randomised control trial

BackgroundGoal-directed fluid therapy (GDFT) has been shown to reduce the complications following a variety of major surgical procedures, possibly mediated by improved organ perfusion and function. We have shown that it is feasible to randomise patients to GDFT or standard fluid management following liver transplant in the cardiac-output optimisation following liver transplantation (COLT) trial. The current study compares end organ function in patients from the COLT trial who received GDFT in comparison to those receiving standard care (SC) following liver transplant. MethodsAdult patients with liver cirrhosis undergoing liver transplantation were randomised to GDFT or SC for the first 12 h following surgery as detailed in a published trial protocol. GDFT protocol was based on stroke volume (SV) optimisation using 250 ml crystalloid boluses. Total fluid administration and time to extubation were recorded. Hourly SV and cardiac output (CO) readings were recorded from the non-invasive cardiac output monitoring (NICOM) device in both groups. Pulmonary function was assessed by arterial blood gas (ABG) and ventilatory parameters. Lung injury was assessed using PaO2:FiO2 ratios and calculated pulmonary compliance. The KDIGO score was used for determining acute kidney injury. Renal and liver graft function were assessed during the post-operative period and at 3 months and 1-year. Results60 patients were randomised to GDFT (n = 30) or SC (n = 30). All patients completed the 12 h intervention period. GDFT group received a significantly higher total volume of fluid during the 12 h trial intervention period (GDFT 5317 (2335) vs. SC 3807 (1345) ml, p = 0.003); in particular crystalloids (GDFT 3968 (2073) vs. SC 2510 (1027) ml, p = 0.002). There was no evidence of significant difference between the groups in SV or CO during the assessment periods. Time to extubation, PaO2: FIO2 ratios, pulmonary compliance, ventilatory or blood gas measurements were similar in both groups. There was a significant rise in serum creatinine from baseline (77 μmol/L) compared to first (87 μmol/L, p = 0.039) and second (107 μmol/L, p = 0.001) post-operative days. There was no difference between GDFT and SC in the highest KDIGO scores for the first 7 days post-LT. At 1-year follow-up, there was no difference in need for renal replacement therapy or graft function. ConclusionsIn this randomised trial of fluid therapy post liver transplant, GDFT was associated with an increased volume of crystalloids administered but did not alter early post-operative pulmonary or renal function when compared with standard care.

Perioperative Continuous Noninvasive Cardiac Output Monitoring in Cardiac Surgery Patients by a Novel Capnodynamic Method

To test the clinical performance of a novel continuous noninvasive cardiac output (CO) monitoring based on expired carbon dioxide kinetics in cardiac surgery patients. A prospective feasibility pragmatic clinical study. A single-center, large community hospital. Thirty-two patients undergoing cardiac surgery were studied during the intraoperative (before cardiopulmonary bypass) and postoperative (in the intensive care unit before extubation) periods. CO was measured simultaneously by the continuous capnodynamic method and by transpulmonary thermodilution during changes in the patient's hemodynamic and/or respiratory conditions. The current recommended comparative statistics for CO measurement methods were analyzed, including bias, precision, and percentage error obtained from Bland-Altman analysis, and concordance between methods obtained from the four-quadrant plot analysis to evaluate the trending ability. Bias ± limits of agreement and percentage error were -0.6 (-1.9 to +0.8; 95% CI of 3.73-5.25) L/min and 31% (n=147 measurements) for the intraoperative period, -0.8 (-2.4 to +0.9; 95% CI of 3.03-5.21) L/min and 41% (n=66) for the postoperative period, and -0.6 (-2.1 to +0.8; 95% CI of 3.74-5.00) L/min and 34% (n=213) for the pooled data. The trending analysis obtained a concordance of 82% (n=65) for the intraoperative and 71% (n=24) for the early postoperative periods. Aggregation of both data sets gave a concordance of 79% (n=89). The continuous capnodynamic method was reliable and in good agreement with the reference method, and had an accuracy and trending ability good enough tomake it a possible future alternative for hemodynamic monitoring in the studied population of elective adult cardiac surgery patients.

COMBED: Rapid non-invasive Cardiac Output Monitoring Baseline assessment in adult Emergency Department patients with haemodynamic instability.

The application of rapid, non-operator-dependent, non-invasive cardiac output monitoring (COM) may provide early physiological information in ED patients with haemodynamic instability (HI). Our primary objective was to assess the feasibility of measuring pre-intervention (baseline) cardiac index (CI) and associated haemodynamic parameters. We performed a prospective observational study of adults shortly after presentation to the ED of a large university hospital with tachycardia or hypotension or both. We applied non-invasive COM for 5min and recorded CI, mean arterial pressure (MAP), stroke volume index (SVI) and systemic vascular resistance index (SVRI). We assessed for differences between those presenting with hypotension or hypotension and tachycardia with tachycardia alone and between those with or without suspected infection. We obtained haemodynamic parameters in 46 of 49 patients. In patients with hypotension or hypotension and tachycardia (n = 15) rather than tachycardia alone (n = 31), we observed a lower MAP (60.8 vs 87.7, P < 0.0001), CI (2.8 vs 3.9, P = 0.0167) and heart rate (85.5 vs 115.4, P < 0.0001). There was no difference in SVI (33.7 vs 33.4, P = 0.93) or SVRI (1970 vs 2088, P = 0.67). Patients with suspected infection had similar haemodynamic values except for a lower SVRI (1706 vs 2237, P = 0.011). Rapid, non-operator-dependent, non-invasive COM was possible in >90% of ED patients presenting with HI. Compared with tachycardia alone, patients with hypotension had lower CI, MAP and heart rate, while those with suspected infection had a lower SVRI. This technology provides novel insights into the early state of the circulation in ED patients with HI.

Hemodynamic changes during pneumoperitoneum and reverse Trendelenburg position in bariatric surgery: An observational study using noninvasive cardiac output monitoring

Background: Patients undergoing bariatric surgeries are at higher perioperative risk due to multiple comorbidities. We studied the hemodynamic changes during pneumoperitoneum and reverse Trendelenburg position in bariatric surgery, using noninvasive cardiac output (CO) monitoring. Methods: In this prospective observational study, 60 patients of the American Society of Anesthesiologists Grade I–II, aged between 18 and 60 years, planned for elective laparoscopic bariatric surgery were included. During the intraoperative period, hemodynamic monitoring was done using an estimated continuous CO (esCCO) monitor. We noted oxygen saturation (SpO2), heart rate, blood pressure (BP), and CO values obtained before induction of general anesthesia and were compared with values obtained after induction, postintubation, after pneumoperitoneum, after reverse Trendelenburg, and every 10 min during the procedure and postextubation. Results: The mean baseline SpO2, pulse rate (PR), systolic BP (SBP), diastolic BP (DBP), and CO was 99.17 ± 1.7, 99.9 ± 1.35 bpm, 136.3 ± 14.5 mm Hg, 83.11 ± 10.5 mm Hg, and 7.59 ± 1.44 L/min, respectively. There was a significant fall in PR, SBP, DBP, and CO after induction of anesthesia and intubation (P = 0.001). After creating pneumoperitoneum and reverse Trendelenburg, the fall in hemodynamic parameters was also significant (P = 0.001). Conclusions: The esCCO noninvasive CO monitor can be used in patients undergoing bariatric surgeries and predict CO during surgery.

Hemodynamic Assessment of Pregnant People with and without Obesity by Noninvasive Bioreactance: A Pilot Study.

Objective This study aimed to identify cardiovascular differences between pregnant people with and without obesity for trimester-specific changes in hemodynamic parameters using noninvasive cardiac output monitoring (NICOM). Study Design This study is a pilot prospective comparative cohort between pregnant people with and without obesity. Hemodynamic assessment was performed with NICOM (12–14, 21–23, and 34–36 weeks) during pregnancy. Results In first trimester, pregnant people with obesity had higher blood pressure, stroke volume (SV), total peripheral resistance index (TPRI), and cardiac output (CO). Pregnant people with obesity continued to have higher SV and cardiac index (second and third trimesters). During the first trimester, body mass index (BMI) positively correlated with SV, TPRI, and CO. Fat mass showed a strong correlation with TPRI. BMI positively correlated with CO during the second trimester and fat mass was positively associated with CO. During the third trimester, TPR negatively correlated with BMI and fat mass. Conclusion Fat mass gain in the period between the first and second trimesters in addition to the hemodynamic changes due to obesity and pregnancy contribute to some degree of left ventricular diastolic dysfunction which was manifested by lower SVs. Future work should investigate the possible causative role of obesity in the cardiovascular changes identified in people with obesity.

Non-invasive continuous cardiac output monitoring in thoracic cancer surgery

BACKGROUND Patients scheduled for thoracic cancer surgery are eligible for goal-directed fluid therapy, but cardiac output monitoring remains challenging in that specific setting. OBJECTIVE We aimed to compare cardiac output as measured with chest bioreactance with that measured by calibrated pulse contour analysis; the hypothesis being that both methods would be interchangeable. DESIGN A prospective monocentre observational study. SETTING A tertiary university hospital. PATIENTS Fifty adult patients undergoing thoracic cancer surgery over a one year period. MAIN OUTCOME MEASURES Simultaneous measurements of cardiac index (CI) with bioreactance (CI-NICOM) and arterial pulse contour analysis calibrated by transthoracic echocardiography (CI-PCA) were performed at eight pre-specified intra-operative time points and following fluid challenge and/or vasoactive agents. Relationships between absolute values and changes in CI were assessed by linear regression. Interchangeability was tested with Bland–Altman analysis and percentage error calculation. A four quadrant plot was used to evaluate trending ability. RESULTS There was a significant difference between CI-PCA and CI-NICOM: 2.4 ± 0.8 (range: 0.9 to 5.8) l min−1 m−2 vs. 2.9 ± 0.9 (range: 0.9 to 7.2) l min−1 m−2, respectively (P &lt; 0.001). A positive relationship was found between both techniques: y = 0.29x + 2.19; r 2 = 0.08 (P &lt; 0.001). Taking CI-PCA as the reference method, there was a systematic overestimation of CI-NICOM by 21% (0.5 l min−1 m−2) and limits of agreement were large: -2.49 to 1.47 l min−1 m−2. The percentage error was 77% and concordance rates were 75 and 70% with and without an exclusion zone of 0.5 l min−1 m−2. CONCLUSION Chest bioreactance is feasible and well tolerated in patients undergoing thoracic surgery for cancer. When compared with calibrated PCA over a wide range of CI values, the technique is moderately correlated, not interchangeable, and provides moderate trending ability. TRIAL REGISTRATION NCT04251637.

A Novel Hypertension Management Algorithm Guided by Hemodynamic Data

A Novel Hypertension Management Algorithm Guided by Hemodynamic Data

Non-invasive cardiac output monitoring (NICOM) in adult congenital heart disease patients with Fontan palliation

RationaleFontan palliation for single ventricle malformations is an increasingly common reason for heart failure in the adult population. Cardiac output (CO) measurement in Fontan physiology is achieved by invasive cardiac catheterization (RHC). Noninvasive CO monitors using thoracic bioreactance (NICOM) have been validated in non-congenital patients but have not been studied in adult Fontan patients. ObjectiveTo compare RHC obtained values of CO using the Fick equation with those measured simultaneously by NICOM in a cohort of adults with Fontan palliation. Methods and resultsIn nineteen patients undergoing routine outpatient RHC, we compared CO values as determined by Fick with those generated by the Starling SV NICOM device. Bland-Altman plots and intraclass correlation coefficients (ICCs) revealed internal consistency within NICOM measurements, however the agreement between RHC and NICOM for CO was poor (ICCs ​∼ ​0.40). We performed sub-analyses using two-sample T-tests and ICCs to determine if clinical cyanosis, acute desaturation, or Fontan pressure affected the difference observed between RHC and NICOM. Neither chronic hypoxia, acute desaturation, nor Fontan pressure measures were found to be associated with the observed difference between the RHC and NICOM measured CO. Discussion and conclusionOur study did not find a correlation between RHC and NICOM derived measures of CO in a cohort of Fontan patients, even in sub-analyses of confounders of Fontan physiology. We observed internal consistency within the device, which may open a role for monitoring of trends rather than absolute values in Fontan patients. Our study was limited due to small sample size.

Неинвазивный мониторинг сердечного выброса у пациентов с политравмой

Актуальность. Стандартом оценки параметров центральной гемодинамики и ответа на инфузионную терапию принято считать мониторинг сердечного выброса. Инновационная технология неинвазивного расчетного непрерывного измерения сердечного выброса (Estimated Continuous Cardiac Output — esCCO) позволяет измерять его в online-режиме и может обеспечивать улучшенный мониторинг гемодинамического статуса пациентов с политравмой. Цель: оценить эффективность и целесообразность неинвазивного непрерывного мониторинга сердечного выброса с помощью технологии esCCO у пациентов в остром периоде политравмы. Материалы и методы. Приведены данные клинического обследования и лечения 40 пациентов с политравмой, доставленных в отделение анестезиологии и интенсивной терапии КНП «Клиническая больница скорой медицинской помощи г. Львова». У 20 пациентов 1-й группы, кроме определения рутинных параметров, проводили мониторинг показателей центральной гемодинамики с помощью модуля esCCO, интегрированного в монитор Life Scope (Nihon Kohden, Япония). Во 2-й (контрольной) группе (n = 20) для сравнительного анализа регистрировали только традиционные показатели — артериальное давление (АД), электрокардиограмму, сатурацию крови (SpO2) — с помощью многофункциональных мониторов Philips IntelliVue (MP20), выполняли стандартные лабораторные анализы. Результаты. С первых по вторые сутки в обеих группах пациентов наблюдались статистически значимые изменения лабораторных показателей: уровень гематокрита снижался с 32,0 ± 1,0 % до 29,0 ± 0,8 % (р &lt; 0,01); содержание гемоглобина крови снижалось в среднем с 91,5 ± 2,1 г/л до 87,0 ± 1,9 г/л (р &lt; 0,05); уровень лейкоцитов возрастал в среднем с (9,8 ± 0,4) • 106 до (12,0 ± 0,5) • 106 (р &lt; 0,001). Эти изменения свидетельствуют о развитии анемии и системной воспалительной реакции в остром периоде после травмы, что оказывает существенное влияние на реологические свойства крови и гемодинамику. У пациентов 1-й группы отмечались стабильные показатели АД (систолическое АД — 122,9 ± 6,2 мм рт.ст., диастолическое АД — 69,7 ± 2,3 мм рт.ст.) по сравнению с контрольной группой (систолическое АД — 112,2 ± 5,9 мм рт.ст., диастолическое АД — 67,5 ± 2,1 мм рт.ст.). У больных 1-й группы наблюдалось уменьшение объема инфузионной терапии на 13,5 % и снижение на 11,5 % ранних осложнений по сравнению с пациентами контрольной группы. Выводы. Мы установили, что в условиях острого периода политравмы на фоне системного воспалительного ответа организма развиваются реологические изменения, которые потенцируют недостаточность кровообращения. Неинвазивный мониторинг показателей центральной гемодинамики с помощью модуля esCCO является простым и информативным методом, позволяющим эффективно ускорить оптимизацию гемодинамического статуса пациентов при политравме.

Clinical Validation of Bioreactance for the Measurement of Cardiac Output in Pregnancy

(Anaesthesia. 2020;75:1307–1313) This study aimed to use 2-dimensional transthoracic echocardiography (TTE) and the Non-Invasive Cardiac Output Monitor (NICOM) to investigate distinct hemodynamic patterns found in pregnancy to determine whether those measurements could be used to predict and prevent preeclampsia and fetal growth restriction. The primary outcome was validation of cardiac output assessment via bioreactance compared against TTE with simultaneously paired recordings.

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

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

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

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

Successive perioperative management of laparoscopic liver resection in the reverse Trendelenburg position for a patient with Fontan physiology: a case report

BackgroundLaparoscopic surgery for a patient with Fontan physiology is challenging because pneumoperitoneum and positive pressure ventilation could decrease venous return and the accumulated partial pressure of arterial carbon dioxide (PaCO2) could increase pulmonary vascular resistance, which might lead to disruption of the hemodynamics.Case presentationA 25-year-old man with Fontan physiology was scheduled to undergo laparoscopic liver resection for Fontan-associated liver disease (FALD) with noninvasive monitoring of cardiac output (CO) by transpulmonary thermodilution in addition to transesophageal echocardiography. The abdominal air pressure was maintained low, and we planned to switch to open abdominal surgery promptly if hemodynamic instability became apparent because of the accumulated PaCO2 or postural change. Consequently, the pneumoperitoneum had limited influence on circulatory dynamics, but central venous pressure significantly decreased with postural change to the reverse Trendelenburg position. Laparoscopic liver resection for FALD was performed successfully with no significant changes in CO and central venous saturation.ConclusionsWith strict circulation management, laparoscopic surgery for a patient with Fontan physiology can be performed safely. Comprehensive hemodynamic assessment by noninvasive transpulmonary thermodilution can provide valuable information to determine the time for shift to open abdominal surgery.

Comparative study between suprasternal and apical windows: a user-friendly cardiac output measurement for the anesthesiologist

IntroductionTransthoracic echocardiography is a safe and readily available tool for noninvasive monitoring of Cardiac Output (CO). The use of the suprasternal window situated at the sternal notch can be an alternative approach for estimating blood flow. The present study aimed to compare two methods of CO calculation. We compared the descending aorta Velocity-Time Integral (VTI) measurement from the suprasternal window view with the standard technique to determine CO that uses VTI measurements from the LVOT (Left Ventricular Outflow Tract) view. We also aimed to find out whether after basic training a non-echocardiographer operator can obtain reproducible measurements of VTI using this approach. MethodsIn the first part of the study, 26 patients without known cardiovascular diseases were evaluated and VTI data were acquired from the suprasternal window by a non-echocardiographer and an echocardiographer. Next, 17 patients were evaluated by an echocardiographer only and VTI and CO measurements were obtained from suprasternal and apical windows. Data were analyzed using the Bland and Altman method (BA), correlation and regression. ResultsWe found a strong correlation between measurements obtained by a non-expert and an expert echocardiographer and detected that an inexperienced trainee can acquire VTI measurements from the suprasternal window view. Regarding agreement between CO measurements, data obtained showed a positive correlation and the Bland and Altman analysis presented a total variation of 38.9%. ConclusionRegarding accuracy, it is likely that TTE (Transthoracic Echocardiogram) measurements of CO from the suprasternal window view are comparable to other minimally invasive techniques currently available. Due to its user-friendliness and low cost, it can be a convenient technique for obtaining perioperative hemodynamic measurements, even by inexperienced operators.

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

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

Maternal haemodynamics during labour epidural analgesia with and without adrenaline.

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

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

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

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

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

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

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

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

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