Cardiac Output Measurements in Septic Patients: Comparing the Accuracy of USCOM to PiCCO

Progress in the Clinical Assessment and Treatment of Myocardial Depression in Critically Ill Patient with Sepsis

Myocardial inhibition is the main cause of death in patients with sepsis.In recent years, methodological differences in the diagnosis, assessment, and treatment of septic myocardial depression have been observed, and how to objectively and accurately evaluate the degree of myocardial depression and the timing of treatment strategies have generally been the focus of this area of research. Based on the relevant research at home and abroad, the current review summarizes the clinical characteristics, methodological diagnosis, and symptomatic treatment of septic myocardial depression. The aim of doing so is to provide a reference for the early identification and treatment of patients with sepsis and myocardial depression.

Towards Biohybrid Lung Development: Establishment of a Porcine In Vitro Model

Lung transplantation (LTx) is the only curative therapy option for patients with end-stage lung diseases, though only available for chosen patients. To provide an alternative treatment option to LTx, we aim for the development of an implantable biohybrid lung (BHL) based on hollow fiber membrane (HFM) technology used in extracorporeal membrane oxygenators. Crucial for long-lasting BHL durability is complete hemocompatibility of all blood contacting surfaces, which can be achieved by their endothelialization. In continuation to successful in vitro investigations using human endothelial cells (ECs), indicating general feasibility, the appropriate porcine in vivo model needs to be prepared and established to fill the translational data gap prior to patient’s application. Therefore, isolation of porcine ECs from carotid arteries (pCECs) was established. Following, pCECs were used for HFM endothelialization and examined under static and dynamic conditions using cell medium or heparinized blood, to assess their proliferation capacity, flow resistance and activation state, especially under clinically relevant conditions. Additionally, comparative hemocompatibility tests between native and endothelialized HFMs were performed. Overall, pure pCECs formed a viable and confluent monolayer, which resisted applied flow conditions, in particular due to physiological extracellular matrix synthesis. Additionally, pCECs remained the non-inflammatory and anti-thrombogenic status, significantly improving the hemocompatibility of endothelialized HFMs. Finally, as relevant for reliable porcine to human translation, pCECs behaved in the same way as human ECs. Concluding, generated in vitro data justify further steps towards pre-clinical BHL examination, in particular BHL application to porcine lung injury models, reflecting the clinical scenario with end-stage lung-diseased patients.

CRRT influences PICCO measurements in febrile critically ill patients

The aim of this study was to investigate whether continuous renal replacement therapy (CRRT) influences the global end-diastolic volume index (GEDVI), cardiac index (CI), and extravascular lung water index (EVLWI) measured by Pulse Index Continuous Cardiac Output (PICCO) in febrile patients. Fifteen fever patients were included in this study. CI, GEDVI, EVLWI, heart rate (HR), and mean arterial pressure (MAP) were measured at five time-points: before CRRT (T0), immediately after CRRT started (T1), 15 min after CRRT started (T2), immediately after CRRT stopped (T3), and 15 min after CRRT stopped (T4). Results have shown that CI and GEDVI were decreased significantly in T1 (CI: 4.09 ± 0.72 vs 2.81 ± 0.58 L/min m², P = 0.000 and GEDVI: 727.86 ± 63.47 vs 531.07 ± 66.63 mL/m², P = 0.000). However, CI and GEDVI were significantly increased in T3 (CI: 4.09 ± 0.72 vs 7.23 ± 1.32 L/min m², P = 0.000 and GEDVI 727.86 ± 63.47 vs 1339.17 ± 121.52 mL/m², P = 0.000). There were no significant differences in T2 and T4. Among the five-time points, no measurement errors were observed with regards to HR, MAP, and EVLWI. Therefore, the data herein contained suggests that PICCO measurements should begin 15 min after the start or stop of CRRT.

Effects of PICCO in the guidance of goal-directed fluid therapy for gastrointestinal function after cytoreductive surgery for ovarian cancer

OBJECTIVE

To explore the effects of PICCO on the Guidance of Goal-Directed Fluid Therapy for gastrointestinal function after cytoreductive surgery for ovarian cancer.

METHODS

A total of 98 patients who received cytoreductive surgery for ovarian cancer under general anesthesia in our hospital were stochastically divided into the observation group and control group, with 49 cases in each group. The observation group received PICCO guided goal-directed fluid therapy, while patients in the control group were treated with conventional fluid therapy. At last, the total amount of infusion, the time required for postoperative gastrointestinal function recovery and related recovery rating, the first time to get out of bed after the surgery and the total hospitalization time were observed and compared between the two groups.

RESULTS

The observation group had less time for gastrointestinal function recovery and had better functional recovery rating as well as other indicators than the control group. Besides, the observation group had less volume of infusion, needed shorter time to get out of bed and had a shorter length of hospital stay than the control group (all P<0.05).

CONCLUSION

PICCO guided goal-directed liquid therapy can effectively improve the recovery of gastrointestinal function and reduce the length of stay in patients with ovarian cancer after cytoreductive surgery.

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

BACKGROUND

There 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.

METHODS

This 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.

RESULTS

Thirty-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.

CONCLUSION

In 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.

Cardiac output measurements via echocardiography versus thermodilution: A systematic review and meta-analysis

Echocardiography, as a noninvasive hemodynamic evaluation technique, is frequently used in critically ill patients. Different opinions exist regarding whether it can be interchanged with traditional invasive means, such as the pulmonary artery catheter thermodilution (TD) technique. This systematic review aimed to analyze the consistency and interchangeability of cardiac output measurements by ultrasound (US) and TD. Five electronic databases were searched for studies including clinical trials conducted up to June 2019 in which patients’ cardiac output was measured by ultrasound techniques (echocardiography) and TD. The methodological quality of the included studies was evaluated by two independent reviewers who used the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2), which was tailored according to our systematic review in Review Manager 5.3. A total of 68 studies with 1996 patients were identified as eligible. Meta-analysis and subgroup analysis were used to compare the cardiac output (CO) measured using the different types of echocardiography and different sites of Doppler use with TD. No significant differences were found between US and TD (random effects model: mean difference [MD], -0.14; 95% confidence interval, -0.30 to 0.02; P = 0.08). No significant differences were observed in the subgroup analyses using different types of echocardiography and different sites except for ascending aorta (AA) (random effects model: mean difference [MD], -0.37; 95% confidence interval, -0.74 to -0.01; P = 0.05) of Doppler use. The median of bias and limits of agreement were -0.12 and ±0.94 L/min, respectively; the median of correlation coefficient was 0.827 (range, 0.140–0.998). Although the difference in CO between echocardiography by different types or sites and TD was not entirely consistent, the overall effect of meta-analysis showed that no significant differences were observed between US and TD. The techniques may be interchangeable under certain conditions.

Emergency department non-invasive cardiac output study (EDNICO): a feasibility and repeatability study

Background

There is little published data investigating non-invasive cardiac output monitoring in the emergency department (ED). We assessed six non-invasive fluid responsiveness monitoring methods which measure cardiac output directly or indirectly for their feasibility and repeatability of measurements in the ED: (1) left ventricular outflow tract echocardiography derived velocity time integral, (2) common carotid artery blood flow, (3) suprasternal aortic Doppler, (4) bioreactance, (5) plethysmography with digital vascular unloading method, and (6) inferior vena cava collapsibility index.

Methods

This is a prospective observational study of non-invasive methods of assessing fluid responsiveness in the ED. Participants were non-ventilated ED adult patients requiring intravenous fluid resuscitation. Feasibility of each method was determined by the proportion of clinically interpretable measurements from the number of measurement attempts. Repeatability was determined by comparing the mean difference of two paired measurements in a fluid steady state (after participants received an intravenous fluid bolus).

Results

76 patients were recruited in the study. A total of 207 fluid responsiveness measurement sets were analysed. Feasibility rates were 97.6% for bioreactance, 91.3% for vascular unloading method with plethysmography, 87.4% for common carotid artery blood flow, 84.1% for inferior vena cava collapsibility index, 78.7% for LVOT VTI, and 76.8% for suprasternal aortic Doppler. The feasibility rates difference between bioreactance and all other methods was statistically significant.

Conclusion

Our study shows that non-invasive fluid responsiveness monitoring in the emergency department may be feasible with selected methods. Higher repeatability of measurements were observed in non-ultrasound methods. These findings have implications for further studies specifically assessing the accuracy of such non-invasive cardiac output methods and their effect on patient outcome in the ED in fluid depleted states such as sepsis.

Electronic supplementary material

The online version of this article (10.1186/s13049-019-0586-6) contains supplementary material, which is available to authorized users.

Influence of injection rates of calibrating standard solution on monitoring pulse indicator continuous cardiac output

OBJECTIVE

This study aimed to investigate the influence of injection rates of calibrating standard solution on monitoring pulse indicator continuous cardiac output (PICCO, made in Germany), and thereby to provide significant references for clinical practice.

METHODS

A total of 108 critical patients in stroke intensive care unit were identified. All these participants received transesophageal cardiac color Doppler ultrasound, and within 15 min PICCO equipment was utilized to monitor the relevant parameters, by means of 0 °C calibrating standard solution, and the injection speeds were 2-4, 5-7, and 8-10 s. Besides, the monitoring indicators were as follows, cardiac index, global ejection fraction, global end diastolic volume index. The potential correlations were evaluated between PICCO and transesophageal cardiac color Doppler ultrasound.

RESULTS

All the data was available, and the monitored parameters of PICOO at 2-4, 5-7, and 8-10 s were positively correlated with the parameters obtained from transesophageal cardiac color Doppler ultrasound (P < 0.05). Specially, it is worth emphasizing that the best correlation between them could be provided when the injection rate was 2-4 s.

CONCLUSION

When the injection rate at 2-4 s, the parameters obtained by PICOO were much closer to that of transesophageal cardiac color Doppler ultrasound. Furthermore, the parameters of PICOO obtained at 2-4 s could better reflect cardiac function of patients.

Next-generation, personalised, model-based critical care medicine: a state-of-the art review of in silico virtual patient models, methods, and cohorts, and how to validation them

Critical care, like many healthcare areas, is under a dual assault from significantly increasing demographic and economic pressures. Intensive care unit (ICU) patients are highly variable in response to treatment, and increasingly aging populations mean ICUs are under increasing demand and their cohorts are increasingly ill. Equally, patient expectations are growing, while the economic ability to deliver care to all is declining. Better, more productive care is thus the big challenge. One means to that end is personalised care designed to manage the significant inter- and intra-patient variability that makes the ICU patient difficult. Thus, moving from current "one size fits all" protocolised care to adaptive, model-based "one method fits all" personalised care could deliver the required step change in the quality, and simultaneously the productivity and cost, of care. Computer models of human physiology are a unique tool to personalise care, as they can couple clinical data with mathematical methods to create subject-specific models and virtual patients to design new, personalised and more optimal protocols, as well as to guide care in real-time. They rely on identifying time varying patient-specific parameters in the model that capture inter- and intra-patient variability, the difference between patients and the evolution of patient condition. Properly validated, virtual patients represent the real patients, and can be used in silico to test different protocols or interventions, or in real-time to guide care. Hence, the underlying models and methods create the foundation for next generation care, as well as a tool for safely and rapidly developing personalised treatment protocols over large virtual cohorts using virtual trials. This review examines the models and methods used to create virtual patients. Specifically, it presents the models types and structures used and the data required. It then covers how to validate the resulting virtual patients and trials, and how these virtual trials can help design and optimise clinical trial. Links between these models and higher order, more complex physiome models are also discussed. In each section, it explores the progress reported up to date, especially on core ICU therapies in glycemic, circulatory and mechanical ventilation management, where high cost and frequency of occurrence provide a significant opportunity for model-based methods to have measurable clinical and economic impact. The outcomes are readily generalised to other areas of medical care.

Non-Invasive Monitoring of Cardiac Output in Critical Care Medicine

Critically ill patients require close hemodynamic monitoring to titrate treatment on a regular basis. It allows administering fluid with parsimony and adjusting inotropes and vasoactive drugs when necessary. Although invasive monitoring is considered as the reference method, non-invasive monitoring presents the obvious advantage of being associated with fewer complications, at the expanse of accuracy, precision, and step-response change. A great many methods and devices are now used over the world, and this article focuses on several of them, providing with a brief review of related underlying physical principles and validation articles analysis. Reviewed methods include electrical bioimpedance and bioreactance, respiratory-derived cardiac output (CO) monitoring technique, pulse wave transit time, ultrasound CO monitoring, multimodal algorithmic estimation, and inductance thoracocardiography. Quality criteria with which devices were reviewed included: accuracy (closeness of agreement between a measurement value and a true value of the measured), precision (closeness of agreement between replicate measurements on the same or similar objects under specified conditions), and step response change (delay between physiological change and its indication). Our conclusion is that the offer of non-invasive monitoring has improved in the past few years, even though further developments are needed to provide clinicians with sufficiently accurate devices for routine use, as alternative to invasive monitoring devices.

Metabolic resuscitation in sepsis: a necessary step beyond the hemodynamic?

Despite the advances made in monitoring and treatment of sepsis and septic shock, many septic patients ultimately develop multiple organ dysfunction (MODS) and die, suggesting that other players are involved in the pathophysiology of this syndrome. Mitochondrial dysfunction occurs early in sepsis and has a central role in MODS development. MODS severity and recovery of mitochondrial function have been associated with survival. In recent clinical and experimental investigations, mitochondrion-target therapy for sepsis and septic shock has been suggested to reduce MODS severity and mortality. This intervention, which might be named "metabolic resuscitation", would lead to improved mitochondrial activity afforded by pharmacological and nutritional agents. Of particular interest in this therapeutic strategy is thiamine, a water-soluble vitamin that plays an essential role in cellular energy metabolism. Critical illness associated with hypermetabolic states may predispose susceptible individuals to the development of thiamine deficiency, which is not usually identified by clinicians as a source of lactic acidosis. The protective effects of thiamine on mitochondrial function may justify supplementation in septic patients at risk of deficiency. Perspectives of supplementation with other micronutrients (ascorbic acid, tocopherol, selenium and zinc) and potential metabolic resuscitators [coenzyme Q10 (CoQ10), cytochrome oxidase (CytOx), L-carnitine, melatonin] to target sepsis-induced mitochondrial dysfunction are also emerging. Metabolic resuscitation may probably be a safe and effective strategy in the treatment of septic shock in the future. However, until then, preliminary investigations should be replicated in further researches for confirmation. Better identification of groups of patients presumed to benefit clinically by a certain intervention directed to "mitochondrial resuscitation" are expected to increase driven by genomics and metabolomics.

A comparison of the non-invasive ultrasonic cardiac output monitor (USCOM) with the oesophageal Doppler monitor during major abdominal surgery

BACKGROUND

Perioperative interventions, targeted to increase global blood flow defined by explicit measured goals, reduce postoperative complications. Consequently, reliable non-invasive estimation of the cardiac output could have far-reaching benefit.

METHODS

This study compared a non-invasive Doppler device - the ultrasonic cardiac output monitor (USCOM) - with the oesophageal Doppler monitor (ODM), on 25 patients during major abdominal surgery. Stroke volume was determined by USCOM (SV_USCOM) and ODM (SV_ODM) pre and post fluid challenges.

RESULTS

A ≥ 10% change (Δ) SV_USCOM had a sensitivity of 94% and specificity of 88% to detect a ≥ 10% Δ SV_ODM; the area under the receiver operating curve was 0.94 (95% CI 0.90-0.99). Concordance was 98%, using an exclusion zone of <10% Δ SV_ODM. 135 measurements gave median SV_USCOM 80 ml (interquartile range 65-93 ml) and SV_ODM 86 ml (69-100 ml); mean bias was 5.9 ml (limits of agreement -20 to +30 ml) and percentage error 30%.

CONCLUSIONS

Following fluid challenges SV_USCOM showed good concordance and accurately discriminated a change ≥10% in SV_ODM.

Recurrent undifferentiated shock: Idiopathic Systemic Capillary Leak Syndrome

Idiopathic Systemic Capillary Leak Syndrome is a potentially fatal disorder that is under diagnosed. It commonly presents as recurrent undifferentiated shock with hypotension, hypoalbuminemia and hemoconcentration. There are three distinct phases that define the syndrome; Prodromal, Extravasation and Recovery.

Can we obtain a noninvasive and continuous estimation of cardiac output? Comparison between three noninvasive methods

Cardiac output (CO) is often desirable for assessing the hemodynamic condition of a patient, especially in critically ill cardiac patients. Various noninvasive methods are available for this purpose. Inert gas rebreathing (IGR) and 2D-Doppler echocardiography methods have been validated. Based on the relationship between pulse wave transit time and stroke volume, the VISMO® provides an estimated continuous cardiac output (esCCO) measurement using only an electrocardiogram, pulse oximeter wave, and cuff arterial blood pressure. Doppler echocardiography is being currently used in every day practice in this setting and IGR is a validated method, thus we wanted to assess the agreement between these 3 methods for noninvasive CO calculation and reproducibility of esCCO. Patients followed in our cardiology department received on the same day a CO analysis by esCCO, Doppler echocardiography and IGR. Thirty-four patients were included (16 women, mean age 65 ± 15 years). Bland and Altman plots showed a good agreement between IGR and 2D-Doppler echocardiography (bias = 0.31 L/minute). Though there was also an agreement between esCCO and the other 2, the bias was rather large: 1.18 L/minute with IGR and 1.51 L/min with 2D-Doppler echo. The intraclass correlation coefficient was poor whatever the methods. However, esCCO had a satisfactory reproducibility and accuracy compared rather well with the other 2. This method could be suitable for patient screening and monitoring.

Optimal management of the critically ill: anaesthesia, monitoring, data capture, and point-of-care technological practices in ovine models of critical care

Animal models of critical illness are vital in biomedical research. They provide possibilities for the investigation of pathophysiological processes that may not otherwise be possible in humans. In order to be clinically applicable, the model should simulate the critical care situation realistically, including anaesthesia, monitoring, sampling, utilising appropriate personnel skill mix, and therapeutic interventions. There are limited data documenting the constitution of ideal technologically advanced large animal critical care practices and all the processes of the animal model. In this paper, we describe the procedure of animal preparation, anaesthesia induction and maintenance, physiologic monitoring, data capture, point-of-care technology, and animal aftercare that has been successfully used to study several novel ovine models of critical illness. The relevant investigations are on respiratory failure due to smoke inhalation, transfusion related acute lung injury, endotoxin-induced proteogenomic alterations, haemorrhagic shock, septic shock, brain death, cerebral microcirculation, and artificial heart studies. We have demonstrated the functionality of monitoring practices during anaesthesia required to provide a platform for undertaking systematic investigations in complex ovine models of critical illness.

Cardiotoxicity After Anthracycline Treatment in Survivors of Adult Cancers: Monitoring by USCOM, Echocardiography and Serum Biomarkers

Background

Anthracyclines are agents with a well known documented anti-tumoral activity. Cardiac side effects are the principal toxicity. Here we evaluate and monitor the onset of late anthracycline-induced cardiotoxicity with real-time CW-Doppler ultrasound cardiac output monitoring (USCOM®) and echocardiography in combination with serum biomarkers.

Methods

Fifty-two patients without cardiac disease who had received an anthracycline-based regimen for various cancer types were included in this study. Patients’ hemodynamic parameters as stroke volume (SV USCOM (mL)) and ejection fraction (EF ECHOCARDIOGRAPHY (%)) were measured with USCOM and echocardiography and correlated to serum biomarkers (NT-pro-BNP and cTnT).

Results

Eighteen patients (34.6%) developed cardiac disease (NYHA I-III). An increasing cumulative anthracycline dose was associated with a decrease of the EF determined by echocardiography as well the SV by USCOM and with a higher NYHA class. Those patients who experienced cardiac disease showed a reduction of the EF and SV and increased serum biomarkers.

Conclusions

Real-time CW-Doppler USCOM, is a fast and reliable method to monitor late hemodynamic changes as a symptom of anthracycline-induced cardiotoxicity comparable to the findings by echocardiography and serum biomarkers.