Spatiotemporal hemodynamic monitoring via configurable skin-like microfiber Bragg grating group

Systemic blood circulation is one of life activity’s most important physiological functions.Continuous noninvasive hemodynamicmonitoring is essential for the management of cardiovascular status.However,it is difficult to achieve systemichemodynamic monitoring with the daily use of current devices due to the lack of multichannel and time-synchronized operationcapability over the whole body.Here,we utilize a soft microfiber Bragg grating group to monitor spatiotemporalhemodynamics by taking advantage of the high sensitivity,electromagnetic immunity,and great temporal synchronizationbetween multiple remote sensor nodes.A continuous systemic hemodynamic measurement technique is developedusing all-mechanical physiological signals,such as ballistocardiogram signals and pulse waves,to illustrate the actualmechanical process of blood circulation.Multiple hemodynamic parameters,such as systemic pulse transit time,heartrate,blood pressure,and peripheral resistance,are monitored using skin-like microfiber Bragg grating patches conformallyattached at different body locations.Relying on the soft microfiber Bragg grating group,the spatiotemporal hemodynamicmonitoring technique opens up new possibilities in clinical medical diagnosis and daily health management.

Major liver resections,perioperative issues and posthepatectomy liver failure:A comprehensive update for the anesthesiologist

Significant advances in surgical techniques and relevant medium-and long-term outcomes over the past two decades have led to a substantial expansion in the indications for major liver resections.To support these outstanding results and to reduce perioperative complications,anesthesiologists must address and master key perioperative issues(preoperative assessment,proactive intraoperative anesthesia strategies,and implementation of the Enhanced Recovery After Surgery approach).Intensive care unit monitoring immediately following liver surgery remains a subject of active and often unresolved debate.Among postoperative complications,posthepatectomy liver failure(PHLF)occurs in different grades of severity(A-C)and frequency(9%-30%),and it is the main cause of 90-d postoperative mortality.PHLF,recently redefined with pragmatic clinical criteria and perioperative scores,can be predicted,prevented,or anticipated.This review highlights:(1)The systemic consequences of surgical manipulations anesthesiologistsmust respond to or prevent,to positively impact PHLF(a proactive approach);and(2)the maximal intensivetreatment of PHLF,including artificial options,mainly based,so far,on Acute Liver Failure treatment(s),to buytime waiting for the recovery of the native liver or,when appropriate and in very selected cases,toward livertransplant.Such a clinical context requires a strong commitment to surgeons,anesthesiologists,and intensivists towork together,for a fruitful collaboration in a mandatory clinical continuum.

Comparing a non-invasive hemodynamic monitor with minimally invasive monitoring during major open abdominal surgery

As part of the enhanced recovery after surgery （ERAS） protocol, the goal-directed fluid management with hemodynamic monitoring can effectively guide perioperative fluid use and significantly improve the outcomes in highrisk patients undergoing major surgeries. Several minimally invasive and non-invasive monitoring devices are commercially available for clinical use. As part of an internal evaluation, we reported the results from three different hemodynamic monitoring devices used in a patient undergoing a major abdominal surgery.

Passive leg raising as an indicator of fluid responsiveness in patients with severe sepsis

BACKGROUND:In the management of critically ill patients,the assessment of volume responsiveness and the decision to administer a fluid bolus constitute a common dilemma for physicians.Static indices of cardiac preload are poor predictors of volume responsiveness.Passive leg raising(PLR) mimics an endogenous volume expansion(VE) that can be used to predict fluid responsiveness.This study was to assess the changes in stroke volume index(SVI) induced by PLR as an indicator of fluid responsiveness in mechanically ventilated patients with severe sepsis.METHODS:This was a prospective study.Thirty-two mechanically ventilated patients with severe sepsis were admitted for VE in ICU of the First Affiliated Hospital,Zhejiang University School of Medicine and Ningbo Medical Treatment Center Lihuili Hospital from May 2010 to December 2011.Patients with non-sinus rhythm or arrhythmia,parturients,and amputation of the lower limbs were excluded.Measurements of SVI were obtained in a semi-recumbent position(baseline) and during PLR by the technique of pulse indicator continuous cardiac output(PiCCO) system prior to VE.Measurements were repeated after VE(500 mL 6%hydroxyethyl starch infusion within 30 minutes)to classify patients as either volume responders or non-responders based on their changes in stroke volume index(ASVI) over 15%.Heart rate(HR),systolic artery blood pressure(ABPs),diastolic artery blood pressure(ABPd),mean arterial blood pressure(ABPm),mean central venous pressure(CVPm)and cardiac index(CI) were compared between the two groups.The changes of ABPs,ABPm,CVPm,and SVI after PLR and VE were compared with the indices at the baseline.The ROC curve was drawn to evaluate the value of ASVI and the change of CVPm(ACVPm) in predicting volume responsiveness.SPSS 17.0 software was used for statistical analysis.RESULTS:Among the 32 patients,22 were responders and 10 were non-responders.After PLR among the responders,some hemodynamic variables(including ABPs,ABPd,ABPm and CVPm)were significantly elevated(101.2±17.6 vs.118.6±23.7,P=0.03;52.8±10.7 vs.64.8±10.7,P=0.006;68.3+11.7 vs.81.9±14.4,P=0.008;6.8±3.2 vs.11.9±4.0,P=0.001).After PLR,the area under curve(AUC) and the ROC curve of △SV1 and ACVPm for predicting the responsiveness after VE were0.882±0.061(95%CI 0.759-1.000) and 0.805±0.079(95%CI 0.650-0.959) when the cut-off levels of ASVI and ACVPm were 8.8%and 12.7%,the sensitivities were 72.7%and 72.7%,and the specificities were 80%and 80%.CONCLUSION:Changes in ASVI and ACVPm induced by PLR are accurate indices for predicting fluid responsiveness in mechanically ventilated patients with severe sepsis.

Pulmonary artery catheterization in acute myocardial infarction complicated by cardiogenic shock:A review of contemporary literature

Acute myocardial infarction(AMI)with left ventricular(LV)dysfunction patients,the most common cause of cardiogenic shock(CS),have acutely deteriorating hemodynamic status.The frequent use of vasopressor and inotropic pharmacologic interventions along with mechanical circulatory support(MCS)in these patients necessitates invasive hemodynamic monitoring.After the pivotal Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial failed to show a significant improvement in clinical outcomes in shock patients managed with a pulmonary artery catheter(PAC),the use of PAC has become less popular in clinical practice.In this review,we summarize currently available literature to summarize the indications,clinical relevance,and recommendations for use of PAC in the setting of AMI-CS.

Hemodynamic monitoring in cardiogenic shock

Cardiogenic shock(CS)is a life-threatening condition characterized by acute end-organ hypoperfusion due to inadequate cardiac output that can result in multiorgan failure,which may lead to death.The diminished cardiac output in CS leads to systemic hypoperfusion and maladaptive cycles of ischemia,inflammation,vasoconstriction,and volume overload.Obviously,the optimal management of CS needs to be readjusted in view of the predominant dysfunction,which may be guided by hemodynamic monitoring.Hemodynamic monitoring enables(1)characterization of the type of cardiac dysfunction and the degree of its severity,(2)very early detection of associated vasoplegia,(3)detection and monitoring of organ dysfunction and tissue oxygenation,and(4)guidance of the introduction and optimization of inotropes and vasopressors as well as the timing of mechanical support.It is now well documented that early recognition,classification,and precise phenotyping via early hemodynamic monitoring(e.g.,echocardiography,invasive arterial pressure,and the evaluation of organ dysfunction and parameters derived from central venous catheterization)improve patient outcomes.In more severe disease,advanced hemodynamic monitoring with pulmonary artery catheterization and the use of transpulmonary thermodilution devices is useful to facilitate the right timing of the indication,weaning from mechanical cardiac support,and guidance on inotropic treatments,thus helping to reduce mortality.In this review,we detail the different parameters relevant to each monitoring approach and the way they can be used to support optimal management of these patients.

Intensive care drug therapy and its potential adverse effects on blood pressure and heart rate in critically ill children

Background Owing to complex treatment,critically ill children may experience alterations in their vital parameters.We investigated whether such hemodynamic alterations were temporally and causally related to drug therapy.Methods In a university pediatric intensive care unit,we retrospectively analyzed hemodynamic alterations defined as values exceeding the limits set for heart rate(HR)and blood pressure(BP).For causality assessment,we used the World Health Organization–Uppsala Monitoring Center(WHO–UMC)system,which categorizes the probability of causality as“certain,”“probable,”“possible,”and“unlikely.”Results Of 315 analyzed patients with 43,200 drug prescriptions,59.7%experienced at least one hemodynamic alteration;39.0%were affected by increased HR,19.0%by decreased HR,18.1%by increased BP,and 16.2%by decreased BP.According to drug information databases,83.9%of administered drugs potentially lead to hemodynamic alterations.Overall,88.3%of the observed hemodynamic alterations had a temporal relation to the administration of drugs;in 80.2%,more than one drug was involved.Based on the WHO–UMC system,a drug was rated as a“probable”causing factor for only 1.4%of hemodynamic alterations.For the remaining alterations,the probability ratings were lower because of multiple potential causes,e.g.,several drugs.Conclusions Critically ill children were frequently affected by hemodynamic alterations.The administration of drugs with potentially adverse effects on hemodynamic parameters is often temporally related to hemodynamic alterations.Hemodynamic alterations are often multifactorial,e.g.,due to administering multiple drugs in rapid succession;thus,the influence of individual drugs cannot easily be captured with the WHO–UMC system.

Passive Leg Raising in Intensive Care Medicine

Fluid challenge is a common diagnostic method to help the physician detennine fluid responsiveness, which is an important component of fluid management in critically ill patients）H Raising legs of a patient induces the transfer of a variable amount of blood （approximately 200-300 ml） contained in the venous reservoir from the limb to central venous compartment. According to Franck-Starling curve, this transient increase of preload might lead to an increase in cardiac output （CO） in thture responders resulting from their preload-reserve status. Many clinical studies have validated passive leg raising （PLR）, and the advantage of PLR is attractive in Intensive Care Unit （ICU）. Recently, PER has been suggested as a simple and potential method to predict fluid responsiveness, which is similar to an ＂auto-fluid challenge＂ without a drop of fluid. However, one study revealed poor application of PLR in the real world, We acknowledged that the lack of education on PLR would result in the current practice. On the other hand, the application of PLR might be not simple in clinical practice, and the holy grail of fluid responsiveness still needs to be discovered. The standard of PLR has not been established, and some questions of PLR merit discussion.