Noninvasive Hemodynamic Monitoring Research Articles

THE PATH OF LEAST RESISTANCE: CHRONIC INDWELLING CATHETER COMPLICATIONS OF FIBRIN SHEATH FORMATION IN A PATIENT WITH PERICARDIAL COLLATERALIZATION

SESSION TITLE: Medical Student/Resident Pulmonary Manifestations of Systemic Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pericardial collateralization and extrapulmonary shunting due to coexistent superior vena cava (SVC) and inferior vena cava (IVC) fibrin sheaths is rare but should be considered in patients with hypotension and hypoxemia with history of vascular catheterization. CASE PRESENTATION: A 33 year old male with end stage renal disease due to congenital kidney disease and chronic hypotension was admitted with recurrent falls. Vital signs showed marked hypotension and hypoxemia requiring vasopressor support and high flow oxygen. No facial plethora or extremity edema was seen on exam. Laboratory testing did not reveal leukocytosis or metabolic abnormalities. Non-invasive hemodynamic monitoring was indicative of distributive and mild cardiogenic shock. CT thorax showed a right lobar consolidate and an occluded proximal SVC with prominent pericardial collateral vessels. CT abdomen and pelvis demonstrated a long tubular intravascular opacity, which was possibly a fibrin sheath from the IVC into the right common femoral vein. Echocardiogram bubble study revealed left sided bubbles that appeared first before right sided bubbles reflective of intracardiac versus intrapulmonary shunt. The patient was treated for pneumonia and weaned off vasopressors in anticipation of possible cardiothoracic surgery. DISCUSSION: Venous stenoses are sequela of central venous hemodialysis catheter access in 41% of dialysis patients (2). We postulate that prior indwelling dialysis catheter placement in this patient contributed to fibrin sheath formation. As a result, a right to left shunt may have arisen with associated pericardial collateral circulation, contributing to hypoxemia through shunt physiology. This may have chronically impeded preload to the right heart, thus lowering stroke volume and cardiac output. The extent of collateralization was not fully seen on imaging, but it is possible some portion of venous return is bypassing the heart entirely and contributing to hypotension. Among the reported cases of patients with systemic-to-pulmonary collateral vessel circulation and shunt, the involvement of both the SVC and IVC has not been characterized (1). Furthermore, reports of patients with collateral pathways from prior catheters and shunts show good hemodynamics in stark contrast to our case (3). CONCLUSIONS: Chronic indwelling dialysis catheter use can result in fibrin sheath formation in the vessel, leading to stenoses of the SVC and IVC. In turn, pericardial circulation can develop which then functions as a right to left shunt. This is potentially the etiology of hypoxia or hypotension in our patient. This should be recognized as one of the complications of long-term indwelling catheters in the SVC or IVC. Reference #1: Kapur, S. et.al. “Where There is Blood, There is a Way: Unusual Collateral Vessels in Superior and Inferior Vena Obstruction” RadioGraphics 2010; 30:67-78 Reference #2: MacRae JM, Ahmed A, Johnson N, et al. “Central vein stenosis: a common problem in patients on hemodialysis”. ASAIO J. 2005;51:77–81. doi: 10.1097/01.MAT.0000151921.95165.1E Reference #3: Gamet A, et.al. “Acquired Systemic-to-pulmonary Venous Shunt or Persistent Left Superior Vena Cava? A Rare Right-to-left Shunt Case-based Discussion.” J Cardiovascular Echogr. 2017 Jul-Sep;27(3)104-106 doi: 10.4103/jcecho.jcecho_42_16 DISCLOSURES: No relevant relationships by Jaskiran Khosa, source=Web Response no disclosure on file for Steve Lee

Noninvasive estimation of aortic hemodynamics and cardiac contractility using machine learning

Cardiac and aortic characteristics are crucial for cardiovascular disease detection. However, noninvasive estimation of aortic hemodynamics and cardiac contractility is still challenging. This paper investigated the potential of estimating aortic systolic pressure (aSBP), cardiac output (CO), and end-systolic elastance (Ees) from cuff-pressure and pulse wave velocity (PWV) using regression analysis. The importance of incorporating ejection fraction (EF) as additional input for estimating Ees was also assessed. The models, including Random Forest, Support Vector Regressor, Ridge, Gradient Boosting, were trained/validated using synthetic data (n = 4,018) from an in-silico model. When cuff-pressure and PWV were used as inputs, the normalized-RMSEs/correlations for aSBP, CO, and Ees (best-performing models) were 3.36 ± 0.74%/0.99, 7.60 ± 0.68%/0.96, and 16.96 ± 0.64%/0.37, respectively. Using EF as additional input for estimating Ees significantly improved the predictions (7.00 ± 0.78%/0.92). Results showed that the use of noninvasive pressure measurements allows estimating aSBP and CO with acceptable accuracy. In contrast, Ees cannot be predicted from pressure signals alone. Addition of the EF information greatly improves the estimated Ees. Accuracy of the model-derived aSBP compared to in-vivo aSBP (n = 783) was very satisfactory (5.26 ± 2.30%/0.97). Future in-vivo evaluation of CO and Ees estimations remains to be conducted. This novel methodology has potential to improve the noninvasive monitoring of aortic hemodynamics and cardiac contractility.

Hemodynamic monitoring with two blood gases: “a tool that does not go out of style”

Introduction. Hemodynamic monitoring of a critically ill patient is an indispensable tool both inside and outside intensive care; we currently have invasive, minimally invasive and non-invasive devices; however, no device has been shown to have a positive impact on the patient's evolution; arterial and venous blood gases provide information on the patient's actual microcirculatory and metabolic status and may be a hemodynamic monitoring tool.
 Objective. To carry out a non-systematic review of the literature of hemodynamic monitoring carried out through the variables obtained in arterial and venous blood gases.
 Material and methods. A non-systematic review of the literature was performed in the PubMed, OvidSP and ScienceDirect databases with selection of articles from 2000 to 2019.
 Results. It was found that there are variables obtained in arterial and venous blood gases such as central venous oxygen saturation (SvcO2), venous-to-arterial carbon dioxide pressure (∆pv-aCO2), venous-to-arterial carbon dioxide pressure/arteriovenous oxygen content difference (∆pv-aCO2/∆Ca-vO2) that are related to cellular oxygenation, cardiac output (CO), microcirculatory veno-arterial flow and anaerobic metabolism and allow to assess tissue perfusion status.
 Conclusion. The variables obtained by arterial and venous blood gases allow for non-invasive, accessible and affordable hemodynamic monitoring that can guide medical decision-making in critically ill patients.

Exhaled breath compositions under varying respiratory rhythms reflects ventilatory variations: translating breathomics towards respiratory medicine

Control of breathing is automatic and its regulation is keen to autonomic functions. Therefore, involuntary and voluntary nervous regulation of breathing affects ventilatory variations, which has profound potential to address expanding challenges in contemporary pulmonology. Nonetheless, the fundamental attributes of the aforementioned phenomena are rarely understood and/or investigated. Implementation of unconventional approach like breathomics may leads to a better comprehension of those complexities in respiratory medicine. We applied breath-resolved spirometry and capnometry, non-invasive hemodynamic monitoring along with continuous trace analysis of exhaled VOCs (volatile organic compounds) by means of real-time mass-spectrometry in 25 young and healthy adult humans to investigate any possible mirroring of instant ventilatory variations by exhaled breath composition, under varying respiratory rhythms. Hemodynamics remained unaffected. Immediate changes in measured breath compositions and corresponding variations occurred when respiratory rhythms were switched between spontaneous (involuntary/unsynchronised) and/or paced (voluntary/synchronised) breathing. Such changes in most abundant, endogenous and bloodborne VOCs were closely related to the minute ventilation and end-tidal CO2 exhalation. Unprecedentedly, while preceded by a paced rhythm, spontaneous rhythms in both independent setups became reproducible with significantly (P-value ≤ 0.005) low intra- and inter-individual variation in measured parameters. We modelled breath-resolved ventilatory variations via alveolar isoprene exhalation, which were independently validated with unequivocal precision. Reproducibility i.e. attained via our method would be reliable for human breath sampling, concerning biomarker research. Thus, we may realize the actual metabolic and pathophysiological expressions beyond the everlasting in vivo physiological noise. Consequently, less pronounced changes are often misinterpreted as disease biomarker in cross-sectional studies. We have also provided novel information beyond conventional spirometry and capnometry. Upon clinical translations, our findings will have immense impact on pulmonology and breathomics as they have revealed a reproducible pattern of ventilatory variations and respiratory homeostasis in endogenous VOC exhalations.

Non-invasive Hemodynamic Monitoring of Fluid Resuscitation in Cirrhotic Patients with Acute Kidney Injury

BACKGROUND: Fluid management of patients with liver cirrhosis and acute kidney injury (AKI) is a complex problem requiring accurate assessment of the intravascular volume status and the cause of the AKI. Echocardiography used in various hemodynamic monitoring as a quick, easy, bedside, and non-invasive tool with great sensitivity.
 AIM: This study aims to evaluate echocardiography as a non-invasive hemodynamic monitoring tool for the assessment of volume status and cardiac function before and after volume expansion in patients with liver cirrhosis presented by AKI.
 PATIENTS AND METHODS: This study included 120 patients with liver cirrhosis and AKI. All patients were subjected to clinical evaluation, laboratory assessment of kidney and liver functions, and echocardiographic assessment of inferior vena cava (IVC) collapsibility index, left ventricular outflow tract velocity time integral (LVOT VTI) variability index, and cardiac output (CO).
 RESULTS: Comparison between responders and non-responders to volume resuscitation regarding the echocardiographic data showed that responders had significantly higher IVC collapsibility index, LVOT VTI variability index, and % of CO increase. IVC collapsibility index and LVOT VTI variability index showed good predictive value of fluid responsiveness.
 CONCLUSIONS: The use of echocardiography is a good tool for hemodynamic monitoring of fluid resuscitation in cirrhotic patients with AKI. The use of echocardiography has limited the use of central venous line only to patients with hemodynamic instability requiring vasoactive support.

Advances in Hemodynamic Monitoring in Heart Failure Patients

Abnormal hemodynamics are associated with poor clinical outcomes in patients with heart failure. Given the invasiveness and unfeasibility of routine right heart catheterization, non-invasive methodologies to monitor hemodynamics are needed. The CardioMEMS™ device is a recently developed technology that enables remote monitoring of pulmonary artery pressures via an implanted sensor located in the distal left pulmonary artery. Along with the CardioMEMS™, a remote dielectric system might be another promising device that reports indirect intra-thoracic filling pressures associated with pulmonary congestion. In patients with advanced heart failure who require left ventricular assist devices, non-invasive hemodynamic monitoring is particularly necessary, given the increased procedural risks of invasive assessments. The HeartWare ventricular assist device flow waveform is a variable under active investigation that might also provide an estimation of filling pressures. This methodology is expected to lead to the development of a smart pump that can adjust its own settings, including the pump speed, automatically by monitoring the hemodynamics.

Hemodynamic effects of carbetocin administered as an intravenous bolus or infusion during cesarean delivery.

BackgroundPostpartum hemorrhage is the leading cause of maternal mortality. Oxytocin being the most popular uterotonic agent, has been routinely administered after both vaginal delivery and cesarean section. Carbetocin is a newer uterotonic agent and provides the benefit of a longer duration of action without additional administration post-delivery.MethodsWe recruited 34 women undergoing elective cesarean section under spinal anesthesia. All patient was received spinal anesthesia using 0.5% hyperbaric Marcaine 8–10 mg in conjugation with fentanyl 20 μg in the left lateral decubitus position. Hartmann’s solution 10–15 ml/kg was administered before carbetocin. The operation started as soon as sensory block at level T4–T6 was confirmed. A non-invasive hemodynamic monitoring cuff (Finometer®) was attached to the patient’s finger soon after the induction of spinal anesthesia. Using the Finometer, we recorded the heart rate and mean arterial pressure at every 15 s, starting from 15 s before the administration of carbetocin to 5 min after. After the removal of the placenta, the bolus group was administered intravenous bolus injection of carbetocin 100 μg and the infusion group was administered carbetocin 100 μg diluted in 50 ml normal saline, over 5 min using an infusion pump.ResultsThe demographic data showed no significant difference between the two groups. Furthermore, there were no significant hemodynamic differences between the two groups.ConclusionsThe method of administration of carbetocin does not influence its hemodynamic effects.

Trends in Central Venous Catheter Insertions by Anesthesia Providers: An Analysis of the Medicare Physician Supplier Procedure Summary From 2007 to 2016.

Central line insertion is a core skill for anesthesiologists. Although recent technical advances have increased the safety of central line insertion and reduced the risk of central line-associated infection, noninvasive hemodynamic monitoring and improved intravenous access techniques have also reduced the need for perioperative central venous access. We hypothesized that the number of central lines inserted by anesthesiologists has decreased over the past decade. To test our hypothesis, we reviewed the Medicare Physician Supplier Procedure Summary (PSPS) database from 2007 to 2016. Claims for central venous catheter placement were identified in the Medicare PSPS database for nontunneled and tunneled central lines. Pulmonary artery catheter insertion was included as a nontunneled line claim. We stratified line insertion claims by specialty for Anesthesiology (including Certified Registered Nurse Anesthetists and Anesthesiology Assistants), Surgery, Radiology, Pulmonary/Critical Care, Emergency Physicians, Internal Medicine, and practitioners who were not anesthesia providers such as Advanced Practice Nurses (APNs) and Physician Assistants (PAs). Utilization rates per 10,000 Medicare beneficiaries were then calculated by specialty and year. Time-based trends were analyzed using Joinpoint linear regression, and the Average Annual Percent Change (AAPC) was calculated. Between 2007 and 2016, total claims for central venous catheter insertions of all types decreased from 440.9 to 325.3 claims/10,000 beneficiaries (AAPC = -3.4, 95% confidence interval [CI], -3.6 to -3.2: P < .001). When analyzed by provider specialty and year, the number of nontunneled line insertion claims fell from 43.1 to 15.9 claims/10,000 (AAPC = -7.1; -7.3 to -7.0: P < .001) for surgeons, from 21.3 to 18.5 claims/10,000 (AAPC = -2.5; -2.8 to -2.1: P < .001) for radiologists, and from 117.4 to 72.7 claims/10,000 (AAPC = -5.2; 95% CI, -6.3 to -4.0: P < .001) for anesthesia providers. In contrast, line insertions increased from 18.2 to 26.0 claims/10,000 (AAPC = 3.2; 2.3-4.2: P < .001) for Emergency Physicians and from 3.2 to 9.3 claims/10,000 (AAPC = 6.0; 5.1-6.9: P < .001) for PAs and APNs who were not anesthesia providers. Among anesthesia providers, the share of line claims made by nurse anesthetists increased by 14.5% over the time period. We observed a 38.3% decrease in claims for nontunneled central lines placed by anesthesiologists from 2007 to 2016. These findings have implications for anesthesiology resident training and maintenance of competence among practicing clinicians. Further research is needed to clarify the effect of decreasing line insertion numbers on line insertion competence among anesthesiologists.

Non-invasive Hemodynamic Monitoring in Prediction of the Outcome and Prognosis in Sepsis

Abstract Background Complex disease syndromes such as sepsis require multimodal diagnostic and therapeutic approaches. Besides the diagnosis of septic shock and early causal therapy, one major challenge in its treatment remains the resuscitation and management of cardiocirculatory and respiratory dysfunction. As Pulmonary artery catheterization poses significant risks and requires specialized training. Technological advances allow for more readily available, noninvasive clinical measurements of hemodynamics. Impedance cardiography (ICG) offers the potential for safe, noninvasive hemodynamic monitoring that can be easily applied. Objective To evaluate the effect of cardiac index, mean arterial blood pressure, heart rate, and oxygen delivery as measured noninvasively by impedance cardiography (ICG) in prediction of the outcome and prognosis in sepsis. Patients and Methods This is a prospective, observational convenience trial of patients presenting to the ED or the ICU with severe sepsis or septic shock. The patients were part of a cohort that was followed at day 1, day 3 and day7, or until hospital discharge or in-hospital death. After Approval is obtained from the research ethics committee of anesthesia and intensive care department, Ain Shams University. Oral informed consent is obtained from the patient or designated surrogate before data collection begins. Results Twenty-three were enrolled; three were excluded due to an inability to complete data acquisition. The mean cardiac index in nonsurvivors (2.3 L / minÆm2, 95% CI = 2.1 to 2.6) was less than that for survivors (3.3, 95% CI = 2.9 to 3.5). Oxygen delivery as well as lactate were less in non-survivors group. A cardiac index of &amp;lt; 2.5 L / minÆm2 had a sensitivity of 43% (95% CI = 18% to 71%), specificity of 93% (95% CI = 80% to 95%), for predicting in-hospital mortality. Conclusions Early, noninvasive measurement of the cardiac index in critically ill severe sepsis and septic shock patients can be performed in the ED for those who meet criteria for EGDT. There appears to be an association between an initial lower cardiac index as measured noninvasively and in-hospital mortality.

Digital arterial pressure pulse wave analysis and cardiovascular events in the general population: the Prevention of Renal and Vascular End-stage Disease study.

Background:Arterial stiffness influences the contour of the digital pressure pulse wave.Method:Here, we investigated whether the digital pulse propagation index (DPPI), based on the digital pressure pulse wave, DPPI is associated with cardiovascular events, heart failure, and mortality in a large population-based cohort. Between 2001 and 2003, DPPI was measured with a PortaPres noninvasive hemodynamic monitoring device (FinaPres Medical Systems, Amsterdam, The Netherlands) in participants of the Prevention of Renal and Vascular End-stage Disease study, a community-based cohort. We assessed the main determinants of the DPPI and investigated associations of DPPI with cardiovascular events and mortality.Results:The study included 5474 individuals. Mean age was 52.3 ± 11.8 years and 50.5% was male. Median baseline DPPI was 5.81 m/s (interquartile range 5.47–6.20). Higher age, mean arterial blood pressure, body height, heart rate, current smoking, and lower HDL cholesterol levels and waist circumference were independent determinants of the DPPI (r2 = 0.43). After adjustment for heart rate, highlogDPPI was associated with all-cause mortality [hazard ratio: 1.67, 95% confidence interval (1.55–1.81) per SD; P < 0.001], cardiovascular mortality [hazard ratio 1.95 (1.72–2.22); P < 0.001], and incident heart failure with reduced ejection fraction [hazard ratio 1.81 (1.60–2.06); P < 0.001]. These associations remained independent upon further adjustment for confounders. Optimal cutoff values for DPPI ranged between 6.1 and 6.3 m/s for all endpoints. After multivariable adjustment, DPPI was no longer associated with coronary artery disease events or cerebrovascular events.Conclusion:The DPPI is associated with an increased risk of development of new onset heart failure with reduced ejection fraction and all-cause and cardiovascular mortality, but not with coronary artery events or cerebrovascular events.

Infiltrative analgesia of the skin flap in children with craniosynostosis after reconstructive surgery on skull bones

The objective of the study is to evaluate the effectiveness of analgesia by infiltration of the skin flap with local anesthetic in children with craniosynostosis after reconstructive surgery.Materials and subjects. 50 children with craniosynostosis, who underwent reconstructive surgery on skull bones, were divided into two groups based on the method of postoperative anesthesia: in Group 1(experimental), the infiltration of the skin flap was used within multimodal anesthesia, while in Group 2, it was standard parenteral use of analgesic drugs. In the postoperative period, pain severity was assessed by FLACC scales, the amount of opioid and non-opioid analgesics consumed was assessed by the formalized Analgesiс Assessment Scale (FSA), and non-invasive hemodynamic monitoring (BP, HR) was performed.Results. The statistical analysis of the results revealed significant differences between groups in the assessment results of FSA and FLACC scales. In Group 1, the level of postoperative pain was significantly lower compared to Group 2. The amount of opioid and non-opioid analgesics consumed was also significantly lower in Group 1.Conclusion. The use of the infiltration of the skin flap as part of multimodal analgesia in children with craniosynostosis, after reconstructive surgery on skull bones significantly reduces the intensity of pain and the amount of opioid analgesics consumed in the postoperative period.

Invasive, minimally invasive and non-invasive hemodynamic monitoring in perioperative medicine

The hemodynamic monitoring is a fundamental part of the patient in the perioperative period, during the last decade the monitoring at the patient's bedside has grown at giant steps, from the emergency area, operating room, to the Intensive Care area. One of its most important advances is the decrease in the use of pulmonary artery catheter, which is being replaced by ultrasound and less invasive monitoring techniques, in this article we will review from the beginning of the monitoring to the most used less invasive monitors currently.

Non-invasive haemodynamic monitoring with Clearsight in patients undergoing spinal anaesthesia for total hip replacement. A prospective observational cohort study.

Background and aim of the work:Patients undergoing elective primary total hip replacement and spinal anesthesia may encounter significant hemodynamic instability.Objective:The study is aimed at observing the haemodynamic modifications after spinal anaesthesia during total hip replacement in patients managed to “preload independence” with goal directed fluid therapy (GDFT) and monitored non-invasively with Clearsight.Methods:Thirty patients, aged 50-80 years, with an American Society of Anaesthesiologists’ (ASA) score II-III, undergoing elective primary total hip replacement and spinal anaesthesia were enrolled. Patients were monitored with the EV1000 platform and the Clearsight finger-cuff and managed with a goal directed fluid therapy.Results:The 79% of the population showed preload independence at baseline. After spinal, the 93% did not show a significant mean arterial pressure reduction. In our population, 79% reported a decrease >10% of the stroke volume during surgery, while 66% in the Recovery Room. Patients showed an improvement in mean arterial pressure, systemic vascular resistances indexed (SVRI), stroke volume (SV) and stroke volume indexed (SVI) at spinal resolution compared to baseline.Conclusions:Our cohort population showed hemodynamic stability throughout the study period, with increased SV and decreased SVRI at spinal resolution compared to basal values. Further randomized prospective studies are advocated in the same setting. (www.actabiomedica.it)

A Novel Non-Invasive Assessment of Cardiac Hemodynamics in Patients With Heart Failure and Atrial Fibrillation.

BackgroundHeart failure (HF) and atrial fibrillation (AF) often coexist. The hemodynamic alterations induced by AF in patients with HF are well studied; however we lack reliable and non-invasive means to study these hemodynamic alterations in ambulatory patients. We sought to evaluate the clinical utility of impedance cardiography (ICG) as a novel and non-invasive tool to evaluate cardiac hemodynamics in ambulatory patients with HF and AF.MethodsThis was a single-center observational study. A convenient sample of ambulatory patients with chronic HF underwent non-invasive electrocardiogram (ECG) and hemodynamic monitoring using BioZ Dx impedance cardiographer. Hemodynamics were automatically computed and ECG data were interpreted by an independent reviewer.ResultsA total of 32 patients (62 ± 14 years of age; 66% male; ejection fraction 33±13%) were enrolled. There were no baseline demographic or clinical differences between those with AF (28%) and those without AF (72%). However, patients with AF exhibited lower stroke volume (60 ± 7 vs. 89 ± 29, P = 0.008), left ventricular work (33 ± 9 vs. 45 ± 13, P = 0.016), cardiac contractility (30 ± 8 vs. 40 ± 13, P = 0.037), and arterial elasticity (13 ± 5 vs. 21 ± 5, P = 0.012), as well as higher cardiac afterload (203 ± 57 vs. 151 ± 49, P = 0.015).ConclusionsUsing non-invasive ICG, we have shown that it is feasible to characterize hemodynamics in ambulatory HF patients. We show that AF compromises left ventricular function in patients with HF and is associated with excess afterload and reduced arterial elasticity.

Блокада крило-піднебінної ямки як компонент мультимодального знеболювання в офтальмохірургії

Materials and methods. The study included 20 patients aged 25 to 84, 11 men and 9 women with various front eye pathologies. 10 patients were anesthetized according to the classic scheme taken in our clinic. In the other 10 patients, the pain relief scheme was supplemented by the implementation of pterygopalatine fossa block. Monitoring during the operation included non-invasive monitoring of hemodynamics, pulsoxymetry, determination of oxygen and carbon dioxide concentration in exhaled air. In postoperative period level of pain was fixed using visual-analogue scale and frequency of postoperative nausea and vomiting. Results. The study found that patients in the groups had no statistically significant differences in sex, age and severity of surgery. At all stages of the study, the severity of pain in patients with the pterygopalatine fossa block was reliably lower than in patients in the control group. The incidence of postoperative nausea and vomiting was also lower in the blockade group.

Comparison of efficacy and safety of preemptive infusion protocols of ephedrine and phenylephrine - prevention of hypotension and effects on hemodynamic parameters during spinal anesthesia for caesarean section

Introduction/Objective. Spinal anesthesia (SA) for cesarean section may lead to significant changes in hemodynamic parameters, especially hypotension. The aim of this study was to determine and compare the efficacy and safety of preemptive infusion protocols of the two most commonly used vasopressors, ephedrine (Group E, n = 29) and phenylephrine (Group P, n = 31) not only on prevention of hypotension but also to determine their effect on hemodynamic parameters, such as stroke volume (SV) and cardiac output (CO) using a continuous non-invasive hemodynamic monitor. Methods. The infusion of ephedrine was administered at the rate of 5 mg/min. immediately after SA. Phenylephrine was administered at an infusion rate of 25 ?g/min for two minutes prior to SA. Results. In Group E, mean systolic blood pressure (SBP) and heart rate (HR) were similar to baseline. CO was higher (p &lt; 0.001), while systemic vascular resistance (SVR) was lower than baseline (p &lt; 0.001). In Group P, mean SBP and diastolic blood pressure (DBP) were lower than baseline, respectively (p = 0.006, p &lt; 0.001). SBP, DBP, CO, SV, SVR, and HR were significantly different between the E and P groups (p &lt; 0.001). Conclusion. E and P vasopressors are both effective in the prevention of hypotension during SA.

271: Continuous maternal hemodynamics monitoring at delivery using a novel, noninvasive, wireless, PPG-based sensor

Existing means of hemodynamic monitoring are invasive, expensive, complex to use and associated with complications. In this study, we utilized an innovative, noninvasive, reflective photoplethysmography based device (Biobeat Technologies Ltd.) that enables maternal hemodynamics continuous monitoring to assess cardiovascular changes during labor and delivery. The Biobeat Monitoring Platform includes a wearable watch, placed on parturient wrist, that automatically samples cardiac output (CO), cardiac index (CI), blood pressure (BP), stroke volume (SV), systemic vascular resistance (SVR), heart rate (HR) and more every 5 seconds and uploads all data to a smartphone-based app and to the cloud, where it can be monitored and analyzed remotely. Eight unselected term parturients (age 29.2±8, years; 4 nullipara; BMI 28.4±5.9 Kg/m2) were recruited after initial calibration to maternal weight and height. Overall, over 150,000 measurements were retrieved. Data was normalized to visual presentation using Excel Data Analysis and regression tool. Average measurements were compared 30 minutes before rupture of membranes (first stage of labor), 30 minutes before delivery (second stage of labor) and 30 minutes after delivery. Cardiac output increases with labor reaching a peak of 8 L/min with delivery, after which, it rapidly declines (5.4 vs. 6.1 vs. 5.8, L/min, p< 0.001). This is mainly due to marked changes in HR up to 110 bpm (78 vs. 90 vs. 86, bpm, p< 0.0001) and a slight change in SV (69.3 vs. 67.6 vs. 68.5, ml/beat, p=0.006)(Figure 1). Mean BP remains relatively stable throughout delivery with a slight increase at delivery, reflecting the increase in CO and decrease in SVR with delivery (Figure 2). This study serves as a proof of concept for application of noninvasive maternal hemodynamic monitoring throughout labor and delivery for research and clinical use. Further studies will implement technology to assess maternal hemodynamics and cardiovascular adaptation during labor and delivery in women with cardiovascular risk factors and pregnancy complications. View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Heart Rate Complexity in US Army Forward Surgical Teams During Pre Deployment Training.

For trauma triage, the US Army has developed a portable heart rate complexity (HRC) monitor, which estimates cardiac autonomic input and the activity of the hypothalamic-pituitary-adrenal (HPA) axis. We hypothesize that autonomic/HPA stress associated with predeployment training in U.S. Army Forward Surgical Teams will cause changes in HRC. A prospective observational study was conducted in 80 soldiers and 10 civilians at the U.S. Army Trauma Training Detachment. Heart rate (HR, b/min), cardiac output (CO, L/min), HR variability (HRV, ms), and HRC (Sample Entropy, unitless), were measured using a portable non-invasive hemodynamic monitor during postural changes, a mass casualty (MASCAL) situational training exercise (STX) using live tissue, a mock trauma (MT) STX using moulaged humans, and/or physical exercise. Baseline HR, CO, HRV, and HRC averaged 72±11b/min, 5.6±1.2L/min, 48±24ms, and 1.9±0.5 (unitless), respectively. Supine to sitting to standing caused minimal changes. Before the MASCAL or MT, HR and CO both increased to ~125% baseline, whereas HRV and HRC both decreased to ~75% baseline. Those values all changed an additional ~5% during the MASCAL, but an additional 10 to 30% during the MT. With physical exercise, HR and CO increased to >200% baseline, while HRV and HRC both decreased to 40 to 60% baseline; these changes were comparable to those caused by the MT. All the changes were P<0.05. Various forms of HPA stress during Forward Surgical Team STXs can be objectively quantitated continuously in real time with a portable non-invasive monitor. Differences from resting baseline indicate stress anticipating an impending STX whereas differences between average and peak responses indicate the relative stress between STXs. Monitoring HRC could prove useful to field commanders to rapidly and objectively assess the readiness status of troops during STXs or repeated operational missions. In the future, health care systems and regulatory bodies will likely be held accountable for stress in their trainees and/or obliged to develop wellness options and standardize efforts to ameliorate burnout, so HRC metrics might have a role, as well.

Noninvasive Hemodynamic Monitoring of Cocaine-Induced Changes in Cardiac Output and Systemic Vascular Resistance in Subjects With Chronic Cocaine Use Disorder.

Cocaine use disorder (CUD) is a common problem in the United States and worldwide. The mechanisms by which cocaine induces acute cardiovascular toxicity are various. When systemically absorbed through inhaled or intravenous routes, cocaine induces an acute rise in the heart rate (HR) and blood pressure (BP) leading to a significant increase in the cardiac output (CO) and myocardial oxygen demand. Subjects with chronic CUD represent a special population that has experienced long-term cocaine exposure, often without showing signs of cardiovascular disease. We herein present prospectively collected data on the acute hemodynamic effects of intravenous cocaine in a cohort of nontreatment-seeking individuals with CUD without cardiovascular disease. Baseline physiologic data were collected while participants underwent infusion of escalating doses of cocaine (10, 20, and 40 mg administered over 2 minutes) at baseline and after receiving single-blind placebo treatment. Continuous noninvasive hemodynamic monitoring was performed throughout the infusion sessions using the ccNexfin finger cuffs (Edwards Lifesciences Corp, Irvine, CA). The recorded arterial BP tracings allowed for the measurement of beat-to-beat changes in HR, BP, stroke volume, CO, and systemic vascular resistance (SVR). None of the subjects experienced a treatment-related serious adverse event. Cocaine produced significant dose-dependent increases in median HR, BP, CO, and +dP/dt (a measure of cardiac contractility) and a significant dose-dependent reduction in median SVR. Intravenous cocaine in a cohort of otherwise healthy subjects with CUD produced dose-dependent increases in CO, largely explained by an increase in HR, accompanied by a dose-dependent decrease in SVR.

Non-invasive hemodynamic monitoring in the acute period of polytrauma as a method to control and correction respiratory and circulatory disorders

Objective – to establish the value of non-invasive monitoring of central hemodynamics during the acute period of polytrauma and its impact on systemic respiratory and circulatory parameters and intensive care treatment using the estimated Continuous Cardiac Output (esCCO), a non-invasive continuous measurement technique of central hemodynamics, which was integrated into the Life Scope monitor (Nihon Kohden, Japan). module.Materials and methods. The study included 170 patients with polytrauma who were treated in our intensive care unit. Patients with severe polytrauma (ISS 20–30 points) were included in the group 1 (n = 70), with an average age of (41.9 ± 2.4) years. The group 2 (n = 100) consisted of patients with moderate polytrauma (ISS 10–19 points), the average age of the patients in this group was (38.7 ± 2.5) years. In sub-groups 1А and 2А adequate circulating blood volume measurement and subsequent support was performed using the esCCO. In subgroups 1B and 2B, the analysis of systemic hemodynamics such as ECG and blood saturation was performed using standard multifunction monitors.Results. Hemodynamic disorders in the form of arterial hypotension &lt; 70 mm Hg on admission occurred in 14.3 % of patients in group 1, and was not observed in patients within the group 2. The normalization of systemic hemodynamics was observed after 24 hours of intensive care therapy, in particular in subgroup 1А a marked increase in the systemic blood pressure and subsequent termination of tachycardia was observed. Normalization of cardiac output and cardiac index in subgroup 1А was observed after 3–6 h of infusion therapy (IT), in the subgroup 2А – after 12 h IT. In the subgroup 1А the infusion volume during the first day differed significantly, 8.9 % less if compared to the infusion volume used in subgroup 1B. In moderate-severity polytrauma, the infusion volume was significantly smaller than in severe polytrauma, and in the subgroup 2А it was significantly lower by 8.6 %, compared to the infusion volume used in the subgroup 2B. The confirmation of the effectiveness of the balanced IT was the normalization of the urine output. Namely: on day 2 in the subgroup 1А the diuresis increased significantly compared to day 1, and in the subgroup 1B it did not change significantly. Intergroup differences in mean daily diuresis in the group 2 were significant after 12 h of IT.Conclusions. Carrying out monitor-controlled infusion and respiratory therapy with the usage of the esCCO monitoring technique allowed to achieve an early normalization of central and systemic hemodynamics during the intensive care of polytrauma patients with a significantly smaller volume of infusion, contributed to the elimination of hypoxia, and was accompanied by a significant reduction, namely by 21.1 %, in the duration of mechanical ventilation in severe polytrauma.