Effect Of Hemodynamic Parameters Research Articles

The Effect of Hemodynamic Parameters on Cerebral Oxygenization During Carotid Endarterectomy.

Objective/IntroductionNear-infrared spectroscopy (NIRS) is a non-invasive technique to detect cerebral ischemia by monitoring changes in regional cerebral oxygenation (rSO2) in the frontal lobes. However, there are no studies showing the changes in NIRS values in response to hemodynamic variations during stages of carotid endarterectomy (CEA) procedure and clinical implications of these changes. The aim of this study was to determine if hemodynamic changes affect NIRS values during carotid endarterectomy and if our results may help to provide strategies for hemodynamic management in these patients.MethodsA total of 50 consecutive patients undergoing CEA were prospectively included in the study. NIRS was measured at first minute after clamping of carotid artery, and then systolic blood pressure was increased above 150 mmHg. NIRS values from both hemispheres were recorded simultaneously at certain time points and were analyzed to evaluate the changes at different stages of operation and to assess correlations with hemodynamic parameters.ResultsNIRS values on the right and left sides were correlated with systolic (right P<0.001, R2:0.24; left P=0.02, R2:0.10) diastolic (right P<0.001, R2:0.36; left P=0.001, R2:0.18) and mean (right P<0.001, R2:0.33; left P=0.003, R2:0.17) blood pressures when the patient was under general anaesthesia. NIRS values were significantly lower than pre-incision values just after clamping of carotid artery in both hemispheres (P=0.005 for the right and P<0.001 for the left side).ConclusionNIRS values measured in our study show that there is a correlation between hemodynamic changes and cerebral oxygenation. This effect is especially pronounced while the patient is asleep and intubated, which implies the importance of close monitoring of patients with carotid disease during any surgery requiring general anaesthesia.

INNOVATIVE USE OF HYDROXOCOBALAMIN WITH THIAMINE, ASCORBIC ACID, AND HYDROCORTISONE IN THE TREATMENT OF A SEPTIC SHOCK PATIENT WITH FULMINANT LEPTOSPIROSIS: A CASE REPORT

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Leptospirosis can escalate to septic shock and multi-organ failure. Despite consistent compliance to sepsis bundle, mortality rate remains high. In 2016, a retrospective study suggested the addition of thiamine, ascorbic acid and hydrocortisone to standard sepsis therapy can improve organ injury, shock time reversal, and mortality rate (1). Adjunctive high dose hydroxocobalamin has also been recently reported to reverse septic shock (2). We are reporting the first innovative use of hydroxocobalamin, thiamine, ascorbic acid, and hydrocortisone to standard sepsis protocol in rapid and successful reversal of septic shock in a case of fulminant leptospirosis. CASE PRESENTATION: A 59-year-old Pacific Islander presented with two days of recurrent headache, vomiting, abdominal pain, and myalgia. He was discharged after receiving antiemetics and fluids. Patient returned two days later with worsening abdominal discomfort, persistent headaches, coughing, and black tarry stool. He was admitted with acute respiratory distress syndrome, septic shock, acute liver and renal failure. Patient was placed on mechanical ventilation; he developed cardiac arrest for a brief period but had return of spontaneous circulation. Initial Sequential Organ Failure Assessment score was 16. With his history of working barefooted in a taro farm, it prompted an order for Leptospira Immunoglobulin M antibody test, which was positive. Along with intravenous fluid and broad-spectrum antibiotics, he required continuous norepinephrine, phenylephrine, vasopressin drips, and hydrocortisone. On day 3, hydroxocobalamin, thiamine, and ascorbic acid were added as adjunctive therapies due to continued hemodynamic compromise. Within 24 hours, he was successfully liberated off all vasopressors. Despite being in the intensive care unit for 16 days and a prolonged hospitalization, he was discharged home and continued to be functional and ambulatory one year later. DISCUSSION: Even with aggressive adherence to sepsis bundle in septic shock, mortality remains high. Despite numerous clinical trials, they have been unsuccessful in reversing this trend. Addition of thiamine, ascorbic acid, and hydrocortisone to multiple vasopressors have been reported to potentially address the hemodynamic derangement. More recently, there has been suggestion that hydroxocobalamin could further contribute to reversing these processes. CONCLUSIONS: This is the first known successfully rapid reversal of septic shock due to fulminant leptospirosis treated with combination of hydroxocobalamin, thiamine, ascorbic acid, and hydrocortisone, added to standard sepsis protocol. The combination of these vitamins and hydrocortisone resulted in synergistic and lasting effect of hemodynamic parameters that can potentially improve quality of health for septic shock survivors. Well-designed prospective studies are warranted to further evaluate their true efficacy. Reference #1: Marik, P. E., Khangoora, V., Rivera, R., Hooper, M. H., & Catravas, J. (2017). Hydrocortisone, Vitamin C, and Thiamine for the Treatment of Severe Sepsis and Septic Shock: A Retrospective Before-After Study. Chest, 151(6): 1229-1238. Reference #2: Lin, Y., & Vu, T. Q. (2019). Use of High-Dose Hydroxocobalamin for Septic Shock: A Case Report. A&A Practice, 12(9): 332-335. DISCLOSURES: No relevant relationships by Angelica Guzman Paz, source=Web Response No relevant relationships by Takkin Lo, source=Web Response

Effect of Hemodynamic Parameters on Physiological Blood Flow through Cardiovascular Disease (CVD) – The Perspective Review

One of the cardiovascular diseases (CVD) that affect the heart is coronary artery disease (CAD). CAD is the disease that leads to fetal death due to plaque formation which blocked blood that carries oxygen to the human body. The tremendous trends of death in cardiovascular disease become worrisome to cardiologists and medical practitioners. Thus, many researchers grab the initiative to study the cardiovascular hemodynamic parameters such as wall shear stress (WSS), blood velocity, endothelial shear stress (ESS), and strain rate in identifying coronary artery disease factors. This paper aims to investigate the hemodynamic parameters that lead to the formation of coronary artery disease and the effect of the parameters on the physiological blood flow. Few research papers were investigated and analyzed by comparing numerical data and images from CFD analysis. Based on the study, the main hemodynamic parameter that produced the formation of coronary artery disease are wall shear stress and related proportionally with velocity, shear stress, and strain rate factors. The result shows the low wall shear stress (WSS) developed the high formation of plaque in the coronary artery and will develop stenosis in an artery leading to a decrease of lumen size and increase of velocity near the plaque region. In conclusion, the evolutions of computational hemodynamic study are bringing huge contributions in identifying coronary artery disease and show a significant relationship with physiological blood flow.

The effect of hemodynamic parameters in patient-based coronary artery models with serial stenoses: normal and hypertension cases

The purpose of this study is to investigate the hemodynamic significance of various degrees of coronary area of stenosis (AS) and multiple sequential stenoses (MSS) in normal and hypertension pressure conditions. MSS in a single branch coronary artery pose challenges to determine the physiological assessment in the prevalent invasive intervention. The hemodynamic parameters of each stenosis are influenced by other stenoses in the single branch of MSS coronary artery. In this study, we entirely use open source tools and techniques for coronary computed tomography angiography (CCTA) image segmentation, 3D reconstruction, grid generation and hemodynamic simulations. The results yield different hemodynamic parameters such as velocity magnitude, mean arterial pressure difference, flow-pressure linear relation, wall shear stress (WSS) and eventually virtual fractional flow reserve (vFFR) allowing for the prediction and the assessment of lumen area severity conditions in MSS coronaries.

Remote Photoplethysmographic Assessment of the Peripheral Circulation in Critical Care Patients Recovering From Cardiac Surgery.

Camera-based photoplethysmography (cbPPG) remotely detects the volume pulse of cardiac ejection in the peripheral circulation. The cbPPG signal is sourced from the cutaneous microcirculation, yields a 2-dimensional intensity map, and is therefore an interesting monitoring technique. In this study, we investigated whether cbPPG is in general sufficiently sensitive to discern hemodynamic conditions. cbPPG recordings of 70 patients recovering from cardiac surgery were analyzed. Photoplethysmograms were processed offline and the optical pulse power (OPP) of cardiac ejection was calculated. Hemodynamic data, image intensity, and patient movements were recorded synchronously. The effects of hemodynamic parameters and measurement conditions on the patient's individual OPP variability and their actual OPP values were calculated in mixed-effects regression models. Mean arterial pressure (MAP), pulse pressure (PP), heart rate (HR), and central venous pressure (CVP) significantly explained the individual OPP variability. PP had the highest explanatory power (19.9%). Averaged OPP significantly increased with PP and MAP (P < 0.001, respectively) and decreased with higher HR (P = 0.024). CVP had a 2-directional, nonsignificant effect on averaged OPP. Image intensity and patient movements did significantly affect OPP. After adjustment for hemodynamic covariables and measurement conditions, the effect of PP and HR remained unchanged, whereas that of MAP vanished. cbPPG is sensitive to hemodynamic parameters in critical care patients. It is a potential application for monitoring the peripheral circulation. Its value in a clinical setting has to be determined.

Hemodynamic parameters and vessel tortuosity: an investigation with a mesenterial vascular network

Purpose: The effect of hemodynamic parameters on vessel tortuosity remains un-clear. Here we investigate the correlation of tortuosity with a set of hemodynamicparameters in a mesenterial vascular network.Methods: A mesenterial vascular network of 389 vessels (131 arteries, 132 veins, and 126 capillaries) was imaged. Eleven hemodynamic parameters were measured (pressure, wall shear stress, diameter, blood velocity and flow, viscosity, haematocrit, partial oxygen saturation, oxygen saturation, wall thickness, and local vessel density). Tortuosity was assessed quantitatively with a validated algorithm and correlation computed with subsets of hemodynamic parameters selected by a lasso regressor.Results: Results suggest that tortuosity is related to pressure, wall shear stress, diameter, blood velocity, viscosity, partial but not full oxygen saturation, and wall thickness for the arteries; diameter, blood flow, hematocrit, and density for the veins; and viscosity (but not hematocrit), partial and full oxygen saturation, and density for the capillaries. The combination of hemodynamic parameters correlating best with tortuosity is the set of all parameters except density (r = 0.64, p &lt; 0.01), using as tortuosity definition the set of tortuosity features (geometric measures) correlating best with a single hemodynamic factor for the arteries.Conclusion: This pilot suggests two general conclusions. First, the quantitative definition of tortuosity (i.e., the set of geometric features adopted) should be tuned to the specific data and problem considered. Second, tortuosity is caused by a combination of hemodynamic factors, not a single one.

Effect of Hemodynamic Parameters on Rate of Blood Loss in Endoscopic Endonasal Surgery

Effect of Hemodynamic Parameters on Rate of Blood Loss in Endoscopic Endonasal Surgery

Conivaptan: New treatment for hyponatremia

The pharmacology, bioavailability and pharmacokinetics, clinical efficacy, adverse effects and toxicities, drug interactions, dosage and administration, and safety issues related to the use of conivaptan are discussed. Conivaptan hydrochloride is a nonpeptide, V1A and V2 vasopressin-receptor antagonist. It is available as an i.v. formulation in 4-mL ampules containing 20 mg of conivaptan hydrochloride. The drug is active both orally and i.v. Conivaptan injection is approved for the treatment of euvolemic hyponatremia in hospitalized patients. Three double-blind, placebo-controlled, randomized, multicenter studies have been conducted in the United States and internationally. The studies used various dosing regimens for conivaptan but maintained the same efficacy endpoints. Each study showed conivaptan to be effective in increasing serum sodium and in water clearance. Conivaptan is being evaluated in the treatment of acute decompensated heart failure and chronic heart failure, but the safety of this drug has not been fully established. The drug has been generally well tolerated in clinical trials with both oral and i.v. administration. The approved dosing regimen consists of a 20-mg i.v. loading dose administered over 30 minutes, followed by a continuous infusion of 20 mg administered over 24 hours. Clinical studies evaluating conivaptan have been short term; longer-term effects of hemodynamic parameters are unknown. Conivaptan, the first vasopressin antagonist approved for the treatment of euvolemic hyponatremia, has a unique mechanism of action that results in free-water excretion and offers a new option for the treatment of resistant hyponatremia in the acute setting when patients have not responded to standard management.