Hemodynamic Variables Research Articles

Impact of age on the outcomes of Takotsubo syndrome

BackgroundThe impact on age on the short-term and long-term prognosis in patients with Takotsubo syndrome (TTS) is unclear. We aimed to evaluate whether age has prognostic implications during hospital stay and long-term follow-up of TTS patients. Methods688 consecutive patients were admitted for TTS in 7 tertiary centers from January-2008 to June-2021. We divided our cohort into two groups (patients <75 years and ≥75 years). Clinical, analytical, and hemodynamic variables as well as in-hospital management were registered and compared between groups. Mortality rates during hospital stay and follow-up were assessed. Adverse cardiovascular events (ACE) were defined as the composite of cardiovascular death, heart failure event, acute myocardial infarction, stroke and symptomatic arrhythmia. ResultsMedian age was 74.7 years and 49.4 % were ≥75 years. 86.9 % were women and 22.3 % were secondary forms of TTS. In-hospital mortality was 3.6 % (1.5 % cardiovascular). Median clinical follow-up was 4.3 years. Mortality during the follow-up period was 23 % (5.0 % cardiovascular) while ACE were 22.5 %, mainly due to heart failure events. Kaplan-Meier curves showed both higher rates of mortality and ACE in ≥75 years group (30.2 % vs 15.8 %; p < 0.001 and 28.3 % vs 16.7 %; p < 0.001). Age was independently associated with higher rates of overall mortality and ACE in patients with TTS. Hypertension, absence of sinus rhythm, Killip class > I and a more impaired coronary microvascular resistance were also associated to ACE in TTS patients. ConclusionsAdvanced age was associated with higher rate of overall mortality and ACE during long-term follow-up in TTS patients.

Cerebral Hemodynamics in Infants with Sickle Cell Disease Indicate Presence of Early Hemodynamic Stress

Introduction: One of the most severe complications of sickle cell disease (SCD) is ischemic brain injury, caused by a combination of decreased oxygen transport delivery related to intravascular vaso-occlusion of sickle erythrocytes and/or cerebral vasculopathy. While newborn screening programs diagnose SCD shortly after birth, routine risk assessment for stroke typically starts with transcranial ultrasound doppler (TCD) at two years of age or later. Yet, little is known about how SCD affects cerebral hemodynamics during infancy, a crucial period for brain development. To address this gap, we used advanced quantitative near-infrared spectroscopy (qNIRS) to non-invasively monitor cerebral tissue hemoglobin concentration (HbT), oxygenation (SO 2), oxygen extraction fraction (cFTOE), blood flow (CBF), and oxygen metabolism (CMRO 2) in infants with SCD. Abnormal CBF and cFTOE indicate hemodynamic stress that may increase stroke risk. Our study aims to investigate the effects of SCD on cerebral oxygen transport in infancy and its associations with age and blood hemoglobin concentration (HgB). Methods: This is a subgroup analysis of a prospective, observational neuroimaging study of SCD at Boston Children's Hospital (NCT 04166526). Inclusion criteria of this subgroup are SCD patients age less than 24 months old at the time of enrollment who are not receiving chronic transfusions. Families read and signed informed consent before participating in research activities. Measurements were conducted with the patients' normally scheduled hematology appointments at Boston Children's Hospital. During each measurement session, bilateral frontal regions of the head were measured up to six times for 30 seconds each. qNIRS variables were compared with literature values obtained with the same optical technologies from a cohort of typically developed infants around 1 year old, equivalent to the median age in this study 1. Correlation analysis was used to analyze qNIRS variables with age and HgB from clinical lab tests. Results: To date, 8 (F/M: 4/4; HbSS/HbS/B +-thalassemia/HbSC: 6/1/1) patients were enrolled with a total of 16 measurements. The meanSD age at measurement was 11.5 5.23 months and the median (IQR) HgB was 9.4 (8.9-10) g/dL. Seven (44%) measurements were performed while patients were receiving treatment with hydroxyurea. There was no difference in HgB in the groups with and without hydroxyurea, though the treatment group was older (mean age: 15.4 vs 8.4 months, P=0.002). Group averages of qNIRS variables are summarized Table 1. Average cFTOE was 0.53 ± 0.07, significantly higher than the reference value of 0.32 (mean difference: 0.21, P&amp;lt;0.001), while the cohort's mean SO 2 of 45.78 ± 7.13% was significantly lower than the reference value of 68% (mean difference: -22.2, P&amp;lt;0.001). Furthermore, cFTOE inversely correlated with HgB (r= -0.63, P=0.04) while SO 2 increased with HgB (r= 0.63, P=0.04). HbT and cerebral blood volume (CBV) were also significantly lower than the reference values (mean difference of -24.8 μM and -0.75 ml/100g, P&amp;lt;0.001 and P&amp;lt;0.02, respectively) and positively correlated with age (r=0.51 and 0.57, P=0.04). CBF did not correlate with either age or HgB. Hemodynamic variables did not differ between groups with and without hydroxyurea, except for HbT and CBV likely secondary to the cohort age difference. Taken together, this suggests that CBF compensatory mechanisms were insufficient to prevent elevated oxygen extraction. Summary: These preliminary results suggest that inadequate oxygen transport to the brain secondary to SCD evokes a compensatory increase in cFTOE starting in early infancy. The progressive hemodynamic stress to brain health during the period of the brain's greatest growth and metabolic demand for oxygen is concerning because of the potential for injury as compensatory mechanisms become exhausted. Hydroxyurea did not reduce this stress, but may have prevented further declines. Recruitment is ongoing to increase the size of the cohort and to continue following patients' trajectories with age. We demonstrated the potential of qNIRS as biomarkers of cerebral hemodynamic compensation to determine when intervention is necessary and evaluate the effectiveness of a chosen intervention in individual patients. 1. Franceschini, M. A. et al. Assessment of infant brain development with frequency-domain near-infrared spectroscopy. Pediatr Res 61, 546-551, 2007.

Exploring Near Infrared Spectroscopy As a Tool for Monitoring Tissue Hemodynamics for Patients with Sickle Cell Disease

Sickle cell disease (SCD) is a genetic disorder that has higher prevalence in people of African ancestry. In the United States, SCD affects about 100,000 people and 1 in 365 African Americans. Sickled red blood cells (RBCs) have a shorter life span and are rigid, causing chronic hemolytic anemia and vaso-occlusive crises. There is a need for accessible diagnostic and monitoring technologies to characterize hemodynamic health, especially for patients with SCD. Near infrared spectroscopy (NIRS) is a noninvasive optical technique that uses light in the near infrared range (650 - 900 nm) to gain information from tissue absorption and light scattering. The purpose of this study is to show that NIRS is sensitive to differences in tissue hemodynamics between patients with SCD and healthy population. We enrolled adults (age ≥ 18 years) of African descent who were not recently transfused under protocol NCT05604547. Baseline hemodynamics and day-to-day variability were quantified in 10 SCD patients with HbSS (six male, four female) and six healthy, ethnically matched participants (four male, two female). We assessed participants with affixed transmission speckle analysis (ATSA) and a dual system frequency domain-NIRS (FD-NIRS) with diffuse correlation spectroscopy (DCS) device to measure blood flow and hemoglobin concentration. Participants underwent a respiratory challenge, three sets of breath holds, with the optical probe on their forehead. Then, the participants underwent a vascular occlusion challenge, a three-minute brachial blood pressure cuff occlusion at 200 mmHg, with the optical probe on their forearm. We also measured skin and adipose tissue thickness (SATT) of the forearm site with ultrasound. Two of the healthy control participants were excluded from the skeletal muscle analysis due to SATT &amp;gt; 8 mm. A Mann-Whitney significance test was used to evaluate the results. From these measurements, we acquired the concentration of oxygenated (O 2Hb), deoxygenated (HHb), and total hemoglobin (tHb); blood flow index (BFi); and tissue oxygen saturation (StO 2) for cerebral and skeletal muscle. The cerebral StO 2 in the SCD cohort was lower than the control group, 55.5 ± 7.4% versus 66.9 ± 2.5% (p = 0.003), respectively. Skeletal muscle StO 2 in the SCD cohort was lower than that in control, 59.2 ± 5.8% versus 66.4 ± 6.7%, respectively, but the difference was not significant (p = 0.19). The muscle O 2Hb in the SCD cohort was lower compared to control: 32.7 ± 6.5 µM versus 51.0 ± 9.2 µM (p = 0.01), respectively. The muscle tHb had a similar trend, with the SCD cohort measuring 55.8 ± 12.0 µM and the control group measuring 76.5 ± 9.0 µM (p = 0.03). The SCD cohort was also found to have lower overall muscle BFi, averaging 5.37 x 10 -9 ± 3.47 x 10 -9 cm/s, whereas the control group had an average of 1.90 x 10 -8 ± 1.33 x 10 -8 cm/s (p = 0.004). We also calculated hemodynamic markers, such as components of the occlusion recovery. The post-occlusion O 2Hb recovery slope for the SCD cohort was 0.31 ± 0.19 µM/s compared with control group at 1.56 ± 0.75 µM/s (p = 0.004). The goal of this study is to compare baseline vascular hemodynamics between patients with SCD and ethnically matched healthy controls. This study is ongoing and preliminary data analysis suggests impaired cardiovascular health in SCD subjects. The cerebral StO 2, muscle O 2Hb, and tHb in the SCD cohort is hypothesized to be a result of the reduced ability of sickled RBC to carry oxygen. There was a significant difference in the cerebral StO 2 but not in the skeletal muscle StO 2, suggesting that there are more dynamic changes seen in the brain than the muscle. This is consistent with previous work using commercial, continuous-wave NIRS systems for a SCD cohort (Barriteau et al. 2022) that also reported significantly lower cerebral StO 2 and lower trending, but not significant, muscle StO 2 values.The post-occlusion O 2Hb recovery upslope is hypothesized to be slower for the SCD cohort due to reduced endothelial function. We plan to assess repeatability of intra-individual NIRS parameters and to compare the non-invasive hemodynamic metrics to clinical markers, such as blood Hb and echocardiogram. These preliminary results indicate that NIRS is sensitive to changes in hemodynamic variations between SCD patients and healthy controls and, therefore, has the potential to serve as a point-of-care technology for individualized clinical management for patients with SCD.

Effect of pre-treatment on induction of anaesthesia with etomidate: A comparison between dexmedetomidine and midazolam–fentanyl combination

Background: Because of its prompt onset of action and clearance, the use of etomidate as an anaesthetic induction agent is increasing in clinical practice. However, etomidate-induced myoclonus (EIM) remains a prevalent issue. Such myoclonic activity can be prevented by the administration of drugs that inhibit subcortical neuronal activity. Aims: This study was designed to compare the effects of pre-treatment with dexmedetomidine and fentanyl–midazolam combination on EIM as well as on attenuation of pharyngolaryngeal reflex. Materials and Methods: One hundred adult patients with the American Society of Anesthesiologists Grades 1 or 2 posted for elective surgery were enrolled and were randomly divided into two groups of 50 patients each. Group D received dexmedetomidine (1 μg/kg) in over 10 min and Group F received midazolam (0.02 mg/kg) + fentanyl (2 μg/kg) intravenously. Haemodynamic variables, incidence and severity of myoclonus were recorded. Results: The incidence of EIM was lower in Group F (26%) when compared to Group D (40%), but the difference was not statistically significant (P = 0.28). Eighteen per cent of the subjects in Group F had Grade 1 myoclonus as compared to 32% of Group D, whereas 8% of the subjects in Group F had Grade 2 myoclonus as compared to 6% of Group D. None of the patients in Group F experienced myoclonus of Grade 3, whereas 2% of the subjects had Grade 3 myoclonus. Conclusion: Administration of a combination of fentanyl and midazolam, along with dexmedetomidine as a pre-treatment, has been found to be an effective strategy for mitigating the incidence of myoclonus.

Haemodynamic changes after atrial fibrillation initiation in patients eligible for catheter ablation: a randomized controlled study.

Atrial fibrillation (AF) haemodynamics is less well studied due to challenges explained by the nature of AF. Until now, no randomized data are available. This study evaluates haemodynamic variables after AF induction in a randomized setting. Forty-two patients with AF who had been referred for ablation to the University Hospital, Linköping, Sweden, and had no arrhythmias during the 4-day screening period were randomized to AF induction vs. control (2:1). Atrial fibrillation was induced by burst pacing after baseline intracardiac pressure measurements. Pressure changes in the right and left atrium (RA and LA), right ventricle (RV), and systolic and diastolic blood pressures (SBP and DBP) were evaluated 30 min after AF induction compared with the control group. A total of 11 women and 31 men (median age 60) with similar baseline characteristics were included (intervention n = 27, control group n = 15). After 30 min in AF, the RV end-diastolic pressure (RVEDP) and RV systolic pressure (RVSP) significantly reduced compared with baseline and between randomization groups (RVEDP: P = 0.016; RVSP: P = 0.001). Atrial fibrillation induction increased DBP in the intervention group compared with the control group (P = 0.02), unlike reactions in SBP (P = 0.178). Right atrium and LA mean pressure (RAm and LAm) responses did not differ significantly between the groups (RAm: P = 0.307; LAm: P = 0.784). Induced AF increased DBP and decreased RVEDP and RVSP. Our results allow us to understand some paroxysmal AF haemodynamics, which provides a haemodynamic rationale to support rhythm regulatory strategies to improve symptoms and outcomes. No NCT01553045. https://clinicaltrials.gov/ct2/show/NCT01553045?term=NCT01553045&rank=1.

Organ perfusion pressure at admission and clinical outcomes in patients hospitalized for acute heart failure.

Hypoperfusion portends adverse outcomes in acute heart failure (AHF). The gradient between end-organ inflow and outflow pressures may more closely reflect hypoperfusion than mean arterial pressure (MAP) alone. The aim of this study was to investigate organ perfusion pressure (OPP), calculated as MAP minus central venous pressure (CVP), as a prognostic marker in AHF. The Sodium NItroPrusside Treatment in Acute Heart Failure (SNIP)-AHF study was a multicentre retrospective cohort study of 200 consecutive patients hospitalized for AHF treated with sodium nitroprusside. Only patients with both MAP and invasive CVP data available from the SNIP-AHF cohort were included in this analysis. The primary endpoint was to assess OPP as a predictor of worsening heart failure (WHF), defined as the worsening of signs and symptoms of heart failure leading to intensification of therapy at 48 h. One hundred and forty-six patients fulfilling the inclusion criteria were included [mean age: 61.1 ± 13.5 years, 32 (21.9%) females; mean body mass index: 26.2 ± 11.7 kg/m2; mean left ventricular ejection fraction: 23.8%±11.4%, mean MAP: 80.2 ± 13.2 mmHg, and mean CVP: 14.0 ± 6.1 mmHg]. WHF occurred in 14 (9.6%) patients. At multivariable models including hemodynamic variables (OPP, shock index, and CVP), OPP at admission was the best predictor of WHF at 48 h [OR 0.91 (95% confidence interval 0.86-0.96), P-value = 0.001] with an optimal cut-off value of 67.5 mmHg (specificity 47.3%, sensitivity 100%, and AUC 0.784 ± 0.054). In multivariable models, including univariable significant parameters available at first bedside assessment, namely New York Heart Association functional class, OPP, shock index, CVP, and left ventricular end-diastolic diameter, OPP consistently and significantly predicted WHF at 48 h. In this retrospective analysis on patients hospitalized for AHF treated with sodium nitroprusside, on-admission OPP significantly predicted WHF at 48 h with high sensitivity.

Effect of AT1 receptor blockade on cardiovascular outcome after cardiac arrest: an experimental study in rats

Angiotensin II receptor 1(AT1) antagonists are beneficial in focal ischemia/reperfusion (I/R). However, in cases of global I/R, such as cardiac arrest (CA), AT1 blocker's potential benefits are still unknown. Wistar male rats were allocated into four groups: Control group (CG)—animals submitted to CA by ventricular fibrillation induced by direct electrical stimulation for 3 min, and anoxia for 5 min; Group AT1 (GAT1)—animals subjected to CA and treated with 0.2 mg/kg of candesartan diluted in dimethylsulfoxide (DMSO) (0.1%); Vehicle Group (VG): animals subjected to CA and treated with 0.2 ml/kg of DMSO and Sham group (SG)—animals submitted to surgical interventions, without CA. Cardiopulmonary resuscitation consisted of group medications, chest compressions, ventilation, epinephrine (20 mcg/kg) and defibrillation. The animals were observed up to 4 h after spontaneous circulation (ROSC) return, and survival rates, hemodynamic variables, histopathology, and markers of tissue injury were analyzed. GAT1 group had a higher rate of ROSC (62.5% vs. 42.1%, p < 0.0001), survival (100% vs. 62.5%, p = 0.027), lower incidence of arrhythmia after 10 min of ROSC (10% vs. 62.5%, p = 0.000), and lower neuronal and cardiac injury scores on histology evaluation (p = 0.025 and p = 0.0052, respectively) than GC group. The groups did not differ regarding CA duration, number of adrenaline doses, or number of defibrillations. AT1 receptor blockade with candesartan yielded higher rates of ROSC and survival, in addition to neuronal and myocardial protection.

Haemodynamic effects of labetalol in isoflurane-anaesthetized dogs that received dexmedetomidine: A randomized clinical trial

ObjectiveTo test whether labetalol improved cardiovascular function in anaesthetized dogs injected with dexmedetomidine. Study designProspective, randomized, blinded, clinical trial. AnimalsA group of 20 healthy client-owned dogs undergoing ovariohysterectomy. MethodsEach dog received dexmedetomidine (5 μg kg–1) and methadone (0.2 mg kg–1) intramuscularly. General anaesthesia was induced with propofol and maintained with isoflurane in oxygen. All dogs were mechanically ventilated, and epidural anaesthesia with lidocaine was performed.Standard anaesthetic monitoring, invasive blood pressure, oesophageal Doppler and near-infrared tissue perfusion/oxygenation were applied. Peak velocity (PV), mean acceleration and stroke distance (SD) from the oesophageal Doppler were recorded. Arterial elastance (Ea) was calculated. Tissue oxygenation (rStO2) was also recorded.Prior to surgery, animals received either 0.1 mg kg–1 of labetalol intravenously (IV) over 60 seconds or the equivalent volume of saline. Data were recorded for 20 minutes.Age, weight and propofol dose were compared with a Wilcoxon rank-sum test. The effects of time, treatment and their interaction with haemodynamic and perfusion variables were analysed with mixed-effect models and Tukey’s post hoc tests. ResultsSignificant effects of the interaction between treatment and time were observed whereby heart rate (HR) was higher in dogs given labetalol (p = 0.01), whereas arterial blood pressure and Ea were lower (p < 0.01). Similarly, PV, SD and rStO2 were higher in the labetalol group, and significant effects were detected for the interaction between treatment and time (p < 0.01). Conclusions and clinical relevanceLabetalol at a dose of 0.1 mg kg–1 IV in dogs under general anaesthesia and administered a pre-anaesthetic medication of dexmedetomidine produced mild vasodilation (reduction of Ea), resulting in an increase in HR and left ventricular outflow. Although labetalol could be an effective option to achieve haemodynamic optimization after dexmedetomidine-induced vasoconstriction, future studies are needed to assess long-term effects.

Establishment and validation of intravenous anesthesia with dexmedetomidine for pigs under assisted spontaneous breathing: A preclinical model of intensive care conditions.

Large animal models are frequently used to investigate new medical approaches. In most cases, animals are kept under general anesthesia and mandatory mechanical ventilation during the experiments. However, in some situations assisted spontaneous breathing is essential, e.g. when simulating conditions in a modern intensive care unit. Therefore, we established an anesthesia regime with dexmedetomidine and midazolam/ketamine in porcine models of assisted spontaneous breathing. The total intravenous anesthesia was used in lung healthy pigs, in pigs with oleic acid induced acute respiratory distress syndrome and in pigs with methacholine induced bronchopulmonary obstruction. We were able to maintain stable conditions of assisted spontaneous breathing without impairment of hemodynamic, respiratory or blood gas variables in lung healthy pigs and pigs with induced acute respiratory distress syndrome for a period of five hours and in pigs with induced bronchopulmonary obstruction for three hours. Total intravenous anesthesia containing dexmedetomidine enables stable conditions of assisted spontaneous breathing in healthy pigs, in pigs with induced acute respiratory distress syndrome and in pigs induced bronchopulmonary obstruction as models of intensive care unit conditions.

Body composition and cardiorespiratory fitness of overweight COVID-19 survivors in different severity degrees: a cohort study

COVID-19 sequelae are varied, and whether they are temporary or permanent is still unknown. Identifying these sequelae may guide therapeutic strategies to improve these individuals' recovery. This prospective cohort aimed to assess body composition, cardiopulmonary fitness, and long-term symptoms of overweight individuals affected by COVID-19. Participants (n = 90) were divided into three groups according to the severity of acute COVID-19: mild (no hospitalization), moderate (hospitalization, without oxygen support), and severe/critical cases (hospitalized in Intensive Care Unit). We assessed body composition with a tetrapolar multifrequency bioimpedance, hemodynamic variables (heart rate, blood pressure, and peripheral oxygen saturation-SpO2) at rest, and the Bruce test with direct gas exchange. Two assessments with a one-year interval were performed. The most prevalent long-term symptoms were memory deficit (66.7%), lack of concentration (51.7%), fatigue (65.6%), and dyspnea (40%). Bruce test presented a time effect with an increase in the distance walked after 1 year just for severe/critical group (p < 0.05). SpO2 was significantly lower in the severe/critical group up to 5 min after the Bruce test when compared to the mild group, and diastolic blood pressure at the end of the Bruce test was significantly higher in the severe/critical group when compared to mild group (p < 0.05; for all comparisons). A time effect was observed for body composition, with increased lean mass, skeletal muscle mass, fat-free mass, and lean mass just for the severe/critical group after 1 year (p < 0.05). Cardiopulmonary fitness parameters did not differ among the groups, except for respiratory quotient with higher values for the severe/critical group when compared to itself after 1 year. All COVID-19 patients might present long-term sequelae, regardless of the acute disease severity. Reassessing and identifying the most prevalent long-term sequelae are essential to perform more precise health promotion interventions.

Role of serum biomarkers in predicting management strategies for acute pulmonary embolism

BackgroundAcute pulmonary embolism (APE) is a condition that can be fatal. The severity of the disease influences therapeutic decisions, and mortality varies significantly depending on the condition's severity. Identification of patients with a high mortality risk is crucial. Since inflammation, hemostatic, and coagulation abnormalities are linked to APE, serum biomarkers may be helpful for prognostication. AimTo evaluate the significance of serum biomarkers in APE risk assessment and the suitability of these biomarkers for management and decision-making. MethodsThis study involved 60 adult patients with APE who were divided according to risk categorization. It was conducted in Chest, Cardiology and Internal Medicine department, Zagazig University Hospitals from December 2022 to May 2023. Several hematological biomarkers and their significance in APE risk assessment were measured with a comparison with the latest risk stratification methods which include haemodynamic measures and right ventricular (RV) dysfunction echocardiographic markers. ResultsEach risk group involved 20 patients (high, intermediate (10 were intermediate-high and 10 were intermediate-low) and low risk group). They were 34 females and 26 males with the mean ± SD of their age was 59.25 ± 13.06 years. Regarding hematological biomarkers, there were statistically significant differences as regards; lymphocytes, platelet to lymphocyte ratio (PLR), albumin, blood urea nitrogen (BUN), C-reactive protein (CRP) and D-dimer with highly statistically significant differences as regards; neutrophil to lymphocyte ratio (NLR), BUN to albumin (B/A) ratio, troponin I (TnI), and brain natriuretic peptide (BNP). TnI had the highest specificity and predictive value positive (PVP) and BNP had the highest sensitivity and predictive value negative (PVN) in predicting high risk groups. The Lymphocyte and NLR showed the lowest sensitivity and the albumin and B/A ratio had the lowest specificity. Regarding transthoracic echocardiography (TEE); there was a statistically significant increase regarding pulmonary artery systolic pressure (PASP) and a highly statistically significant increase regarding the right ventricle/left ventricle (RV/LV) ratio. There were statistically significant decreases regarding tricuspid annular plane systolic excursion (TAPSE) and peak systolic velocity of tricuspid annulus (S′) among risk groups. ConclusionAPE prognosis can be judged accurately by simultaneously measuring a few biomarkers along with haemodynamic variables and echocardiographic parameters of RV dysfunction.

Pain Control and Hemodynamic Changes due to Moderate Sedation during Cardiac Catheterization

Background: Moderate sedation is a practice of promoting patient comfort during cardiac catheterization. However, few studies have evaluated the effectiveness of moderate sedation in patients undergoing cardiac catheterization. Objective: To determine the efficacy of moderate sedation in patients undergoing cardiac catheterization. Materials and Methods: The authors retrospectively analyzed patients undergoing cardiac catheterization. They were divided into the moderate sedation group, which received midazolam, fentanyl, or combined midazolam and fentanyl, and the control group, which received no sedative medication. The primary endpoint was self-reported pain score during the procedure. The secondary endpoint was a hemodynamic variation during the procedure. Propensity-score matching was used to reduce confounding biases. Results: One hundred ninety-six patients were included, with 111 patients in the moderate sedation group and 85 patients in the control group. The proportion of patients who experienced any pain was significantly lower in the moderate sedation group than in the control group at 3.6% versus 11.8% (p=0.028). No significant difference was found in the average change in the systolic blood pressure at –9 mmHg versus –4 mmHg (p=0.097) and the heart rate at –1 bpm versus –2 bpm (p=0.289) obtained at baseline and that at the end of the procedure between the moderate sedation group and the control group. However, the change in the diastolic blood pressure (DBP) measured at baseline and at the end of the procedure was significantly lower in the moderate sedation group than in the control group at –4 mmHg versus –1 mmHg (p=0.039). Conclusion: Moderate sedation by using a low-dose fentanyl, midazolam, or combined fentanyl and midazolam is associated with fewer episodes of pain and better DBP stability during cardiac catheterization. Keywords: Conscious sedation; Midazolam; Coronary angiography; Percutaneous coronary intervention; Cardiac catheterization

Liver fibrosis emulation: Impact of the vascular fibrotic alterations on hemodynamics

The liver circulatory system comprises two blood supply vascular trees (the hepatic artery and portal venous networks), microcirculation through the hepatic capillaries (the sinusoids), and a blood drainage vascular tree (the hepatic vein network). Vasculature changes due to fibrosis —located predominantly at the microcirculation level— lead to a marked increase in resistance to flow causing an increase in portal pressure (portal hypertension). Here, we present a liver fibrosis/cirrhosis model. We build on our 1D model of the healthy hepatic circulation, which considers the elasticity of the vessels walls and the pulsatile character of blood flow and pressure, and recreate the deteriorated liver vasculature due to fibrosis. We emulate altered sinusoids by fibrous tissue (stiffened, compressed and splitting) and propose boundary conditions to investigate the impact of fibrosis on hemodynamic variables within the organ. We obtain that the sinusoids stiffness leads to changes in the amplitude and shape of the blood flow and pressure waveforms but not in their mean value. For the compressed and splitting sinusoids, we observe significant increases in the mean value and amplitude of the pressure waveform in the altered sinusoids and in the portal venous network. In other words, we obtain the portal hypertension clinically observed in fibrotic/cirrhotic patients. We also study the extent of the spreading fibrosis by performing the structural fibrotic changes in an increasingly number of sinusoids. Finally, we calculate the portal pressure gradient (PPG) in the model and obtain values in agreement with those reported in the literature for fibrotic/cirrhotic patients.

Postoperative Pulmonary Artery Pulsatility Index Improves Prediction of Right Ventricular Failure After Left Ventricular Assist Device Implantation

This study evaluated whether the postoperative pulmonary artery pulsatility index (PAPi) is associated with postoperative right ventricular dysfunction after durable left ventricular assist device (LVAD) implantation. Single-center retrospective observational cohort study. The University of Kansas Medical Center, a tertiary-care academic medical center. Sixty-seven adult patients who underwent durable LVAD implantation between 2017 and 2019. All patients underwent open cardiac surgery with cardiopulmonary bypass under general anesthesia with pulmonary artery catheter insertion. Clinical and hemodynamic data were collected before and after surgery. The Michigan right ventricular failure risk score and the European Registry for Patients with Mechanical Circulatory Support score were calculated for each patient. The primary outcome was right ventricular failure, defined as a composite of right ventricular mechanical circulatory support, inhaled pulmonary vasodilator therapy for 48 hours or greater, or inotrope use for 14 days or greater or at discharge. Thirty percent of this cohort (n=20) met the primary outcome. Preoperative transpulmonary gradient (odds ratio [OR] 1.15, 95% CI 1.02-1.28), cardiac index (OR 0.83, 95% CI 0.71-0.98), and postoperative PAPi (OR 0.85, 95% CI 0.75-0.97) were the only hemodynamic variables associated with the primary outcome. The addition of postoperative PAPi was associated with improvement in the predictive model performance of the Michigan score (area under the receiver operating characteristic curve 0.73 v 0.56, p=0.03). An optimal cutoff point for postoperative PAPi of 1.56 was found. The inclusion of postoperative PAPi offers more robust predictive power for right ventricular failure in patients undergoing durable LVAD implantation, compared with the use of existing risk scores alone.

Pain Assessment Using the Analgesia Nociception Index (ANI) in Patients Undergoing General Anesthesia: A Systematic Review and Meta-Analysis.

The analgesia nociception index (ANI) has emerged as a potential measurement for objective pain assessment during general anesthesia. This systematic review and meta-analysis aimed to evaluate the accuracy and effectiveness of ANI in assessing intra- and post-operative pain in patients undergoing general anesthesia. We conducted a comprehensive search of Ovid-MEDLINE, Ovid-EMBASE, Cochrane Central Register of Controlled Trials, Google Scholar, public clinical trial databases (ClinicalTrials and Clinical Research Information Service), and OpenSIGLE to identify relevant studies published prior to May 2023 and included studies that evaluated the accuracy and effectiveness of ANI for intra- or post-operative pain assessment during general anesthesia. Among the 962 studies identified, 30 met the eligibility criteria and were included in the systematic review, and 17 were included in the meta-analysis. For predicting intra-operative pain, pooled sensitivity, specificity, diagnostic odds ratio (DOR), and area under curve of ANI were 0.81 (95% confidence interval [CI] = 0.79-0.83; I2 = 68.2%), 0.93 (95% CI = 0.92-0.93; I2 = 99.8%), 2.32 (95% CI = 1.33-3.30; I2 = 61.7%), and 0.77 (95% CI = 0.76-0.78; I2 = 87.4%), respectively. ANI values and changes in intra-operative hemodynamic variables showed statistically significant correlations. For predicting post-operative pain, pooled sensitivity, specificity, and DOR of ANI were 0.90 (95% CI = 0.87-0.93; I2 = 58.7%), 0.51 (95% CI = 0.49-0.52; I2 = 99.9%), and 3.38 (95% CI = 2.87-3.88; I2 = 81.2%), respectively. ANI monitoring in patients undergoing surgery under general anesthesia is a valuable measurement for predicting intra- and post-operative pain. It reduces the use of intra-operative opioids and aids in pain management throughout the perioperative period.

Prediction of Return of Spontaneous Circulation in a Pediatric Swine Model of Cardiac Arrest Using Low-Resolution Multimodal Physiological Waveforms.

Monitoring physiological waveforms, specifically hemodynamic variables (e.g., blood pressure waveforms) and end-tidal CO2 (EtCO2), during pediatric cardiopulmonary resuscitation (CPR) has been demonstrated to improve survival rates and outcomes when compared to standard depth-guided CPR. However, waveform guidance has largely been based on thresholds for single parameters and therefore does not leverage all the information contained in multimodal data. We hypothesize that the combination of multimodal physiological features improves the prediction of the return of spontaneous circulation (ROSC), the clinical indicator of short-term CPR success. We used machine learning algorithms to evaluate features extracted from eight low-resolution (4 samples per minute) physiological waveforms to predict ROSC. The waveforms were acquired from the 2nd to 10th minute of CPR in pediatric swine models of cardiac arrest (N = 89, 8-12 kg). The waveforms were divided into segments with increasing length (both forward and backward) for feature extraction, and machine learning algorithms were trained for ROSC prediction. For the full CPR period (2nd to 10th minute), the area under the receiver operating characteristics curve (AUC) was 0.93 (95% CI: 0.87-0.99) for the multivariate model, 0.70 (0.55-0.85) for EtCO2 and 0.80 (0.67-0.93) for coronary perfusion pressure. The best prediction performances were achieved when the period from the 6th to the 10th minute was included. Poor predictions were observed for some individual waveforms, e.g., right atrial pressure. In conclusion, multimodal waveform features carry relevant information for ROSC prediction. Using multimodal waveform features in CPR guidance has the potential to improve resuscitation success and reduce mortality.

Effect of Analgesic Low-Dose Ketamine Infusions on the Cardiovascular Response: A Retrospective Analysis

BACKGROUND: Low-dose ketamine infusion (LDKI) has shown effectiveness for treating acute pain associated with surgical and nonsurgical (traumatic, neuropathic, and acute cancer-related) origin as an adjuvant to opioids. The increasing use of LDKI as an opioid-sparing agent in multimodal analgesia requires a better understanding of its effects on the cardiovascular response, a known dose-dependent side effect of ketamine administration. We investigated the cardiovascular response of acute pain patients treated with LDKI. OBJECTIVES: The aim of the present study was to evaluate the effect of LDKI in hemodynamic variables (blood pressure [BP] and heart rate [HR]) during LDKI analgesia for up to 48 hours of treatment in an acute pain setting. Secondary objectives were to evaluate psychomimetic effects. STUDY DESIGN: Retrospective unicentric cohort design. SETTING: The study was conducted at an academic university hospital. METHODS: We conducted a single-center retrospective cohort analysis of adult patients who underwent LDKI to treat surgical and nonsurgical acute pain. We obtained data from the Hospital San Vicente Fundación Health Documentation System database and evaluated the medical records of 318 patients with surgical and nonsurgical pain. Patients received a 0.1 mg/kg/h ketamine infusion as part of a multimodal analgesic plan. Baseline systolic BP (SBP), diastolic BP (DBP), mean arterial pressure (MAP), and HR values were compared with those measured after 24 and 48 hours of treatment. Pain level and psychomimetic effects were measured at 24 and 48 hours. Cardiovascular complications and treatment duration were also recorded. Patients with a history of psychiatric, cardiovascular, or cognitive disease were excluded from the study. This study was registered in the clinicaltrials.gov database (identifier: NCT03979105). RESULTS: No statistical differences in SBP, DBP, MAP, or HR were observed when baseline and post-LDKI treatment values were compared (P &lt; 0.05). When comparing hemodynamic variables after exposure to LDKI in patients with and without hypertension, we did not observe statistically significant differences in mean HR, systolic arterial pressure, diastolic arterial pressure, or MAP values at 24 and 48 hours. The frequency of severe pain was reduced from 72% on day 0 to 4.4% on day 1 and 6.2% on day 2 post-LDKI. Observed psychomimetic effects were confusion 4.39%, hallucinations 2.51%, and nightmares 1.25%. No major cardiovascular events were observed. LIMITATIONS: This study was limited by its retrospective design, the lack of a comparative matching cohort, and the good general condition of the majority of patients included in the study. CONCLUSIONS: LDKI (0.1 mg/kg/h) was not associated with significant changes in baseline BP or HR. Our results suggest that as an adjuvant in multimodal analgesia for surgical and nonsurgical acute pain, LDKI has a low impact on the cardiovascular response. KEY WORDS: Ketamine, adverse effects, tachycardia, hypertension, postoperative pain, chronic postsurgical pain

Numerical analysis of hemodynamic parameters in stenosed arteries under pulsatile flow conditions

This research studies the changes in flow patterns and hemodynamic parameters of diverse shapes and sizes of stenosis. Six different shapes and sizes of stenosis are constructed to investigate the variations in hemodynamics as the morphology changes. Changes in shape (trapezoidal and bell-shaped) and sizes of stenosis change the stresses on the walls and their flow patterns. TAWSS and OSI results specify that trapezoidal stenosis exerts greater stress than bell-shaped stenosis. Also, as the length of the trapezoidal stenosis increases, the TAWSS increases, whereas the trend is the opposite for bell-shaped stenosis. Later, this paper also studies different degrees of stenosis extracted from real images. Changes in velocity flow patterns, wall shear stress (WSS), Time-averaged wall shear stress (TAWSS) and Oscillatory shear index (OSI) have been studied for these images. Results illustrate that the peak velocity rises drastically as the stenosis percentage increases. Negative velocity is seen close to the artery's walls, indicating flow separation. This flow separation region is seen throughout the cycle except in the accelerating flow region. An increase in stenosis also increases WSS and TAWSS drastically. Negative WSS is seen downstream of stenosis, indicating flow recirculation. Such negative WSS in the blood vessels also promotes endothelial dysfunction. OSI values greater than 0.2 are seen near the stenosis region, indicating atherosclerosis growth. Regions of high OSI and low TAWSS are also identified, indicating probable regions of plaque development.

Variations of Middle Cerebral Artery Hemodynamics Due to Aneurysm Clipping Surgery

Abstract Cerebral aneurysms are potentially life-threatening cerebrovascular conditions where a weakened blood vessel in the brain bulges or protrudes over time. The most common way to treat aneurysms is surgical clipping, an approach where blood flow to the aneurysm is blocked by a permanently placed clip on the artery. However, not all aneurysms are identical; thus, there has been a need for patient-specific treatment options, where each aneurysm is treated based on its individual characteristics. Computational fluid dynamics (CFD) modeling can offer insights to predict how different treatment procedures will affect cerebral hemodynamics. In that regard, the goal of this pilot study was to investigate the flow characteristics and hemodynamic parameters in cerebral arteries before and after neurosurgical clipping. For this purpose, two patient-specific cerebral artery geometries with at least one aneurysm at the middle cerebral artery bifurcation were selected from an online dataset. A companion postclipping model was created for each geometry by removing the aneurysm from the original geometry. Tetrahedral mesh elements were then generated and CFD simulations were conducted to compare the blood velocity profile, secondary flow, flow streamline, and wall shear stress in the computational models with and without aneurysm. Results showed that the clipping treatment led to changes in the velocity profiles, secondary flow structures, and wall shear stress in the middle cerebral artery. In conclusion, our results suggest that CFD modeling can assist in predicting hemodynamic parameters prior to treatment, thus facilitating more tailored planning for each patient’s treatment.

Effectiveness of the oral Clonidine as a pre-anesthetic medicine for thyroidectomy surgery; A randomized clinical trial.

Hemodynamic disturbance is a common problem in patients undergoing thyroid surgery. It may be due to episodic increases in thyroid hormones (thyroid storm) or stimulation of the carotid sinus baroreflex. The aim of the present study was to investigate effectiveness of the pre-operative oral Clonidine on reducing these hemodynamic changes during total thyroidectomy surgery. In a prospective, randomized, double-blind study, 80 patients scheduled for elective total thyroidectomy were randomized to receive either 0.2 mg Clonidine (n=40) or a matched placebo (n=40) orally sixty minutes before entering the operating room. Hemodynamic variables, the duration of surgery, estimated amount of blood loss and the dose of administered remifentanil were recorded for further analysis. Oral Clonidine was found to be significantly better in maintaining stable hemodynamics compared to the control group. Also, In the Clonidine group, the estimated amount of blood loss (110.4±10 ml vs. 182.2±11.4 mL, P=0.04), duration of the surgery (78.26±55.2 min vs. 105.16±61.75 min, P=0.027) and administered dose of remifentanil (26.67±6.6 μg vs. 216.2±14.8 μg, P=0.01) were also significantly lower than the control group. Pre-operative administration of 0.2 mg oral Clonidine in patients undergoing total thyroidectomy results in improved perioperative hemodynamic stability and reduced response to perioperative stress.