Impact of geometric and hemodynamic changes on a mechanobiological model of atherosclerosis.

BACKGROUND AND OBJECTIVE: In this work, the analysis of the importance of hemodynamic updates on a mechanobiological model of atheroma plaque formation is proposed. METHODS: For that, we use an idealized and axisymmetric model of carotid artery. In addition, the behavior of endothelial cells depending on hemodynamical changes is analyzed too. A total of three computational simulations are carried out and their results are compared: an uncoupled model and two models that consider the opposite behavior of endothelial cells caused by hemodynamic changes. The model considers transient blood flow using the Navier-Stokes equation. Plasma flow across the endothelium is determined with Darcy's law and the Kedem-Katchalsky equations, considering the three-pore model, which is also employed for the flow of substances across the endothelium. The behavior of the considered substances in the arterial wall is modeled with convection-diffusion-reaction equations, and the arterial wall is modeled as a hyperelastic Yeoh's material. RESULTS: Significant variations are noted in both the morphology and stenosis ratio of the plaques when comparing the uncoupled model to the two models incorporating updates for geometry and hemodynamic stimuli. Besides, the phenomenon of double-stenosis is naturally reproduced in the models that consider both geometric and hemodynamical changes due to plaque growth, whereas it cannot be predicted in the uncoupled model. CONCLUSIONS: The findings indicate that integrating the plaque growth model with geometric and hemodynamic settings is essential in determining the ultimate shape and dimensions of the carotid plaque.

Quantitative analysis of hemodynamic changes induced by the discrepancy between the sizes of the flow diverter and parent artery.

The efficacy of flow diverters is influenced by the strut configuration changes resulting from size discrepancies between the stent and the parent artery. This study aimed to quantitatively analyze the impact of size discrepancies between flow diverters and parent arteries on the flow diversion effects, using computational fluid dynamics. Four silicone models with varying parent artery sizes were developed. Real flow diverters were deployed in these models to assess stent configurations at the aneurysm neck. Virtual stents were generated based on these configurations for computational fluid dynamics analysis. The changes in the reduction rate of the hemodynamic parameters were quantified to evaluate the flow diversion effect. Implanting 4.0 mm flow diverters in aneurysm models with parent artery diameters of 3.0-4.5 mm, in 0.5 mm increments, revealed that a shift from oversized to undersized flow diverters led to an increase in the reduction rates of hemodynamic parameter, accompanied by enhanced metal coverage rate and pore density. However, the flow diversion effect observed transitioning from oversizing to matching was less pronounced when moving from matching to undersizing. This emphasizes the importance of proper sizing of flow diverters, considering the benefits of undersizing and not to exceed the threshold of advantages.

Hemodynamic changes in the prone position according to fluid loading after anaesthesia induction in patients undergoing lumbar spine surgery: a randomized, assessor-blind, prospective study.

INTRODUCTION: A change from the supine to prone position causes hemodynamic alterations. We aimed to evaluate the effect of fluid preloading in the supine position, the subsequent hemodynamic changes in the prone position and postoperative outcomes. PATIENTS AND METHODS: This prospective, assessor-blind, randomized controlled trial was conducted between March and June 2023. Adults scheduled for elective orthopaedic lumbar surgery under general anaesthesia were enrolled. In total, 80 participants were randomly assigned to fluid maintenance (M) or loading (L) groups. Both groups were administered intravenous fluid at a rate of 2 ml/kg/h until surgical incision; Group L was loaded with an additional 5 ml/kg intravenous fluid for 10 min after anaesthesia induction. The primary outcome was incidence of hypotension before surgical incision. Secondary outcomes included differences in the mean blood pressure (mBP), heart rate, pleth variability index (PVi), stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index and cardiac index before surgical incision between the two groups. Additionally, postoperative complications until postoperative day 2 and postoperative hospital length of stay were investigated. RESULTS: Hypotension was prevalent in Group M before surgical incision and could be predicted by a baseline PVi >16. The mBP was significantly higher in Group L immediately after fluid loading. The PVi, SVV and PPV were lower in Group L after fluid loading, with continued differences at 2-3 time points for SVV and PPV. Other outcomes did not differ between the two groups. CONCLUSION: Fluid loading after inducing general anaesthesia could reduce the occurrence of hypotension until surgical incision in patients scheduled for surgery in the prone position. Additionally, hypotension could be predicted in patients with a baseline PVi >16. Therefore, intravenous fluid loading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position. TRIAL NUMBER: KCT0008294 (date of registration: 16 March 2023).

Fluid preloading could reduce the occurrence of hypotension in the prone position. Hypotension could be predicted in patients with a baseline PVi >16. Intravenous fluid preloading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position.

Evaluation of the Acute Anaphylactoid Reactogenicity of Nanoparticle-Containing Medicines and Vaccines Using the Porcine CARPA Model.

A small fraction, up to 10%, of people treated intravenously with state-of-the-art nanoparticulate drugs or diagnostic agents develop an acute infusion reaction which can be severe or even lethal. Activation of the complement (C) system can play a causal, or contributing role in these atypical, "pseudoallergic" reactions, hence their name, C activation-related pseudoallergy (CARPA). Intravenous (i.v.) administration of the human reaction-triggering (very small) dose of a test sample in pigs triggers a symptom tetrad (characteristic hemodynamic, hematological, skin, and laboratory changes) that correspond to the major human symptoms. Quantitating these changes provides a highly sensitive and reproducible method for assessing the risk of CARPA, enabling the implementation of appropriate preventive measures. Accordingly, the porcine CARPA model has been increasingly used for the safety evaluation of therapeutic and diagnostic nanomedicines and, recently, mRNA-lipid nanoparticle vaccines. This chapter provides details of the experimental procedure followed upon using the model.

Hemodynamic changes and perinatal outcome associated with umbilical artery thrombosis: a retrospective study.

OBJECTIVE: Poor fetal and perinatal outcomes in fetuses associated with umbilical artery thrombosis (UAT), such as severe intrauterine growth restriction (IUGR) and intrauterine asphyxia have been reported by some case series. Its hemodynamic impact remains unclear. The aim of this study was to evaluate the hemodynamic changes and perinatal outcome in UAT fetuses with a relatively large sample. METHODS: We included singleton fetuses diagnosed with UAT and with at least one available Doppler evaluation before the end of pregnancy in our center from 2016 to 2023. Fetuses with structural abnormalities and with no follow-up results were excluded. Doppler waveforms from the Umbilical artery (UA), middle cerebral artery (MCA), ductus venosus (DV) and uterine artery (UtA) were routinely evaluated according to ISUOG Practice Guidelines from diagnosis. The same sample of GA-matched normal fetuses with Doppler measurements during the same period were randomly selected as control group. RESULTS: Eighty-nine singleton fetuses with UAT with at least one Doppler evaluation before the end of pregnancy were identified, 13 fetuses with no follow-up results were excluded. After comprehensive prenatal counseling, 14 cases received urgent cesarean section, the remaining 55 cases received expectant management, the median day between GA at diagnosis and end of pregnancy was 13 (5-53) days (range, 2-159). 7 (7/76, 9.2%) cases occurred stillbirth, and the incidence of IUGR and Neonatal Intensive Care Unit (NICU) admission were 18.4% (14/76) and 13.2% (10/76) respectively. 49 fetuses (49/76, 64.5%) combined with Doppler abnormalities. UA abnormalities (35/76, 46.1%) and MCA abnormalities (34/76, 44.7%) were the most changes at presentation. Compared to control group, UA-EDV was significantly increased in UAT fetuses [21.84 (15.59-26.64) vs. 16.40 (12.43-20.70) cm/s, p < 0.001], UA-PI and UA-RI significantly decreased [0.68 (0.57-0.84) vs. 0.92 (0.79-1.11), p<0.001; 0.51 (0.44-0.59) vs. 0.62 (0.55-0.68), p < 0.001, respectively]. Both the MCA-PSV and MCA-EDV were significantly higher in UAT fetuses [54.60 (48.00-61.34) vs. 44.47 (29.66-57.60) cm/s, p < 0.001; 11.19 (7.84-17.60) vs. 8.22 (5.21-12.00) cm/s, p < 0.001, respectively], this led to a lower MCA-PI and MCA-RI. Meanwhile, DV-PIV was significantly higher in UAT fetuses [0.6 (0.47-0.87) vs. 0.45 (0.37-0.55), p < 0.001], CPR and UtA-PI were no significant difference between these two groups. Multivariate logistic regression analysis showed that DV-PIV was an independent risk factor for adverse pregnancy outcomes (OR 161.922, p<0.001), the area under the ROC curve (AUC) was 0.792 (95% CI 0.668-0.917; p < 0.001). CONCLUSION: Our data showed serious adverse pregnancy consequences are combined with UAT fetuses. Hemodynamic changes in UAT fetuses showed the remaining artery for compensation and brain perfusion derangement. With a comprehensive and standardized Doppler evaluation, progression of fetal deterioration may be detailed presented.

Manejo anestésico para cirugía tiroidea. Una revisión no sistemática / Anesthetic management for thyroid surgery. A non-systematic review

Resumen: Las hormonas tiroideas forman parte fundamental del mantenimiento de la homeostasia, se encuentra particularmente relacionado con la función cardiovascular. Los estados distiroideos clínicos o subclínicos pueden comprometer este sistema en forma significativa durante los procedimientos quirúrgicos. Existen múltiples fármacos que pueden modificar la patología tiroidea en mayor o menor medida, disminuyendo el riesgo de complicaciones en la eventualidad de una cirugía. La utilización de anestesia general, ya sea balanceada o total endovenosa, se ha convertido en el estándar de oro, por la menor tasa de complicaciones asociadas. Durante el período perioperatorio se debe mantener un monitoreo estricto de la función cardiovascular para detectar alteraciones en forma temprana e iniciar las correcciones necesarias.

Abstract: Thyroid hormones are a fundamental part of the maintenance of homeostasis, it is particularly related to cardiovascular function. Clinical or subclinical dysthyroid states can significantly compromise this system during surgical procedures. There are multiple drugs that can modify the thyroid pathology to a greater or lesser extent, reducing the risk of complications in the event of surgery. The use of general anesthesia, whether balanced or total intravenous, has become the Gold standard, due to the lower rate of associated complications. During the perioperative period, strict monitoring of cardiovascular function must be maintained to detect alterations early and initiate the necessary corrections.

Habit-DisHabit Design with a Quadratic Equation: A Better Model of the Hemodynamic Changes in Preschoolers during the Dimension Change Card Sorting Task.

General linear modeling (GLM) has been widely employed to estimate the hemodynamic changes observed by functional near infrared spectroscopy (fNIRS) technology, which are found to be nonlinear rather than linear, however. Therefore, GLM might not be appropriate for modeling the hemodynamic changes evoked by cognitive processing in developmental neurocognitive studies. There is an urgent need to identify a better statistical model to fit into the nonlinear fNIRS data. This study addressed this need by developing a quadratic equation model to reanalyze the existing fNIRS data (N = 38, Mage = 5.0 years, SD = 0.69 years, 17 girls) collected from the mixed-order design Dimensional Change Card Sort (DCCS) task and verified the model with a new set of data with the Habit-DisHabit design. First, comparing the quadratic and cubic modeling results of the mixed-order design data indicated that the proposed quadratic equation was better than GLM and cubic regression to model the oxygenated hemoglobin (HbO) changes in this task. Second, applying this quadratic model with the Habit-DisHabit design data verified its suitability and indicated that the new design was more effective in identifying the neural correlates of cognitive shifting than the mixed-order design. These findings jointly indicate that Habit-DisHabit Design with a quadratic equation might better model the hemodynamic changes in preschoolers during the DCCS task.

In vivo monitoring of hemodynamic changes in ischemic stroke using photoacoustic tomography.

Ischemic stroke occurs when a blood vessel supplying the brain is blocked, leading to decreased blood flow. Early diagnosis and treatment are crucial. However, existing clinical imaging methods have limitations, such as safety issues and low time resolution. To address these challenges, we propose using photoacoustic tomography (PAT) with a contrast agent, known for its high resolution and contrast capabilities. Our study involved imaging brain vasculature in three groups: normal, unilateral common carotid artery ligation (UCAL), and middle cerebral artery occlusion (MCAO). On the ischemic stroke side, we observed reduced blood vessel density and hemodynamic changes were evident after injecting indocyanine green for PAT. The photoacoustic intensity was notably lower in the ligated sides of the UCAL and MCAO groups, with statistically significant differences between the three groups. This work highlights PAT's potential as a powerful tool for early diagnosis and guidance in ischemic stroke cases.

Cognitive impairment in post-acute sequelae of COVID-19 and short duration myalgic encephalomyelitis patients is mediated by orthostatic hemodynamic changes.

Introduction: Cognitive impairment is experienced by people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and post-acute sequelae of COVID-19 (PASC). Patients report difficulty remembering, concentrating, and making decisions. Our objective was to determine whether orthostatic hemodynamic changes were causally linked to cognitive impairment in these diseases. Methods: This prospective, observational cohort study enrolled PASC, ME/CFS, and healthy controls. All participants underwent clinical evaluation and assessment that included brief cognitive testing before and after an orthostatic challenge. Cognitive testing measured cognitive efficiency which is defined as the speed and accuracy of subject's total correct responses per minute. General linear mixed models were used to analyze hemodynamics and cognitive efficiency during the orthostatic challenge. Additionally, mediation analysis was used to determine if hemodynamic instability induced during the orthostatic challenge mediated the relationship between disease status and cognitive impairment. Results: Of the 276 participants enrolled, 256 were included in this study (34 PASC, 71 < 4 year duration ME/CFS, 69 > 10 year ME/CFS duration, and 82 healthy controls). Compared to healthy controls, the disease cohorts had significantly lower cognitive efficiency scores immediately following the orthostatic challenge. Cognitive efficiency remained low for the >10 year ME/CFS 2 and 7 days after orthostatic challenge. Narrow pulse pressure less than 25% of systolic pressure occurred at 4 and 5 min into the orthostatic challenge for the PASC and ME/CFS cohorts, respectively. Abnormally narrow pulse pressure was associated with slowed information processing in PASC patients compared to healthy controls (-1.5, p = 0.04). Furthermore, increased heart rate during the orthostatic challenge was associated with a decreased procedural reaction time in PASC and < 4 year ME/CFS patients who were 40 to 65 years of age. Discussion: For PASC patients, both their disease state and hemodynamic changes during orthostatic challenge were associated with slower reaction time and decreased response accuracy during cognitive testing. Reduced cognitive efficiency in <4 year ME/CFS patients was associated with higher heart rate in response to orthostatic stress. Hemodynamic changes did not correlate with cognitive impairment for >10 year ME/CFS patients, but cognitive impairment remained. These findings underscore the need for early diagnosis to mitigate direct hemodynamic and other physiological effects on symptoms of cognitive impairment.

A Preliminary Feasibility Study on Hemodynamic Changes Following Feyh-Kastenbauer Retractor Insertion During Transoral Robotic Surgeries.

 Introduction Transoral robotic surgery (TORS) has become increasingly popular for the removal of pharyngeal and laryngeal cancers with the objective to improve functional and aesthetic outcomes. Feyh-Kastenbauer (FK) retractor is one such routinely used retractor during TORS. The setting up of this retractor has been seen to be accompanied by hemodynamic fluctuations. Methodology This prospective observational study was carried out on 30 patients undergoing TORS. All patients were administered general anesthesia using a pre-defined anesthesia protocol. The primary outcome was to compare hemodynamic fluctuations following endotracheal intubation with that after FK retractor insertion. Any requirement of a bolus dose of sevoflurane and fentanyl was recorded in response to hemodynamic fluctuations recorded in secondary outcomes. Results There was no statistically significant increase in mean heart rate, systolic, diastolic, and mean arterial blood pressure from baseline to endotracheal intubation and following retractor insertion (p=0.810, p=0.2, p=0.6, p=0.3 respectively). On subgroup analysis, hypertensive patients reported a greater rise in blood pressure following two minutes post FK retractor insertion compared to non-hypertensive patients (p=0.03). Out of 30 patients, five patients required a bolus dose of sevoflurane. Conclusion FK retractor insertion had a comparable hemodynamic response as endotracheal intubation during TORS. Hypertensive patients showed a rise in blood pressure at both endotracheal intubations and at FK retractor insertion.

Comparative Study of Gabapentin, Clonidine and Placebo in Alleviating the Hemodynamic Changes Due to Tracheal Intubation and Laryngoscopy.

INTRODUCTION: Hemodynamic changes during laryngoscopy and tracheal intubation must be reduced for safe and effective anesthesia. The present study was conducted to compare the efficacy of oral clonidine, gabapentin and placebo in alleviating the hemodynamic changes due to tracheal intubation and laryngoscopy. METHODS: This was a double-blinded randomized controlled trial conducted on 90 patients who were undergoing elective surgery and were randomized into three groups. Group I (n=30) received a placebo, group II (n=30) received gabapentin and group III (n=30) received clonidine as premedication before anesthesia induction. Patient heart rate and pressor response were recorded periodically and compared between the groups. RESULTS: There was no significant difference in the baseline heart rate (HR) and mean arterial pressure (MAP) between the groups. HR elevation was observed in all three groups and found to be significant (p=0.0001) but the increase was higher in the placebo (15 min: 80.80± 15.41) and lower in the clonidine group (15 min: 65.53± 12.43). The elevation in systolic and diastolic blood pressure was least and transient in the gabapentin group, as compared to placebo and clonidine group. Intra-operatively, the requirement of opioids was higher in the placebo as compared to clonidine and gabapentin (p < .001). CONCLUSION: Clonidine and gabapentin were effective in reducing the hemodynamic changes during laryngoscopy and intubation.

Efficacy of Intravenous Clonidine Premedication in the Prevention of Adverse Hemodynamic Changes During Intubation in Patients Undergoing Laparoscopic Surgery in Comparison with Placebo.

Context: Laparoscopic surgeries involve the creation of pneumoperitoneum, which produces significant hemodynamic changes. Alpha-2 adrenergic receptor agonists like clonidine are used as adjuvants during aesthesia for analgesic, sedative, sympatholytic and cardiovascular stabilizing effects. Aims: This study aims to assess the efficacy of intravenous (i.v.) clonidine premedication in the prevention of adverse hemodynamic changes during intubation in a patient undergoing laparoscopic surgery in comparison with (normal saline) placebo. Settings and Design: Eighty patients undergoing elective laparoscopic surgery were randomly assigned into two groups to receive either clonidine 3 µg.kg-1 diluted in normal saline or an equivalent quantity of normal saline administered intravenously 20 min before surgery. Materials and Methods: The primary outcome was to compare the efficacy of clonidine premedication in the prevention of adverse hemodynamic changes during intubation in patients undergoing laparoscopic surgery. Other outcome parameters observed were requirements of induction agents and intraoperative analgesia and postoperative adverse effects. Statistical Analysis Used: Analysis of variance has been used to find the significance of study parameters between three or more groups of patients; Chi-square/Fisher exact test has been used to find the significance of study parameters on a categorical scale between two or more groups. Results: Heart rate reduced significantly after 10 min 3 µg.kg-1 clonidine administration and the decrease persisted throughout induction and intubation. The fluctuations of systolic, diastolic, and mean arterial pressures were high in the control group when compared with the clonidine group, throughout induction and intubation. Conclusions: Premedication with i.v. clonidine is a relatively safe and effective method that provides stable hemodynamics and protection against stress responses induced during laryngoscopy and intubation in patients undergoing laparoscopic surgery.

Hemodynamic stability during menstrual cycle in women undergoing elective surgery.

Objective: Hemodynamic changes occur in almost one-third of patients undergoing spinal anesthesia, which are likely to effect vital organ. The aim of this study is to determine the hemodynamic effect of spinal anesthesia during different phases of menstrual cycle. Methods: This is a descriptive cross-sectional study, two hundred and seventy-three patients who underwent spinal anesthesia for elective surgery were enrolled in this study. Of all the patients, 141 patients were in the luteal phase and 132 patients were in the follicular phase of their menstrual cycle. Analytical epidemiological study was conducted using questionnaires. Blood pressure and heart rate of patients before, immediately after, and 1 h after spinal anesthesia were recorded, and the data were analyzed using SPSS software. Results: In the follicular phase before anesthesia, systolic blood pressure (SBP) was 127.5 ± 3.9, diastolic blood pressure (DBP) was 80.3 ± 6.2 mmHg and heart rate (HR) was 82.0 ± 8.5bpm, while, immediately after the induction of anesthesia following recordings were measured; 109.7 ± 9.13, 71.8 ± 2.8 mmHg and 70.0 ± 8.10bpm, respectively. In the luteal phase, it was 126.9 ± 3.12, 81.6 ± 9.3 mmHg and 80.2 ± 4.4bpm, and 122.0 ± 9.12, 78.6 ± 8.5 mmHg and 75.9 ± 6.5bpm respectively before and immediately after anesthesia, these changes in the menstrual phase was significant (P < 0.001). In the follicular phase an hour after spinal anesthesia, the mean SBP was 100.3 ± 3.9, DBP was 71.2 ± 7.5, MAP was 87.0 ± 4.7 mmHg and HR 67.5 ± 5.7bpm and following was seen in luteal phase; 115.4 ± 1.8, 75.9 ± 2.3, 97.3 ± 3.5 mm Hg and 74.0 ± 7.4bpm, respectively. These values were significantly lower in the follicular phase (P < 0.001). Conclusion: Spinal anesthesia in the luteal phase as compared to the follicular phase of the menstrual cycle shows less variation in hemodynamic parameters.

Improvement of hemodynamic parameters in aortic stenosis patients with transcatheter valve replacement by using impedance cardiography.

Background: The hemodynamic changes of patients with aortic stenosis (AS) who underwent transcatheter valve replacement (TAVR) have not been completely investigated. Methods and results: We enrolled 74 patients with AS who underwent TAVR and assessed cardiac function changes at 1 week post-operation by impedance cardiography (ICG) in a supine position at rest for more than 15 min. Of the 74 patients, 47 had preserved left ventricular ejection fraction (LVEF ≥ 50%; preserved-LVEF group) and 27 had reduced LVEF (LVEF <50%; reduced-LVEF group). TAVR improved the cardiac structure and function, as evidenced by the decrease in the left ventricular end-diastolic (LVED), left atrial diameter (LAD), and an increase in the LVEF. We observed a decrease in N-terminal pro-brain natriuretic peptide (NT-proBNP) level compared to that before treatment. Moreover, patients with reduced LVEF had a more significant reduction of NT-proBNP than those with preserved LVEF. Meanwhile, the blood pressure of patients had no significant differences pre- and post-operation. Based on ICG, there were no changes in the parameter of cardiac preload [thoracic fluid content (TFC)]. We observed an improvement in parameters of diastolic cardiac function [left ventricular ejection time (LVET) and pre-ejection period (PEP)]. And we detected converse results in parameters of heart systolic function [systolic time ratio (STR), cardiac output (CO), cardiac index (CI), stroke index (SI), and stroke volume (SV)] and cardiac afterload [stroke systemic vascular resistance (SSVR) and SSVR-index (SSVRI)]. In addition, TFC level was decreased in patients with thoracic volume overload after valve replacement. Subgroup analysis showed that the changes in those parameters were more noticeable in patients with reduced LVEF than that with preserved LVEF. Moreover, we observed no effects on parameters of heart systolic function and heart afterload in the LVEF ≥ 50% group before and after TAVR. Conclusion: Our data revealed a beneficial effect of TAVR in diastolic function and preload as detected by the ICG. But the LV systolic function and cardiac afterload were not improved in patients with LVEF <50%. The result indicated that ICG could be used as an important technique to monitor the cardiac condition of patients after aortic valve replacement.

Comparative study of intubating conditions and hemodynamic changes during awake fiber-optic intubation using midazolam with fentanyl versus dexmedetomidine in cases of difficult airway.

Background: The aim of the study is to compare intubating conditions and hemodynamic changes during awake fiber-optic intubation (AFOI) using midazolam and fentanyl versus dexmedetomidine in cases of difficult airway. Materials and Methods: A randomized prospective study was conducted in the department of oral and maxillofacial surgery, with a total of 60 patients, 18-55 years of age, ASA class I-II, of either sex with anticipated difficult airway planned for elective surgery. They were divided into two groups; group I patients received 1 µg/kg of dexmedetomidine and then an infusion of 0.5 to 0.7 µg/kg/hr of dexmedetomidine, whereas group II patients received 1 µg/kg of intra-venous (iv) fentanyl and 0.05 mg/kg of iv midazolam with additional doses of 0.02 mg/kg to achieve a Ramsay Sedation Scale score of ≥2. The ease of placement of the fiber-optic scope and the endotracheal tube and the patient's reaction to placement of the fiber-optic scope were assessed on a scale of 1-4 and were recorded as endoscopist satisfaction score and patient discomfort score, respectively. Results: The endoscopy time ranged from 2.66 ± 1.00 (group I) to 3.90 ± 0.96 (group II) minutes and was found to be statistically significant (p < 0.05). Also, the patient discomfort score was recorded during endoscopy (1-4) and ranged from 1.3 ± 0.53 (group I) and 2.33 ± 0.66 (group II) and was found to be statistically significant (p value < 0.05). Patients undergoing the procedure who received dexmedetomidine were thus more comfortable than those who received fentanyl and midazolam combination. Conclusion: Dexmedetomidine provided better intubating conditions, patient tolerance, higher endoscopist satisfaction, and reduced hemodynamic responses compared to fentanyl and midazolam combinations. Also, the major advantage of dexmeditomidine for preservation of airway with a lesser degree of respiratory depression allows for safer use of AFOI in cases of difficult airway.

Adverse effects associated with the use of N95 mask among health-care workers at the COVID-19 care units: A cross-sectional study in Sulaimani city, Iraq.

BACKGROUND: Health-care workers have to use the N95 mask as a part of the protection kit during the COVID-19 pandemic. The adverse effects of such practice are not fully elucidated. The study aims to evaluate negative impacts of N95 face masks on health-care personnel at COVID-19 care units. MATERIALS AND METHODS: One hundred and twenty-two health-care workers (aged 20-58 years) from various health-care settings in Sulaimani, Iraq, from January to August 2020, were enrolled in this prospective, cross-sectional study. The physiological variables (blood pressure, heart rate, and oxygen saturation) were recorded before putting on the N95 mask and postremoval of the mask. The incidence of adverse effects such as headache, difficulty breathing, redness, irritation, and dizziness were also reported as a number and percent at the end of the work shift. RESULTS: There was a statistically significant difference in the physiological parameters after removal of the mask compared with baseline. Only diastolic pressure was significantly lower in those working >6 h when compared to those working 1-6 h. The changes in physiological markers were poorly and nonsignificantly associated with the duration of wearing the mask. Moreover, 67.2%-70.5% of the participants complain of headaches and breathing difficulties, while 45.9%-51.6% reported signs of itching, redness, and irritation. However, health-care workers who put on the face mask >6 h showed signs of headache, breathing difficulties, and itching at the exposed areas higher than those working for 1-6 h. CONCLUSION: N95 mask negatively impacts the physiological variables of health-care providers. The adverse effects may lead to excessive exhaustion after long shifts in the intensive care unit during treatment of COVID-19 patients.

Transcranial ultrasound diagnostic value of hemodynamic cerebral changes in preterm infants for early-onset sepsis.

Background: Due to the limitation of blood culture diagnosis, this study sought to evaluate the cerebral hemodynamic changes by Doppler ultrasound for timely and objective diagnosis techniques in preterm infants with early onset-neonatal sepsis. Methods: In this retrospective study, 86 preterm infants treated at the Department of Neonatology, Renmin Hospital of Wuhan University from January 1, 2019 to March 31, 2021, were divided into the following 2 groups: (I) the early onset neonatal sepsis (EONS) group (G1, n=41); (II) the normal control group (G2, n=45). The cerebral hemodynamic changes were examined by transcranial ultrasound. Stata15.0 and SPSS26.0 software were used for the data analysis. The pair-wise comparisons of the receiver operating characteristic (ROC) curves were on the MedCalc18.2.1 software. For all the statistical analyses, P value <0.05 was considered significant. Results: Sex, birth weight, and gestational age did not differ significantly between the groups (P>0.05); the peak systolic velocity (PSV), mean velocity (MV), end diastolic velocity (EDV) (cm/s), resistivity index (RI), pulsatility index (PI) of the anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) differed significantly between 2 groups (P<0.05). In relation to the diagnostic sensitivity, the area under the receiver operating characteristic (AUROC) analyses showed that compared to IL-6 (0.95, 1.00), EDV of the ACA, and PSV, EDV and MV of the MCA and PCA had a higher sensitivity than the others (AUROC: 1, all 95% CI: 1.00, 1.00). The diagnostic points of the EDV and MV of the ACA were 9.8 and 17.3 cm/s, respectively, the PSV, EDV, and MV of the MCA were 55.9, 10.9, and 20.4 cm/s, respectively, and the PSV, EDV, and MV of the PCA were 27.5, 7.5, and 9.8 cm/s, respectively. Conclusions: The study showed that PI increases and RI decreases, MV increases, and cerebral blood flow increases in EONS. Further, the EDV and MV of the ACA and the PSV, EDV, and MV of the MCA and PCA showed higher sensitivity than IL-6.

Maternal Low Volume Circulation Relates to Normotensive and Preeclamptic Fetal Growth Restriction.

This narrative review summarizes current evidence on the association between maternal low volume circulation and poor fetal growth. Though much work has been devoted to the study of cardiac output and peripheral vascular resistance, a low intravascular volume may explain why high vascular resistance causes hypertension in women with preeclampsia (PE) that is associated with fetal growth restriction (FGR) and, at the same time, presents with normotension in FGR itself. Normotensive women with small for gestational age babies show normal gestational blood volume expansion superimposed upon a constitutionally low intravascular volume. Early onset preeclampsia (EPE; occurring before 32 weeks) is commonly associated with FGR, and poor plasma volume expandability may already be present before conception, thus preceding gestational volume expansion. Experimentally induced low plasma volume in rodents predisposes to poor fetal growth and interventions that enhance plasma volume expansion in FGR have shown beneficial effects on intrauterine fetal condition, prolongation of gestation and birth weight. This review makes the case for elevating the maternal intravascular volume with physical exercise with or without Nitric Oxide Donors in FGR and EPE, and evaluating its role as a potential target for prevention and/or management of these conditions.

Acute Changes in Heart Rate Variability to Glucose and Fructose Supplementation in Healthy Individuals: A Double-Blind Randomized Crossover Placebo-Controlled Trial.

BACKGROUND: It is unknown how different types of carbohydrates alter the cardio-autonomic system in healthy individuals. Therefore, the aim of this study was to investigate how heart-rate variability changes to single dose ingestion of glucose, fructose, glucose and fructose, and an artificial sweetener (sucralose). METHODS: In a double-blind randomized crossover placebo-controlled setting, 15 participants received all study-specific substances in liquid form. During each 2-h visit, venous blood glucose was measured in a 5-min interval while heart-rate variability was measured continuously via Holter-electrocardiograph. RESULTS: Ingestion of different types of carbohydrates and sucralose showed significant differences for heart rate (p < 0.001), SDNN (p < 0.008), RMSSD (p < 0.001), pNN50 (p < 0.001) and blood pressure (p < 0.001). Different glucose levels significantly altered parameters of heart-rate variability and blood pressure (all p < 0.001), while the rate of change in blood glucose led to changes in heart rate variability, but not in heart rate (p = 0.25) or blood pressure (p = 0.99). CONCLUSIONS: Ingestion of different types of carbohydrates lead to reductions in heart-rate variability compared to a placebo. Blood glucose values above or below 70-90 mg/dL decreased heart rate variability while this was also seen for rapid glucose changes, yet not as pronounced. Healthy individuals should be conscious about carbohydrate intake while maintaining blood glucose levels between 70-90 mg/dL.

A naturally hypersensitive porcine model may help understand the mechanism of COVID-19 mRNA vaccine-induced rare (pseudo) allergic reactions: complement activation as a possible contributing factor.

A tiny fraction of people immunized with lipid nanoparticle (LNP)-enclosed mRNA (LNP-mRNA) vaccines develop allergic symptoms following their first or subsequent vaccinations, including anaphylaxis. These reactions resemble complement (C) activation-related pseudoallergy (CARPA) to i.v. administered liposomes, for which pigs provide a naturally oversensitive model. Using this model, we injected i.v. the human vaccination dose (HVD) of BNT162b2 (Comirnaty, CMT) or its 2-fold (2x) or 5-fold (5x) amounts and measured the hemodynamic changes and other parameters of CARPA. We observed in 6 of 14 pigs transient pulmonary hypertension along with thromboxane A2 release into the blood and other hemodynamic and blood cell changes, including hypertension, granulocytosis, lymphopenia, and thrombocytopenia. One pig injected with 5x CMT developed an anaphylactic shock requiring resuscitation, while a repeat dose failed to induce the reaction, implying tachyphylaxis. These typical CARPA symptoms could not be linked to animal age, sex, prior immune stimulation with zymosan, immunization of animals with Comirnaty i.v., or i.m. 2 weeks before the vaccine challenge, and anti-PEG IgM levels in Comirnaty-immunized pigs. Nevertheless, IgM binding to the whole vaccine, used as antigen in an ELISA, was significantly higher in reactive animals compared to non-reactive ones. Incubation of Comirnaty with pig serum in vitro showed significant elevations of C3a anaphylatoxin and sC5b-9, the C-terminal complex. These data raise the possibility that C activation plays a causal or contributing role in the rare HSRs to Comirnaty and other vaccines with similar side effects. Further studies are needed to uncover the factors controlling these vaccine reactions in pigs and to understand their translational value to humans.