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

OBJECTIVE: To test whether labetalol improved cardiovascular function in anaesthetized dogs injected with dexmedetomidine. STUDY DESIGN: Prospective, randomized, blinded, clinical trial. ANIMALS: A group of 20 healthy client-owned dogs undergoing ovariohysterectomy. METHODS: Each 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. RESULTS: Significant 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 RELEVANCE: Labetalol 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.

Application Value of Sevoflurane Combined with Brachial Plexus Block in Children with Humeral Fracture Surgery and its Effect on Hemodynamics: A Clinical and Anatomical Study

SUMMARY: To observe the effect of sevoflurane combined with brachial plexus block (BPB) in children with humeral fracture surgery and its effect on hemodynamics. 84 children who received surgical treatment of humeral fracture in our hospital from September 2019 to September 2022 were selected. According to different anesthesia methods, the children were divided into control group and study group. The control group only received laryngeal mask sevoflurane; the study group received laryngeal mask sevoflurane combined with BPB. The operation situation, hemodynamic indexes, stress level, pain and adverse reactions of children was observed. The postoperative awakening time in the study group was lower than control group, the postoperative pain onset time in the study group was higher than control group (P0.05). Postoperative 2h, the levels of serum cortisol, b-endorpin, norepinephrine and epinephrine in the study group were lower than control group (P0.05). Sevoflurane combined with BPB is helpful to shorten the postoperative awakening time of children with humeral fracture, reduce the degree of postoperative pain, improve hemodynamics, and reduce stress response, and has good safety.

El objetivo fue observar el efecto del sevoflurano combinado con bloqueo del plexo braquial (BPB) en niños con cirugía de fractura de húmero y su efecto sobre la hemodinámica. Se seleccionaron 84 niños que recibieron tratamiento quirúrgico de fractura de húmero en nuestro hospital desde septiembre de 2019 hasta septiembre de 2022. Según diferentes métodos de anestesia, los niños se dividieron en grupo control y grupo de estudio. El grupo control solo recibió sevoflurano en mascarilla laríngea; el grupo de estudio recibió sevoflurano con mascarilla laríngea combinado con BPB. Se observó la situación operatoria, índices hemodinámicos, nivel de estrés, dolor y reacciones adversas de los niños. El tiempo hasta el despertar postoperatorio en el grupo de estudio fue menor que el del grupo control, el tiempo de aparición del dolor postoperatorio en el grupo de estudio fue mayor que el del grupo control (P0,05). A las 2 horas postoperatorias, los niveles séricos de cortisol, β-endorfina, norepinefrina y epinefrina en el grupo de estudio fueron más bajos que los del grupo control (P 0,05). El sevoflurano combinado con BPB es útil para acortar el tiempo de despertar del posoperatorio de los niños con fractura de húmero, reduce el grado de dolor postoperatorio, mejora la hemodinámica y reduce la respuesta al estrés, además de tener buena seguridad.

Cambios Hemodinámicos Asociados a Exodoncias de Terceros Molares Inferiores con el Uso de Articaína 4 % y/o Lidocaína 2 %: Una revisión sistemática / Hemodynamic Changes Associated with Lower Third Molar Extractions with the Use of Articaine 4 % and/or Lidocaine 2 %: A systematic Review

La exodoncia de los terceros molares inferiores es uno de los procedimientos clínicos más comunes en el cual el control del dolor mediante el bloqueo anestésico del nervio alveolar inferior, bucal y lingual resulta ser fundament al y la manera más común de hacerlo es mediante la infiltración de soluciones de anestesia local. Entre ellos la lidocaína y articaína son algunos de los más comunes y pueden estar asociado a vasoconstrictores como la epinefrina que puede provocar aumento de la presión arterial y frecuencia cardíaca razón por la cual se hace necesario la monitorización de cambios hemodinámicos durante la cirugía. Describir los cambios hemodinámicos asociados al uso de lidocaína al 2 % y/ o articaína al 4 % en la presión sistólica y diastólica, frecuencia cardiaca y saturación parcial de oxígeno en relación a distintos tiempos operatorios. Se realizó una revisión sistemática en las bases de datos de PubMed, SCOPUS, Web of Science y Sciencedirect. Se analizaron 7 ensayos clínicos controlados en los que utilizaron articaína al 4 % y/o lidocaína al 2 % con epinefrina al 1:100,000 y/o 1:200,000 en volúmenes de 1,8 a 5,4 mL, en los cuales evaluaron la presión sistólica y diastólica, frecuencia cardiaca y saturación parcial de oxígeno en distintos tiempos de la cirugía. Si bien hubo cambios en PAS, PAD, FC y SPO2, todas se mantuvieron dentro de rangos normales bajo el uso de articaína al 4 % y lidocaína al 2 % con epinefrina 1:100,000 y/o 1:200,000 a volúmenes de 1,8 a 5,4mL medidas a distintos tiempos operatorios.

The extraction of lower third molars is one of the most common clinical procedures in which pain control through anesthetic blockade of the lower alveolar, buccal and lingual nerves turns out to be essential and the most common way to do it is through the infiltration of solutions of local anesthesia. Among them, lidocaine and articaine are some of the most common and may be associated with vasoconstrictors such as epinephrine, which can cause an increase in blood pressure and heart rate, which is why it is necessary to monitor hemodynamic changes during surgery. To describe the hemodynamic changes associated with the use of 2 % lidocaine and/or 4 % articaine in systolic and diastolic pressure, heart rate and partial oxygen saturation in relation to different operative times. A systematic review was carried out in the PubMed, SCOPUS, Web of Science and Sciencedirect databases. Seven controlled clinical trials were analyzed in which 4 % articaine and/or 2 % lidocaine were used with epinephrine at 1:100,000 and/or 1:200,000 in volumes of 1,8 to 5,4 mL, in which systolic pressure was evaluated. and diastolic, heart rate and partial oxygen saturation at different times of surgery. Although there were changes in SBP, DBP, HR and SPO2, all remained within normal ranges under the use of 4 % articaine and 2 % lidocaine with epinephrine 1:100,000 and/or 1:200,000 at volumes of 1,8 to 5 .4mL measured at different operative times.

Local Anaesthetics Combined with Vasoconstrictors in Controlled Hypertensive Patients Undergoing Dental Procedures: Systematic Review and Meta-Analysis / Uso de Anestésicos Locales con Vasoconstrictor en Pacientes con Hipertensión Controlada Durante la Atención Odontológica: Una Revisión Sistemática y Metaanálisis

The aim of this systematic review is to assess the safety of local anaesthetics (LA) combined with vasoconstrictors (VC) for patients with controlled hypertension undergoing dental procedures. A comprehensive search strategy were used to identify all relevant randomized controlled trials (RCTs) that evaluated the effect of LA combined with VC. All searches covered the period from 1990 to February 2021. We performed a meta-analysis using random-effect models and assessed overall certainty in evidence using GRADE approach. Our search strategy yielded 1262 references. Finally, seven randomised trials were included, but only three were included in the meta-analysis. The use of LA with VC may result in little to no difference in the heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), but the certainty of the evidence was assessed as low. Death, stroke, acute myocardial infarction, need for hospitalization, pain and bleeding were not reported by the included studies. The hemodynamic changes using VC do not imply an increased risk of occurrence of adverse cardiovascular events. The use of VC could even be recommendable considering their multiple advantages.

El objetivo de esta revisión sistemática es evaluar la seguridad del uso de anestésicos locales (AL) combinados con vasoconstrictor (VC) en pacientes con hipertensión controlada durante procedimientos dentales. Se realizó una estrategia de búsqueda para identificar todos los estudios clínicos aleatorizados (ECA) relevantes que evaluaban el efecto del AL combinado con VC. Todos los estudios fueron del periodo entre 1990 a febrero del 2021. Se realizó un meta-análisis usando modelos de efecto aleatorizado y una revisión de la certeza de la evidencia usando el método GRADE. Nuestra estrategia de búsqueda arrojó 1262 referencias. Finalmente, siete estudios clínicos aleatorizados fueron incluidos, de los cuales tres fueron incluidos en el meta-análisis. El uso de AL con VC produce una pequeña a ninguna diferencia en el pulso cardiaco, presión sistólica y diastólica, pero la certeza de la evidencia fue baja. Muerte, infarto agudo al miocardio, accidente cerebrovascular, necesidad de hospitalización, dolor y hemorragia no fueron reportados en los estudios incluidos. Los cambios hemodinámicos en el uso de VC no implican un aumento de riesgo de ocurrencia de efectos adversos cardiovasculares. El uso de VC puede ser recomendable considerando sus múltiples ventajas.

Preoperative sedation in children with congenital heart disease: 50% and 95% effective doses, hemodynamic effects, and safety of intranasal dexmedetomidine.

STUDY OBJECTIVE: To determine the 50% and 95% effective doses (ED50 and ED95, respectively), hemodynamic effects, and safety of intranasal dexmedetomidine for preoperative sedation in pediatric patients with congenital heart disease (CHD) with a left-to-right shunt. DESIGN: Double-blind sequential allocation trial. SETTING: Pediatric preoperative waiting area. PATIENTS: 86 pediatric patients ASA physical status II-III scheduled for cardiac surgery, aged1-month to 6-years-old with left-to-right type CHD. INTERVENTIONS: Children were divided into three groups according to age: infants (1 month-1 year), toddlers (1-3 years), and preschoolers (3-6 years). The first patient in all groups received intranasal dexmedetomidine (2 µg/kg), using the up-and-down Dixon method, and the and the next patient's dose was dependent on the previous patient's response. MEASUREMENTS: Assessment using the Modified Observer's Assessment of Alertness/Sedation Scale and the Mask Acceptance Scale was performed before and every 5 min after treatment. Pulse oxygen saturation and heart rate were recorded at baseline, at 10-min intervals, and after admission to the operating room. Systolic pulmonary artery pressure was measured before anesthesia induction. MAIN RESULTS: The respective ED50 (95% confidence interval [CI]) and ED95 (95% CI) values for preoperative sedation using intranasally administered dexmedetomidine were 3.1 (2.8-3.3) and 3.5 (3.3-4.0) µg/kg for infants; 3.4 (3.2-3.6) and 3.9 (3.7-4.4) µg/kg for toddlers; and 2.4 (2.2-2.6) and 2.9 (2.6-3.3) µg/kg for preschoolers. ED50 was lower for preschoolers than for toddlers (p < 0.001) and infants (p = 0.044). No obvious difference in ED50 was found between infants and toddlers. There was no significant difference in sedation onset time among the groups, and no adverse events were observed during sedation in all patients. CONCLUSIONS: Intranasal dexmedetomidine can be safety used for preoperative sedation in children with CHD and is effective for sedation when dosed appropriately. Trial registrationclinicaltrials.gov (ChiCTR2100047472); registered 20 June 2021.

Effect of Clemastine Fumarate on Perioperative Hemodynamic Instability Mediated by Anaphylaxis During Cardiopulmonary Bypass Surgery.

BACKGROUND Perioperative hemodynamic instability mediated by anaphylaxis is a life-threatening complication in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). This study aimed to evaluate the effect of clemastine fumarate in this specific patient population. MATERIAL AND METHODS We enrolled 100 participants who met the inclusion criteria and randomly allocated them to the treatment group and the placebo group. Participants in the treatment group and the placebo group were treated separately with an injection of clemastine fumarate and saline, respectively. Plasma histamine concentration and blood pressure were quantified at 5 timepoints during the perioperative period, and differences between the 2 groups were assessed by repeated-measures ANOVA. The postoperative complications and in-hospital mortality also were evaluated. All participants were followed up for 7 days after cardiac surgery. RESULTS Plasma histamine concentrations increased in both groups but were statistically significantly lower in the treatment group during the perioperative period (P=0.007). Diastolic blood pressure (P=0.014) and mean arterial pressure (P=0.024) in the treatment group were significantly higher than in the placebo group during the perioperative period. The coefficients of variation for systolic (13.9±4.2% vs 17.2±4.4%, P<0.01) and diastolic (12.9±4.9% vs 15.3±5.2%, P=0.02) blood pressure were significantly lower in the treatment group compared with the placebo group. CONCLUSIONS Pretreatment with clemastine fumarate restrains the increase in histamine concentration and provides safer hemodynamics in patients undergoing cardiac surgery with CPB.

Regionally selective cardiovascular responses to adenosine A2A and A2B receptor activation.

Adenosine is a local mediator that regulates changes in the cardiovascular system via activation of four G protein-coupled receptors (A1 , A2A , A2B , A3 ). Here, we have investigated the effect of A2A and A2B -selective agonists on vasodilatation in three distinct vascular beds of the rat cardiovascular system. NanoBRET ligand binding studies were used to confirm receptor selectivity. The regional hemodynamic effects of adenosine A2A and A2B selective agonists were investigated in conscious rats. Male Sprague-Dawley rats (350-450 g) were chronically implanted with pulsed Doppler flow probes on the renal artery, mesenteric artery, and the descending abdominal aorta. Cardiovascular responses were measured following intravenous infusion (3 min for each dose) of the A2A -selective agonist CGS 21680 (0.1, 0.3, 1 µg kg-1 min-1 ) or the A2B -selective agonist BAY 60-6583 (4,13.3, 40 µg kg-1 min-1 ) following predosing with the A2A -selective antagonist SCH 58261 (0.1 or 1 mg kg-1 min-1 ), the A2B /A2A antagonist PSB 1115 (10 mg kg-1 min-1 ) or vehicle. The A2A -selective agonist CGS 21680 produced a striking increase in heart rate (HR) and hindquarters vascular conductance (VC) that was accompanied by a significant decrease in mean arterial pressure (MAP) in conscious rats. In marked contrast, the A2B -selective agonist BAY 60-6583 significantly increased HR and VC in the renal and mesenteric vascular beds, but not in the hindquarters. Taken together, these data indicate that A2A and A2B receptors are regionally selective in their regulation of vascular tone. These results suggest that the development of A2B receptor agonists to induce vasodilatation in the kidney may provide a good therapeutic approach for the treatment of acute kidney injury.

Mechanisms of action of SGLT2 inhibitors and their beneficial effects on the cardiorenal axis.

Large clinical studies conducted with sodium-glucose co-transporter 2 inhibitors (SGLT2i) in patients with type 2 diabetes and heart failure with reduced ejection fraction have demonstrated their ability to achieve both cardiac and kidney benefits. Although there is huge evidence on SGLT2i-mediated clinical benefits both in diabetic and non-diabetic patients, the pathophysiological mechanisms underlying their efficacy are still poorly understood. Some favorable mechanisms are likely due to the prompt glycosuric action which is associated with natriuretic effects leading to hemodynamic benefits as well as a reduction in glomerular hyperfiltration and renin-angiotensin-aldosterone system activation. In addition to the renal mechanisms, SGLT2i may play a relevant role in cardiorenal axis protection by improving the cardiomyocyte metabolism, by exerting anti-fibrotic and anti-inflammatory actions, and by increasing cardioprotective adipokine expression. New studies will be needed to better understand the specific molecular mechanisms that mediate the SGLT2i favorable effects in patients suffering diabetes. Our aim is to first discuss about the molecular mechanisms underlying the cardiovascular benefits of SGLT2i in each of the main organs involved in the cardiorenal axis. Furthermore, we update on the most recent clinical trials evaluating the beneficial effects of SGLT2i in treatment of both diabetic and non-diabetic patients suffering heart failure.

Endothelial cell ferroptosis mediates monocrotaline-induced pulmonary hypertension in rats by modulating NLRP3 inflammasome activation.

Inflammation triggers pulmonary vascular remodelling. Ferroptosis, a nonapoptotic form of cell death that is triggered by iron-dependent lipid peroxidation and contributes to the pathogenesis of several inflammation-related diseases, but its role in pulmonary hypertension (PH) has not been studied. We examined endothelial cell ferroptosis in PH and the potential mechanisms. Pulmonary artery endothelial cells (PAECs) and lung tissues from monocrotaline (MCT)-induced PH rats were analysed for ferroptosis markers, including lipid peroxidation, the labile iron pool (LIP) and the protein expression of glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1) and NADPH oxidase-4 (NOX4). The effects of the ferroptosis inhibitor ferrostatin-1 (Fer-1) on endothelial cell ferroptosis and pulmonary vascular remodelling in MCT-induced rats were studied in vitro and in vivo. Ferroptosis was observed in PAECs from MCT-induced PH rats in vitro and in vivo and was characterized by a decline in cell viability accompanied by increases in the LIP and lipid peroxidation, the downregulation of GPX4 and FTH1 expression and the upregulation of NOX4 expression. High-mobility group box 1 (HMGB1)/Toll-like receptor 4 (TLR4)/NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome signalling was measured by western blotting. These changes were significantly blocked by Fer-1 administration in vitro and in vivo. These results suggest that Fer-1 plays a role in inhibiting ferroptosis-mediated PAEC loss during the progression of PH. The ferroptosis-induced inflammatory response depended on the activation of HMGB1/TLR4 signalling, which activated the NLRP3 inflammasome in vivo. We are the first to suggest that pulmonary artery endothelial ferroptosis triggers inflammatory responses via the HMGB1/TLR4/NLRP3 inflammasome signalling pathway in MCT-induced rats. Treating PH with a ferroptosis inhibitor and exploring new treatments based on ferroptosis regulation might be promising therapeutic strategies for PH.

Experimental study to assess the impact of vasopressors administered during maintenance of the brain-dead donation in the quality of the intestinal graft.

BACKGROUND: The hemodynamic maintenance of brain-dead donors will influence the quality of the organs procured for transplantation, including the intestine. Although norepinephrine (NE) and dopamine (DA) are commonly used to sustain mean arterial pressure in humans, there are no standardized protocols for their use during maintenance of brain-dead donors. Our aim was to compare the effects of each drug, in the intestinal graft quality using a rat brain-dead donation model. METHODS: Wistar rats (N = 17) underwent brain death (BD) for 2 hours with NE (NE group) or with DA (DA group) administration; the control group was mechanically ventilated for 2 hours without BD. Jejunum biopsies were obtained at the end of the maintenance period. Histological damage was evaluated using Park-Chiu scale. Villi/crypt ratio, mucosal thickness, Goblet cell count, and villi density were evaluated using ImageJ software (US National Institutes of Health, Bethesda, MD). Barrier damage was assessed by bacterial translocation culture counting on liver samples. The inflammatory status of the intestine was evaluated by CD3+ counting by immunohistochemistry and gene expression analysis of interleukin (IL)-6, IL-22, and CXCL10. RESULTS: Norepinephrine-treated donors had higher focal ischemic injury in the intestinal mucosa without a substantial modification of morphometrical parameters compared with DA-treated donors. CD3+ mucosal infiltration was greater in intestines procured from brain-dead donors, being highest in NE (p ˂ 0.001). Local inflammatory mediators were affected in BD: DA and NE groups showed a trend to lower expression of IL-22, whereas CXCL10 expression was higher in NE versus control group. Brain death promoted intestinal bacterial translocation, but the use of NE resulted in the highest bacterial counting in the liver (p ˂ 0.01). CONCLUSION: Our results favor the use of DA instead of NE as main vasoactive drug to manage BD-associated hemodynamic instability. Dopamine may contribute to improve the quality of the intestinal graft, by better preserving barrier function and lowering immune cell infiltration.

BACKGROUND: The hemodynamic maintenance of brain-dead donors will influence the quality of the organs procured for transplantation, including the intestine. Although norepinephrine (NE) and dopamine (DA) are commonly used to sustain mean arterial pressure in humans, there are no standardized protocols for their use during maintenance of brain-dead donors. Our aim was to compare the effects of each drug, in the intestinal graft quality using a rat brain-dead donation model. METHODS: Wistar rats (N = 17) underwent brain death (BD) for 2 hours with NE (NE group) or with DA (DA group) administration; the control group was mechanically ventilated for 2 hours without BD. Jejunum biopsies were obtained at the end of the maintenance period. Histological damage was evaluated using Park-Chiu scale. Villi/crypt ratio, mucosal thickness, Goblet cell count, and villi density were evaluated using ImageJ software (US National Institutes of Health, Bethesda, MD). Barrier damage was assessed by bacterial translocation culture counting on liver samples. The inflammatory status of the intestine was evaluated by CD3 + counting by immunohistochemistry and gene expression analysis of interleukin (IL)-6, IL-22, and CXCL10. RESULTS: Norepinephrine-treated donors had higher focal ischemic injury in the intestinal mucosa without a substantial modification of morphometrical parameters compared with DA-treated donors. CD3 + mucosal infiltration was greater in intestines procured from brain-dead donors, being highest in NE ( p ˂ 0.001). Local inflammatory mediators were affected in BD: DA and NE groups showed a trend to lower expression of IL-22, whereas CXCL10 expression was higher in NE versus control group. Brain death promoted intestinal bacterial translocation, but the use of NE resulted in the highest bacterial counting in the liver ( p ˂ 0.01). CONCLUSION: Our results favor the use of DA instead of NE as main vasoactive drug to manage BD-associated hemodynamic instability. Dopamine may contribute to improve the quality of the intestinal graft, by better preserving barrier function and lowering immune cell infiltration.

Effect of methylene blue on hemodynamic and metabolic response in septic shock patients.

INTRODUCTION: Septic shock is a lethal disease responsible for a large proportion of deaths in the Intensive Care Unit (ICU), even with therapy centered on fluid resuscitation, use of vasopressors and empirical antibiotic therapy applied within the first hour of diagnosis. Considering the multifactorial pathophysiology of septic shock and the mechanism of action of vasopressors, some patients may not respond adequately, which can lead to the maintenance of vasodilatation, hypotension and increased morbidity, and mortality. This protocol aims to verify whether the use of methylene blue in septic patients with an early diagnosis can contribute to an earlier resolution of a shock compared to standard treatment. METHODS AND ANALYSIS: This is a study protocol for a single-center randomized clinical trial design in an ICU of a tertiary university hospital. In this study, we intend to include 64 patients aged between 18 and 80 years with a diagnosis of septic shock, of any etiology, with up to 72 hours of evolution after volume restoration, using norepinephrine at a dose ≥0.2 µg/kg/min and vasopressin at a dose of 0.04 IU/min. After the initial approach, we will randomize patients into two groups, standard care, and standard care plus methylene blue. The sample size was calculated in order to show 30% differences in septic shock resolution between groups. The Research Ethics Committee approved the study, and all patients included will sign an informed consent form (Clinical registration: RBR-96584w4).

Pharmacological antagonism of EP2 receptor does not modify basal cardiovascular and respiratory function, blood cell counts, and bone morphology in animal models.

The EP2 receptor has emerged as a therapeutic target with exacerbating role in disease pathology for a variety of peripheral and central nervous system disorders. We and others have recently demonstrated beneficial effects of EP2 antagonists in preclinical models of neuroinflammation and peripheral inflammation. However, it was earlier reported that mice with global EP2 knockout (KO) display adverse phenotypes on fertility and blood pressure. Other studies indicated that EP2 activation with an agonist has a beneficial effect of healing fractured bone in animal models. These results impeded the development of EP2 antagonists, and EP2 antagonism as therapeutic strategy. To determine whether treatment with EP2 antagonist mimics the adverse phenotypes of the EP2 global KO mouse, we tested two EP2 antagonists TG11-77. HCl and TG6-10-1 in mice and rats while they are on normal or high-salt diet, and by two different administration protocols (acute and chronic). There were no adverse effects of the antagonists on systolic and diastolic blood pressure, heart rate, respiratory function in mice and rats regardless of rodents being on a regular or high salt diet. Furthermore, chronic exposure to TG11-77. HCl produced no adverse effects on blood cell counts, bone-volume and bone-mineral density in mice. Our findings argue against adverse effects on cardiovascular and respiratory systems, blood counts and bone structure in healthy rodents from the use of small molecule reversible antagonists for EP2, in contrast to the genetic ablation model. This study paves the way for advancing therapeutic applications of EP2 antagonists against diseases involving EP2 dysfunction.

Hemodynamic Responses to Crystalloid and Colloid Fluid Boluses during Noncardiac Surgery.

BACKGROUND: Colloids are thought to sustain blood pressure and cardiac index better than crystalloids. However, the relative effects of intraoperative hydroxyethyl starch and crystalloid administration on the cardiac index and blood pressure remain unclear. This study therefore tested in this subanalysis of a previously published large randomized trial the hypothesis that intraoperative goal-directed colloid administration increases the cardiac index more than goal-directed crystalloid administration. Further, the effects of crystalloid and colloid boluses on blood pressure were evaluated. METHODS: This planned subanalysis of a previous trial analyzed data from 973 patients, of whom 480 were randomized to colloids and 493 were randomized to crystalloids. Fluid administration was guided by esophageal Doppler. The primary outcome was the time-weighted average cardiac index during surgery between the colloid and crystalloid group. The secondary outcomes were the cardiac index just after bolus administration, time elapsed between boluses, and the average real variability during surgery. The study recorded cardiac index, corrected flow time, and blood pressure at 10-min intervals, as well as before and after each bolus. RESULTS: Time-weighted average of cardiac index over the duration of anesthesia was only slightly greater in patients given colloid than crystalloid, with the difference being just 0.20 l · min-1 · m-2 (95% CI, 0.11 to 0.29; P < 0.001). However, the hazard for needing additional boluses was lower after colloid administration (hazard ratio [95% CI], 0.60 [0.55 to 0.66]; P < 0.001) in a frailty time-to-event model accounting for within-subject correlation. The median [quartiles] number of boluses per patient was 4 [2, 6] for colloids and 6 [3, 8] for crystalloids, with a median difference (95% CI) of -1.5 (-2 to -1; P < 0.001). The average real mean arterial pressure variability did not differ significantly between the groups (difference in means [95% CI] of -0.03 (-0.07 to 0.02) mmHg, P = 0.229). CONCLUSIONS: There were not clinically meaningful differences in the cardiac index or mean pressure variability in patients given goal-directed colloid and crystalloids. As might be expected from longer intravascular dwell time, the interval between boluses was longer with colloids. However, on a case basis, the number of boluses differed only slightly. Colloids do not appear to provide substantial hemodynamic benefit.

Oral L-Arginine (5 g/day) for 14 Days Improves Microcirculatory Function in Healthy Young Women and Healthy and Type 2 Diabetes Mellitus Elderly Women.

OBJECTIVE: The aim of this study was to investigate the effect of oral supplementation with L-arginine on serum biochemical profile, blood pressure, microcirculation, and vasoreactivity/endothelial function in young controls, and elderly women with and without type 2 diabetes mellitus (T2DM). METHODS: Healthy young (n = 25), healthy elderly (n = 25), and elderly women with type 2 diabetes mellitus (T2DME, n = 23, glycated Hb ≥6.4% and mean of 7.7 years for duration of the disease), aged 18-30 and older than 65 years, respectively, were included in the study. All patients underwent biochemical analysis (fasting glycemia and lipidogram), arterial blood pressure, nailfold videocapillaroscopy (capillary diameters, functional capillary density [FCD], peak red blood cell velocity [RBCVmax] after 1 min ischemia, time to reach peak RBCV [TRBCVmax]), and venous occlusion plethysmography (vasoreactivity), before and after 14 days of oral supplementation with L-arginine (5 g/day). RESULTS: L-Arginine did not change fasting glycemia and lipidogram, but it decreased systolic, diastolic, and mean arterial pressure in elderly women, increased RBCVmax in all groups, and did not decrease TRBCVmax in T2DME. Capillary diameters and FCD remained unchanged in all groups. L-Arginine improved vasoreactivity during reactive hyperemia and after sublingual nitroglycerin (0.4 mg) in all groups. CONCLUSION: L-Arginine supplementation (5g/day during 14 days) was able to improve vascular/microvascular health in the elderly women with or without T2DM.

Effect of drug interventions on cerebral hemodynamics in ischemic stroke patients.

The ischemic penumbra is sensitive to alterations in cerebral perfusion. A myriad of drugs are used in acute ischemic stroke (AIS) management, yet their impact on cerebral hemodynamics is poorly understood. As part of the Cerebral Autoregulation Network led INFOMATAS project (Identifying New Targets for Management and Therapy in Acute Stroke), this paper reviews some of the most common drugs a patient with AIS will come across and their potential influence on cerebral hemodynamics with a particular focus being on cerebral autoregulation (CA). We first discuss how compounds that promote clot lysis and prevent clot formation could potentially impact cerebral hemodynamics, before focusing on how the different classes of antihypertensive drugs can influence cerebral hemodynamics. We discuss the different properties of each drug and their potential impact on cerebral perfusion and CA. With emerging interest in CA status of AIS patients, either during or soon after treatment when timely reperfusion and salvageable tissue is at its most critical, the properties of these pharmacological agents may be relevant for modelling cerebral perfusion accuracy and for setting individualised treatment strategies.

Renal Denervation in Combination With Angiotensin Receptor Blockade Prolongs Blood Pressure Trough During Hemorrhage.

Majority of patients with hypertension and chronic kidney disease (CKD) undergoing renal denervation (RDN) are maintained on antihypertensive medication. However, RDN may impair compensatory responses to hypotension induced by blood loss. Therefore, continuation of antihypertensive medications in denervated patients may exacerbate hypotensive episodes. This study examined whether antihypertensive medication compromised hemodynamic responses to blood loss in normotensive (control) sheep and in sheep with hypertensive CKD at 30 months after RDN (control-RDN, CKD-RDN) or sham (control-intact, CKD-intact) procedure. CKD-RDN sheep had lower basal blood pressure (BP; ≈9 mm Hg) and higher basal renal blood flow (≈38%) than CKD-intact. Candesartan lowered BP and increased renal blood flow in all groups. 10% loss of blood volume alone caused a modest fall in BP (≈6-8 mm Hg) in all groups but did not affect the recovery of BP. 10% loss of blood volume in the presence of candesartan prolonged the time at trough BP by 9 minutes and attenuated the fall in renal blood flow in the CKD-RDN group compared with CKD-intact. Candesartan in combination with RDN prolonged trough BP and attenuated renal hemodynamic responses to blood loss. To minimize the risk of hypotension-mediated organ damage, patients with RDN maintained on antihypertensive medications may require closer monitoring when undergoing surgery or experiencing traumatic blood loss.

Alpha-terpineol prevents myocardial damage against isoproterenol-MI induced in Wistar-Kyoto rats: new possible to promote cardiovascular integrity.

Alpha-terpineol (TPN) is one of the major components of the resin obtained from Protium heptaphyllum. This plant has been utilized as medicine by Brazilian indigenous tribes to treat cardiovascular diseases. Scientific reports have shown that the TPN possesses vasorelaxant and antihypertensive effects. This study was conducted to assess the cardioprotective action of TPN against isoproterenol (ISO)-induced cardiotoxicity. Wistar rats were randomly divided into six groups. Rats were orally administered with TPN (25, 50, and 75 mg/kg, respectively) for 15 days, and ISO was administered (85 mg/kg, subcutaneously) on the 14th and 15th days. At the end of the experiment, the hemodynamic, baroreflex test, ECG, biochemical, histological, and morphometric changes were monitored from control and experimental groups, i.e., on the 15th day. ISO-induced myocardial infarcted rats showed an increase in mortality rates, cardiac marker enzymes, tachycardia, hypertrophy, myocardium necrosis, edema, hemorrhagic areas, infiltration of inflammatory cells like lymphocytes, and increased myocardial infarct size. However, pretreatment with TPN significantly inhibited these effects of ISO. The histopathological findings obtained for the myocardium further confirmed the biochemical results. Thus, the present study provides evidence for the efficacy of TPN against ISO-induced myocardial infarction in rats.

Hemodynamic Effects of Levosimendan in Outpatients With Advanced Heart Failure: An Echocardiographic Pilot Study.

ABSTRACT: Infusions of levosimendan delivered in ambulatory/outpatient settings have been shown to improve quality of life and reduce hospitalizations in patients with advanced heart failure (HF). The aim of this pilot study was to evaluate the effects of ambulatory infusion of levosimendan on echocardiographic markers of perfusion, congestion, and cardiovascular efficiency. Thirty patients with diagnosed advanced HF underwent ambulatorial infusion of levosimendan at a total dose of 6.25 mg as a part of a repetitive biweekly treatment strategy with the inotrope. Standardized transthoracic echocardiography and Doppler examinations, were performed 1 hour before and 48 hours after completion of ambulatory infusion. At 48 hours after ambulatory infusion of levosimendan, a significant increase in the stroke volume (37.47 ± 12.38 mL/beat vs. 45.47 ± 14.48 mL/beat; P < 0.05) and cardiac output (2.64 ± 0.66 L/min vs. 3.26 ± 0.57 L/min; P < 0.05) occurred. Significant postreductions versus prereductions were also recorded in left atrial pressure (27.37 ± 6.62 mm Hg vs. 22.82 ± 4.17 mm Hg; P < 0.01), mean pulmonary artery pressure (27.69 ± 4.64 mm Hg vs. 23.24 ± 5.32; P < 0.01), and inferior vena cava diameter (23.81 ± 7.63 mm vs. 18.53 ± 4.82 mm; P < 0.01). Significant improvements were noted in the resting cardiac power output (0.46 ± 0.15 watt vs. 0.53 ± 0.22 watt; P < 0.01) and the resting cardiac power index (0.24 ± 0.08 watt/m2 vs. 0.28 ± 0.11 watt/m2; P < 0.01). In outpatients with advanced HF, infusion of levosimendan was associated with hemodynamic responses that may contribute to the clinical benefit previously reported in such patients.