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Introduction: Transthoracic echocardiography is a safe and readily available tool for noninvasive monitoring of Cardiac Output (CO). The use of the suprasternal window situated at the sternal notch can be an alternative approach for estimating blood flow. The present study aimed to compare two methods of CO calculation. We compared the descending aorta Velocity-Time Integral (VTI) measurement from the suprasternal window view with the standard technique to determine CO that uses VTI measurements from the LVOT (Left Ventricular Outflow Tract) view. We also aimed to find out whether after basic training a non-echocardiographer operator can obtain reproducible measurements of VTI using this approach., Methods: In the first part of the study, 26 patients without known cardiovascular diseases were evaluated and VTI data were acquired from the suprasternal window by a non-echocardiographer and an echocardiographer. Next, 17 patients were evaluated by an echocardiographer only and VTI and CO measurements were obtained from suprasternal and apical windows. Data were analyzed using the Bland and Altman method (BA), correlation and regression., Results: We found a strong correlation between measurements obtained by a non-expert and an expert echocardiographer and detected that an inexperienced trainee can acquire VTI measurements from the suprasternal window view. Regarding agreement between CO measurements, data obtained showed a positive correlation and the Bland and Altman analysis presented a total variation of 38.9%., Conclusion: Regarding accuracy, it is likely that TTE (Transthoracic Echocardiogram) measurements of CO from the suprasternal window view are comparable to other minimally invasive techniques currently available. Due to its user-friendliness and low cost, it can be a convenient technique for obtaining perioperative hemodynamic measurements, even by inexperienced operators., (Copyright © 2021 Sociedade Brasileira de Anestesiologia. Published by Elsevier España, S.L.U. All rights reserved.)

Introduction: adenosine monophosphate-activated protein kinase (AMPK) plays a prominent role as a metabolic stress sensor, and it has recently been suggested that the renin-angiotensin system, in addition to its role in stress regulation, may play a significant role in regulating the AMPK system. This study aimed to evaluate the effects of candesartan, an angiotensin II receptor blocker, on cardiac and hepatic AMPK activity basally as well as after surgical stress under general anesthesia., Materials and Methods: Male Wistar rats were treated with 5 mg/kg/day candesartan in their drinking water for two weeks. Levels of cardiac and hepatic AMPK activity were determined, using a kinase activity assay, basally and after surgical stress under general anesthesia., Results: Chronic administration of candesartan increased hepatic AMPK activity approximately 4 times (p<0.05) while no significant change was demonstrated in cardiac AMPK. Cardiac and hepatic AMPK activities were not significantly increased by surgical stress alone performed under anesthesia. However, chronic treatment with candesartan decreased AMPK activity in both liver and heart after surgical stress under anesthesia (p<0.01 for both comparisons)., Conclusions: While chronic candesartan treatment may stimulate AMPK activity in certain organs such as the liver, when combined with surgical stress under anesthesia it inhibits pathways regulating AMPK activity., (© The Author(s) 2013.)

5' adenosine monophosphate-activated protein kinase (AMPK) plays a prominent role as a metabolic stress sensor. The role of hypothalamic AMPK in response to restraint and surgical stress has not been previously investigated. It has been recently suggested that the renin-angiotensin system, in addition to its role in stress regulation, may play a significant role in regulating metabolic pathways including the regulation of the AMPK system. This study was thus aimed to evaluate the effects of candesartan, an angiotensin II AT1 receptor blocker drug, on hypothalamic AMPK activity under basal conditions and after restraint in conscious rats or after surgical stress under general anesthesia. Male Wistar rats were treated with 5 mg/kg/day candesartan in the drinking water for 2 weeks. The hypothalamic AMPK activity was determined under basal and stress conditions, using a kinase activity assay. Chronic administration of candesartan significantly increased hypothalamic AMPK activity. Hypothalamic AMPK activity was also increased by restraint stress whereas no change was observed during surgical stress under anesthesia. The high levels of hypothalamic AMPK activation observed in candesartan-treated rats were not changed by restraint stress but were reduced to control levels by anesthesia and surgery. In conclusion, chronic candesartan treatment and restraint stress in conscious rats stimulate the hypothalamic AMPK activity, whereas surgical stress under anesthesia inhibits pathways regulating the AMPK activity even in candesartan-treated rats.

Neuroglucopenia induced by 2-deoxy-D-glucose (2DG) activates hypothalamic glucoreceptors leading to increased hepatic glucose production and insulin inhibition. This response is similar to what is observed with intravenous injection of angiotensin II (Ang II). However, the involvement of an angiotensin-converting enzyme inhibitor on neuroglucopenia has not been investigated. The aim of this study was to determine the effects of chronic enalapril treatment on plasma glucose, insulin and lipid levels in response to neuroglucopenia. Male Holtzman rats (120-170 g) were chronically treated with enalapril (10 mg/kg per day) in the drinking water for two weeks. On the day of experiment the animals received an i.v. enalapril final dose one hour before the neuroglucopenic stress by 2DG infusion (500 mg/kg), and blood samples were drawn before and 5, 10, 20, 30 and 60 minutes following infusion. The hyperglycaemic response to 2DG was not significantly changed by enalapril treatment. The enalapril-treated group exhibited a peak of plasma insulin higher than controls. Plasma triglyceride showed a significant increase only in the enalapril group after neuroglucopenic stress (p < 0.05).These data show that chronic enalapril treatment changes insulin and triglyceride responses to neuroglucopenia, suggesting an effect on glucose-induced insulin secretion and the storage of triglycerides.

Background and Objectives: Cerebral relaxation during intracranial surgery is necessary, and hiperosmolar therapy is one of the measures used to this end. Frequently, neurosurgical patients have sodium imbalances. The objective of the present study was to quantify and determine cerebral relaxation and duration of hydroelectrolytic changes secondary to the use of mannitol versus hypertonic isoncotic solution (HIS) during neurosurgery., Methods: Cerebral relaxation and hydroelectrolytic changes were evaluated in 29 adult patients before de beginning of infusion, and 30 and 120 minutes after the infusion of equiosmolar loads of approximately 20% mannitol (250 mL) or HIS (120 mL). The volume of intravenous fluids infused and diuresis were recorded. A p < 0.05 was considered significant., Results: A statistically significant difference in cerebral relaxation between both groups was not observed. Although several changes in electrolyte levels and acid-base balance with mannitol or HIS reached statistical significance only the reduction in plasma sodium 30 minutes after infusion of mannitol, mean of 6.42 ± 0.40 mEq.L(-1), and the increase in chloride, mean of 5.41 ± 0.96 mEq.L(-1) and 5.45 ± 1.45 mEq.L(-1) 30 and 120 minutes after infusion of HIS, caused a transitory dislocation of serum ion levels from normal range. The mannitol (20%) group had a significantly greater diuresis at both times studied compared with HIS group., Conclusions: A single dose of hypertonic isoncotic saline solution [7.2% NaCl/6% HES (200/0.5)] and mannitol (20%) with equivalent osmolar loads were effective and safe in producing cerebral relaxation during elective neurosurgical procedures under general anesthesia., (Copyright © 2011 Elsevier Editora Ltda. All rights reserved.)

Background and Objectives: The neuraxial techniques currently represent the most effective methods for pain control during labor and the epidural block using ultradiluted anesthetic solutions is considered the gold standard promoting adequate pain relief with minimum side effects. In some situations however the use of these techniques is limited by the existence of maternal contraindications, or structural or material obstacles. In these cases, the alternatives are still precarious and scarce offering little optimistic results and of dubious effectiveness., Content: This article presents through a literature review the available information on the use of remifentanil as an alternative technique for analgesia during labor discussing aspects of pharmacokinetics, analgesia efficacy, maternal satisfaction and maternal/fetal side effects., Conclusions: The initial data show that remifentanil is a promising option to be employed in situations where the parturient cannot or does not want to receive the neuraxial analgesia., (Copyright 2010 Elsevier Editora Ltda. All rights reserved.)

Background and Objectives: The anesthetic management of a parturient with unruptured intracranial aneurysm scheduled to undergo cesarean section is interesting, since it has several particularities associated with pregnancy-related physiologic changes that are associated with the risk of aneurismal rupture during the anesthetic procedure. Studies on this subject are rare in the literature and, therefore, the dissemination of those cases is important., Case Report: This is a 31-year old female at term with unruptured intracranial aneurysm scheduled for cesarean section under epidural block. The procedure evolved without maternal or fetal intercurrences., Conclusions: Evidence-based recommendations for obstetric anesthesia in patients with unruptured intracranial aneurysm are lacking. Experimental or clinical data confirming or refuting general anesthesia or regional blocks in this context do not exist. Thus, the decision of which technique should be used is individual, considering the risks and benefits of each procedure and the experience of the anesthesiologist.

Aim: To measure circulating angiotensins at different stages of human cirrhosis and to further evaluate a possible relationship between renin angiotensin system (RAS) components and hemodynamic changes., Methods: Patients were allocated into 4 groups: mild-to-moderate liver disease (MLD), advanced liver disease (ALD), patients undergoing liver transplantation, and healthy controls. Blood was collected to determine plasma renin activity (PRA), angiotensin (Ang) I, Ang II, and Ang-(1-7) levels using radioimmunoassays. During liver transplantation, hemodynamic parameters were determined and blood was simultaneously obtained from the portal vein and radial artery in order to measure RAS components., Results: PRA and angiotensins were elevated in ALD when compared to MLD and controls (P < 0.05). In contrast, Ang II was significantly reduced in MLD. Ang-(1-7)/Ang II ratios were increased in MLD when compared to controls and ALD. During transplantation, Ang II levels were lower and Ang-(1-7)/Ang II ratios were higher in the splanchnic circulation than in the peripheral circulation (0.52 +/- 0.08 vs 0.38 +/- 0.04, P < 0.02), whereas the peripheral circulating Ang II/Ang I ratio was elevated in comparison to splanchnic levels (0.18 +/- 0.02 vs 0.13 +/- 0.02, P < 0.04). Ang-(1-7)/Ang II ratios positively correlated with cardiac output (r = 0.66) and negatively correlated with systemic vascular resistance (r = -0.70)., Conclusion: Our findings suggest that the relationship between Ang-(1-7) and Ang II may play a role in the hemodynamic changes of human cirrhosis.

Aim: To evaluate the effect of beta-blockade on angiotensins in the splanchnic and peripheral circulation of cirrhotic patients and also to compare hemodynamic parameters during liver transplantation according to propranolol pre-treatment or not., Methods: Patients were allocated into two groups: outpatients with advanced liver disease(LD) and during liver transplantation(LT). Both groups were subdivided according to treatment with propranolol or not. Plasma was collected through peripheral venipuncture to determine plasma renin activity(PRA), Angiotensin(Ang) I, Ang II, and Ang-(1-7) levels by radioimmunoassay in LD group. During liver transplantation, hemodynamic parameters were determined and blood samples were obtained from the portal vein to measure renin angiotensin system(RAS) components., Results: PRA, Ang I, Ang II and Ang-(1-7) were significantly lower in the portal vein and periphery in all subgroups treated with propranolol as compared to non-treated. The relationships between Ang-(1-7) and Ang I levels and between Ang II and Ang I were significantly increased in LD group receiving propranolol. The ratio between Ang-(1-7) and Ang II remained unchanged in splanchnic and peripheral circulation in patients under beta-blockade, whereas the relationship between Ang II and Ang I was significantly increased in splanchnic circulation of LT patients treated with propranolol. During liver transplantation, cardiac output and index as well systemic vascular resistance and index were reduced in propranolol-treated subgroup., Conclusion: In LD group, propranolol treatment reduced RAS mediators, but did not change the ratio between Ang-(1-7) and Ang II in splanchnic and peripheral circulation. Furthermore, the modification of hemodynamic parameters in propranolol treated patients was not associated with changes in the angiotensin ratio.

In the past few years the classical concept of the renin-angiotensin system (RAS) has experienced substantial conceptual changes. The identification of the renin/prorenin receptor, the angiotensin-converting enzyme homologue ACE2 as an angiotensin peptide processing enzyme, Mas as a receptor for Ang-(1-7) and the possibility of signaling through ACE, have contributed to switch our understanding of the RAS from the classical limited-proteolysis linear cascade to a cascade with multiple mediators, multiple receptors, and multi-functional enzymes. In this review we will focus on the recent findings related to RAS and, in particular, on its role in diabetes by discussing possible interactions between RAS mediators, endothelium function, and insulin signaling transduction pathways as well as the putative role of ACE2-Ang-(1-7)-Mas axis in disease pathogenesis.

Background and Objectives: Allergy to natural rubber latex products has become a major source of concern, affecting both patients and healthcare workers. This report aimed at describing an accidental diagnosis of latex allergy after urological surgery under spinal anesthesia when patient presented clinical manifestations of anaphylactic shock., Case Report: Male patient, 16 years old, with posterior urethra lesion who had been managed for the last 3 years with chronic indwelling latex urethral catheter due to two previous unsuccessful attempts to restore urinary drainage. During surgery under spinal anesthesia, patient presented soon after peritoneal cavity exploration, confusion, dyspnea, generalized pruritus and erythema, bronchospasm, arterial hypotension and tachycardia. Clinical manifestations faded gradually after treatment. During hospital stay and after blowing a toy balloon, patient developed contact hives on the face and bronchospasm, which were promptly treated. Prick and serologic test for latex-specific IgE have confirmed the diagnostic hypothesis of latex allergy., Conclusions: The combination of patients clinical history and lab findings have allowed for the identification of latex allergy. This entity is becoming highly relevant, especially for risk patients, as in this case report.