Brain-heart crosstalk: the many faces of stress-related cardiomyopathy syndromes in anaesthesia and intensive care.

Neurogenic stress cardiomyopathy (NSC) is a well-known syndrome complicating the early phase after an acute brain injury, potentially affecting outcomes. This article is a review of recent data on the putative role of localization and lateralization of brain lesions in NSC, cardiac innervation abnormalities, and new polymorphisms and other genetic causes of the sympathetic nervous system over-activity. Concerns regarding the management of stress-related cardiomyopathy syndromes during the perioperative period are also discussed. Future clinical research should explore whether specific factors explain different patient susceptibilities to the disease and should be directed towards early identification and stratification of patients at risk, so that such patients can be more carefully monitored and appropriately managed in critical care and during the perioperative period.

Brain-lung crosstalk in critical care: how protective mechanical ventilation can affect the brain homeostasis.

The maintenance of brain homeostasis against multiple internal and external challenges occurring during the acute phase of acute brain injury may be influenced by critical care management, especially in its respiratory, hemodynamic and metabolic components. The occurrence of acute lung injury represents the most frequent extracranial complication after brain injury and deserves special attention in daily practice as optimal ventilatory strategy for patients with acute brain and lung injury are potentially in conflict. Protecting the lung while protecting the brain is thus a new target in the modern neurointensive care. This article discusses the essentials of brain-lung crosstalk and focuses on how mechanical ventilation may exert an active role in the process of maintaining or treatening brain homeostasis after acute brain injury, highlighting the following points: 1) the role of inflammation as common pathomechanism of both acute lung and brain injury; 2) the recognition of ventilatory induced lung injury as determinant of systemic inflammation affecting distal organs, included the brain; 3) the possible implication of protective mechanical ventilation strategy on the patient with an acute brain injury as an undiscovered area of research in both experimental and clinical settings.

Usefulness and limits of near infrared spectroscopy monitoring during endovascular neuroradiologic procedures.

BACKGROUND: Transcranial cerebral oximetry (TCCO) with near-infrared spectroscopy (NIRS) is a non-invasive, bedside technique, which allows the continuous measurement of regional cerebral oxygenation. The aim of this study was to evaluate TCCO monitoring during endovascular neuroradiologic procedures. METHODS: Adult patients undergoing elective endovascular embolization of cerebral aneurysms, arteriovenous malformations, dural arteriovenous fistulas and meningiomas under general anesthesia were included in the study, over a period of 12 months. Twenty-eight procedures in 25 patients were analyzed. RESULTS: Regional cerebral oxygenation rSO(2) readings were significantly different according to the different phases of the neuroendovascular procedure. An effect of the underlying cerebral pathology on regional cerebral oxygenation rSO(2) recording, in relation to the different stage of the interventional procedure, was also evident, the more invasive the procedure the greater the impact on rSO(2) reading. NIRS monitoring contributed to a prompt diagnosis and management of two adverse intraoperative events and helped in early evaluation of prognosis. CONCLUSION: TCCO with NIRS is a promising monitoring tool to assess the balance between oxygen supply and demand during neuroradiologic procedures. Nevertheless, some limits should be acknowledged, such as the study of the posterior circulation and artefacts related to contrast agent injection. A careful understanding of the undergoing step of the procedure as well of the possible influence of intrinsic and extrinsic factors affecting recording is important for interpretation of data.

Significance of hypoxemia screening in candidates for liver transplantation: our experience.

Hepatopulmonary syndrome (HPS) is recognized as one of the causes of hypoxemia in patients with chronic liver disease. This complication is responsible for increased mortality and increased perioperative risk in liver transplantation candidates. Recent data from the literature suggest extending the screening for HPS to all candidates for liver transplantation. The aim of this retrospective study was to evaluate the incidence of hypoxemia among a population of patients awaiting liver transplantation. Using pulse oximetry as a screening tool for hypoxemia, 39 of 198 patients (20%) were hypoxemic. The results of this study confirmed the importance of screening for hypoxemia among patients awaiting liver transplantation. In these patients, a more accurate evaluation of respiratory function should be performed to confirm or exclude the diagnosis of HPS.

The importance of predicting the prognosis in patients with hepatopulmonary syndrome: a simple scoring system.

Hepatopulmonary syndrome (HPS) is a pulmonary vascular disorder, complicating hepatic diseases, and is responsible for an increased morbidity and mortality among patients awaiting liver transplantation. Nowadays, it is recognized as an independent risk factor for death in this patient population. The severity of hypoxemia and the advanced stage of the liver dysfunction are determinants for the prognosis. Therefore, the possibility to be successful, thus improving survival, consists of addressing HPS at an earlier stage, giving more attention to moderate evidences of this pathology instead of the severe ones. On the basis of scientific evidence, we suggest a simple scoring system to predict prognosis among patients with HPS, founded on the integration of two main factors: the severity of hepatic disease, expressed as class of Child-Pugh, and the severity of the hypoxemia. This model of prognostic evaluation has the objective of estimating the additional risk of these patients, thereby avoiding a deleterious underestimate of risk and an arbitrariness of management.

Hepatopulmonary syndrome: a concern for the anesthetist? Pre-operative evaluation of hypoxemic patients with liver disease.

Liver cirrhosis and other chronic hepatic diseases are followed in a subset of affected patients by gas exchange abnormalities resulting from a syndrome called hepatopulmonary syndrome (HPS). The structural basis of this clinical entity is an alteration of pulmonary vasculature resulting in abnormal vasodilatation and mismatching of ventilation and perfusion of the lung. Dilatation of the capillary bed near the gas exchange area is the most important factor implicated; it precludes O2 molecules diffusing to the centrum of the dilated vessels to oxygenate venous blood. Contrast (microbubbles) echocardiography and lung perfusion scan are, respectively, the screening tests with the highest sensitivity and specificity for HPS diagnosis. Because of the high morbidity and mortality of HPS, clinicians have been trying to understand the pathophysiology of pulmonary vasodilatation in the hope that the process can be reversed pharmacologically or surgically. An imbalance between production and clearance of vasoactive circulating substances has been implicated in the pathogenesis of HPS with glucagon and nitric oxide among the principal responsible factors. To date various molecules have been implicated for therapy but without definitive positive results. Liver transplantation remains the only real therapy for HPS, and resolution of gas exchange defects outlines the possible functional reversible nature of vascular abnormalities of this syndrome. The need to perform surgery under general anesthesia for hepatic and extrahepatic procedures in patients with HPS is followed by an increased peri-operative risk. The authors emphasize the role of pre-operative clinical evaluation for proper patient management during the peri-operative period.

[Treatment of substernal goiter. Our experience]. / Il trattamento del gozzo immerso. La nostra esperienza.

The Authors, after having reviewed substernal goitre natural history, report their five-year experience with this disease, underlining clinical features, therapeutic management, positive results. They examine the several proposed classifications and stress haemodynamic and respiratory complications. At last they shortly discuss about diagnostics and, mainly, about correct therapeutic approach which has two aims to resolve the symptomatology and to prevent relapses.

Oxidative stress causes nuclear factor-kappaB activation in acute hypovolemic hemorrhagic shock.

Nuclear Factor kappaB (NFkappaB) is an ubiquitous rapid response transcription factor involved in inflammatory reactions and exerts its action by expressing cytokines, chemokines, and cell adhesion molecules. We investigated the role of NF-kappaB in acute hypovolemic hemorrhagic (Hem) shock. Hem shock was induced in male anesthetized rats by intermittently withdrawing blood from an iliac catheter over a period of 20 min (bleeding period) until mean arterial blood pressure (MAP) fell and stabilized within the range of 20-30 mmHg. Hemorrhagic shocked rats died in 26.3 +/- 2.1 min following the discontinuance of bleeding, experienced a marked hypotension (mean arterial blood pressure = 20-30 mmHg) and had enhanced plasma levels of Tumor Necrosis Factor-alpha (200 +/- 15 pg/ml, 20 min after the end of bleeding). Furthermore, aortas taken 20 min after bleeding from hemorrhagic shocked rats showed a marked hypo-reactivity to phenylephrine (PE; 1nM to 10 microM) compared with aortas harvested from sham shocked rats. Hem shocked rats also had increased levels of TNF-alpha mRNA in the liver (15-20 min after the end of bleeding) and enhanced plasma levels of 2,5-dihydroxybenzoic acid (2,5-DHBA; 6 +/- 2.2 microm), 2,3-dihydroxybenzoic acid (2,3-DHBA; 13 +/- 2.1 microm), both studied to evaluate OH(*) production. Electrophoretic mobility shift assay showed that liver NF-kappaB binding activity increased in the nucleus 10 min after the end of hemorrhage and remained elevated until the death of animals. Western blot analysis suggested that the levels of inhibitory IkappaBalpha protein in the cytoplasm became decreased at 5 min after the end of bleeding. IRFI-042, a vitamin E analogue (20 mg/kg intraperitoneally 2 min after the end of bleeding), inhibited the loss of IkappaBalpha protein from the cytoplasm and blunted the increase in NF-kappaB binding activity. Furthermore IRFI-042 increased survival time (117.8 +/- 6.51 min; p <.01) and survival rate (vehicle = 0% and IRFI-042 = 80%, at 120 min after the end of bleeding), reverted the marked hypotension, decreased liver mRNA for TNF-alpha, reduced plasma TNF-alpha (21 +/- 4.3 pg/ml), and restored to control values the hypo-reactivity to PE. Our results suggest that acute blood loss (50% of the estimated total blood volume over a period of 20 min) causes early activation of NF-kappaB, likely through an increased production of reactive oxygen species. This experiment indicates that NF-kappaB-triggered inflammatory cascade becomes early activated during acute hemorrhage even in the absence of resuscitation procedures.

[Anesthesiologic problems in candidates for delayed surgery]. / Problemi anestesiologici nel paziente candidato alla chirurgia differita.

In preparing and maintaining a proper anaesthetic plan in the patient with subarachnoid haemorrhage undergoing delayed surgery, various concerns occur to the anaesthesist and the intensivist. These problems are related to the intracranic pathology but also to the structural, biochemical and functional changes occurring in a lot of organs and systems. Aim of anaesthetic approach is a correct preoperative evaluation and the maintenance of intracranic and systemic homeostasis. Systemically it is frequent the evidence of electrocardiographic abnormalities, due in same instances to myocardial hypoperfusion, of respiratory dysfunctions, of idroelettrolitic and metabolic changes leading to hypovolemia, hyponatremia and hypokalemia, and of coagulation disorders. With regards to the cerebral homeostasis, it is imperative to prevent rebleeding and vasospasm and the related neurologic damage. It is important the preoperative correction of the systemic dysfunctions, the prevention of the secondary neurologic damage, the stabilization of hemodynamic responses to various noxious stimuli, the provision of a good surgical field, and the achievement of a stable recovery; all these with the help of a proper clinical and instrumental monitoring.