Stroke units could be a valid alternative to intensive care units for patients with low-grade aneurysmal subarachnoid haemorrhage.

BACKGROUND AND PURPOSE: According to current guidelines, patients with aneurysmal subarachnoid haemorrhage (aSAH) are mostly managed in intensive care units (ICUs) regardless of baseline severity. We aimed to assess the prognostic and economic implications of initial admission of patients with low-grade aSAH into a stroke unit (SU) compared to initial ICU admission. METHODS: We reviewed prospectively registered data from consecutive aSAH patients with a World Federation of Neurosurgery Societies grade <3, admitted to our Comprehensive Stroke Centre between April 2013 and September 2018. Clinical and radiological baseline traits, in-hospital complications, length of stay (LOS) and poor outcome at 90 days (modified Rankin Scale score > 2) were compared between the ICU and SU groups in the whole population and in a propensity-score-matched cohort. RESULTS: Of 131 patients, 74 (56%) were initially admitted to the ICU and 57 (44%) to the SU. In-hospital complication rates were similar in the ICU and SU groups and included rebleeding (10% vs. 7%; P = 0.757), angiographic vasospasm (61% vs. 60%; P = 0.893), delayed cerebral ischaemia (12% vs. 12%; P = 0.984), pneumonia (6% vs. 4%; P = 0.697) and death (10% vs. 5%; P = 0.512). LOS did not differ between groups (median [interquartile range] 22 [16-30] vs. 19 [14-26] days; P = 0.160). In adjusted multivariate models, the location of initial admission was not associated with long-term poor outcome either in the whole population (odds ratio [OR] 1.16, 95% confidence interval [CI] 0.32-4.19; P = 0.825) or in the matched cohort (OR 0.98, 95% CI 0.24-4.06; P = 0.974). CONCLUSIONS: A dedicated SU, with care from a multidisciplinary team, might be an optimal alternative to ICU for initial admission of patients with low-risk aSAH.

Synthetic MRI in subarachnoid haemorrhage.

AIM: To evaluate the reliability of synthetic magnetic resonance imaging (SyMRI) for detecting complications associated with subarachnoid haemorrhage (SAH), such as ischaemic lesions, hydrocephalus, or bleeding complications. MATERIALS AND METHODS: Twenty patients with SAH, who underwent a conventional brain MRI and a SyMRI on a 3 T MRI machine. Comparable conventional and synthetic T2-weighted fluid attenuated inversion recovery (FLAIR) images were acquired. The presence of ischaemic lesions, hydrocephalus, extra-axial blood collections as well as the volumes of grey matter (GMv), white matter (WMv), and cerebrospinal (CSFv) were compared. The acquisition times of both sequences was also analysed. RESULTS: The concordance between the two techniques was excellent for the detection of ischaemic lesions and extra-axial collections (kappa = 0.80 and 0.88 respectively) and good for the detection of hydrocephalus (kappa = 0.69). No significant differences were detected in the number of ischaemic lesions (p=0.31) or in the Evans index (p=0.11). The WMv and CSFv measures were also similar (p=0.18 and p=0.94, respectively), as well as the volume of ischaemic lesions (p=0.79). Compared to conventional MRI, the SyMRI acquisition time was shorter regardless of the number of sections (32% and 6% time reduction for 4 or 3 mm section thickness, respectively). CONCLUSIONS: SyMRI allows the detection of potential complications of SAH in a similar way to conventional MRI with a shorter acquisition time.

Radiomic-based nonlinear supervised learning classifiers on non-contrast CT to predict functional prognosis in patients with spontaneous intracerebral hematoma.

PURPOSE: To evaluate if nonlinear supervised learning classifiers based on non-contrast CT can predict functional prognosis at discharge in patients with spontaneous intracerebral hematoma. METHODS: Retrospective, single-center, observational analysis of patients with a diagnosis of spontaneous intracerebral hematoma confirmed by non-contrast CT between January 2016 and April 2018. Patients with HIE > 18 years and with TCCSC performed within the first 24 h of symptom onset were included. Patients with secondary spontaneous intracerebral hematoma and in whom radiomic variables were not available were excluded. Clinical, demographic and admission variables were collected. Patients were classified according to the Modified Rankin Scale (mRS) at discharge into good (mRS 0-2) and poor prognosis (mRS 3-6). After manual segmentation of each spontaneous intracerebral hematoma, the radiomics variables were obtained. The sample was divided into a training and testing cohort and a validation cohort (70-30% respectively). Different methods of variable selection and dimensionality reduction were used, and different algorithms were used for model construction. Stratified 10-fold cross-validation were performed on the training and testing cohort and the mean area under the curve (AUC) were calculated. Once the models were trained, the sensitivity of each was calculated to predict functional prognosis at discharge in the validation cohort. RESULTS: 105 patients with spontaneous intracerebral hematoma were analyzed. 105 radiomic variables were evaluated for each patient. P-SVM, KNN-E and RF-10 algorithms, in combination with the ANOVA variable selection method, were the best performing classifiers in the training and testing cohort (AUC 0.798, 0.752 and 0.742 respectively). The predictions of these models, in the validation cohort, had a sensitivity of 0.897 (0.778-1;95%CI), with a false-negative rate of 0% for predicting poor functional prognosis at discharge. CONCLUSION: The use of radiomics-based nonlinear supervised learning classifiers are a promising diagnostic tool for predicting functional outcome at discharge in HIE patients, with a low false negative rate, although larger and balanced samples are still needed to develop and improve their performance.

Optimizing the Definition of Ischemic Core in CT Perfusion: Influence of Infarct Growth and Tissue-Specific Thresholds.

BACKGROUND AND PURPOSE: CTP allows estimating ischemic core in patients with acute stroke. However, these estimations have limited accuracy compared with MR imaging. We studied the effect of applying WM- and GM-specific thresholds and analyzed the infarct growth from baseline imaging to reperfusion. MATERIALS AND METHODS: This was a single-center cohort of consecutive patients (n = 113) with witnessed strokes due to proximal carotid territory occlusions with baseline CT perfusion, complete reperfusion, and follow-up DWI. We segmented GM and WM, coregistered CTP with DWI, and compared the accuracy of the different predictions for each voxel on DWI through receiver operating characteristic analysis. We assessed the yield of different relative CBF thresholds to predict the final infarct volume and an estimated infarct growth-corrected volume (subtracting the infarct growth from baseline imaging to complete reperfusion) for a single relative CBF threshold and GM- and WM-specific thresholds. RESULTS: The fixed threshold underestimated lesions in GM and overestimated them in WM. Double GM- and WM-specific thresholds of relative CBF were superior to fixed thresholds in predicting infarcted voxels. The closest estimations of the infarct on DWI were based on a relative CBF of 25% for a single threshold, 35% for GM, and 20% for WM, and they decreased when correcting for infarct growth: 20% for a single threshold, 25% for GM, and 15% for WM. The combination of 25% for GM and 15% for WM yielded the best prediction. CONCLUSIONS: GM- and WM-specific thresholds result in different estimations of ischemic core in CTP and increase the global accuracy. More restrictive thresholds better estimate the actual extent of the infarcted tissue.

Dyslipidemias and stroke prevention: Recommendations of the Study Group of Cerebrovascular Diseases of the Spanish Society of Neurology.

OBJECTIVE: We present an update of the Spanish Society of Neurology's recommendations for prevention of both primary and secondary stroke in patients with dyslipidaemia. DEVELOPMENT: We performed a systematic review to evaluate the main aspects of the management of dyslipidaemias in primary and secondary stroke prevention and establish a series of recommendations. CONCLUSIONS: In primary prevention, the patient's vascular risk should be determined in order to define target values for low-density lipoprotein cholesterol. In secondary prevention after an atherothrombotic stroke, a target value <55 mg/dL is recommended; in non-atherothombotic ischaemic strokes, given the unclear relationship with dyslipidaemia, target value should be established according to the vascular risk group of each patient. In both primary and secondary prevention, statins are the drugs of first choice, and ezetimibe and/or PCSK9 inhibitors may be added in patients not achieving the target value.

Recommendations of the Spanish Society of Neurology for the prevention of stroke. Interventions on lifestyle and air pollution.

OBJECTIVE: To update the recommendations of the Spanish Society of Neurology regarding lifestyle interventions for stroke prevention. DEVELOPMENT: We reviewed the most recent studies related to lifestyle and stroke risk, including randomised clinical trials, population studies, and meta-analyses. The risk of stroke associated with such lifestyle habits as smoking, alcohol consumption, stress, diet, obesity, and sedentary lifestyles was analysed, and the potential benefits for stroke prevention of modifying these habits were reviewed. We also reviewed stroke risk associated with exposure to air pollution. Based on the results obtained, we drafted recommendations addressing each of the lifestyle habits analysed. CONCLUSIONS: Lifestyle modification constitutes a cornerstone in the primary and secondary prevention of stroke. Abstinence or cessation of smoking, cessation of excessive alcohol consumption, avoidance of exposure to chronic stress, avoidance of overweight or obesity, a Mediterranean diet supplemented with olive oil and nuts, and regular exercise are essential measures in reducing the risk of stroke. We also recommend implementing policies to reduce air pollution.

Stroke prevention in patients with arterial hypertension: Recommendations of the Spanish Society of Neurology's Stroke Study Group.

OBJECTIVE: To update the recommendations of the Spanish Society of Neurology on primary and secondary stroke prevention in patients with arterial hypertension. DEVELOPMENT: We proposed several questions to identify practical issues for the management of blood pressure (BP) in stroke prevention, analysing the objectives of blood pressure control, which drugs are most appropriate in primary prevention, when antihypertensive treatment should be started after a stroke, what levels we should aim to achieve, and which drugs are most appropriate in secondary stroke prevention. We conducted a systematic review of the PubMed database and analysed the main clinical trials to address these questions and establish a series of recommendations. CONCLUSIONS: In primary stroke prevention, antihypertensive treatment should be started in patients with BP levels >  140/90 mmHg, with a target BP of < 130/80 mmHg. In secondary stroke prevention, we recommend starting antihypertensive treatment after the acute phase (first 24 hours), with a target BP of < 130/80 mmHg. The use of angiotensin-II receptor antagonists or diuretics alone or in combination with angiotensin-converting enzyme inhibitors is preferable.

Stroke prevention in patients with type 2 diabetes or prediabetes. Recommendations from the Cerebrovascular Diseases Study Group, Spanish Society of Neurology. / Prevención de ictus en pacientes con diabetes mellitus tipo 2 o prediabetes. Recomendaciones del Grupo de Estudio de Enfermedades Cerebrovasculares de la Sociedad Española de Neurología.

OBJECTIVE: To update the Spanish Society of Neurology's guidelines for stroke prevention in patients with type 2 diabetes or prediabetes, analysing the available evidence on the effect of metabolic control and the potential benefit of antidiabetic drugs with known vascular benefits in addition to conventional antidiabetic treatments in stroke prevention. DEVELOPMENT: PICO-type questions (Patient, Intervention, Comparison, Outcome) were developed to identify practical issues in the management of stroke patients and to establish specific recommendations for each of them. Subsequently, we conducted systematic reviews of the PubMed database and selected those randomised clinical trials evaluating stroke as an independent variable (primary or secondary). Finally, for each of the PICO questions we developed a meta-analysis to support the final recommendations. CONCLUSIONS: While there is no evidence that metabolic control reduces the risk of stroke, some families of antidiabetic drugs with vascular benefits have been shown to reduce these effects when added to conventional treatments, both in the field of primary prevention in patients presenting type 2 diabetes and high vascular risk or established atherosclerosis (GLP-1 agonists) and in secondary stroke prevention in patients with type 2 diabetes or prediabetes (pioglitazone).

Dyslipidemias and stroke prevention: recommendations of the Study Group of Cerebrovascular Diseases of the Spanish Society of Neurology. / Dislipidemias y prevención del ictus: recomendaciones del Grupo de Estudio de Enfermedades Cerebrovasculares de la Sociedad Española de Neurología.

OBJECTIVE: We present an update of the Spanish Society of Neurology's recommendations for prevention of both primary and secondary stroke in patients with dyslipidaemia. DEVELOPMENT: We performed a systematic review to evaluate the main aspects of the management of dyslipidaemias in primary and secondary stroke prevention and establish a series of recommendations. CONCLUSIONS: In primary prevention, the patient's vascular risk should be determined in order to define target values for low-density lipoprotein cholesterol. In secondary prevention after an atherothrombotic stroke, a target value <55mg/dL is recommended; in non-atherothombotic ischaemic strokes, given the unclear relationship with dyslipidaemia, target value should be established according to the vascular risk group of each patient. In both primary and secondary prevention, statins are the drugs of first choice, and ezetimibe and/or PCSK9 inhibitors may be added in patients not achieving the target value.

Value of Posterior circulation ASPECTS and Pons-Midbrain Index on non-contrast CT and CT Angiography Source Images in patients with basilar artery occlusion recanalized after mechanical thrombectomy. / Valor de la escala ASPECTS de circulación posterior y del índice puente-mesencéfalo en imágenes de TC sin contraste y angiografía por TC en pacientes con oclusiones de la arteria basilar recanalizados tras trombectomía mecánica.

PURPOSE: Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy. METHODS: Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.<8) and PMI (≥3vs.<3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate. RESULTS: CTASI pc-ASPECTS, dichotomized at <8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived. CONCLUSION: PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.

Leukoaraiosis May Confound the Interpretation of CT Perfusion in Patients Treated with Mechanical Thrombectomy for Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: Leukoaraiosis frequently coexists in patients with acute stroke. We studied whether leukoaraiosis could confound the interpretation of CTP findings in patients treated with mechanical thrombectomy. MATERIALS AND METHODS: We analyzed 236 patients with stroke treated with mechanical thrombectomy and studied with CTP, of whom 127 (53.8%) achieved complete reperfusion. Periventricular white matter hyperintensities on MR imaging and hypodensities on NCCT were assessed through the Fazekas score. CTP-predicted nonviable tissue was defined as relative CBF <30%, and final infarct volume was quantified in DWI. We estimated mean MTT, CBV, and CBF in the asymptomatic hemisphere. In patients achieving complete reperfusion, we assessed the accuracy of nonviable tissue to predict final infarct volume using the intraclass correlation coefficient across periventricular hyperintensity/hypodensity Fazekas scores and variable relative CBF cutoffs. RESULTS: MTT was longer (Spearman ρ = 0.279, P < .001) and CBF was lower (ρ = -0.263, P < .001) as the periventricular hyperintensity Fazekas score increased, while CBV was similar across groups (ρ = -0.043, P = .513). In the subgroup of patients achieving complete reperfusion, nonviable tissue-final infarct volume reliability was excellent in patients with periventricular hyperintensity Fazekas score grade 0 (intraclass correlation coefficient, 0.900; 95% CI, 0.805-0.950), fair in patients with periventricular hyperintensity Fazekas scores 1 (intraclass correlation coefficient, 0.569; 95% CI, 0.327-0.741) and 2 (intraclass correlation coefficient, 0.444; 95% CI, 0.165-0.657), and poor in patients with periventricular hyperintensity Fazekas score 3 (intraclass correlation coefficient, 0.310; 95% CI, -0.359-0.769). The most accurate cutoffs were relative CBF <30% for periventricular hyperintensity Fazekas score grades 0 and 1, relative CBF <25% for periventricular hyperintensity Fazekas score 2, and relative CBF <20% for periventricular hyperintensity Fazekas score 3. The reliability analysis according to periventricular hypodensity Fazekas score grades on NCCT was similar to that in follow-up MR imaging. CONCLUSIONS: In patients with stroke, the presence of leukoaraiosis confounds the interpretation of CTP despite proper adjustment of CBF thresholds.

Metformin-associated hyperlactacidaemia acidosis: Diagnosis rate in standard clinical practice and its relationship with renal failure. / Acidosis con hiperlactacidemia por metformina: frecuencia de su diagnóstico en la práctica clínica habitual y relación con la insuficiencia renal.

BACKGROUND AND OBJECTIVES: Observational study on the difference between the number of cases of acidosis with hyperlactacidaemia suspected of being caused by metformin diagnosed in standard clinical practice and the incidence of this condition according to the datasheet. The study also explored the relationship between renal function and metformin-associated hyperlactacidaemia acidosis. PATIENTS: We identified cases of acidosis between 2013 and 2014 by analysing the minimum basic data set and laboratory requests. We selected patients who presented venous lactate levels >2.7 mmol/L at the time they were treated and for whom the use of outpatient metformin was confirmed. The causal relationship with metformin was independently evaluated by several researchers. The incident cases were calculated based on the number of patients who had been dispensed a drug containing metformin during the same period in the study area. RESULTS: We identified 476 cases of acidosis. Metformin was suspected of causing the condition of acidosis with hyperlactacidaemia in 20 of these cases, which represents an incidence rate of 6.57/10,000 patients. Eighty-five percent of the cases presented acute renal failure. CONCLUSIONS: The apparent incidence of acidosis with hyperlactacidaemia in patients treated with metformin is greater than that established in the datasheet (<1/10,000). The onset of metformin-associated hyperlactacidaemia acidosis is related to acute renal impairment.

The response to IV rt-PA in very old stroke patients.

The use of rtPA in stroke patients aged >80 years remains controversial and it is debated whether there are sex-based differences in the response to rtPA. We assessed the clinical value of thrombolytic therapy in patients aged >80 years (elderly group) in comparison with a non-elderly group, and evaluated the existence of sex differences in the response to rtPA. All consecutive patients (n = 157) treated with rtPA were prospectively assessed since July 2001, including 49 elderly patients who fulfilled the National Institute of Neurological Disorders and Stroke (NINDS) criteria. Changes of the National Institute of Health Stroke Scale (NIHSS) score at 1 h, 24 h, and 7 days after rtPA administration, favourable outcome at day 90 [(modified Rankin Scale) mRS 0-1, or 2 if mRS = 2 before the stroke], symptomatic bleedings, and death rates were compared between elderly and non-elderly patients. Using logistic regression, baseline NIHSS score [odds ratio (OR) 0.59, 95% confidence interval (CI) 0.41-0.84] was an independent predictor of favourable outcome, but not sex (OR 0.72, 95% CI 0.33-1.56), or age >80 years (OR 0.74, 95% CI 0.32-1.70). The rates of clinical improvement, mortality, or symptomatic CNS bleeding were also unrelated to age and sex. In conclusion, the response to IV rtPA is not impaired in elderly stroke patients and male and female are equally responsive.

Intracerebroventricular injection of oxidant and antioxidant molecules affects long-term potentiation in urethane anaesthetized rats.

Production of superoxide anions in the incubation medium of hippocampal slices can induce long-term potentiation (LTP). Other reactive oxygen species (ROS) such as hydrogen peroxide are able to modulate LTP and are likely to be involved in aging mechanisms. The present study explored whether intracerebro-ventricular (ICV) injection of oxidant or antioxidant molecules could affect LTP in vivo. With this aim in mind, field excitatory post-synaptic potentials (fEPSPs) elicited by stimulation of the perforant pathway were recorded in the dentate gyrus of the hippocampal formation in urethane-anesthetized rats. N-acetyl-L-cysteine, hydrogen peroxide (H2O2) or hypoxanthine/xanthine-oxidase solution (a superoxide producing system) were administrated by ICV injection. The control was represented by a group injected with saline ICV. Ten minutes after the injection, LTP was induced in the granule cells of the dentate gyrus by high frequency stimulation of the perforant pathway. Neither the H(2)O(2) injection or the N-acetyl-L-cysteine injection caused any variation in the fEPSP at the 10-min post-injection time point, whereas the superoxide generating system caused a significant increase in the fEPSP. Moreover, at 60 min after tetanic stimulation, all treatments attenuated LTP compared with the control group. These results show that ICV administration of oxidant or antioxidant molecules can modulate LTP in vivo in the dentate gyrus. Particularly, a superoxide producing system can induce potentiation of the synaptic response. Interestingly, ICV injection of oxidants or antioxidants prevented a full expression of LTP compared to the saline injection.

Interleukin 10, monocytes and increased risk of early infection in ischaemic stroke.

BACKGROUND AND PURPOSE: The pathophysiology of stroke-associated infection (SAI) is uncertain. The cytokine profile and peripheral white cell response were assessed in patients with or without SAI. METHODS: The incidence of SAI was assessed in 110 patients with ischaemic stroke allocated antibiotic prophylaxis or placebo within 24 h of clinical onset. Peripheral white cell counts, interleukin (IL)6, tumour necrosis factor (TNF)alpha and IL10 were measured in plasma. RESULTS: 17 (15%) patients developed infection and showed time-dependent increases of total white cell count, neutrophils, monocytes, lymphocytes, IL6 and IL10, whereas TNFalpha and the TNFalpha/IL10 ratio decreased. In logistic regression, IL10 (odds ratio (OR) 1.08, 95% confidence interval (CI) 1.01 to 1.16), monocyte count (OR 1.42, 95% CI 1.08 to 1.87) and National Institute for Health Stroke Survey score on admission (OR 1.17, 95% CI 1.05 to 1.31) were independent predictors of systemic infection. CONCLUSIONS: SAI is associated with stroke severity, excessive IL10-mediated response and an increased number of circulating monocytes. These results support the finding that acute ischaemic brain injury triggers a blood-borne anti-inflammatory response that decreases the antimicrobial drive of the immune system.

[Focal epileptic seizures mimicking a stroke: neuroimaging and electroencephalographic correlations]. / Crisis epilépticas focales que imitan un ictus: neuroimagen y correlaciones electroencefalográficas.

TITLE: Crisis epilépticas focales que imitan un ictus: neuroimagen y correlaciones electroencefalográficas.

Perfusion Deficits and Mismatch in Patients with Acute Lacunar Infarcts Studied with Whole-Brain CT Perfusion.

BACKGROUND AND PURPOSE: The incidence and significance of perfusion abnormalities on brain imaging in patients with lacunar infarct are controversial. We studied the diagnostic yield of CTP and the type of perfusion abnormalities in patients presenting with a lacunar syndrome and in those with MR imaging-confirmed lacunar infarcts. MATERIALS AND METHODS: A cohort of 33 patients with lacunar syndrome underwent whole-brain CTP on admission. Twenty-eight patients had an acute ischemic lesion at follow-up MR imaging; 16 were classified as lacunar infarcts. Two independent readers evaluated NCCT and CTP to compare their diagnostic yield. In patients with DWI-confirmed lacunar infarcts and visible deficits on CTP, the presence of mismatch tissue was measured by using different perfusion thresholds. RESULTS: The symptomatic acute lesion was seen on CTP in 50% of patients presenting with a lacunar syndrome compared with only 17% on NCCT, and in 62% on CTP compared with 19% on NCCT, respectively, in patients with DWI-confirmed lacunar infarcts. CTP was more sensitive in supratentorial than in infratentorial lesions. In the nonblinded analysis, a perfusion deficit was observed in 12/16 patients with DWI-confirmed lacunar infarcts. The proportion of mismatch tissue was similar in patients with lacunar infarcts or nonlacunar strokes (32% versus 36%, P = .734). CONCLUSIONS: Whole-brain CTP is superior to NCCT in identifying small ischemic lesions, including lacunar infarcts, in patients presenting with a lacunar syndrome. Perfusion deficits and mismatch are frequent in lacunar infarcts, but larger studies are warranted to elucidate the clinical significance of these CTP findings.

Efecto antagonista del flumazenil sobre el isoflurano en la emersión de la anestesia general / Antagonist effect of flumazenil on isofluran in reversion of general anesthesia

INTRODUCTION AND OBJECTIVES: Isoflurane, an inhalational general anesthetic widely used in medical practice, belonging to the group of volatile liquids together with desflurane and sevoflurane, with various properties including sedation, hypnosis and anesthesia of patients undergoing treatment. surgical acts. Volatile inhalational anesthetics (halogenated) as mechanism of action, has the property of increasing inhibitory synaptic transmission at postsynaptic level by potentiating ion channels regulated by ligand activated by alpha-aminobutyric acid (GABA). Flumazenil is a benzodiazepine antagonist belonging to the group of imidazobenzodiazepine. It is currently known that there is no specific drug capable of antagonizing the effects of halogenates that allow the rapid and complete recovery of general anesthesia, for this reason this work focuses its efforts on demonstrating whether flumazenil has the ability to reverse the actions of the patient. isoflurane and allow an early restoration of the level of consciousness. MATERIAL AND METHODS: The study to be performed is a clinical type of longitudinal, prospective, unicentric and double blind. The sample will be formed by patients who are going to be subjected to a balanced general anesthesia. The sample will be divided into 2 large groups: group C (control) and group F (Flumazenil). At the end of the surgery, the mixture will be administered according to the selected group in a random manner (Flumazenil 0.25 mg or 0.9% solution in a 20 cc syringe) and the time of extubation, recovery time of the level of consciousness, time of discharge UCPA and hemodynamic state (FC, TAM and SO2). RESULTS: The flumazenil group showed a significantly shorter time from injection to extubation than the placebo group (p = 0.007). Differences in terms of shorter times needed to achieve Aldrete of 9 points in the flumazenil group (P = 0.04) were observed as were shorter anesthetic arousal times represented by a Ramsey 2. Heart rate, mean arterial pressure and saturation they had similar values between the 2 groups. CONCLUSION: The study showed that a single dose of 0.25 mg of flumazenil administered at the end of the surgical act, just after completing all surgical stimulation was beneficial (P = 0.007) in the context of extubation times and shorter anesthetic arousal times.

INTRODUCCIÓN Y OBJETIVOS: El isoflurano un anestésico general inhalatorio usado ampliamente en la práctica médica, perteneciente al grupo de los líquidos volátiles junto con el desflurano y sevoflurano, con variadas propiedades entre las que se encuentran la sedación, hipnosis y anestesia de los pacientes sometidos a actos quirúrgicos. Los anestésicos inhalatorios volátiles (halogenados) como mecanismo de acción, tiene la propiedad de aumentar la transmisión sináptica inhibidora a nivel postsináptico potenciando los canales iónicos regulados por ligando activados por ácido alfa-aminobutírico (GABA). El flumazenil es un antagonista benzodiazepínico perteneciente al grupo de los imidazobenzodiazepina. Se conoce actualmente que no existe un fármaco específico capaz de antagonizar los efectos de los halogenados que permitan la recuperación rápida y completa de la anestesia general, por tal motivo este trabajo centra sus esfuerzos en demostrar si el flumazenil tiene la capacidad para revertir las acciones del isoflurane y permitir un restablecimiento temprano del nivel de conciencia. MATERIALES Y MÉTODOS: El estudio a realizar es de tipo clínico de corte longitudinal, prospectivo, unicéntrico y doble ciego. La muestra se conformará por pacientes que vayan a ser sometidos a anestesia general balanceada. Se procederá a dividir la muestra en 2 grandes grupos: grupo C (control) y grupo F (flumazenil). Al final de la cirugía se administrará la mezcla según grupo seleccionado de manera al azar (flumazenil 0,25 mg o solución 0,9% en una jeringa de 20 cc) y se valorará el tiempo de extubación, tiempo de recuperación del nivel de conciencia, tiempo de alta de la UCPA y estado hemodinámico (FC, TAM y SO2). RESULTADOS: El grupo de flumazenil presentó un tiempo desde la inyección hasta la extubación significativamente más bajo que el grupo placebo (p = 0,007). Se observaron diferencias en términos de tiempos más bajos necesario para alcanzar Aldrete de 9 puntos en el grupo flumazenil (P = 0,04) al igual que tiempos de despertar anestésico más cortos representados por un Ramsey 2. La frecuencia cardíaca, presión arterial media y la saturación tuvieron valores similares entre los 2 grupos. CONCLUSIÓN: El estudio demostró que una única dosis de 0,25 mg de flumazenil administrado al final del acto quirúrgico, justo después de culminar toda estimulación quirúrgica fue beneficiosa (P = 0,007) en el contexto de tiempos de extubación y tiempos de despertar anestésico más cortos.

Posterior hypothalamic activity and cortical control during the PGE1 hyperthermia.

The firing rate of the posterior hypothalamic neurones and interscapular brown adipose tissue and colonic temperatures (TIBAT and TC) were monitored in 36 urethane-anaesthetized male Sprague-Dawley rats before and after an intracerebroventricular (i.c.v.) injection of 400 ng prostaglandin E1 (PGE1) or saline. The i.c.v. injection was preceded by functional decortication in half of each group. The results show an increase of firing rate, TIBAT and TC after PGE1 injection in the rats without decortication. Functional decortication significantly reduced these enhancements. These findings demonstrate that the posterior hypothalamus plays a significant role in the hyperthermia induced by PGE1 and that the cerebral cortex is involved in the control of posterior hypothalamic activity.

Nitric oxide reduces the thermogenic changes induced by lateral hypothalamic lesion.

The experiment described here tests the effect of intracerebroventricular (icv) injection of nitric oxide (NO) precursors, such as L-arginine (L-arg) and nitroprusside (NP), on the thermogenic changes induced by lesion of the lateral hypothalamus (LH). The firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), along with IBAT and colonic temperatures (TIBAT and TC) were monitored in urethane-anaesthetized male Sprague-Dawley rats lesioned in the LH. These variables were measured before and after an icv injection of 4 mumol L-arg or 400 nmol NP. The same variables were also monitored in: a) lesioned rats with icv administration of saline; b) sham-lesioned animals with icv injection of L-arg or NP; c) sham-lesioned rats with icv injection of saline. The results show that L-arg or NP injection reduces the increases in firing rate. TIBAT and TC induced by LH lesion. These findings suggest that NO plays a key role in the thermogenic changes following LH lesion.