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Fairfax S.T.,Biomedical science | Holwerda S.W.,Medical Pharmacology and Physiology | Credeur D.P.,Medical Pharmacology and Physiology | Zuidema M.Y.,Internal Medicine | And 7 more authors.
Journal of Physiology | Year: 2013

Sympathetic vascular transduction is commonly understood to act as a basic relay mechanism, but under basal conditions, competing dilatory signals may interact with and alter the ability of sympathetic activity to decrease vascular conductance. Thus, we determined the extent to which spontaneous bursts of muscle sympathetic nerve activity (MSNA) mediate decreases in forearm vascular conductance (FVC) and the contribution of local α-adrenergic receptor-mediated pathways to the observed FVC responses. In 19 young men, MSNA (microneurography), arterial blood pressure and brachial artery blood flow (duplex Doppler ultrasound) were continuously measured during supine rest. These measures were also recorded in seven men during intra-arterial infusions of normal saline, phentolamine (PHEN) and PHEN with angiotensin II (PHEN+ANG). The latter was used to control for increases in resting blood flow with α-adrenergic blockade. Spike-triggered averaging was used to characterize beat-by-beat changes in FVC for 15 cardiac cycles following each MSNA burst and a peak response was calculated. Following MSNA bursts, FVC initially increased by +3.3 ± 0.3% (P= 0.016) and then robustly decreased to a nadir of -5.8 ± 1.6% (P < 0.001). The magnitude of vasoconstriction appeared graded with the number of consecutive MSNA bursts; while individual burst size only had a mild influence. Neither PHEN nor PHEN+ANG infusions affected the initial rise in FVC, but both infusions significantly attenuated the subsequent decrease in FVC (-2.1 ± 0.7% and -0.7 ± 0.8%, respectively; P < 0.001 vs. normal saline). These findings indicate that spontaneous MSNA bursts evoke robust beat-by-beat decreases in FVC that are exclusively mediated via α-adrenergic receptors. © 2013 The Physiological Society.

Flores M.P.,ME3 | de Castro A.P.C.R.,Anesthesiology | Nascimento J.D.S.,Head of the CET SBA
Revista Brasileira de Anestesiologia | Year: 2012

Background and objectives: Pain treatment involves the usage of common and opioid analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs) and adjuvant analgesics. Traditionally, these drugs are administered systemically or into the neuraxis. However, when analgesics are applied through these pathways, they are associated with significant side effects, which can hinder its use. Topical administration of analgesics is an alternative. The objective of this paper is to discuss topical analgesics, the mechanisms of action and clinical efficacy. Content: This is a review paper addressing the usage of the topical local anesthetics: capsaicin, clonidine, tricyclic antidepressants, ketamine, opioids and cannabinoids, discussing mechanism of action and effectiveness. Conclusions: Topical analgesics are promising as a strategy for pain treatment, as they are associated with lower incidence of side effects. The benefit of local anesthetics, NSAID's and capsaicin is well established. However, the efficacy of clonidine, tricyclic antidepressants, ketamine, opioids and cannabinoids is still questionable. Studies have shown that the multimodal approach is an alternative, but studies are needed to confirm this hypothesis. © 2012 Elsevier Editora Ltda.

Gallardo-Mayo C.,Anesthesiology | Garrido-Elustondo S.,Research Section | Calvo-Manuel E.,Hospital Clinico San Carlos de Madrid | Zamorano-Gomez J.L.,Instituto Cardiovascular
European Journal of Clinical Investigation | Year: 2011

Background and Objective Increased carotid intima-media thickness (CIMT) is associated with cardiovascular events. The purpose of this study was to identify advanced subclinical atherosclerosis in patients who are at low or intermediate risk. Methods Thousand hundred and eighteen Spanish subjects were prospectively enrolled in an ambulatory screening of cardiovascular risk (CVR). Three hundred and twenty patients aged over 30years with low-intermediate CVR according to European SCORE function underwent carotid ultrasonography. Carotid IMT and plaque assessment were performed using high-resolution B-mode ultrasonography. Participants with abnormal CIMT were reclassified to high CVR. Results According to SCORE function, 104 patients (32·5%) were of low CVR and 216 (67·5%) of intermediate CVR. Mean carotid IMT was 0·62±0·13mm, and carotid plaque was found in 35 (10·9%) patients. Carotid ultrasonography changed the risk stratum in 59 (18·4%) patients, who were reclassified to high CVR. Reclassification was more frequent in the intermediate CVR group than in the low CVR group (22·7% vs. 9·6%, P=0·005) and was associated to age (P=0·002), history of arterial hypertension (P<0·001) and increased systolic blood pressure (P=0·05). Conclusions CIMT calculated by high-resolution B-mode ultrasonography could become an important tool in preventive medicine. Measuring CIMT may be useful in identifying asymptomatic individuals with subclinical atherosclerosis not detected by the actual CVR functions. © 2010 The Authors. European Journal of Clinical Investigation © 2010 Stichting European Society for Clinical Investigation Journal Foundation.

To describe contrast-enhanced ultrasound (CEUS) patterns of pneumonia, to characterize CEUS patterns and to determine the clinical value of deviant CEUS patterns. N = 50 patients with radiologically diagnosed alveolar pneumonia were investigated by CEUS and retrospectively evaluated. Pulmonary enhancement was differentiated from bronchial arterial enhancement by measurement of time to enhancement from the application of the contrast agent (CA). The echogenicity of the CA enhancement was evaluated (isoechoic/hypoechoic) using the spleen as an "in vivo reference". In addition, the homogeneity of the CA enhancement (homogeneous/ inhomogeneous) was recorded. The patients were divided into two groups according to the CEUS pattern (type 1/type 2) and compared to each other in terms of age, days of hospitalization, comorbidity, rate of complications and the presence of pleural effusion. The majority showed a type 1 CEUS pattern consisting of a pulmonary arterial supply (92 %), an isoechoic extent of enhancement (74 %) and a homogeneous enhancement (78 %) of the CA in the pulmonary lesions. The only significant difference found between the two groups was the average age. Pneumonia most likely shows a type 1 CEUS pattern consisting of a pulmonary arterial supply, an isoechoic extent of enhancement compared to the spleen and a homogeneous enhancement of the CA in the pulmonary lesions. Prognostic value of a type 2 CEUS pattern (bronchial arterial supply and/or hypoechoic extent of enhancement and/or inhomogeneous enhancement) in pneumonia regarding days of hospitalization, comorbidity, rate of complications and the presence of pleural effusion could not be shown. © Georg Thieme Verlag KG Stuttgart · New York.

Widmer B.,Sydney Orthopaedic Research Institute | Lustig S.,Sydney Orthopaedic Research Institute | Lustig S.,Lyon University Hospital Center | Scholes C.J.,Sydney Orthopaedic Research Institute | And 4 more authors.
Knee | Year: 2013

Background: While single shot femoral nerve blocks and indwelling femoral nerve catheters provide significant peri-operative analgesia, there are small but serious risks of neurovascular complications. We aimed to determine the incidence and characterise the nature of neural complications arising from femoral nerve blocks performed for knee surgery. Methods: One thousand eight hundred and two patients receiving a femoral nerve block for knee surgery during the study period were screened. Patients with possible neurological symptoms were evaluated with a detailed physical examination and self-report questionnaires. Also measures of depression, anxiety and tension/stress were collected. Results: In the patients screened, an incidence of 1.94% was found. Of the 24 patients available for testing, 4 had bilateral symptoms following bilateral nerve blocks. All had sensory abnormalities in the distribution of the femoral nerve. The incidence was significantly higher in females (females = 2.5%, males = 0.83% p = 0.01) and in patients receiving a single shot block (single shot = 2.66%, femoral catheter = 0.93, p = 0.01).Conclusions: The incidence of neurological complication after FNB was higher in this series than typically reported and the symptoms significantly influenced the quality of life in the affected cases. The decision to include a femoral nerve block in the peri-operative analgesic regimen should be made on an individual basis considering the risks and benefits. Level of evidence: Therapeutic level IV. © 2012 Elsevier B.V.

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