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Adrenergic Agents (adrenergic + agent)
Selected AbstractsEffect of adrenergic stimulation on cutaneous microcirculation immediately after surgical adventitiectomy in a rat skin flap modelMICROSURGERY, Issue 6 2008Jean-Pierre H. Lecoq M.D. Chronic sympathetic denervation leads to the development of supersentivity to adrenergic agents. Free flap surgery results in the disruption of the autonomic nerve fibers running along the anastomosed vessels. We therefore investigated the early effect of surgical sympathectomy on the reactivity of cutaneous microcirculation challenged to adrenergic agents. Two epigastric flaps were elevated and exposed in 15 rats. On the right flap (Side A), a circular adventitiectomy of the feeder vessels was realized to provide surgical sympathectomy. On the left flap (Side N), vessels were kept intact. The following drugs were then given intravenously successively: phenylephrine (10 and 15 ,g kg,1), norepinephrine (10 ,g kg,1), prazocin (1 mg kg,1) followed by norepinephrine (10 ,g kg,1). Cutaneous microcirculation was assessed using Laser-Doppler Flowmeters simultaneously on the two flaps after each drug administration. Mean arterial pressure was also measured. On side N, phenylephrine and norepinephrine resulted in a transient increase in cutaneous microcirculation followed by a more prolonged reduction. On side A, only the initial increase was observed, which was greater and longer as compared with side N, and paralleled the increase in mean arterial pressure. After prazocin pre-treatment, norepinephrine produced a transient increase in cutaneous microcirculation similar on both sides, and parallel to the changes in arterial pressure. No decrease in cutaneous microcirculation was observed. Immediately after surgical adventitiectomy, the vasoconstriction produced by ,-adrenergic agents is prevented. No denervation-induced hypersentivity is observed. Surgical sympathectomy might protect cutaneous flaps from vasoconstriction induced by endogenous catecholamines release. © 2008 Wiley-Liss, Inc. Microsurgery, 2008. [source] Responses to inhaled bronchodilators in infancy are not linked with asthma in later childhood,,PEDIATRIC PULMONOLOGY, Issue 5 2006Mari K. Hyvärinen MD Abstract Many doctors consider wheezing infants and young children who respond to ,-adrenergic agents to be asthmatics, or at least at risk for later asthma. The aim of this study was to compare responses to inhaled albuterol and racemic epinephrine in infancy between children with and without asthma later in childhood. In a crossover study setting, 100 acutely wheezing infants aged less than 24 months were randomized to receive inhalations of either racemic epinephrine and placebo, or albuterol and placebo. Clinical evaluation consisted of measurements of respiratory rate, heart rate, and oxygen saturation, and clinical assessment of the respiratory distress assessment instrument (RDAI) score, consisting of wheezing and chest indrawings. The asthma status of the children was evaluated at three clinical follow-up visits, at 4.0, 7.2, and 12.3 (median) years of age. Responses to bronchodilating agents, when respiratory rates and RDAI scores were used as outcome measures, were not different in future asthmatics compared to nonasthmatics. However, oxygen saturation was significantly higher after albuterol inhalation in children who had asthma at all three visits (92.67% confidence interval (CI), 91.39,93.96) than in those without asthma at these visits (92.52% CI, 91.79,93.25), but lower, correspondingly, after racemic epinephrine (91.97% CI, 90.74,93.19 vs. 93.04% CI, 92.29,93.79) and placebo (91.38% CI, 90.49,92.28 vs. 93.12% CI, 92.60,93.65) inhalations (P,=,0.04). In conclusion, we were not able to confirm that future asthmatics respond better than future nonasthmatics to bronchodilating agents during wheezing in infancy. More studies are needed to characterize the subset of infants who benefit from bronchodilating treatment in infancy. Pediatr Pulmonol. 2006; 41:420,427. © 2006 Wiley-Liss, Inc. [source] Effect of nebulized albuterol on blood glucose in patients with diabetes mellitus with and without cystic fibrosisPEDIATRIC PULMONOLOGY, Issue 2 2005P. König MD Abstract Over 90% of cystic fibrosis (CF) patients are treated with bronchodilators, and 6% have diabetes. Some with asthma also have diabetes, and most are treated with bronchodilators. Systemic administration of adrenergic agents can cause increases in blood glucose, but the effect of inhaled agents is unclear. A double-blind study was performed on 10 patients with type 1 diabetes mellitus (DM) without CF (3 male, 7 female, mean age 25.5 years) and 9 patients with insulin-dependent CF-related diabetes (CFRD) (8 male, 1 female, mean age 21.9 years). On 2 separate days before 9 AM fasting and the morning dose of insulin, 2.5 mg of albuterol or nebulized placebo were given. Blood glucose was measured by finger stick with a glucose reflectance meter before and 15, 30, 45, and 60 min after treatment. No significant changes from baseline or differences between placebo and albuterol occurred in either group. The mean maximum increase from baseline in DM was 20 mg/dl on placebo, and 38 mg/dl on albuterol; in the CFRD, the respective changes were 7 and 7 mg/dl. Two DM patients had a >,50 mg/dl increase on albuterol vs. placebo; no CFRD patients had differences of such magnitude. DM patients had greater increases from baseline than CFRD patients on placebo and albuterol. Differences reached statistical significance at 30 and 45 min on placebo, and 45 min on albuterol. Albuterol 2.5 mg by nebulizer causes no clinically significant increases in blood glucose in DM or CFRD patients. Diabetes patients without CF have a significantly greater increase of glucose with time (placebo or albuterol) than CFRD patients. Pediatr Pulmonol. 2005; 40:105,108. © 2005 Wiley-Liss, Inc. [source] The investigation of putative agents, using an in vitro model, to prevent cavernosal smooth muscle dysfunction during low-flow priapismBJU INTERNATIONAL, Issue 8 2008Asif Muneer OBJECTIVE To investigate the effect of putative agents for preventing irreversible smooth muscle dysfunction, using an in vitro model of low-flow priapism (a condition conventionally managed using a combination of corporal blood aspiration and instillation of ,-adrenergic agonists), as failure of detumescence results in a high incidence of erectile dysfunction. MATERIALS AND METHODS We investigated the effects of several agents (N-acetylcysteine, BayK 8644, glutathione, digoxin, calcium and N, -nitro- l -arginine methyl ester) on the recovery of smooth muscle tone after exposure to 4 h of a combination of hypoxia, glucopenia and acidosis in corpus cavernosum isolated from rabbit. RESULTS After 4 h of ischaemia, none of the agents were able to prevent irreversible smooth muscle dysfunction. CONCLUSION Prolonged low-flow priapism leads to smooth muscle dysfunction and fibrosis within the corpus cavernosum. When ,-adrenergic agents fail to reverse the condition, surgical intervention is required. We showed that the administration of novel agents, including antioxidants, does not prevent smooth muscle dysfunction. [source] The management of low-flow priapism with the immediate insertion of a penile prosthesisBJU INTERNATIONAL, Issue 9 2002R.W. Rees Objective ,To evaluate the outcome of patients undergoing the immediate insertion of a penile prosthesis as a treatment for acute low-flow priapism. Patients and methods ,Eight patients presenting with low-flow priapism with a mean duration of 91 h (range 32,192) were prospectively evaluated. All had failed conservative management with the instillation of ,-adrenergic agents, and four had already undergone shunt procedures elsewhere. Immediate management consisted of the insertion of a malleable prosthesis in six patients and an inflatable prosthesis in two. One of the malleable prostheses was subsequently changed to an inflatable device. Results ,There were no early complications, with all patients being satisfied with the end result, and seven having sexual intercourse. One patient developed a penile deformity after surgery, cause by fibrosis around one inflatable cylinder. All patients have maintained their penile length. Conclusions ,Prolonged low-flow priapism results in a variable degree of cavernosal fibrosis and a subsequent loss of penile length. The delayed insertion of a penile prosthesis can be difficult, with high complication rates. The immediate insertion of a penile prosthesis in patients with prolonged low-flow priapism is simple and maintains penile length. This should always be offered to the patient at initial presentation, as the complication rate is low and the subsequent outcome excellent. [source] | ||||||||||