Cardiac microcirculatory effects of beta-adrenergic blockade during sympathetic stimulation.

The effects of beta-adrenergic blockade on cardiac transcapillary exchange were examined at rest and during sympathetic stimulation. Multiple indicator dilution experiments were carried out in closed-chest anesthetized dogs at rest and during carotid occlusion, either under basal conditions or after beta-adrenergic blockade with alprenolol. beta-Adrenergic blockade at rest had no effect on coronary flow or transcapillary exchange in comparison with the control situation, but it abolished the increase in coronary flow and in the permeability/surface area product for labeled sucrose produced by carotid occlusion. High coronary resistance values in beta-blocked animals with carotid occlusion were associated with a high degree of heterogeneity in capillary transit times, but the overall relation between coronary flow and the capillary permeability/surface area product was unchanged. The findings indicate that beta-blockade increases coronary resistance during sympathetic stimulation and, simultaneously, decreases the coronary blood flow and capillary permeability/surface area product while increasing the heterogeneity of capillary transit times.     

First evidence of fatal hantavirus nephropathy in India, mimicking leptospirosis.

Sir, In a recent Indian serosurvey [1], it was announced that ‘noreports of hantavirus infections in humans from India existed[before 2005]’. We wish to point out that serologicaland clinical evidence of hantavirus infection in India was alreadywell documented before 2005. From 1998 on, we screened leptospirosis-suspected cases in Indiafor the only known cosmopolitan hantavirus serotype, Seoul virus(SEOV). Wild rats are the reservoir     

Physician knowledge of herbal toxicities and adverse herb-drug interactions.

OBJECTIVE: To determine how knowledgeable physicians are regarding the toxic effects and drug interactions of herbal remedies. METHODS: An anonymous voluntary demographic survey and 16-question, multiple-choice quiz was distributed at educational meetings of emergency medicine and internal medicine physicians. The primary outcome measures were to determine whether significant associations existed between quiz scores and the amount of clinical experience, or between quiz scores and self-assessed familiarity with the topic of herbal toxicities and adverse herb-drug interactions. RESULTS: A total of 142 surveys and quizzes were completed by 59 attending physicians, 57 resident physicians, and 26 medical students. The mean subject score on the quiz was only slightly higher than would have occurred from random guessing. Neither the amount of the subjects' clinical experience, nor their self-assessed familiarity with herbal toxicities and drug interactions correlated significantly with the score on the quiz. CONCLUSION: The physicians and medical students surveyed had little training in herbal toxicities and drug interactions. They generally rated their familiarity with these topics as 'poor', and their scores on the quiz bore out this assessment as correct. Educational efforts might improve physician knowledge of the adverse effects of herbal remedies.     

Ipsilateral cluster headache and chronic paroxysmal hemicrania: two case reports

We report two patients with ipsilateral attacks of cluster headache and chronic paroxysmal hemicrania. The first patient, a 33-year-old man, started having attacks of chronic cluster headache at the age of 27. At 33, they were replaced by typical attacks of ipsilateral chronic paroxysmal hemicrania which showed a dramatic improvement with indomethacin 150 mg daily. After two days of complete remission, cluster headache attacks reappeared and persisted until verapamil, 360 mg a day, was added to indomethacin. The second patient, a 45-year-old man, first developed attacks of episodic cluster headache at the age of 35. At 44, he experienced ipsilateral typical attacks of chronic paroxysmal hemicrania, and two months later attacks of cluster headache. Under verapamil 240 mg daily, attacks of cluster headache disappeared, but those of chronic paroxysmal hemicrania increased in frequency until indomethacin 150 mg daily was added. These observations suggest a close relationship but not a similarity between cluster headache and chronic paraoxysmal hemicrania, and show the practical therapeutic interest of maintaining this distinction.     

Hypointense transcerebral veins at T2*-weighted MRI: a marker of hemorrhagic transformation risk in patients treated with intravenous tissue plasminogen activator.

Prediction of hemorrhagic transformation (HT) in patients treated by intravenous recombinant tissue-type plasminogen activator (rt-PA) is a challenging issue in acute stroke management. HT may be correlated with severe hypoperfusion. Signal changes may be observed at susceptibility-weighted magnetic resonance imaging (MRI) within large perfusion defects. A signal drop within cerebral veins at T2*-weighted gradient-echo MRI may be expected in severe ischemia, and may indicate subsequent risk of HT. The authors prospectively searched for an abnormal visibility of transcerebral veins (AVV) within the ischemic area in patients with hemispheric ischemic stroke, before they were treated with intravenous rt-PA therapy. Any correlation between AVV and baseline clinical or MRI findings, or further HT, was noted. An AVV was present in 23 of 49 patients (obvious, n = 8; moderate, n = 15), and was supported by severe hemodynamic changes at baseline MRI. The AVV was correlated with the occurrence of parenchymal hematoma type 2 at computed tomography during the first week (r = 0.44, P = 0.002). Five of six type 2 parenchymal hematomas occurred in association with obvious AVV. At multiple regression analysis, two baseline MRI factors had an independent predictive value for HT risk during the first week: the AVV and the cerebral blood volume ratio (Nagelkerke R2 = 0.48).     

Invasive ventilation in the emergency department: Part 2: Implications for patient safety

The use of mechanical ventilation in the Emergency Department requires adequate resources in order to maintain patient safety and avoid potential risks. Moreover, developments in technology require increased knowledge of mechanical ventilation techniques to address the complexity of decision-making involved. Organisational issues and system factors have the potential to negatively impact on the ability of the emergency service to provide optimum care to patients receiving mechanical ventilation. These issues include staffing and skill-mix, demand on emergency services, role-delineation, scope of practice, and current mechanisms for monitoring of quality and safety. Furthermore, in response to advances in ventilator technology, current education programs for both nursing and medical staff require review to ensure that they provide comprehensive information about the types of ventilation techniques now available and the relative risks and benefits associated with their application.This article is the second in a two-part series and explores the educational and organisational factors that impact upon safety and quality of care delivered to patients receiving mechanical ventilation in the emergency department. Recommendations for future policy development, curriculum review and reporting mechanisms to support further research in the application of mechanical ventilation in the emergency department are made.     

Urinary output of endogenous monoamine oxidase inhibitor and isatin during acute migraine attacks

Summary Urinary output of endogenous monoamine oxidase (MAO) inhibitory activity, was significantly raised in serial samples collected across a migraine attack compared with collections during attack-free periods and in healthy controls, which did not differ from each other. There was a highly significant correlation in output between isatin, a major fraction of the MAO inhibitory activity, and output of the MAO inhibitory activity itself. However, although there was a tendency towards increased isatin excretion during migraine attacks, it failed to reach statistical significance.