Background: The attempts to explain the unpredictability of extent of spinal block provided by plain local anesthetic solutions have resulted in many clinical reports; however, causes of this uncertainty are as yet unknown. Recently, normal values of the human cerebrospinal fluid densities have been studied showing important interindividual variations, especially between females and males. The current study was designed to evaluate as primary endpoint the influence of cerebrospinal fluid density values on the extent of spinal block with plain bupivacaine. The ancillary endpoints were search of factors explaining the interindividual differences in cerebrospinal fluid density values reported and determination of the relation between upper extent and regression of spinal anesthesia.
Methods: Sixty-four consecutive patients undergoing peripheral orthopedic surgery with spinal block were enrolled. Spinal anesthesia was performed in the lateral decubitus position with the operated side upward. Two milliliters of cerebrospinal fluid was sampled before injection of 3 ml plain bupivacaine 0.5%. The patient was immediately turned supine and remained in the horizontal position until the end of the study. Maximal sensory block level and time to sensory regression to L4 were determined for each patient enrolled. Cerebrospinal fluid and bupivacaine densities as well as cerebrospinal proteins, glucose, sodium, and chloride concentrations were measured.
Results: A highly significant correlation between cerebrospinal fluid density and maximal sensory block level was found (P = 0.0004). However, this correlation was poorly predictive (R2 = 0.37). Cerebrospinal fluid density, proteins, and glucose concentrations were significantly higher in men than in women: 1.000567 +/- 0.000091 versus 1.000501 +/- 0.000109 g/ml (P = 0.014), 0.46 +/- 0.18 versus 0.32 +/- 0.13 g/l (P = 0.001), and 3.27 +/- 0.7 versus 2.93 +/- 0.5 mm (P = 0.023), respectively. A highly significant (P = 0.0004) and predictive (R2 = 0.73) inverse correlation was found between maximal upper sensory extent and sensory regression to L4. 相似文献
Zusammenfassung
Die artifizielle Hibernation hemmt und verzögert die Vermehrung und die Ausbreitung von Virus Aujeszky im ZNS. peripher infizierter Kaninchen erheblich.
Hierdurch findet die frühere Beobachtung 1, wonach die Dauer der Inkubationsperiode und des Krankheitsverlaufes des M. Aujeszky bei Kaninchen beträchtlich verlängert ist, eine hinreichende Erklärung. 相似文献
Ferroelectric property that induces electrocaloric effect was investigated in Ba(GexTi1−x)O3 ceramics, known as BTGx. X-ray diffraction analysis shows pure perovskite phases in tetragonal symmetry compatible with the P4mm (No. 99) space group. Dielectric permittivity exhibits first-order ferroelectric-paraelectric phase transition, confirmed by specific heat measurements, similar to that observed in BaTiO3 (BTO) crystal. Curie temperature varies weakly as a function of Ge-content. Using the direct and indirect method, we confirmed that the adiabatic temperature change ΔT reached its higher value of 0.9 K under 8 kV/cm for the composition BTG6, corresponding to an electrocaloric responsivity ΔT/ΔE of 1.13 × 10−6 K.m/V. Such electrocaloric responsivity significantly exceeds those obtained so far in other barium titanate-based lead-free electrocaloric ceramic materials. Energy storage investigations show promising results: stored energy density of ~17 mJ/cm3 and an energy efficiency of ~88% in the composition BTG5. These results classify the studied materials as candidates for cooling devices and energy storage applications. 相似文献
An enormous increase in the application of wireless communication in recent decades has intensified research into consequent increase in human exposure to electromagnetic (EM) radiofrequency (RF) radiation fields and potential health effects, especially in school children and teenagers, and this paper gives a snap overview of current findings and recommendations of international expert bodies, with the emphasis on exposure from Wi-Fi technology indoor devices. Our analysis includes over 100 in vitro, animal, epidemiological, and exposure assessment studies (of which 37 in vivo and 30 covering Wi-Fi technologies). Only a small portion of published research papers refers to the “real” health impact of Wi-Fi technologies on children, because they are simply not available. Results from animal studies are rarely fully transferable to humans. As highly controlled laboratory exposure experiments do not reflect real physical interaction between RF radiation fields with biological tissue, dosimetry methods, protocols, and instrumentation need constant improvement. Several studies repeatedly confirmed thermal effect of RF field interaction with human tissue, but non-thermal effects remain dubious and unconfirmed.Key words: exposure to RF fields, e-school, radiofrequency, SAR相似文献
Long-term effectiveness and repeated administration of botulinum toxin A are the basis for its use in both neuromuscular disorders and certain painful conditions. Botulinum toxin A has been recently approved for migraine treatment, and its off-label use extends to other craniofacial pain disorders. However, recently it was reported that, after repeated injection, botulinum toxin loses its antinociceptive efficacy in rats. In present study with a similar design, we compared the effects of single and repeated injections of botulinum toxin in formalin-induced orofacial pain. No statistically significant differences were found between single or repeatedly treated animal groups. Our results are in line with the clinical experience and suggest that botulinum toxin can be re-administered in orofacial pain treatment. 相似文献
OBJECTIVES: The purpose of this investigation was to examine the relationship between psychosocial variables and working conditions, and nurses' coping methods and distress in response to the severe acute respiratory syndrome (SARS) crisis in Canada. PARTICIPANTS AND PROCEDURE: The sample consisted of 333 nurses (315 women, 18 men) who completed an Internet-mediated questionnaire that was posted on the Registered Nurses' Association of Ontario (RNAO) website between March and May 2004. The questionnaire was restricted to respondents who had to authenticate their RNAO membership with a valid username and password before accessing the questionnaire. This served a dual purpose: to ensure that only RNAO nurses completed the questionnaire and thereby safeguarding the generalizability of the findings; and second, to prevent any one nurse from contributing more than once to the overall sample. RESULTS: Correlational analysis yielded several significant relationships between psychosocial variables and working conditions, and the traditional correlates of burnout and stress. Three multiple regression analysis revealed that the model we evolved--including higher levels of vigor, organizational support, and trust in equipment/infection control initiative; and lower levels of contact with SARS patients, and time spent in quarantine--predicted to lower levels of avoidance behavior, emotional exhaustion, and state anger. CONCLUSIONS: By employing models of stress and burnout that combine psychosocial variables and working conditions, researchers can account for significant amounts of variance in outcomes related to burnout. These findings highlight the importance of vigor and perceived organizational support in predicting nurses' symptoms of burnout. For healthcare administrators, this means that a likely strategy for assuaging the negative outcomes of stress should address nurses' psychosocial concerns and the working conditions that they face during novel times of crisis. 相似文献
Pulmonary inflammatory myofibroblastic tumor encompasses a heterogeneous spectrum of reactive, infectious, and neoplastic entities. It is composed of spindle-shaped myofibroblastic cells in a background of inflammatory cells and collagen fibres. Actinomycosis is a bacterial infection. It infects the lower respiratory tracts by inhalation or aspiration of oropharyngeal or upper gastrointestinal materials. Only eight cases of pulmonary IMT associated with actinomycosis have been reported in the literature so far. This is the ninth case reported. 相似文献
The authors present the case of a 58-year-old woman. At presentation the patient complained of vertigo and noise in the ears with six months history, and from headache, accompanied by nausea and vomiting from three months. The physical examination of the patient found no abnormalities. The neurological examination revealed discoordination syndrome and mild hemiparesis of the left limbs. Computed tomography of the brain without and with contrast medium showed oval tumor, localized in the region of trigonum collaterale and the posterior horn of the right lateral ventricle. Operative intervention was performed after a preoperative management of the patient: transcortical fenestration of the brain in the region of trigonum collaterale and the posterior horn of the right lateral ventricle. The tumor was totally removed. It is well isolated, oval in shape, with feeding blood vessel from plexus chorioideus and was attached to the wall of the ventricle with several thin bridges. Macroscopically the tumor was 3 cm in diameter, with smooth walls, well capsulated, grey-brownish in color and with firm elastic consistence. The histological findings revealed meningioma--meningotheliomatose variant. 相似文献
Background: The usefulness of peripheral nerve blockade in the anesthetic management of hip surgery has not been clearly established. Because sensory afferents from the hip include several branches of the lumbar plexus, the authors hypothesized that a lumbar plexus block could reduce pain from a major hip procedure.
Methods: In a double-blind prospective trial, 60 patients undergoing total hip arthroplasty were randomized to receive general anesthesia with (plexus group, n = 30) or without (control group, n = 30) a posterior lumbar plexus block. The block was performed after induction using a nerve stimulator, and 0.4 ml/kg bupivacaine, 0.5%, with epinephrine was injected. General anesthesia was standardized, and supplemental fentanyl was administered per hemodynamic guidelines. Postoperative pain and patient-controlled intravenous morphine use were serially assessed for 48 h.
Results: The proportion of patients receiving supplemental fentanyl intraoperatively was more than 3 times greater in the control group (20 of 30 vs. 6 of 29, P = 0.001). In the postanesthesia care unit, a greater than fourfold reduction in pain scores was observed in the plexus group (visual analogue scale [VAS] pain score at arrival 1.3 +/- 2 vs. 5.6 +/- 3, P < 0.001), and "rescue" morphine boluses (administered if VAS > 3) were administered 10 times less frequently (in 2 of 28 vs. in 22 of 29 patients, P < 0.0001). Pain scores and morphine consumption remained significantly lower in the plexus group until 6 h after randomization (VAS at 6 h, 1.4 +/- 1.3 vs. 2.4 +/- 1.4, P = 0.007; cumulative morphine at 6 h, 5.6 +/- 4.7 vs. 12.6 +/- 7.5 mg, P < 0.0001). Operative and postoperative (48 h) blood loss was modestly decreased in the treated group. Epidural-like distribution of anesthesia occurred in 3 of 28 plexus group patients, but no other side-effects were noted. 相似文献