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The purpose of this investigation was to compare the efficacy of three different cardiopulmonary resuscitation techniques: (a) standard cardiopulmonary resuscitation (CPR), (b) active compression-decompression cardiopulmonary resuscitation (ACD-CPR) with the rescuer standing beside the patient (ACD-B), and (c) ACD-CPR with the rescuer in a standing position over the patient (ACD-S). The physiological responses of the rescuers when performing these techniques were also evaluated. A total of 14 experienced professional rescuers of a mobile intensive care unit (32 ± 6 years), participated in this investigation. On 3 different days (randomised order), each of them performed on a manikin (a) CPR, (b) ACD-B, and (c) ACD-S. Parameters indicative of both CPR performance (time to exhaustion, compression depth and efficacy), and rescuers' physiological responses (blood lactate; minute ventilation (VE); heart rate (HR); oxygen uptake V(O2); respiratory exchange rate (RER); and percentage of V(O2max) were monitored during the trials. The main findings of this investigation were: (a) the evidence of a greater physiological load for the rescuers during the ACD-CPR techniques compared to CPR, which caused a longer performance time with CPR as compared to ACD-CPR; (b) the overall absence of physiological differences between ACD-B and ACD-S; and (c) a modest decrease in mechanical efficacy for ACD-S when compared to ACD-B. Sin financiación 1.555 JCR (1998) Q2, 6/21 Emergency medicine and critical Care UEM

The aim of the present investigation was to evaluate the influence of the physical fitness of a cardiopulmonary resuscitation (CPR) provider on the performance of and physiologic response to CPR. To this end, comparisons were made of sedentary and physically active subjects in terms of CPR performance and physiologic variables. Two study groups were established: group P (n = 14), composed of sedentary, professional CPR rescuers (mean [± SD]; age, 34 ± 6 years; V̇O2max, 32.5 ± 5.5 mL/kg/min), and group Ex (n = 14), composed of physically active, nonexperienced subjects (age, 34 ± 6 years; V̇O2max, 44.5 ± 8.5 mL/kg/min). Each subject was required to perform an 18-min CPR session, which involved manual external cardiac compressions (ECCs) on an electronic teaching mannequin following accepted standard CPR guidelines. Subjects' gas exchange parameters and heart rates (HRs) were monitored throughout the trial. Variables indicating the adequacy of the ECCs (ECC depth and the percentage of incorrect compressions and hand placements) also were determined. Overall CPR performance was similar in both groups. The indicators of ECC adequacy fell within accepted limits (ie, an ECC depth between 38 and 51 mm). However, fatigue prevented four subjects from group P from completing the trial. In contrast, the physiologic responses to CPR differed between groups. The indicators of the intensity of effort during the trial, such as HR or percentage of maximum oxygen uptake (V̇O2max) were higher in group P subjects than group Ex subjects, respectively (HRs at the end of the trial, 139 ± 22 vs 115 ± 17 beats/min, p < 0.01; percentage of V̇O2max after 12 min of CPR, 46.7 ± 9.7% vs 37.2 ± 10.4%, p < 0,05). These results suggest that a certain level of physical fitness may be beneficial to CPR providers to ensure the adequacy of chest compressions performed during relatively long periods of cardiac arrest. Sin financiación 0.599 SJR (1999) Q1, 49/200 Cardiology and Cardiovascular Medicine, 8/49 Critical Care and Intensive Care Medicine, 14/78 Pulmonary and Respiratory Medicine UEM

A new method for measuring the absolute efficiency of Isotope Separation On-Line (ISOL) systems is described. The overall efficiency is deduced from the ratio between the rate of the radioactive beam detected after analysis and the rate of incident radioactive beam in the target. It is shown that the unfolding of the different efficiencies, i.e., diffusion, effusion, ionisation and transport allows us to deduce the diffusion constants when the absolute efficiency data is obtained as a function of the target temperature. Using this technique we extracted the fundamental Arrhenius constants for diffusion of Ar and Ne in Carbon targets used in the SIRa experiments at GANIL.

Intact and castrated male rats were injected daily for 10 days, beginning at 35 days of age, with either oil or one of the following steroids: testosterone propionate, dihydrotestosterone benzoate, androsterone acetate, androstenedione, androstandiol, or estradiol benzoate. Doses were 200 micrograms/rat/day for all androgens and 0.5 microgram or 2 micrograms/rat/day for estradiol. Significant increments in prolactin levels (fourfold over control values) in intact and castrated males were obtained after testosterone propionate and androstenedione treatment. Dihydrotestosterone, androsterone, and androstandiol did not induce any changes in either intact or castrated rats. Estradiol-treated males showed a four- and sevenfold increment in serum prolactin with the 0.5- and 2-microgram doses, respectively. These results suggest that androgens have a role in the control of prolactin secretion, particularly those that can be aromatized to estrogens by different tissues, including the hypothalamus.