Time and space scattered volcanism of Mt. Etna driven by strike-slip tectonics.

High-resolution seismic reflection, magnetic and gravity data, acquired offshore of Etna volcano, provide a new insight to understanding the relationship between tectonics and spatial-temporal evolution of volcanism. The Timpe Plateau, a structural high pertaining to the Hyblean foreland domain, located offshore of southeastern Mt. Etna, is speckled by volcanics and strongly affected by strike-slip tectonics. Transpressive deformation produced a push-up and a remarkable shortening along WNW-ESE to NW-SE trending lineaments. Fault segments, bounding basinal areas, show evidence of positive tectonic inversion, suggesting a former transtensive phase. Transtensive tectonics favoured the emplacement of deep magmatic intrusive bodies and Plio-Quaternary scattered volcanics through releasing zones. The continuing of wrench tectonics along different shear zones led to the migration of transtensive regions in the Etna area and the positive inversion of the former ones, where new magma ascent was hampered. This process caused the shifting of volcanism firstly along the main WNW-ESE trending "Southern Etna Shear Zone", then towards the Valle del Bove and finally up to the present-day stratovolcano.

Nitric oxide test during cardiac catheterization decreases the serum concentrations of S100B protein in adult patients with idiopathic pulmonary hypertension.

OBJECTIVE: Cardiac catheterization (CC) is a life-threatening procedure in adult patients. Complicated by idiopathic arterial pulmonary hypertension (IPAH), there is a potential risk of central nervous system (CNS) damage. We measured serum levels of a well-established brain damage marker, namely S100B, collected before, during and after CC in adult patients in whom the nitric oxide (NO) test had been performed. MATERIAL AND METHODS: In 12 adult patients who had undergone CC for IPAH diagnosis, we recorded clinical and standard monitoring procedures (laboratory variables and echocardiographic patterns) and serum concentrations of S100B before (time 0), during (time 1) and after the NO test (time 2) and at 24 h after (time 3) the procedure in samples obtained from the systemic and pulmonary circulation. Patients were subdivided into NO test responders (n=6) and non-responders (n=6). Neurological evaluation was performed at admission and at discharge from hospital. RESULTS: Adult patients subjected to CC showed no overt neurological injury at discharge from hospital. No significant differences (p > 0.05 for all) in S100B serum levels between groups at times 0, 1 and 3 have been shown independently from the sampling site. It was noteworthy that the concentration of protein in the responders group at time 2 was significantly decreased (p < 0.05, for all) compared to the responder group and to baseline values. A significant correlation was found between arterial oxygen partial pressure and individual S100B concentration in the pulmonary and systemic bloodstream in the entire study group (R = -0.66 and R = 0.71, respectively; p < 0.05, for both). CONCLUSIONS: The data suggest that S100B protein assessment, as well as the NO test, may be useful when monitoring possible CNS damage during CC in patients with IPAH, and may also be valuable in relation to brain functions, especially when performed as an emergency procedure in severely hypoxic patients.

The development and evaluation of new versions of the written examination for the American Heart Association Advanced Cardiac Life Support provider course.

STUDY OBJECTIVE: To create new versions of the written, multiple-choice examination used in the American Heart Association (AHA) Advanced Cardiac Life Support course, evaluate their reliability and difficulty, and then design revised versions with improved reliability and of standardized difficulty. DESIGN: Psychometric evaluation of new versions of the AHA Advanced Cardiac Life Support test and revisions. SETTING: AHA Advanced Cardiac Life Support courses. PARTICIPANTS: Candidates for completion of AHA Advanced Cardiac Life Support provider courses in five states. INTERVENTION: The course content was divided into 11 content areas that were weighted for importance and appropriateness for testing in a multiple-choice format. The weights were used to construct a blueprint for a 50-question, multiple-choice examination. Five versions of the examination were then constructed based on the content blueprint, drawing from new questions and expert revision of previously written questions. Reliability and difficulty were assessed using 915 administrations at five different sites nationwide. The initial test versions differed in their degree of difficulty, which was not explained by demographic factors. The results were used to revise three of the versions to improve reliability and equalize difficulty of the versions. MEASUREMENTS AND MAIN RESULTS: The final five versions have estimated reliability ranging from Cronbach's alpha of .62 to .86. Mean scores ranged from 87.4% to 89.1%. CONCLUSION: After field testing and revision, five examinations with acceptable reliability and roughly equal difficulty were constructed. The new examinations test the participants' knowledge of important aspects of resuscitation science and practice based on a blueprint of the course content.

New developments in cardiopulmonary resuscitation.

Since the last revision of the American Heart Association's guidelines in 1985, several new developments of clinical importance have occurred in the field of cardiopulmonary resuscitation. These include enhanced access to and earlier use of defibrillation, the use of high-dose epinephrine when standard doses fail, the assessment of resuscitative efforts with end-tidal CO2 monitoring and the addition of two new drugs, amiodarone (for refractory ventricular fibrillation) and adenosine (for paroxysmal supraventricular tachycardia). Time will determine the ultimate role of these advancements in the management of cardiac arrest.

Pneumomediastinum, pneumothorax, and subcutaneous emphysema after alternate cocaine inhalation and marijuana smoking.

Previous reports have indicated the association of marijuana and cocaine abuse along with prolonged Valsalva maneuvers and the use of positive pressure devices. In most cases, the use of a single drug has been related to barotrauma. We present an adolescent male who developed this complication after alternate use of marijuana and cocaine without positive pressure devices. The increasing problem of drug abuse in the adolescent population in the United States is known to all of us. Clinicians who deal with adolescent patients should include questioning about drug abuse in the standard evaluation of chest pain.

Automatic and semiautomatic external defibrillator/pacers: futuristic emergency devices.

Automatic and semiautomatic defibrillator/pacers are new devices that combine many of the functions of an ECG unit, an external pacemaker, and a defibrillator into one unit with a built-in logic system. These devices are well researched and are gaining acceptance by the American Heart Association, emergency room physicians, and others concerned with emergency treatment of cardiac arrest, fibrillation, and potentially fatal dysrhythmias. These instruments are dependable, easy to use, and may in the future have a potential value for some dental practitioners who treat high risk cardiac patients or those using deep sedation and general anesthesia.

Objectifying testing of the MEGA CODE station: a system of shorthand.

We have developed a system of shorthand for MEGA CODE that allows advanced cardiac life support (ACLS) instructors to record accurately the events of simulated codes as they occur in the teaching and testing of this station. The method is easy to learn. Incorporation of the method into the ACLS provider course would enable instructors to more accurately reconstruct arrest scenarios and facilitate the process of providing the student with meaningful feedback. The instructor's flexibility in making up the code is maximized, and a lasting document of a student's performance is produced.

Comparison of two techniques for detecting cardiac activity in infants.

In the 1980 Standards and Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiac Care, the recommended method for determining cardiac arrest in infants was changed from palpation of the apical impulse to palpation of the brachial pulse. The importance of adequately assessing the heart beat before initiating chest compressions due to the potential hazards is well established. This study was designed to ascertain which pulse parents could palpate most readily and accurately count within a given time. The results demonstrated the brachial pulse was much easier to palpate and more accurately counted by parents than the apical impulse. These findings formed the basis for the 1980 revised recommendation for determining cardiac arrest in infants.