[High level of student smokers in Madrid compared with a similar previous study of 2014]. / Tabaquismo en los estudiantes de alto nivel académico en la Comunidad de Madrid y comparación con estudio previo similar realizado en 2014.

Smoking is a public health problem that affects young people, and influenced by the environment and cultural level. OBJECTIVES: To determine smoking prevalence among high-level baccalaureate students in the Autonomous Community of Madrid during the 2018-2019 academic year. To assess the influence of the socio-cultural environment on the onset of youth smoking. To compare the results with previous studies conducted on students of baccalaureate of excellence (BE) and the general population. POPULATION AND METHODS: Cross-sectional study on BE students in the Autonomous Community of Madrid. Using an anonymous questionnaire, they were asked about tobacco, alcohol and drug consumption, as well as the influence of the environment, friends, and family in the beginning. To compare with previous studies. RESULTS: A total of 740 valid questionnaires were collected, of which 430 (58.1%) were female, an overall mean age of 16.57±0.61 years, and 53 (7.18%) were smokers. The majority 39 (78%) of smokers acknowledged their friends' influence at its onset. Alcohol was consumed by 349 (47.48%) and other drugs by 109 (15.27%). Being a smoker was related to alcohol, other drugs, a smoking mother, smoking siblings and smoking friends. CONCLUSIONS: Smoking prevalence among students of BE in Autonomous Community of Madrid continues to be lower than the prevalence of adolescents of their age and there are no variations from previous reports. Starting smoking is related to smoking by friends, siblings, and the mother and with the consumption of alcohol and other substances. Education is very important in the beginning and prevention of smoking, and it is necessary to implement prevention programs at early ages in order to promote their effectiveness, and aimed at young people, parents and teachers.

[Validation of segmentation techniques for positron emission tomography using ex-vivo images of oncological surgical specimens]. / Validación de técnicas de segmentación para la tomografía por emisión de positrones mediante imágenes ex-vivo de piezas quirúrgicas oncológicas.

OBJECTIVE: To design a novel ex-vivo acquisition technique to establish a common framework to validate different segmentation techniques for oncological PET images. To evaluate several automatic segmentation algorithms on this set of images. MATERIAL AND METHODS: In 15 patients with cancer, ex-vivo PET studies of surgical specimens removed during surgery were performed after injection of (18)F-FDG. Images were acquired in two scanners: a clinical PET/CT and a high-resolution PET scanner. Real tumor volume was determined in each patient, and a reference image was generated for segmentation of each tumor. Images were segmented with 12 automatic algorithms and with a standard method for PET (relative threshold at 42%) and results were evaluated by quantitative parameters. RESULTS: It has been possible to demonstrate by segmentation of PET images of surgical specimens that on high resolution PET images, 8 out of 12 evaluated segmentation techniques outperformed the standard method, whose value is 42%. However, none of the algorithms outperformed the standard method when applied on images from the clinical PET/CT. Due to the great interest of this set of PET images, all studies have been published on the Internet in order to provide a common framework for validation and comparison of different segmentation techniques. CONCLUSIONS: We have proposed a novel technique to validate segmentation techniques for oncological PET images, acquiring ex-vivo PET studies of surgical specimens. We have demonstrated the usefulness of this set of PET images by evaluating several automatic segmentation algorithms.

Phrenic nerve block caused by interscalene brachial plexus block: effects of digital pressure and a low volume of local anesthetic.

BACKGROUND AND OBJECTIVES: Interscalene brachial plexus block (ISB) is associated with phrenic block and diaphragmatic paralysis when high volumes (40-50 mL) of local anesthetic are injected. The goal of our study was to test if a low volume of local anesthetic administered while maintaining proximal digital pressure might more selectively block the brachial plexus and decrease the frequency of phrenic nerve block. METHODS: Twenty healthy patients undergoing ISB for orthopedic surgery of the upper extremity were randomly allocated to receive either 20 mL 1.5% mepivacaine while proximal digital pressure to the site of puncture was performed, or 40 mL 1.5% mepivacaine without digital pressure. Spirometry and clinical data were evaluated at baseline, 10, and 90 minutes after accomplishing the block and after the motor and sensory block resolved. Diaphragmatic excursion during deep inspiration was also evaluated 90 minutes after the block was performed, with the patient in the sitting position. RESULTS: Interscalene brachial plexus block produced diaphragmatic paralysis in all patients included in the study, as demonstrated by the pulmonary function testing and the chest radiograph. No significant differences were found in any of the parameters studied. At 10 minutes, baseline functional residual capacity had diminished by 34 +/- 10% in the 40 mL group and 37 +/- 13% in the 20 mL group. Maximum cephalad sensory dermatome level was also similar in both groups, being C 3 or above in all patients. Ipsilateral hemidiaphragmatic motion was similar in both groups (3.2 +/- 2.3 cm in the 40 mL group and 2.6 +/- 1.7 cm in the 20 mL group). However, in no case was dyspnea manifested. CONCLUSIONS: Decreasing the volume of local anesthetic and applying proximal digital pressure to the site of injection is not effective in reducing the cervical block spread and the frequency or intensity of diaphragmatic paralysis during interscalene ISB.