Case-control study of arsenic in drinking water and kidney cancer in uniquely exposed Northern Chile.

Millions of people worldwide are exposed to arsenic in drinking water. The International Agency for Research on Cancer has concluded that ingested arsenic causes lung, bladder, and skin cancer. However, a similar conclusion was not made for kidney cancer because of a lack of research with individual data on exposure and dose-response. With its unusual geology, high exposures, and good information on past arsenic water concentrations, northern Chile is one of the best places in the world to investigate the carcinogenicity of arsenic. We performed a case-control study in 2007-2010 of 122 kidney cancer cases and 640 population-based controls with individual data on exposure and potential confounders. Cases included 76 renal cell, 24 transitional cell renal pelvis and ureter, and 22 other kidney cancers. For renal pelvis and ureter cancers, the adjusted odds ratios by average arsenic intakes of <400, 400-1,000, and >1,000 µg/day (median water concentrations of 60, 300, and 860 µg/L) were 1.00, 5.71 (95% confidence interval: 1.65, 19.82), and 11.09 (95% confidence interval: 3.60, 34.16) (Ptrend < 0.001), respectively. Odds ratios were not elevated for renal cell cancer. With these new findings, including evidence of dose-response, we believe there is now sufficient evidence in humans that drinking-water arsenic causes renal pelvis and ureter cancer.

Bloqueo supraclavicular bilateral con ecografía / Bilateral supraclavicular blockade with ultrasound

El manejo analgésico de los pacientes con trauma bilateral de hombro o tercio proximal del brazo es difícil. La estrategia multimodal basada en administración de anestésicos locales en el plexo braquial parece ser la más efectiva, pero hacer bloqueos bilaterales tiene riesgos asociados, como son: la parálisis del nervio frénico, la toxicidad por anestésicos locales y el neumotórax bilateral. Estos pueden ser disminuidos con una aproximación supraclavicular al plexo braquial y el uso de ultrasonografía. Describimos el manejo de un paciente con trauma bilateral de hombro y tercio proximal de húmero, quien es llevado a cirugía de osteosíntesis bilateral de húmero y presenta dolor postoperatorio severo que no responde a dosis altas de opiáceos y antiinflamatorios. Es manejado inicialmente con bloqueo supraclavicular bilateral guiado por ecografía con volumen bajo de anestésico local y posteriormente administración continua de bupivacaína, con una valoración del dolor de 2/10 a las 24 h y 3/10 a las 48 h. Concluimos que el bloqueo supraclavicular bilateral es una opción para el manejo del dolor agudo en cirugía de hombro y tercio proximal de húmero. La administración continua de anestésicos locales al plexo braquial contribuye a mantener la respuesta analgésica.

Analgesic management in patients with bilateral trauma to the shoulder or the proximal third of the arm is difficult. The multimodal strategy based on the administration of local analgesics to the brachial plexus appears to be the most effective; however, there are risks associated with bilateral blocks, including phrenic nerve palsy, toxicity due to local anesthetics, and bilateral pneumothorax. These risks may be diminished using an ultrasound-guided supraclavicular approach to the brachial plexus. This paper describes the management of a patient with bilateral injury to the shoulder and the proximal third of the humerus. The patient is taken to bilateral humeral fixation surgery and develops severe post-operative pain which does not respond to high-dose opioids and anti-inflammatory agents. He is managed initially with bilateral ultrasound-guided supraclavicular block using a low volume of a local anesthetic followed by continuous administration of bupivacaine. Pain assessment was 2/10 at 24 hours and 3/10 at 48 hours. We concluded that bilateral supraclavicular blockade is an option in the acute management of pain after surgery to the shoulder and the proximal third of the humerus. Continuous administration of local anesthetics to the brachial plexus helps maintain the analgesic response.