In this month's Archimedes podcast, section editor Bob Phillips discusses the ADC blog series on the basics of evidence based medicine http://goo.gl/CQM4P8 and two questions regarding diagnostic cerebral catheterisation http://goo.gl/ulmSr6 and measuring serum sodium from capilliary blood samples http://goo.gl/uAFhKH. There's also a bonus treat of a haematological top tip.