Titles in the Pocket Tutor series give practical guidance on subjects that medical students and foundation doctors need help with ‘on the go’, at a highly-affordable price that puts them within reach of those rotating through modular courses or working on attachment.   Topics reflect information needs stemming from today’s integrated undergraduate and foundation courses: Common presentations Investigation options (e.g. ECG, imaging) Clinical and patient-orientated skills (e.g. examinations, history-taking) The highly-structured, bite-size content helps novices combat the ‘fear factor’ associated with day-to-day clinical training and provides a detailed resource that students and junior doctors can carry in their pocket.    Key points All hospital doctors deal with ABGs (arterial blood gases) but knowledge is commonly assumed and students lack confidence interpreting them Logical, sequential content: relevant basic science, understanding normal results and the building blocks of abnormal results, then clinical disorders Clinical disorders illustrated by representative test results and brief accompanying text that clearly identifies the defining feature of the result (in other words, what is it that makes this diabetic ketoacidosis?) Fully-updated second edition features new sections on capillary blood gases, venous blood gases, obesity and all illustrations now in full colour