Selected ICUs will, following consent, also undertake blood and urine sampling on days 1, 3 and 5 for genomic, proteomic and metabolomic studies. Information will be recorded on a bar−coded paper clinical report form (CRF) at the bedside. The CRFs will be securely stored locally and copied to the research coordinator, where they will be archived. The data will be entered independently by the research coordinator and one of the investigators into a secure, central web−based electronic database for storage of clinical data and the calculation of derived values. The patient codes for genetic analysis will be derived directly from the clinical database. Those undertaking genotyping will be blinded to the clinical details and these two databases will be brought together at the time of analysis only under the direct supervision of one of the principal investigators.