Table 1.

Investigations at preoperative assessment²

Investigation	ASA 1	ASA 2	ASA 3–5
Full blood count	Minor surgery: not routinely Major surgery: yes	Minor surgery: not routinely Major surgery: yes	Minor surgery: not routinely Major surgery: yes
Urea and electrolytes	Minor surgery: not routinely Major surgery: yes	Minor surgery: not routinely Major surgery: yes	Minor surgery: If at risk of acute kidney injury Major surgery: yes
Coagulation screen	Minor surgery: not routinely Major surgery: not routinely	Minor surgery: not routinely Major surgery: not routinely	Minor surgery: not routinely Major surgery: discuss with consultant anaesthetist
ECG	Minor surgery: not routinely Major surgery: not routinely	Minor surgery: not routinely Major surgery: not routinely	Minor surgery: discuss with consultant anaesthetist Major surgery: discuss with aconsultant anaesthetist