1	antithrombocytic agent/ or acetylsalicylic acid/ or anticoagulant agent/
2	(anti?platelet* or anti platelet* or anti?thrombo* or anti thrombo* or anti?coagulant or anti coagulant or aspirin* or clopidogrel or prasugrel or ticagrelor or ticlopidine or (platelet and aggregation and inhibitor*) or (anti and thrombosis)).mp.
3	1 or 2
4	general surgery/
5	(surgery or (operative and procedure*) or (operative and surgical and procedure*) or (surgical and procedure*)).mp.
6	4 or 5
7	exp bleeding/ or bleeding.mp. or ischaemic.mp.
8	3 and 6 and 7
9	((crossover procedure or double blind procedure or single blind procedure).sh. or (crossover* or cross over*).ti,ab. or placebo*.ti,ab,sh. or (doubl* adj blind*).ti,ab. or (controlled adj3 (study or design or trial)).ti,ab. or allocat*.ti,ab. or trial*.ti,ab. or randomized controlled trial.sh. or random*.ti,ab.) not ((exp animal/ or animal.hw. or nonhuman/) not (exp human/ or human cell/ or (human or humans).ti.))
10	8 and 9