The incidence of peri-operative pulmonary complications varies, depend
ing on surgery and patient related determinants. Risk factors include
upper abdominal or thoracic surgery, duration of anaesthesia, age, obe
sity, smoking history and underlying respiratory diseases such as COPD
. The preoperative evaluation of patients undergoing general surgery i
s predominantly based on medical history and physical examination. A p
reoperative chest radiograph and pulmonary function tests are indicate
d in some high risk patient groups, and in all patients about to under
go lung resection surgery. If in this latter group, the preoperative l
ung function is severely compromised, a quantitative perfusion scan an
d exercise testing may be useful for the assessment of the operative r
isk. Prevention of postoperative pulmonary complications should begin
with discontinuation of smoking at least 8 weeks prior to surgery. In
high risk patients preoperative chest physiotherapy, including incenti
ve spirometry, is clearly beneficial.