Editing Perioperative mortality (section)

===Lungs===
Many factors can influence the risk of postoperative pulmonary complications (PPC).  (A major PPC can be defined as a postoperative pneumonia, respiratory failure, or the need for reintubation after extubation at the end of an anesthetic.  Minor post-operative pulmonary complications include events such as atelectasis, bronchospasm, laryngospasm, and unanticipated need for supplemental oxygen therapy after the initial postoperative period.) <ref>{{cite journal | vauthors = Cook MW, Lisco SJ | title = Prevention of postoperative pulmonary complications | journal = International Anesthesiology Clinics | volume = 47 | issue = 4 | pages = 65–88 | year = 2009 | pmid = 19820479 | doi = 10.1097/aia.0b013e3181ba1406 | s2cid = 9060298 }}</ref>  Of all patient-related risk factors, good evidence supports patients with advanced age, ASA class II or greater, functional dependence, chronic obstructive pulmonary disease, and congestive heart failure, as those with increased risk for PPC.<ref name="Smetana 2006 581–595">{{cite journal | vauthors = Smetana GW, Lawrence VA, Cornell JE | title = Preoperative pulmonary risk stratification for noncardiothoracic surgery: systematic review for the American College of Physicians | journal = Annals of Internal Medicine | volume = 144 | issue = 8 | pages = 581–95 | date = April 2006 | pmid = 16618956 | doi = 10.7326/0003-4819-144-8-200604180-00009 | s2cid = 7297481 | doi-access =  }}</ref>  Of operative risk factors, surgical site is the most important predictor of risk for PPCs (aortic, thoracic, and upper abdominal surgeries being the highest-risk procedures, even in healthy patients.<ref>{{cite journal | vauthors = Smetana GW | s2cid = 20581319 | title = Postoperative pulmonary complications: an update on risk assessment and reduction | journal = Cleveland Clinic Journal of Medicine | volume = 76 | issue = Suppl 4 | pages = S60-5 | date = November 2009 | pmid = 19880838 | doi = 10.3949/ccjm.76.s4.10 | doi-access = free }}</ref>  The value of preoperative testing, such as spirometry, to estimate pulmonary risk is of controversial value and is debated in medical literature.  Among laboratory tests, a serum albumin level less than 35 g/L is the most powerful predictor and predicts PPC risk to a similar degree as the most important patient-related risk factors.<ref name="Smetana 2006 581–595"/>

[[Respiratory therapy]] has a place in preventing [[pneumonia]] related to [[atelectasis]], which occurs especially in patients recovering from thoracic and abdominal surgery.{{Citation needed|date=August 2011}}.