Background and Goal of Study: 
Anemia is common in patients undergoing thoracic surgery due to three main risk factors including iron deficiency anemia, chronic disease anemia, iatrogenic anemia (1), all of which can be prevented and treated.
The incidence of anemia was found as 26% in a multicenter study involving  patients undergoing cardiac surgery, which increased to 47 % in patients having elective vascular surgery (2). However data on the incidence of preoperative anemia for thoracic surgery are limited (3). We hypotized that the incidance of anemia may be higher than expected, which may be  associated with both perioperative complications.   

Materials and Methods: After obtaining the instutional board approval, this retrospective study enrolled 107 patients older than 18 years who underwent thoracic surgery by a thoracotomy or thoracoscopy between January 2016 and July 2017. We recorded demographic features, pre- and postoperative hemograms and other laboratory tests, comorbidities, the transfusions of blood and blood products, complications, mortality, type of surgery, rate of re-exploration, length of ICU and hospital stay. The patients were classified into two groups according to the presence or absence of anemia. The anemia was defined according to the WHO criteria as a hemoglobin level < 12 g/dL in woman and < 13,0 g/dL in man (4). 
Results and Discussion: The incidence of anemia was 43.9 %, being higher in man with 57,4%. Compared with patients without anemia, patients with anemia had a significantly increased length of hospital stay, higher rate of ICU admission, higher levels of pre- and postoperative creatinine and lower levels of postoperative Hb and Htc and lower value of preoperative INR (p ˂ 0.05, Table 1).
The patients who required ICU admission significantly differed from those who did not in low levels of preoperative Hb, pre- and postoperative Htc and increased duration of operation, hospital stay and intraoperative ES use (p ˂ 0.05, Table 2).

Conclusion(s): Our findings suggest that the incidence of anemia is high in patients undergoing thoracic surgery. Eventhough the rate of mortality is not affected, anemia is associated with a higher rate of ICU admission and longer hospital stay. Additionally an increased intraoperative use of ES is likely to contribute to morbidity by exposing patients to transfusion-associated complications. 
In order to reduce anemia-induced perioperative complications the treatment of anemia during preoperative period should be considered who are candidate for thoracic surgery.
References (optional): 
1.	Karski JM, Mathieu M, Cheng D, Carroll J, Scott G. Etiology of preop- erative anemia in patients undergoing scheduled cardiac surgery. Can J Anaesth. 1999;46:979–982. 
2.	Gupta PK, Sundaram A, Mactaggart JN, Johanning JM, Gupta H, Fang X, Forse RA, Balters M, Longo GM, Sugimoto JT, Lynch TG, Pipinos II. Preoperative anemia is an independent predictor of postoperative mortality and adverse cardiac events in elderly patients undergoing elective vascular operations. Ann Surg. 2013 Dec;258(6):1096-102.
3.	Yovino S, Kwok Y, Krasna M, Bangalore M, Suntharalingam M. An association between preoperative anemia and decreased survival in early-stage non-small-cell lung cancer patients treated with surgery alone. Int J Radiat Oncol Biol Phys. 2005 Aug 1;62(5):1438-43.
4.	World Health Organization. Iron deficiency anaemia: assessment, pre- vention, and control: 2001. Available at: http://whqlibdoc.who.int/hq/ 2001/WHO_NHD_01.3.pdf. Accessed November 21, 2007. 




09 / The effect of preoperative anemia on postoperative morbidity and mortality in patients undergoing thoracic surgery