“…Mennella and Zangrillo (2011) categorized risk factors into patient-related factors, procedure-related factors and postoperative care-related factors [10]. Patient-related risk factors include old age especially those above 70 years [11,12], morbid obesity [13,14], smoking [12,15,16], diabetes [17], and symptomatic lung diseases [10,18,19]. Procedure-related risk factors include anesthesia [10,20,21], type of cardiac surgery [4], surgical incision [22], use of topical cooling [10,21], and cardiopulmonary bypass machine [21–24].…”