Single lung ventilation, also known as 'One Lung' ventilation, is a method of ventilation which was first conceptualized by physiologists Eduard Pflüger and Claude Bernard who studied gas exchange in dogs using a lung isolation catheter. Wolffberg isolated the two lungs using the catheter in 1871 which is the first reported concept of an endobronchial single-lumen tube. The first instance of clinical use in humans was by Loewy and von Schrotter with lower lobe bronchus catheterized under fluoroscopic control. Head designed the first double-lumen tube in 1889 which had two tracheal cannulas - one short tracheal and one longer endobronchial one. Gale and Walters in 1932 advanced Head's design and created the prototype for the modern-day double-lumen tubes. Double lumen tubes paved the way for one-lung ventilation offering better control of ventilation and more efficient separation of the two lungs. Single lung ventilation involves ventilating one lung and letting the other collapse for providing surgical exposure in the thoracic cavity or isolating ventilation to one lung. The protective role of the single lung ventilation involves protecting one lung from the ill effects of fluid from the other lung - which may be blood, lavage fluid, malignant or purulent secretions. Thus it is prudent to ensure perfect placement of the tube as a misplaced tube defeats the goals of lung isolation or differential ventilation. This is ensured by bronchoscopy done after tube placement and after any position changes thereafter. One lung ventilation is used to facilitate a wide variety of procedures on ipsilateral thoracic or mediastinal structures as well as to provide lung isolation; this is made possible by the use of double-lumen tubes, bronchial blockers, and endobronchial tubes. Familiarity with the use of these instruments and the physiology of one-lung ventilation is essential to the performance of safe anesthesia. This information can be published in our peer-reviewed journal with impact factors and are calculated using citations not only from research articles but also review articles (which tend to receive more citations), editorials, letters, meeting abstracts, short communications, and case reports. The inclusion of these publications provides the opportunity for editors and publishers to manipulate the ratio used to calculate the impact factor and try to increase their number rapidly. Impact factor plays a major role for the particular journal. Journal with higher impact factor is considered to be more important than other ones.