One lung ventilation (OLV) has become a standard procedure for the vast majority of interventions in pulmonary surgery. It is used in both techniques: thoracotomy and videothoracoscopy (VATS)(1).~OLV can be provided by double lumen tube (DLT) or bronchial blocker. There are advantages and disadvantages of both techniques, but DLT is more recommended because it allows total emptying of the operated lung. Air and secretion can be aspirated through the wide lumen of the tube during the surgery (2, 3).~There are many kinds of DLT which differ according to shape and material. Most commonly used are left sided DLT which are placed into left main bronchus and right or left lungs can be closed or emptied. Left sided tube have a hook which is placed on the carina to prevent displacement of the tube. There are also DLT without the hook which are more gentle and easier to place in the left main bronchus (4,5). After the insertion of the left tube without the hook, bronchoscopy is recommended to check the position of the tube (6,7,8,9).~Some severe complications (injury of the bronchial tree) after insertion of the hooked tube are found in the literature (10). The investigators have published such complication from our experience (11).~Each anesthesiologist decides individually which kind of DLT to use as there are no studies which have objectivised the advantage of either technique. There is only one study where they have compared both techniques but they have found no difference. That is why the investigators decided to study which technique is better so this can be included in our standard operative procedure.
One lung ventilation (OLV) has become a standard procedure for the vast majority of interventions in pulmonary surgery. It is used in both techniques: thoracotomy and videothoracoscopy (VATS).~OLV can be provided by double lumen tube (DLT) with or without the hook. In our study the investigators want to find out if there is any advantage with one or another.