An algorithm for difficult double lumen tube placement and troubleshooting a malpositioned double lumen tube harnessing A, B, Cs of lung isolation

Abstract

INTRODUCTION Double lumen tubes (DLTs) remain the gold-standard lung isolation devices to prevent soilage (abscess, blood) of the normal lung or control ventilation in certain thoracic surgeries (bronchopleural fistula, lung-resection, oesophagectomy, etc.).[1] Optimal DLT placement is an art and science garnered by practice and learning from the experience of others. DLTs have evolved from bulky red-rubber devices with carinal hooks (left-sided Carlen’s catheter; right-sided White’s catheter) to roomier lumens (Bryce-Smith, Robertshaw) and modern disposable tubes (Bronchocath; Sheridan; Portex). Broadly, difficulty in DLT placement may be encountered at four levels: difficulty in manoeuvering the tip of DLT to glottis; DLT impaction at glottis; DLT impaction at cricoid cartilage/bronchial opening and DLT entering the wrong bronchus. We have devised from our clinical experience, an algorithm with stepwise instructions on how to proceed in each of these situations [Figure 1], incorporating recent advances like video laryngoscope-guided DLT insertion,[2] augmentation of the curved bronchial lumen tip of the left-sided DLT to reduce misplacement into the right bronchus,[3] two novel DLTs that do not require a fibreoptic bronchoscope (FOB) for correct positioning and certain bronchial blockers (BBs).[45] Importance of preoxygenation and monitoring vital parameters throughout the procedure cannot be over-emphasised. Re-examination of the DLT/BBs using a bronchoscope after lateral positioning is necessary.Figure 1: Algorithm for managing difficult DLT placement for one-lung ventilation. (BB = Bronchial blocker; DLT = Double lumen tube; FOB = Fibreoptic bronchoscope; LT = Left; RT = Right; SLT = Single lumen tube; BP=Bronchopleural)DISCUSSION Some of the algorithmic steps merit further explanation. C-Mac D-blade guided DLT placement The D-blade is known to improve glottic visualisation, improving the Cormack–Lehane grade by at least one grade compared to a normal blade. The distal concavity of the DLT is shaped as per the D-blade concavity, and the DLT blue/bronchial cuff can be visualised on the monitor as it disappears through the vocal cords. Although the rest of the procedure beginning with anticlockwise rotation of the DLT is still blind, this technique has the added advantage of reduced cuff rupture.[2] The incidence of wrong-sided placement is slightly higher but is easily rectified using the FOB. Ambu VivaSight DLT These DLTs are an improvement over the blind insertion techniques and have an integrated camera attached at the distal end of the tracheal lumen via which each step of DLT placement is displayed on the designated monitor screen.[4] Ankor three-cuffed DLT These may be advantageous where FOB is unavailable/cannot pass through the narrow-lumen DLT (<32 French). Besides the routine tracheal and bronchial cuffs, a third carinal cuff is provided. After the disappearance of the deflated blue cuff through the vocal cords and anticlockwise rotation of the left DLT, the carinal cuff is inflated via the carinal pilot balloon and this third cuff blocks the right bronchial opening, so that the bronchial DLT lumen is directed to the left main bronchus. Once positioned, the tracheal and bronchial cuffs are inflated and the carinal cuff is deflated.[5] Bronchial blockers (BBs) They are useful options when difficult anatomy precludes proper DLT placement. BBs may have a single/double cuff and may come with/without a designated single lumen tube (SLT). We describe here the most useful ones (a prototype of each category) for the anaesthesiologists’ armamentarium. Lung isolation using BB and DLT in combination has also been reported.[6] Single-cuff bronchial blocker (Coopdech BB) After tracheal intubation with a 7.5 mm SLT, a FOB is inserted through SLT followed by a Coopdech BB. Once the BB is 2 cm above the carina, it is rotated 90° clockwise to enter the right bronchus or anticlockwise to enter the left bronchus.[7] If unsuccessful