PERSISTENT AIR LEAK WITH INFLATED PILOT BALLOONProperly securing the airway with endotracheal tube (ETT) is an important part of general anaesthesia practise. Examining the endotracheal cuff for proper functioning prior to intubation is a common practice. Problems with the one way inflation valve, inflation tube, pilot balloon and cuff can be easily detected with simple testing. However, some ETT manufacturing defects may go undetected prior to intubation. Here we report a case of air leak in a patient with an intact ETT inflation system.CASE REPORTA xx years old female patient was posted for a routine XXXXXXXXXX surgery under general anaesthesia. Induction was done using propofol, fentanyl, atracurium and the patient was intubated with a 7.5 mm internal diameter (ID) endotracheal tube, cuff was inflated and tube fixed at 21 cm . An audible leak was heard from the patient after intubation. The pilot balloon was again inflated with additional 2 ml of air in case the tube was of smaller size and the leak was occuring from the edges, but the leak still persisted. Using an aneroid manometer, the pilot balloon pressure was checked and was found to be 28 cm of water. Check laryngoscopy was done to confirm proper position of the cuff was done. We found that black line was just below the level of vocal cord and the cuff was in proper position. We decided to change the the endotracheal tube and inserted a new ET tube with same ID. cuff was inflated and pressure was checked with the manometer. After the change of ETT, no leak was found and anaesthesia was maintained adequate throughout on the procedure. The pt was extubated on completion of the procedure. On examining the initial ETT we could not find any visible defect. To further check for any defect we submerged the tube under water, while occluding the distal end and connected the proximal end to ambu. We found source of bubbling near the site of inflation line entering the ETT. DISCUSSIONManufacturing defects are still commonly encountered by an anaesthesiologist in their routine practise.1-4 Some of the defects can be easily detected with visual inspection and test inflation of the cuff prior to insertion. There are some concerns regarding checking of sterile endotracheal tube prior to intubation as some contamination may occur leading to infection. However a statement approved by ASA house delegates stated that packed endotracheal tubes can be opened and checked for cuff detects and replaced into the packaging. Such repacked tube can be safely used later uptil 48 hours.5Most commonly the site of air leaks are localized to the one way valve, pilot balloon, inflation line or cuff can be detected promptly if ETT tube is checked prior to intubation. Some defects may not be noticed even on inspection as was in our case.Generally leak may occur either due to defect in cuff inflation system or may occur with an intact inflation system.6 Leaks with an intact inflation system may be due to migration of ETT upwards, inadequate inflation of cuff, malposition of oropharyngeal tube into trachea, insertion of smaller size tube, abnormal shape of the cuff and high peak airway pressure. In case a leak is detected, a stepwise approach to ascertain the site of leak should be followed. This includes checking of the cuff for deflation. In case the cuff system is normal, ETT position should be checked using laryngoscopy/bronchoscopy should be tried. over inflation of cuff can be tried in case leaks around cuff is detected. packing of airway and decreasing the peak pressure can also be attempted. In case of leak still persists, replacement of ETT during surgery should be done.In this case we could not detect the manufacturing defect even after visual inspection and cuff inspection. Pasupuleti et al reported a case of air leak with intact cuff system in a case of disposable 7mm flexometallic ETT.7 They found a defect near the insertion of inflation tube on ETT, which became more pronounced on straightening the tube. These reports indicate that these type of defects maybe be present in all types of ETT tube and may not become apparent even after thorough preinduction inspection of ETT, highlighting the importance of a stepwise approach for diagnosing of the cause of the leak and steps taken to correct the leak.CONCLUSION In case of occult air leak from the ETT a stepwise approach to detect and correct the source of the leak should be done by the anaesthesiologist including following the recommended ASA guidelines for checking the anesthesia workstation and airway equipment prior to induction. REFERENCESSingha SK, Kujur S. Unusual manufacturing defect of the endotracheal tube: Problem revisited. Indian J Crit Care Med. 2016 Feb; 20(2): 130–131.Baldemir R, Akçaboy Y, Akçaboy ZN, Gö?ü? N. Endotracheal Tube Obstruction: A Manufacturing Defect. Turk J Anaesthesiol Reanim. 2015 Feb; 43(1): 62–64.Sofi K, El-Gammal K. Endotracheal tube defects: Hidden causes of airway obstruction. Saudi J Anaesth. 2010 May-Aug; 4(2): 108–110.Goyal R, NarmadhaLakshmi K. Endotracheal tube cuff leak: Minor product defect or lack of cuff pressure monitoring? Indian J Crit Care Med. 2015 Jun; 19(6): 362–363.Statement on the Standard Practice for Infection Prevention and Control Instruments for Tracheal Intubation. American Society of Anesthesiology, Committee of Origin: Committee on Quality Management and Departmental Administration (QMDA). Approved by the ASA House of Delegates on October 20, 2010, and last amended on October 28, 2015. Retrieved from: http://www.asahq.org/~/media/sites/asahq/files/public/resources/standards-guidelines/statement-on-standard-practice-for-infection-prevention-for-tracheal-intubation.pdf.El-Orbany M, Salem MR. Endotracheal tube cuff leaks: causes, consequences, and management. Anesth Analg. 2013 Aug;117(2):428-34. Pasupuleti H, Samantaray A, Surapneni K, Natham H. Air leak with intact cuff inflation system: A case report with brief review of literature. Indian J Anaesth. 2015 Nov; 59(11): 760–761.