This case represents various important lessons. First, one should follow algorithmic approach when evaluating for the cause of air leak (Fig. 5). The assessment should begin either from the patient end or ventilator end, so that all possible causes can be easily identified. From the patient end, when we assess, we look for the endotracheal or tracheostomy cuff for cuff leak. Cuff pressure can be checked with Lange’s pressure monitor. It can become a part of routine monitoring of patients. The catheter mount which has a flip valve can be the commonest site for air leak. The HME (heat moisture exchanger) filter which has a CO2 sampling port, if open, can cause air leak. Then, check the ventilator circuit and water traps. The attachment of ventilator circuit to the ventilator can be loose and may get disconnected. With the help of imaging such as CXR, ultrasound, or CT scan, one can identify the anatomical and parenchymal lung diseases causing air leak. If the patient has ICD (intercostal drain), if it is not positioned properly, one of the ports can be in the subcutaneous plane and can lead to air leak. In the patient of chest trauma, the presence of open chest wound can lead to inadequate minute ventilation due to air leak.
Regarding this particular case, malpositioning of Ryle’s tube was the cause of air leak. It is not a routine practice across all the hospitals to confirm Ryle’s tube position by CXR. The confirmation by auscultation with insufflation of air method is not specific to confirm the placement of tube as the test may be false positive, and also, it may not ensure the correct positioning of Ryle’s tube [1].
In the evaluation of air leak in patients requiring mechanical ventilation as shown by Gonzalez et al., air leak can cause persistent hypercapnia, and one can take practical measures to reduce the volume of air leak [2]. McInnis et al. described, a rare case of air leak due to esophageal malignancy invading the left main bronchus [3]. Lazarus et al. described the bronchoscopic management for persistent air leak [4]. There are various causes for persistent air leak in post thoracic surgery patients. Cerfolio’s classification is used for the grading of air leaks. Dugan et al. explained various methods used in the management of such patients [5].
Identification of correct etiology is important, in order to decide about the further plan of management. In our case, it was a malpositioned Ryle’s tube which led to air leak. Doing CXR for confirmation of tubes and catheters is required. Especially, in case of Ryle's tube, as auscultation is not enough to confirm the position, CXR is considered as an optimum and feasible method [1]. The article by Fan et al. describes various methods for the confirmation of Ryle’s tube position and advantages and disadvantages of each [1].