Prevention of migration of endotracheal tubes used for aided nasogastric tube placement in anaesthetized patients.

Sir,

During bariatric surgery procedures, the anaesthesiologists help facilitate proper placement of nasogastric tubes (NGTs) and bougies to size the gastric pouch. They help perform leak tests with saline, methylene blue or air to ensure staple-line or anastomotic integrity. They ensure complete removal of all gastric tubes before gastric division to avoid unplanned stapling and transection of these tubes. After the surgery is performed, they re-insert the NGT tube under vision watching the monitor carefully while the tube is advanced to avoid disruption of the anastomosis.

NGT insertion in an anaesthetised patient is however a very cumbersome procedure for the anaesthesiologist with the need to burrow under sterile drapes to approach the oral cavity and the need to use a laryngoscope and Magill's forceps to advance the tube 1–2 cms at a time to avoid coiling in the oropharynx because of the flexibility and slippery nature of a lubricated NGT through the compromised lumen of the oesophagus secondary to the inflated endotracheal bulb.[1] Several techniques to simplify this procedure have been recommended in the literature.[234567] Of these a quick and easy way often adopted intra-operatively by many anaesthesiologists is to pass a paediatric endotracheal tube (ETT) nasally and a NGT is passed down this tube directly to the oesophagus without coiling or trauma.[234] The ETT can be then be removed from around the NGT without displacement of the tube. Correct position of NGT is confirmed by injection of air and auscultation over the epigastrium, aspiration of gastric contents or direct visualisation/palpation at surgery. An ETT is preferred over a nasopharyngeal airway as guide for NGT insertion because of its length.

We would like to share our experience of a possible undesired event associated with this manoeuvre to create awareness and for adoption of necessary precautions. We recently encountered three patients undergoing bariatric procedures for treatment of their morbid obesity spread over three different centres that were complicated by intra-operative migration of the guiding nasal ETT into the oesophagus after dislodgement of the tube from its connector by this manoeuvre [Figure 1a and b]. In all three cases unaware of tube dislodgment (as the connector was the only visible portion), the NGT was threaded pushing the tube further downwards. In all three cases, the tube could not be readily accessed for removal through the mouth and were managed by endoscopic retrieval in two and retrieval through a gastrostomy in one [Figure 2a and b].

Figure 1

(a) Endoscopic image of the proximal end of migrated nasal endotracheal tube in the oesophagus after displacement of the tube connector, (b) Endoscopic image of the body of the migrated nasal endotracheal tube in the oesophagus after displacement of the tube connector

Figure 2

(a) Endoscopic image of the visualization and grasping of the migrated nasal endotracheal tube in the oesophagus, (b) Endoscopic image of the retrieval of the migrated nasal endotracheal tube from the oesophagus

Portex® ETT connectors easily get separated from the tube if attached shallowly resulting in dislodgement of the tube. The simplest precaution to prevent dislodgement is to encircle a 1-cm wide tape at the proximal end of tube and secure it to the connector or use a one-size larger tracheal tube connector, which can be easily and snugly fit into the proximal end of the tube.[8] Furthermore, the Portex® ETTs used should be larger than the NGT as a snugly fitting NGT can easily carry the ETT also with it. Precautionary measures should always be implemented to avoid this unnecessary intra-operative complication.