|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 1 | Page : 116-117
Anesthesia workstation ventilator malfunction due to accidental misplacement of a nasogastric tube
Prerana Nirav Shah, Rakesh Narayanaswamy, Shruti Khobragade
Department of Anaesthesiology, GSMC and KEMH, Parel, Mumbai, Maharashtra, India
|Date of Web Publication||4-Feb-2016|
Dr. Prerana Nirav Shah
Department of Anaesthesiology, GSMC and KEMH, Parel, Mumbai - 400 012, Maharashtra
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Shah PN, Narayanaswamy R, Khobragade S. Anesthesia workstation ventilator malfunction due to accidental misplacement of a nasogastric tube. J Anaesthesiol Clin Pharmacol 2016;32:116-7
|How to cite this URL:|
Shah PN, Narayanaswamy R, Khobragade S. Anesthesia workstation ventilator malfunction due to accidental misplacement of a nasogastric tube. J Anaesthesiol Clin Pharmacol [serial online] 2016 [cited 2019 Oct 19];32:116-7. Available from: http://www.joacp.org/text.asp?2016/32/1/116/173375
A 13-year-old boy weighing 27 kg diagnosed to have hypersplenism was advised splenectomy with splenorenal shunt. General anesthesia was administered with a cuffed endotracheal tube ID 6 mm using a ventilator, circle absorber and standard gas flows. A nasogastric tube 12F was inserted through left nostril and fixed at 45 cm mark after confirming the position by auscultation. Intraoperatively, when the surgeon requested for continuous gastric decompression, ventilator bellows deflated and patient was not getting ventilated. Ventilation was taken over manually. Ventilator showed negative pressure in breathing system. Immediately a semi-closed circuit was connected to the patient, and 100% oxygen was given but the patient could not be ventilated with the ventilator. Suspecting some malfunction in the anesthesia machine, another anesthesia workstation was attached to the patient. However, it did not help. Meanwhile, suction of nasogastric tube was stopped, and it was possible to ventilate using ventilator of workstation. Later on again when surgeons asked for gastric decompression, the problem recurred. We therefore suspected that the cause of the problem was a tracheal position of the nasogastric tube. A hissing sound was heard at every breath from the ventilator at the NG tube tip.This was confirmed by connecting it to a capnograph which showed an end-tidal carbon dioxide waveform. Nasogastric tube was repositioned in esophagus. Surgery continued for 5 h uneventfully. The later period was uneventful.
Although nasogastric tube insertion is simple and a routine practice, inadvertent entry to trachea can cause serious complications. The tube may enter the trachea because of the proximity of the larynx to the esophagus.  This may also cause pneumothorax.  The tube may coil up in the patient's throat, particularly if the patient retches. Several complications like laryngospasm have been attributed to its misplacement under anesthesia. 
Auscultation of the epigastric region after insufflation of air through the tube (the "whoosh" test) is usually done. The confirmation of the correct position must be confirmed as per suggested guidelines. 
Misplacement of a nasogastric tube in the trachea, leading to possible life-threatening disaster like scenario should be borne in mind. Many hospitals have developed checklists to avoid complications related to nasogastric tube. Any complications that do occur should be reported on a critical incident form. Tube position should be checked after coughing or vomiting. Capnography or colorimetric capnometry for identification of feeding tube placement in mechanically ventilated adult patients is recommended.  Its correct intragastric position can be verified by capnography, checking the aspirate for acidic pH of 5.5 or below,  and by an X-ray if possible. In our case, there was no deflation of bellows with the standard amount of set gas flows. Hence, there was no obvious leak detected. Accidental displacement of a nasogastric tube into the trachea that was connected to continuous suction caused the ventilator bellows to deflate and "malfunction" of ventilator. Other possible causes of deflation of bellows could be the fault in the anesthesia machine, leaks in circuit and vaporizer.
| References|| |
Granier I, Leone M, Garcia E, Geissler A, Durand-Gasselin J. Nasogastric tube: Intratracheal malposition and entrapment in a bronchial suture. Ann Fr Anesth Reanim 1998;17:1232-4.
Zausig YA, Graf BM, Gust R. Occurrence of a pneumothorax secondary to malpositioned nasogastric tube: A case report. Minerva Anestesiol 2008;74:735-8.
Nanjegowda N, Umakanth S, Undrakonda V. Laryngospasm during extubation. Can nasogastric tube be the culprit? BMJ Case Rep 2013;2013 pii:bcr2013009645.