A 79-year-old man presented with symptoms of shortness of breath. He was bedridden with hypertension and sequelae of cerebral hemorrhage and was receiving nasogastric (NG) tube feeding. In the emergency department, right upper lobe pneumonia with pleural effusion was diagnosed, central venous catheterization was placed, and antibiotics were started. A percutaneous drain was placed for the pleural effusion to relieve his dyspnea, and he was admitted to the hospital. Chest X-ray taken on admission (Fig. 1A). After reviewing the chest X-ray, the duty physician removed the old NG tube, inserted a new tube, and took another chest X-ray (Fig. 1B). What abnormalities are observed on the chest imaging?

The chest X-ray performed upon admission (Figs. 1A and 2A) demonstrated that the NG tube tip was located in the mid-esophagus, indicating proximal migration. To correct this, the NG tube needed to be advanced further until the tip reached the stomach cavity. Because the existing NG tube was old, the duty doctor decided to replace it with a new one.

A chest X-ray taken after the procedure revealed that the NG tube tip had inserted into the right bronchus (Figs. 1B and 2B). This is a serious complication that can lead to pneumothorax and other major respiratory issues, often presenting without symptoms [1]. Administering fluids or a diet through a misplaced NG tube can exacerbate these complications. Therefore, the misplaced NG tube was immediately removed. There is an increased risk of repeated misplacement on reinsertion (up to one-third) and a high incidence of complications associated with nighttime intubation [2]. Because it was nighttime and the patient’s condition was unstable, the NG tube reinsertion was postponed until the next day.

On the following morning, a new attempt was made to insert an NG tube. However, a subsequent chest X-ray (Figs. 1C and 2C) revealed that the tube had bended within the esophagus with the tip directed towards the oral side. This configuration could increase the risk of aspiration if fluids or a diet were administered. The tube was therefore removed and reinserted. Following reinsertion, air was injected into the tube and a gurgling sound was heard over the upper abdomen, suggesting correct placement. The tube was secured and another chest X-ray was obtained (Figs. 1D and 2D). On chest X-ray, the leading end of the NG tube was found to be about 10 cm into the stomach cavity, but a loop formation was found in the pharynx. The tube was readjusted accordingly. Review of the previous chest X-ray revealed a similar pharyngeal loop formation to the previous image (Fig. 1C), as well as a suspicious pharyngeal loop formation (Fig. 1B), indicating a recurrent pattern of tube misplacement.

The placement of an NG tube can lead to a variety of complications, including tracheobronchopleural complications, intravascular penetration, intracranial entry, tube kinking, and enteric perforation [1]. In approximately 2% of cases, the tube tip is inadvertently placed into the respiratory tract, resulting in serious complications such as pneumothorax, hemothorax, and pleural feeding in 0.7% of cases. Mortality rates associated with these complications can be as high as 0.3% [3]. While the use of a guidewire during tube placement is often associated with respiratory complications, these complications can also occur without guidewire use. Instilling fluids into the airway through a misplaced NG tube can result in severe respiratory compromise.

The correct placement of an NG tube can be confirmed by injecting approximately 20 cc of air into the tube and auscultating the upper abdomen for a gurgling sound, or by aspirating gastric contents which should be yellow and acidic. However, chest X-ray remains the gold standard for confirming tube placement within the stomach [2]. Due to individual patient anatomical variations, the risk of repeated misplacement, and consequently, pneumothorax, is increased in some patients [2]. While a post-insertion chest X-ray is generally sufficient for guidewire-less intubations, it is recommended to obtain a chest X-ray after inserting the tube approximately 35 cm when using a guidewire, to confirm correct placement before further advancement [2].