Effect of Nasogastric Tube on Aspiration Risk: Results from 147 Patients with Dysphagia and Literature Review.

Abstract

Nasogastric tube (NGT) is a common feeding strategy for patients at risk of endotracheal aspiration with an oral diet. With NGT feeding, however, swallowing of small amounts saliva cannot be avoided. We investigated whether the aspiration rate when swallowing 1mL of fluid increased in patients using an NGT in different dysphagia severities. One hundred forty-seven patients who had been receiving NGT feeding underwent a videofluoroscopic swallowing study (VFSS). During VFSS, subjects were offered 1mL of fluid twice: initially, with the tube inserted (NGT-in) and, subsequently, with the tube removed (NGT-out). Aspiration depth was determined using the 8-point Penetration-Aspiration Scale (PAS) (0 points, no aspiration/penetration; 8 points, aspiration passing the vocal cords with no ejection efforts). PAS-diff was computed (PASNGT-in-PASNGT-out), and a positive PAS-diff (PAS-diff > 0) meant increased aspiration depth in the presence of NGT. After VFSS, diet recommendations were made according to dysphagia severity assessment: non-oral feeding (n = 59), diet modification (n = 74), and diet as tolerated (n = 13). Cognitive level (mini-mental state examination, MMSE) and general functional level (Modified Barthel Index, MBI) were compared between the PAS-diff > 0 and PAS-diff ≤ 0 groups. Aspiration severity did not significantly change after NGT removal (PASNGT-in, 2.45 ± 2.40; PASNGT-out, 2.57 ± 2.58; P = .50). Regardless of recommended diet, PAS-diff values were not significantly different (P = .49). MMSE and MBI were not significantly different (P = .23 and .94) between subjects with PAS-diff > 0 (n = 25) and PAS-diff ≤ 0 (n = 121). In conclusion, the risk of aspirating a small amount of fluid was not significantly different before and after NGT removal, regardless of swallowing function, cognitive level, or general functional level.