Feeding tubes are used frequently for individuals who cannot take oral nutrition safely or who cannot maintain their nutrition and hydration needs. Nasogastric tubes are the most frequently used alternative means of nutrition, although orogastric feeding tubes may be used for some patients such as those who have suffered facial trauma.1-3 Because an orogastric tube traverses the entire pathway that a bolus travels during all 3 stages of swallowing (from the mouth through the pharynx and into the stomach), it is often assumed that its presence may result in increased risk of aspiration. Although nasogastric tubes do not cross the oral cavity, they do traverse the pharynx and esophagus, and whether their presence increases aspiration risk is often a concern for clinicians. There are a number of studies that have examined the effects of various tubes in the oropharynx and esophagus on aspiration status in individuals with normal swallowing function and those who are risk for dysphagia. This article will review the current state of the evidence.

Research indicates there are alterations in swallow physiology when a nasogastric feeding tube is present, although aspiration does not appear to increase. Removal of a feeding tube prior to instrumental assessment of swallowing is not necessary. It is important to bear in mind that swallow physiology of older individuals appears to be particularly susceptible to the impact that a foreign object in the pharynx has on swallow physiology. Additionally, placement of a flexible endoscope for the evaluation of swallowing has been found to effect some swallow duration measures in individuals with normal swallow function.

The effects of the presence of foreign objects, such as orogastric and nasogastric feeding tubes and manometric tubes in the pharynx during swallowing have been studied in individuals with normal swallow function,4,5 with dysphagia subsequent to stroke,6,7 as well as with a broad range of medical diagnoses.8,9 Findings have been equivocal. Some reports have noted significant alterations in swallow physiology. Huggins et al.4 found statistically significant changes in swallow duration measures, i.e., decreased duration of stage transition (initiation of the pharyngeal swallow) and increased duration of pharyngeal response as a result of feeding tube placement, in 10 young adults with normal swallow function. Effects on swallow duration measures were greater for wide-bore than for fine-bore tubes. The authors hypothesized that decreased duration of stage transition in the presence of a nasogastric tube could be due to mechanical stimulation of the pharyngeal walls or indicate an anticipatory behavior such as that observed by Kidder et al. in response to presence of an endoscope tube in the pharynx.10 Although changes in swallow duration were noted in the Huggins et al study, none of the non-temporal measures of swallowing, such as bolus containment and pharyngeal clearance, were significantly affected.

Similar results were found in 22 individuals with dysphagia following stroke.7 Although no differences reached statistical significance, several swallow duration times appeared to be affected by presence of a nasogastric feeding tube. Specifically, oral transit and pharyngeal transit times were decreased when the nasogastric tube was removed. In contrast to Huggins et al., the authors observed decreased duration of stage transition when the nasogastric feeding tube was removed. The authors suggested that the prolonged duration of tube placement in their participants (average time = 20.3 days) resulted in sensory accommodation in the pharynx and delayed initiation of the pharyngeal swallow.

Robbins et al.5 examined the effects of manometry tube placement in the pharynx and, similar to feeding tube effects noted previously, found significant alterations in swallow duration measures, i.e., increases in duration of hyoid maximal elevation and duration of hyoid maximal anterior excursion. In addition, the presence of a manometry tube led to a higher incidence of laryngeal penetration for the oldest subjects (>70 years old).

Others have reported that there is no difference in swallow safety between tube in and tube out conditions. deLarminat and colleagues8 compared swallow latency times in two groups of patients, one with and one without nasogastric tubes in place and found no differences between conditions. Dziewas et al.6 completed FEES with 25 individuals with stroke with and without a nasogastric tube in place and found no differences in salient findings, i.e., saliva pooling, spillage, residue, and penetration-aspiration scale scores, between conditions. Leder and Suiter9 examined a large, heterogeneous sample of patients, 630 with and 630 without a nasogastric tube in place, and found no statistically significant differences in incidence of aspiration between the two groups. However, presence of a nasogastric tube did appear to increase the amount of residue in the valleculae and the pyriform sinuses (p < .05). Subsequent studies in which the effects of nasogastric11 and orogastric12 were evaluated within the same individual, no significant differences for aspiration status were found between tube in or out conditions. Finally, Butler and colleagues13 evaluated swallowing endoscopically with and without a manometric catheter in place and found no differences in penetration-aspiration scores between conditions.

In the only study to date that specifically examined effects of presence of a flexible endoscope on swallow physiology, Suiter and Moorhead14 completed VFSS in a group of 14 individuals with normal swallow function. Swallow function was examined with and without a flexible endoscope placed in the pharynx. Although not statistically significant, differences were found in swallow duration measures. Stage transition duration was nearly twice as long for the scope out condition as for the scope in condition. In addition, duration of hyoid maximum excursion and duration of maximum hyoid anterior movement were shorter during the scope in condition. No differences in residue scale scores, number of swallows to clear the bolus, or penetration-aspiration scale scores were noted.

Research indicates there are alterations in swallow physiology when a nasogastric feeding tube is present, although aspiration does not appear to increase. Removal of a feeding tube prior to instrumental assessment of swallowing is not necessary. It is important to bear in mind that swallow physiology of older individuals appears to be particularly susceptible to the impact that a foreign object in the pharynx has on swallow physiology. Additionally, placement of a flexible endoscope for the evaluation of swallowing has been found to effect some swallow duration measures in individuals with normal swallow function.

References

    1. Finucane P, Aslan SM, Duncan D. Percutaneous endoscopic gastrostomy in elderly patients. Postgrad Med J. 1991;67:371-3.
    2. DiSario JA. Future considerations in aspiration pneumonia in the critically ill patient: what is not known, areas for future research, and experimental methods. JPEN J Parenter Enteral Nutr. 2002;26 Suppl 6:S75-8. Discussion S79.
    3. Dennis MS, Lewis SC, Warlow C, FOOD Trial Collaboration. Effect of timing and method of enteral tube feeding for dysphagic stroke patients (FOOD): a multicenter randomized controlled trial. Lancet. 2005;365:764-72.
    4. Huggins PS, Tuomi SK, Young C. Effects of nasogastric tubes on the young, normal swallowing mechanism. Dysphagia. 1999;14:157-161.
    5. Robbins J, Hamilton JW, Lof GL, Kempster GB. Oropharyngeal swallowing in normal adults of different ages. Gastroenterology. 1992;103:823-829.
    6. Dziewas R, Warnecke T, Hamacher C, Teismann I, Kraemer C, Ritter M, Ringlestein EB, Schaebitz WR. Do nasogastric tubes worsen dysphagia in patients with acute stroke? BMC Neurol. 2008;23:28.
    7. Wang TG, Wu MC, Chang YC, Hsaio TY, Lien IN. The effect of nasogastric tubes on swallowing function in persons with dysphagia following stroke. Arch Phys Med Rehabil. 2006;87:1270-1273.
    8. deLarminat V, Montravers P, Dureuil B, Desmonts JM. Alteration in swallowing reflex after extubation in intensive care unit patients. Crit Care Med. 1995;23:486-490.
    9. Leder SB, Suiter DM. Effect of nasogastric tubes on incidence of aspiration. Arch Phys Med Rehabil. 2008;89:648-651.
    10. Kidder TM, Langmore SE, Martin BJ. Indications and techniques of endoscopy in evaluation of cervical dysphagia: comparison with radiographic techniques. Dysphagia. 1994;9:256-261.
    11. Fattal M, Suiter DM, Warner HL , Leder SJ. Effect of presence/absence of a nasogastric tube in the same person on incidence of aspiration. Otolaryngol Head Neck Surg. 2011;145:796-800.
    12. Leder SB, Lazarus CL, Suiter DM, Acton LM. Effect of orogastric tubes on aspiration status and recommendations for oral feeding. Otolaryngol Head Neck Surg. 2011;144:372-5.
    13. Butler SG, Stuart A, Markley L, Rees C. Penetration and aspiration in healthy older adults as assessed during endoscopic evaluation of swallowing. Ann Otol Rhinol Laryngol. 2009;118:190-198.
    14. Suiter DM, Moorhead MK. Effects of flexible fiberoptic endoscopy on pharyngeal swallow physiology. Otolaryngol Head Neck Surg. 2007;137:956-958.
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Debra Suiter, Ph.D., CCC-SLP, BCS-S
Debra Suiter is the Director of the Voice and Swallow Clinic and Associate Professor in the Department of Communication Sciences and Disorders. She received a Master’s Degree in Speech Pathology in 1993 and a Doctoral Degree in Speech and Hearing Science in 2001, both from The University of Tennessee-Knoxville. She has worked in a number of clinical service settings, including acute care, acute rehabilitation, long-term care, and outpatient settings. Debra has extensive experience in working with adults with swallowing disorders. She is a Board Certified Specialist in Swallowing and Swallowing Disorders and currently serves on the Boards of the American Board for Swallowing and Swallowing Disorders and the Dysphagia Research Society. Debra’s specialized training includes the evaluation and treatment of swallowing disorders. She works as a member of the multidisciplinary ALS clinic under the direction of Dr. Edward Kasarskis. Additionally, she is a certified provider of Lee Silverman Voice Treatment (LSVT) for treatment of voice changes associated with Parkinson Disease and related disorders. Debra has presented on the topics of swallowing and swallowing disorders at local, national and international conferences and has published the results of her research in a number of peer-reviewed publications. She is also the co-author of a book on The Yale Swallow Protocol that she and Dr. Steven Leder from Yale University School of Medicine developed.

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