Benjamin Link, age 74, was admitted to the hospital for hip-replacement surgery related to crippling arthritis and chronic pain. (This case is a composite based on our experience.) He has a 12-year history of Parkinson's disease and had been taking carbidopa-levodopa (Sinemet and others) 25-100 mg four times daily. Upon admission the medication was suspended because of preoperative fasting and then, later, postoperative nausea. This worsened his Parkinson's symptoms, including difficulty in swallowing. Mr. Link is now drowsy as a result of the anesthesia and is receiving morphine by patient-controlled pump, both of which increase the risk of impaired swallowing, which could lead to aspiration.
On his second postoperative day, the nurse notices that Mr. Link is coughing while the nursing assistant gives him breakfast. She also hears gurgling sounds, which worsen after he drinks juice. Mr. Link is drooling and speaks in a soft, hoarse voice. He doesn't have fever or chills, but on auscultation the nurse detects faint crackles in the base of Mr. Link's left lung. The physician is notified; the nurse suspects that Mr. Link had been aspirating during meals.
IMPLEMENTING THE TRY THIS APPROACHES
Although the evidence available on the effectiveness of many preventive strategies is limited,18, 19 the approaches summarized in Try This: Preventing Aspiration in Older Adults with Dysphagia (page 45) are the ones best known for decreasing the risk of aspiration in this population. (To understand the importance of this assessment, see Why Assess for Aspiration in Patients with Dysphagia? page 42.)
Dietary modifications are recommended by a speech pathologist or other clinician trained in the assessment of swallowing. Thickened liquids may be recommended. For example, one study found that patients with neurogenic dysphagia aspirated less often when liquids thickened to the consistency of nectar or pudding were provided than when thin liquids were given.20 But thickened liquids aren't recommended in all cases of dysphagia; therefore, working with a speech pathologist to determine the specific needs of the patient is critical.
Oral care. Poor oral hygiene and tooth decay have been correlated with the occurrence of aspiration pneumonia,11, 12, 17 and good oral care has been associated with a lower rate of pneumonia.10
Mr. Link receives a bedside dysphagia workup by the speech pathologist. She observes no overt aspiration of liquids during the evaluation but determines that Mr. Link is at risk for dysphagia because of his age, Parkinson's disease status, altered medication regimen, and sedation from the analgesia. Therefore, the nurse implements the Try This approaches to promote swallowing. The nurse asks the physical therapist to complete her work with Mr. Link at least 30 minutes before mealtimes, which will allow him time to rest before eating. At mealtimes, the nurse helps Mr. Link to sit upright at a 45[degrees] angle, the highest permitted by postoperative orders. The nurse instructs the nursing assistant to feed Mr. Link slowly, giving him small amounts and alternating solids with liquids-all suggested in the Try This approaches.
Next, the nurse reviews Mr. Link's medication list, looking for drugs that may be causing sedation and thus impairing the coughing or swallowing reflex. She also talks with Mr. Link about his home routine of eating meals and taking medications. She wants to get him back on a medication schedule to decrease the dysphagia and other symptoms of Parkinson's disease.
To promote chewing and swallowing, the nurse looks for missing teeth or missing or poorly fitting dentures. She finds that his dentures fit well and that his oral hygiene is adequate. The nurse tells him about the importance of good oral hygiene, including cleaning his dentures and rinsing his mouth with mouthwash. (To watch the segment of the online video on preventing aspiration during hand feeding, go to http://links.lww.com/A227.
IMPLEMENTING THE TRY THIS APPROACHES FOR TUBE FEEDING
Good oral hygiene is also important for patients fed by tube. In a comparison of three groups of institutionalized older adults (those fed orally, those fed by nasogastric tube, and those fed by percutaneous enterogastric tube), tube-fed patients had a higher prevalence of oropharyngeal pathogenic bacteria than those fed orally.21 Oral bacteria levels were highest in those receiving nasogastric tube feedings. This suggests to us that tube-fed patients (especially those receiving nasogastric feedings) are at higher risk for bacterial pneumonia if aspiration occurs than are those who receive oral feedings. (To see the segment of the online video on preventing aspiration during tube feeding, go to http://links.lww.com/A228.
Tube placement. Correct placement of the feeding tube is also critical to the prevention of aspiration. A tube inadvertently positioned in the trachea or lung causes "aspiration by proxy" if tube feeding is initiated or medications are administered. In addition, a tube whose ports are situated in the esophagus increases the risk of regurgitation and aspiration.22 For these reasons, radiographic confirmation of placement is strongly recommended before a tube is first used. In adults, an abdominal X-ray is preferred over a chest X-ray; it can determine where the tube ends in the gastrointestinal tract.23 Thereafter, the nurse can use a variety of tests at the bedside to help determine the tube's position: observing the length of the tube extending from the insertion site and the appearance and volume of fluid withdrawn from the tube, for example.24, 25 Contents withdrawn by a syringe from a gastric tube during feedings usually have the appearance of curdled or unchanged formula. While the pH of gastrointestinal contents is buffered by enteral formula, fluid withdrawn from gastric tubes usually has a lower pH than that of fluid withdrawn from small-bowel feeding tubes.26 The volume of fluid withdrawn from gastric tubes is typically higher than that withdrawn from small-bowel tubes.24
Although there is no agreement on how much gastric residual volume is too much, many do agree that it's wise to measure gastric residual volume when feeding by tube.27-29 This is a reasonable view; a high gastric residual volume increases the risk of gastroesophageal reflux and subsequent aspiration of gastric contents into the trachea. In one study, investigators reported a high correlation coefficient (0.93) between gastric residual volume and gastroesophageal reflux in 19 critically ill patients.30 The most frequently cited volume of concern is 200 mL or greater.3, 27, 29
Tube site and feeding method may also play roles in preventing aspiration. Compared with gastric tube feeding, duodenojejunal (small intestine) tube feeding may be associated with a lower incidence of aspiration.3 This is especially true if the patient has significantly slowed gastric motility. Also, the risk of aspiration continues after placement of a gastrostomy tube.31, 32 The consensus statement of the North American Summit on Aspiration in the Critically Ill Patient recommends continuous feeding (rather than intermittent feeding) in patients at high risk for aspiration.3 In a comparison of pump-assisted and gravity-controlled drip feeding for patients with percutaneous endoscopic gastrostomy tubes, those receiving pump-assisted feedings had less vomiting, regurgitation, and aspiration.33
Unless contraindicated, the head of the bed for a patient receiving tube feedings should be elevated more than 30[masculine ordinal indicator]. There is evidence that a sustained supine position (with the head of the bed flat) increases the probability of aspiration.6, 34 For more information, see Preventing Aspiration During Nasogastric, Nasointestinal, or Gastrostomy Tube Feedings at http://links.lww.com/A363.
COMMUNICATING THE STRATEGIES
Mr. Link's nurse will instruct him, as well as his family caregivers and nursing assistants, in strategies to promote swallowing. The nurse already requested the physical therapist to complete postoperative therapy at least 30 minutes before meals and will coordinate the prescribed bedside dysphagia evaluation with the speech pathologist. While the chin-flexed position may be helpful for Mr. Link, different positions may be better for others.35, 36 For example, a patient recovering from head and neck surgery will need to work with a speech pathologist to determine the best feeding position to minimize the risk of aspiration during feeding.37 The occupational therapist and speech pathologist can be helpful in determining the correct feeding position for patients. The nurse will arrange and coordinate the prescribed dietetic assessment and assure that Mr. Link receives the correct diet. (To view the segment of the online video on assessing and preventing aspiration, go to http://links.lww.com/A229.
As the nurse suspected, Mr. Link's modified barium swallow test shows a slowing of swallowing function. Aspiration is not noted. The nurse works with Mr. Link, his wife and daughter, the nursing assistant, and the speech pathologist to continue using the Try This approaches. His lung crackles resolve spontaneously. Mr. Link's functional status improves and he is discharged home. The nurse instructs Mr. Link's wife and daughter on how to do the Heimlich maneuver. A follow-up evaluation 30 days later shows an improvement in Mr. Link's swallowing function. (For the segment of the online video on risk-reduction strategies, go to http://links.lww.com/A230.
Symptoms of Dysphagia and Aspiration
Symptoms of dysphagia and aspiration may include the following:
* coughing during meals
* hoarse voice following meals
* gurgling sounds in the throat
* drooling
* upper respiratory infection
* pneumonia
Symptoms of Aspiration Pneumonia in Older Adults
Any of the following symptoms should alert the practitioner that the patient may have aspiration pneumonia.
* elevated respiratory rate
* fever
* cough
* chills
* pleuritic chest pain
* crackles (rales)
* delirium, increased confusion, or falls
Marrie TJ. Clin Infect Dis 2000;31(4):1066-78.
CONSIDER THIS
What are the considerations for special populations? The need to promote swallowing and decrease the risk of aspiration in patients may be indicated for a variety of medical conditions. A patient with advanced dementia may forget how to chew or swallow, and it may be helpful for a nurse to demonstrate chewing or to gently stroke the area under the chin with a downward motion while the patient is swallowing. A pureed diet may be indicated to decrease the risk of choking. Patients with advanced dementia or hemiparesis, localized disease or injury affecting the oropharyngeal area, may unknowingly pocket food in their cheeks; it's important to visually inspect the oral cavity for food (including under the dentures) during and after meals. These patients are at risk for choking or aspirating if left unobserved with food in their mouths. In addition, in patients with hemiparesis or oropharyngeal disease or injury, the caregiver can place the food on the side of the mouth that doesn't have weakness or paralysis.
What are the ethical considerations of using feeding tubes in patients with dementia? A 1999 cross-sectional study by Mitchell and colleagues found that 34% of residents with advanced cognitive impairment in Medicare- or Medicaid-certified nursing homes had feeding tubes.38 However, the wisdom of placing feeding tubes in this population has been questioned. In a review article, Finucane and colleagues noted a lack of evidence showing that tube feedings result in weight gain or reduced aspiration in those with advanced dementia.39 Also, a 1992 study of 40 neurologically impaired nursing home residents (including seven with dementia) who received tube feedings found that they continued to lose weight and lean body mass.40
There is also no evidence that tube feedings promote survival or decrease aspiration in patients with severe Alzheimer's disease.39, 41 Less social interaction during mealtimes is a drawback to tube feedings, as is the loss of pleasure that comes with feeling, tasting, and swallowing food. Further, tube feedings may cause diarrhea and abdominal discomfort.39 For these reasons, the Alzheimer's Association discourages the use of feeding tubes in people with advanced Alzheimer's disease but respects patient and surrogate preferences.42 Initiating tube feedings in this population is an individual or family decision with possible legal, cultural, and religious implications and remains a highly controversial ethical issue for some.43, 44
REFERENCES