The American Association of Critical-Care Nurses (AACN) is helping critical care nurses be vigilant against aspiration.
The Prevention of Aspiration Practice Alert offers research-based actions to reduce the likelihood patients will aspirate.
To create practice alerts like this, the AACN keeps its finger on the pulse of what nurses are thinking about. Nurses can submit questions to clinical practice specialists like Linda Bell, MSN, RN. Her job is to shepherd the alert writers through the process.
"We try to go for the questions practitioners are asking when creating the document," she explains.
Clinical practice specialists will also monitor online forums to see what topics generate buzz. Issues that fall into what Bell calls "the triple whammy of importance" - high on the radar for CMS, reimbursement and patient safety - will sift down to the clinical level.
"When any guidelines or recommendations are written, you like to validate that practice is current and what reasonable nurses would do," Bell said.
Guideline authors use researched-based evidence, not only from nursing, but from other disciplines too, and develop the recommendations based on that research.
The primary author of the Prevention of Aspiration Practice Alert is Norma Metheny, PhD, RN, FAAN, associate dean for research at Saint Louis University School of Nursing in Missouri. Metheny, like all authors, was chosen because of her strong background in a given area. "We go to the best source we can," noted Bell.
Critically ill patients have an increased risk for aspirating oropharyngeal secretions and regurgitated gastric contents. Although large-volume aspirations occur sometimes , small-volume, clinically-silent aspirations are much more common.
A study identified frequent microaspirations in approximately 50% of critically ill, mechanically ventilated patients who were receiving tube feedings. Since there are no bedside tests for such miscrosapirations, the efforts to detect and prevent them take on added importance.
"Nurses play a primary role in reducing risk for aspiration," Metheny said, however, "it is truly a team effort." When dealing with patients at risk of aspirating, nurses will consult with respiratory therapists, dietitians and physicians to address some of the steps of recommended practice.
But which patients should nurses be on the lookout for raised risk? Metheny outlined those who are more susceptible to aspiration. They include, but are not-limited to:
- patients who cannot tolerate an elevated head-of-bed position;
- patients with a low level of consciousness;
- patients with an endotracheal tube or a tracheostomy;
- patients on mechanical ventilation;
- patients with feeding tubes; and
- patients who have suffered a stroke.
It's not surprising then that the Practice Alert suggestions line up with these patient scenarios.
Maintain head-of-bed elevation at an angle of 30- 45 degrees, unless contraindicated.
Evidence shows that patients in a prolonged supine position are at a greater risk for aspiration and also, ventilator-associated pneumonia. While most clinicians tend to use 30 degree head-of-bed elevation, "for high-risk patients, such as those who are mechanically ventilated while receiving tube feedings, a 45 degree elevation is favored," explained Metheny.
The LSU Medical Center in Shreveport, La., is just one of the numerous facilities around the country that have implemented the AACN's prevention of aspiration standards. Sheree Stephens, MSN, RN, CCRN, CCNS, critical care nurse specialist, noted that unless there is a physician order for the head of bed to remain flat, all patients in each of the adult and pediatric ICUs have the bed elevated 35 degrees. "Once they're stable we get them up," Stephens said.
Use sedatives as sparingly as feasible.
Sedation reduces patients' cough and gag reflexes, preventing the body from handling oropharyngeal secretions and refluxed gastric contents. Although some degree of sedation is needed due to pain and anxiety, Metheny explained, "Heavy sedation to facilitate endotracheal tube tolerance and ventilator synchronization is used less frequently today than in the past, largely because of improved mechanical ventilators."
At LSU Medical Center, clinicians follow the Richmond Agitation Sedation Scale (RASS) to determine the minimum dose the patients need. Patients who are able to tolerate it undergo a daily awakening. The morning shift turns off sedatives at 6 a.m. and wakes the patients. If the patient is alert, tolerates weaning and is ready for extubation, the healthcare team does so. If the patient does not tolerate weaning and is anxious, the sedatives are started back at half the dose and titrated to maintain the ordered RASS. Besides aspiration, Stephens said, "Prolonged use of sedatives sets a patient up for delirium," another reason to limit it.
For tube-fed patients, assess placement of the feeding tube at 4-hour intervals. For patients receiving gastric tube feedings, assess for gastrointestinal intolerance to the feedings at 4-hour intervals. For tube-fed patients, avoid bolus feedings in those at high risk for aspiration.
It's not uncommon for feeding tubes to shift position and, if feedings are administered at the wrong site, the risk of aspiration increases. Those tube-fed patients who frequently regurgitate gastric contents raise their aspiration risk. Metheny advised her fellow nurses to check position of feeding tubes often, especially before administering large volumes of fluid. To check for intolerance to tube feedings, nurses measure gastric residual volumes and observe for abdominal distention, nausea and vomiting. Stephens noted that at the LSU Medical Center, nurses check residuals to make sure patients are tolerating tube feedings, then waste the residuals. According to a national survey of more than 2,000 critical care nurses cited by Metheny, most check tube placement every 4-6 hours anyway.
Maintain endotracheal cuff pressures at an appropriate level, and ensure secretions are cleared from above the cuff before it is deflated.
Keeping the cuff inflated helps reduce the volume of secretions that can seep into the respiratory track. Ideally, cuff pressure is measured and adjusted every 8-12 hours. "Because a sizable volume of secretions can accumulate above the cuff, clinicians routinely remove these secretions before the cuff is deflated," said Metheny. This area is a prime example of interdisciplinary cooperation at the LSU Medical Center, where respiratory therapists monitor cuff pressure. They use tools like hi-low ET tubes with the suction hole above the cuff and oral care kits with long catheters for suction.
Obtain swallowing assessment before oral feedings are started for recently extubated patients who have experienced prolonged intubation.
Intubation interferes with the mechanisms of swallowing. Studies have shown more than 20% of recently extubated patients experience dysphagia. Most likely, a speech pathologist will conduct the swallowing assessment before introducing the patient to oral feeding.
All the steps require input from across the disciplines. At morning rounds at the LSU Medical Center, a dietitian, respiratory therapist, attending physician, pharmacist and nurse set daily goals for each patient. "We're trying to move the patient out of the ICU and eventually out of the hospital," Stephens explained. "As long as they follow the standards, nurses can do a good job in preventing aspiration. Nurses are above all a voice for that patient."
Danielle Bullen is on staff at ADVANCE. Contact: DBullen@advanceweb.com