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Q: For many years, blue dye was our standard for checking for aspiration of stomach contents in patients who were being fed via enteral feeding tube. Is there an alternative liquid that can be used for this purpose? If not, what method do you recommend?

A: As you have indicated, it is not appropriate to use FD&C Blue #1 for verification of aspiration in patients who are being fed via enteral feeding tube even though it had been a practice for over 30 years. As a result of toxicity issues related to Blue #1, the Food and Drug Administration issued the following Public Health Advisory: REPORTS OF BLUE DISCOLORATION AND DEATH IN PATIENTS RECEIVING ENTERAL FEEDINGS TINTED WITH THE DYE, FD&C BLUE NO. 1. (1) Below are some excerpts that will provide the findings associated with the recommendation that the FDA incorporated in this advisory..

"The Food and Drug Administration (FDA) would like you to be aware of several reports of toxicity, including death, temporally associated with the use of FD&C Blue No. 1 (Blue 1) in enteral feeding solutions. In these reports, Blue 1 was intended to help in the detection and/or monitoring of pulmonary aspiration in patients being fed by an enteral feeding tube. Reported episodes were manifested by blue discoloration of the skin, urine, feces, or serum and some were associated with serious complications such as refractory hypotension, metabolic acidosis and death. Case reports indicate that seriously ill patients, particularly those with a likely increase in gut permeability (e.g., patients with sepsis), may be at greater risk for these complications. Because these events were reported voluntarily from a population of unknown size, it is not possible to establish the incidence of these episodes. At this time, the FDA believes practitioners should be aware of the following points:

* Use of Blue 1-tinted enteral feedings for detecting aspiration has been associated with several serious adverse events, including death, although a direct causal relationship has not been definitely established.

* The safety of Blue 1-tinted enteral feedings for detecting aspiration has not been documented.

* Based on the reports received to date, patients at risk for increased intestinal permeability, which includes those with sepsis, burns, trauma, shock, surgical interventions, renal failure, celiac sprue, or inflammatory bowel disease, appear to be at increased risk of absorbing Blue 1 from tinted enteral feedings.

* In addition to the possibility of systemic toxicity, Blue 1-tinted enteral feedings may interfere with diagnostic stool examinations, such as the hemoccult test.

* Other blue dyes, such as methylene blue and FD&C Blue No. 2, may have similar if not greater toxicity potential than Blue 1 and would not be appropriate replacements."

The AACN Practice Alert (PA)12 titled "Blue Dye in Enteral Feeding" also provides background information and references as to why blue dye should not be used for detection of aspiration.

"Research and case reports of aspiration have shown that dye in enteral feedings is not visually detectable in situations similar to aspiration pneumonia. (2-5) A recent consensus statement on methods for identifying aspiration in critically ill patients recommended that dye be eliminated from enteral feeding since it lacks sensitivity for identifying aspiration of gastric contents. (6)

* The addition of dye to enteral feeding has been associated with several adverse events, including gastric bacterial colonization and diarrhea, systemic dye absorption, and death. (7-10) The FDA recently issued a Public Heath Advisory based on reports of toxicity and death associated with dye in enteral feeding, although a direct causal relationship has not yet been definitively confirmed. (9) The majority of reported cases of toxicity and/or death occurred in patients with sepsis.

* Use of glucose testing of tracheal aspirates, (2,11) once proposed as a method for identification of gastric aspiration, is no longer recommended as a viable strategy."

Why is it important to monitor for aspiration of enteral feedings? The reason is clearly stated in the article from the Distinguished Research Lecture presentation at the AACN National Teaching Institute, May 22, 2006. (13) Dr. Norma Metheny summarizes this in the abstract of the article:

"The most dreaded complication of tube feedings is tracheobronchial aspiration of gastric contents. Strong evidence indicates that most critically ill tube-fed patients receiving mechanical ventilation aspirate gastric contents at least once during their early days of tube feeding. Those who aspirate frequently are about 4 times more likely to have pneumonia develop than are those who aspirate infrequently."

Therefore, since it is a standard to not use FD&C blue #1, FD&C blue #2, methylene blue or glucose testing of tracheal secretions for checking for aspiration of enteral formula, what is the best practice to check for aspiration as well as preventing its occurrence?

These questions are answered in the AACN Practice Alert (12) titled "Verification of Feeding Tube Placement," the "AACN Procedure Manual for Critical Care" (14) and the AACN Protocols for Practice, "Care of Mechanically Ventilated Patients." (15) The key points are as follows:

* Always verify proper position of a blindly placed enteral feeding tube by abdominal X-ray upon initial placement and anytime there is a question about proper position.

* Use bedside techniques routinely to ensure the feeding tube remains in the proper position. Helpful techniques are measuring pH and observing the appearance of fluid that is withdrawn from the feeding tube. DO NOT rely on auscultation as it is unreliable in determining proper tube placement.

* Elevate the head of the bed 30-45 degrees, unless contraindicated.

* Monitor gastric residual and tolerance of feeding; every 6 hours initially for continuous feedings.

The Practice Alert defines the appearance of fluids withdrawn from the feeding tube based on location of the feeding tube and notes the pH you would expect to see depending on the location of the feeding tube. For instance, a pH of 6.0 or greater would indicate that the feeding tube was located in the tracheobronchial tree or the pleural space. Thus, checking pH and assessing color of secretions obtained when suctioning patients may be the best indicator we have at this time to evaluate aspiration. Dr. Norma Metheny has done work on using other methods, and a literature search could be performed using CINAHL, which is available to members on the AACN Web site, www.aacn.org.

References:

(1.) FDA Public Health Advisory, REPORTS OF BLUE DISCOLORATION AND DEATH IN PATIENTS RECEIVING ENTERAL FEEDINGS TINTED WITH THE DYE, FD&C BLUE NO. 1; September 29, 2003. Available at the following Web site: http://www.cfsan.fda.gov/~dms/colltr2.html.

(2.) Potts R, Zaroukian M, Guerrero P, Baker C. Comparison of blue dye visualization and glucose oxidase test strip methods for detecting pulmonary aspiration of enteral feedings in intubated adults. Chest. 1993;103:117-121.

(3.) Thompson-Henry S, Braddock B. The modified Evan's blue dye procedure fails to detect aspiration in the tracheostomized patients: Five case reports. Dysphagia. 1995;10:172-174.

(4.) Metheny N, Dahms T, Stewart B, et al. Efficacy of dye-stained enteral formula in detecting pulmonary aspiration in intubated adults. Chest. 2002;122:276-281.

(5.) McClave S, Lukan J, Stefater J, et al. Poor validity of residual volumes as a marker for risk of aspiration in critically ill patients. Critical Care Medicine. 2005;33(2):324330.

(6.) McClave S, DeMeo M, DeLegge M, et al. North American Summit on Aspiration in Critically Ill Patients: Consensus statement. JPEN. 2002;26:S80-85.

(7.) File T, Tan J, Thomson R, et al. An outbreak of pseudomonas aeruginosa ventilator-associated respiratory infection and the significance of gastric colonization preceding nosocomial pneumonia. Infect Control Hosp Epidemiol. 1995;16:417-418.

(8.) Maloney J, Halbower A, Fouty R, et al. Systemic absorption of food dye in patients with sepsis (letter). N Engl J Med. 2000;343:1047-1048.

(9.) Bell R, Fishman S. Eosinophilia from food dye added to enteral feedings (letter). N Engl J Med. 1990;322:1822.

(10.) Acheson D. FDA Public Health Advisory: Reports of blue discoloration and death in patients receiving enteral feedings tinted with the dye, FD&C Blue No. 1. FDA Web site. Accessed September, 29, 2003, http://www.cfsan.fda.gov/~dms/col-ltr2.html.

(11.) Metheny N, St.John R, Clouse R. Measurement of glucose in tracheobronchial secretions to detect aspiration of enteral feedings. Heart and Lung. 1998;27:285-292.

(12.) Practice Alerts are available at www.aacn.org > Clinical Practice> Practice Alerts.

(13.) Metheny N. Preventing Respiratory Complication of Tube Feeding: EvidenceBased Practice. AJCC 2006;15(4):360-369.

(14.) AACN Procedure Manual for Critical Care (5th ed). Lynn-McHale Wiegand D, Carlson K (Eds). Elsevier Saunders; 2005: 1142-1149, 1162-1166.

(15.) AACN Protocols for Practice: Care of Mechanically Ventilated Patients (2nd Ed.). Burns S (Ed) Jones and Bartlett; 2007:193-252.