Efficacy of dye-stained enteral formula in detecting pulmonary aspiration.
OBJECTIVE
To determine the extent to which a mixture of human gastric juice and enteral formula stained with two concentrations of FD&C Blue No. 1 food dye (0.8 and 1.5 mL/L) is visible in suctioned tracheobronchial secretions following three forced small-volume pulmonary aspirations over a 6-h period in an animal model.


METHODS
Experimental 2 x 3 repeated measures.


METHODS
Animal laboratory and an acute care hospital.


METHODS
Ninety New Zealand white rabbits weighing approximately 3 kg each, and 90 acutely ill adults who furnished gastric juice.


METHODS
A mixture of human gastric juice and enteral formula stained with 0.8 or 1.5 mL of dye per liter was instilled intratracheally over a 30-min period into anesthetized intubated animals at baseline, 2 h, and 4 h. A total of 0.4 mL/kg of the mixture was instilled at each session. Ninety minutes after each instillation, suctioned secretions were examined for visible dye and blood.


RESULTS
Dye was visible in 46.3% of the secretions (125 of 270). The concentration of dye had no significant effect on dye visibility. Blood that was present in 114 of 270 of the secretions (42.2%) interfered with dye visibility in all but two secretions. For reasons unknown, even in the absence of blood, dye visibility decreased from 90.2% (55 of 61 secretions) after the first aspiration event to only 61% (25 of 41 secretions) after the third aspiration event.


CONCLUSIONS
Findings from this animal model study do not support the use of the dye method to detect repeated small-volume aspirations. For clinicians who choose to use the dye method in selected situations, it appears that a dye concentration of 0.8 mL/L may be as effective in detecting aspiration as a 1.5 mL/L concentration.
Metheny
Norma A
NA
School of Nursing, Saint Louis University, St. Louis, MO 63104, USA. methenna@slu.edu
Dahms
Thomas E
TE
Stewart
Barbara J
BJ
Stone
Kathleen S
KS
Edwards
Sharon J
SJ
Defer
Julie E
JE
Clouse
Ray E
RE
D000818:Animals; D004750:Enteral Nutrition; D005505:Food Coloring Agents; D005750:Gastric Juice; D006801:Humans; D011015:Pneumonia, Aspiration / Q000175:diagnosis* / Q000209:etiology; D011817:Rabbits; D012680:Sensitivity and Specificity
D005505:Food Coloring Agents