Description

Metheny et al analyzed enteral feeding tube aspirates to help determine the location of the feeding tube tip. This can help determine if tube placement is appropriate. The authors are from Saint Louis and Washington Universities in Missouri and Oregon Health Sciences University in Portland.


 

Patients: 15 to 95 years of age with over half >= 60. Half of patients in the study were receiving H2-receptor antagonists while 1% of patients were receiving omeprazole.

 

Parameters:

(1) pH

(2) pepsin concentration

(3) trypsin concentration

Parameter

Finding

Points

aspirate pH

<= 6.0

0

 

> 6.0

1

pepsin concentration

< 100 µg/mL

0

 

>= 100 µg/mL

1

trypsin concentration

<= 30 µg/mL

0

 

> 30 µg/mL

1

 

 

Placement

pH

Pepsin

Trypsin

lung

1 (100%)

0 (100%)

0 (100%)

intestine

1 (94%), 0 (6%)

1 (6%), 0 (94%)

1 (94%), 0 (6%)

stomach

1 (24%), 0 (76%)

1 (78%), 0 (22%)

1 (15%), 0 (85%)

 

In the implementation the following categories will be used:

(1) consistent with lung placement (pH = 1, pepsin = 0, trypsin = 0)

(2) probable intestinal placement (pH = 1, pepsin = 0, trypsin = 1)

(3) probable gastric placement (pH = 0, pepsin = 1, trypsin = 0)

(4) uncertain intestine vs gastric, with decision based on product of percentages for each result showing intestine vs gastric (arguable since findings are not independent of each other, but may be good enough)

 

Limitations:

• Acid suppression in the stomach may reduce pH and pepsin levels.

• Reflux of small bowel fluids into the stomach may affect the aspirate composition.

• The feeding solution may contaminate the aspirate.

 


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