A 84 yo woman arrives in ED in midnight coming from a nursing because of a reported episode of coffee ground vomiting.
Respiratory rate, heart rate and blood pressure are normal, abdomen is not distended, hemoglobin level is 10 g/dl. On rectal examination you find normal stool.
She takes warfarin.

Can a nasogasric lavage (NGL) contribute to rule out an upper gastrointestinal bleeding (UGB)?

Conclusion

NGL has two advantages:
Diagnostic (if positive)
Help the endoscopist to perform a better exam (remove blood and clots)

On the other hand, NGL has also two disvantages:
It is nasogastric and not nasoduodenal because the pilory is often closed.
It is one of the most painful procedures performed in ED.

A negative NGL does not help to rule out an UGB. Furthermore, nasogastric lavage cannot be used to determine the need of urgent endoscopy, in fact there is no place for NGL in the Blatchford Score.

Bibliography

FD Srygley et al.
Does this patient have a severe upper gastrointestinal bleed?
JAMA march 14 2012 vol 307 n. 10

DJ Pallin et al.
Is nasogatric tube lavage in patients with acute upper GI bleeding indicated or antiquated?
Gastrointestinal Endoscopy Nov 2011, vol 74 n.5