Although criteria have been established to assess the quality of sputu
m specimens, no criteria for assessing the quality of endotracheal suc
tion aspirates (ETSA) exist. Therefore, we compared the Gram stain (GS
) and culture results for 504 consecutive ETSA specimens. Results reco
rded for GS included the numbers of squamous epithelial cells (SEC) an
d polymorphonuclear leukocytes (PML) per low-power field (LPF) (magnif
ication, X 100) as well as the quantities and types of organisms per h
igh-power field (HPF) (magnification, x 1,000). Culture results were q
uantitated by organism. Only 15% of ETSA specimens tested by GS contai
ned > 10 SEC per LPF, and 21, 20, and 59% had less-than-or-equal-to 10
, 11 to 24, and greater-than-or-equal-to 25 PML per LPF, respectively.
For 40% of ETSA specimens, no organisms were visible by GS. Of these
specimens, 40% were sterile, 48% grew normal oropharyngeal flora (NF)
only, 5% grew 1+ NF (i.e., > 10 colonies in the first quadrant) and 1 gram-negative rods (GNR), and 7% grew less-than-or-equal-to 1+ GNR ei
ther alone or in mixed culture. The mean numbers of organisms recovere
d from ETSA with less-than-or-equal-to 10 SEC per LPF and >10 SEC per
LPF were 2.35 and 4.05, respectively. We therefore recommend that ETSA
specimens that show no organisms by GS be rejected, in addition to th
ose with > 10 SEC per LPF. Application of these rejection criteria ena
bled us to reject 847 (41%) of 2,068 ETSA specimens over a 6-month per
iod. This represents a saving of approximately $66,000/year in unneces
sary laboratory charges to patients.