REJECTION CRITERIA FOR ENDOTRACHEAL ASPIRATES FROM ADULTS

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.