Early detection of lower respiratory tract infection: the value of the gram-stained sputum smear.

In some clinical laboratories the routine examination of sputum includes a Gram-stained smear. Of specimens examined in this study the Gram-stained smear was found to be useful, but fallible in predicting bacterial culture results. Smear results requested urgently by clinicians should be relayed with caution. However, the predictive negative value of the Gram stain was encouraging.