The cytological examination of sputum is a valuable diagnostic aid, but the necessary specimens have not always been readily obtainable. A new technique involving the inhalation of an aerosol was devised, the inhalant consisting of 10% sodium chloride in 15% propylene glycol. It was used in 20 patients and yielded between 1 and 10 cc. of sputum in every one of 45 trials. Thirty-three of the 45 specimens were satisfactory for cytological examination. None of these patients had given satisfactory specimens before. This procedure is suggested for use especially in patients with suspected malignant pulmonary disease.
Berkson DM, Snider GL. HEATED HYPERTONIC AEROSOL IN COLLECTING SPUTUM SPECIMENS FOR CYTOLOGICAL DIAGNOSIS. JAMA. 1960;173(2):135-138. doi:10.1001/jama.1960.03020200007002