To determine whether water or 0.9% saline should be used as diluent for endobronchial drug administration. Twelve adult patients. Patients were endobronchially administered 2 mg/kg lidocaine as marker substance in either 10 mL 0.9% saline or 10 mL distilled water during general anesthesia. The differences in mean lidocaine plasma levels at five minutes (water vs saline, 2.35 vs 1.59 micrograms/mL) and ten minutes (water vs saline: 2.67 vs 1.88 micrograms/mL) were significant (P less than .05). With the initial mean PaO2 being almost (157 mm Hg; F1O2, 0.3) in the two groups, there was a mean drop of about 60 mm Hg in the saline-diluent group, but only about 40 mm Hg in the water-diluent group one minute after administration (P less than .05).
The use of water resulted in better absorption of lidocaine and less impairment of the PaO2.
Plasma lidocaine levels and PaO2 with endobronchial administration: dilution with normal saline or distilled water?