Fig. 4. Effect of the positively charged lidocaine analog QX-314 instilled either in the alveolar space (10⁻⁵m; n = 3) or intravenously (n = 3) at the same dose as intravenous lidocaine, i.e. , a bolus 2 mg/kg dose followed by a continuous infusion at a rate of 2 mg · kg⁻¹· h⁻¹until the end of experiment (n = 3). Intravenous QX-314 decreased alveolar liquid clearance over 1 h compared with controls; there was no effect when QX-314 was given in the air spaces. Values are mean ± SE. *P < 0.05 versus  controls.