Alkalinization of intra-cuff lidocaine and use of gel lubrication protect against tracheal tube-induced emergence phenomena

We sought to determine the benefits of using alkalinized lidocaine 40 mg to fill the cuff of a tracheal tube (ETT) in combination with water-soluble gel lubrication to prevent post-intubation sore throat. The work included an in vitro study of the diffusion of alkalinized lidocaine solution through the low-pressure, high-volume cuff of an ETT. We also performed a randomized controlled study (n=20 patients in each group) that included a group who received an alkalinized lidocaine-filled ETT cuff with lubrication of the tube using water-soluble gel (Group G), and two control groups who received an alkalinized lidocaine-filled cuff with ETT lubrication with water (Group W) or an air-filled cuff with ETT lubrication with water (Group C). Water-soluble gel lubrication (Group G) produced a lower incidence of sore throat during the 24-h post-extubation period than lubrication with water alone in the cuffs filled with alkalinized lidocaine (Group W), and compared with the air control group. The ability of lidocaine to pass through the cuff of an ETT when water-soluble gel and/or water alone was used as a lubricant was similar, as determined by lidocaine plasma concentrations (Cmax 45 ng ml−1). Cough and restlessness before tracheal extubation were decreased in patients with the alkalinized lidocaine-filled cuffs compared with the air-filled cuffs. After extubation, nausea, vomiting, dysphonia and hoarseness were greater for patients with air-filled cuffs compared with the lidocaine-filled cuffs. No significant difference between the groups was recorded in arterial blood pressure and heart rate. In vitro data suggest that the lower the NaHCO3 injection volume, the greater the release of lidocaine across a low-pressure, high-volume cuff. These data show benefits of using an alkalinized lidocaine-filled ETT cuff in combination with water-soluble gel lubrication in preventing post-intubation sore throat.