Aerosolized lidocaine during invasive mechanical ventilation: in vitro characterization and clinical efficiency to prevent systemic and cerebral hemodynamic changes induced by endotracheal suctioning in head-injured patients.

Background: In patients with severe brain injury, endotracheal suctioning (ETS) can increase intracranial pressure (ICP) and reduce cerebral perfusion pressure (CPP). The aim of this prospective, blinded clinical trial was to assess the effectiveness of aerosolized lidocaine to prevent increase of ICP induced by ETS in mechanically ventilated head-injured patients.

Methods: First, we measured the particle size of aerosolized lidocaine produced by a vibrating plate nebulizer. Second, we measured the cerebral hemodynamic response to tracheal suctioning in patients in a neurosurgical intensive care unit with and without pretreatment of aerosolized lidocaine.

Results: Particle size distribution of aerosolized lidocaine was suitable to reach the bronchotracheal target during mechanical ventilation. In 15 patients included in this study, aerosolized lidocaine by itself did not induce significant changes in ICP. ETS caused an increase in ICP (variation: 6±2 mm Hg, P<0.05) with a concomitant decrease in CPP (variation: 2±2 mm Hg, P<0.05) that was maximal at 1 minute after NaCl aerosolization. This was prevented by aerosolization of lidocaine (variation of ICP: 1±1 mm Hg, and CPP: -1±1 mm Hg, P<0.05).

Conclusions: Aerosolized lidocaine (2 mg/kg) can prevent ETS-induced increases in ICP, without modifying systemic and cerebral hemodynamics in deeply sedated patients.