Background: A previous study showed less postoperative neurocognitive impairment in open-chamber cardiac surgery patients given lidocaine for 48 hours after induction of anesthesia. In the present study, we aimed to test the benefit of a 12-hour infusion in a broader group of cardiac surgery patients, including those undergoing coronary artery bypass graft surgery.
Methods: This was a randomized, double-blind, intention-to-treat trial. Before cardiac surgery, 158 patients completed 7 neurocognitive tests and a self-rating scale for memory. They received a 12-hour infusion of either lidocaine in a standard antiarrhythmic dose or placebo, beginning at induction of anesthesia. The cognitive tests and memory scale were repeated at postoperative weeks 10 and 25. A deficit in any cognitive test was defined as a decline in score by more than or equal to the preoperative group standard deviation.
Results: All tests were completed by 118 and 107 patients at 10 and 25 weeks, respectively. The proportions of patients in the lidocaine and placebo groups exhibiting a deficit in one or more tests were as follows: 45.8% versus 40.7% at 10 weeks, and 35.2% versus 37.7% at 25 weeks (not significant). There were no significant differences between groups in self-ratings of memory function or length of intensive care unit or hospital stay.
Conclusions: Lidocaine was not neuroprotective. The result of the previous trial may represent a type 1 error. Alternatively, benefit may be more likely for open-chamber surgery patients exposed to larger numbers of emboli or with a longer lidocaine infusion.