Continuous Lidocaine Infusion as Adjunctive Analgesia in Intensive Care Unit Patients

Despite a paucity of data, the role of intravenous lidocaine (IVLI) as adjunctive analgesia in the intensive care unit (ICU) seems promising due to a low potential to contribute to respiratory depression. A retrospective chart review was conducted to evaluate the safety and effectiveness of IVLI for the treatment of pain in ICU patients with varying degrees of organ dysfunction from March 2014 to March 2016. The primary outcomes included the time to a ≥20% reduction in pain scores after the initiation of IVLI and the difference in opioid requirements as well as pain scores prior to and during IVLI therapy. Other variables included the presence of IVLI-related adverse events and the dosage and duration of IVLI. A total of 21 ICU patients were included from 2 different hospitals. The mean time to a ≥20% reduction in pain scores from the start of IVLI was 3.3 hours (SD = 2.2). The median morphine dose equivalents required during 6, 12, and 24 hours pre-IVLI were significantly higher compared to the same time periods after IVLI (18.3 vs 10 mg, P = .002; 41.8 vs 18.3 mg, P = .002; 93.5 vs 30.5 mg, P = .037). Neurological adverse effects of lidocaine were noted in 3 patients, but the effects were reversed on IVLI discontinuation. This report suggests that IVLI as an adjunctive agent in the treatment of acute pain may be a potential option in ICU patients who are refractory to opioids or those in whom opioid-induced respiratory depression is a concern.