We suggest that i.v. lidocaine should be regarded as a ‘high-risk’ medicine. Individual anaesthetists may feel that, in selected patients, i.v. lidocaine may be beneficial as part of a multimodal peri-operative pain management strategy. What is lidocaine injection? Lidocaine is a local anesthetic (numbing medication) that is used to numb an area of your body to help reduce pain or discomfort caused by invasive medical procedures such as surgery, needle punctures, or insertion of a catheter or breathing tube. Lidocaine injection is used to cause numbness or loss of feeling for patients having certain medical procedures (by blocking certain nerves using the brachial plexus, intercostal, lumbar, or epidural blocking techniques). Lidocaine IV provides significant pain relief, reduces concurrent opioid consumption (synergistic analgesia), and can decrease opioid-induced nausea and vomiting. Inpatients at UCSF can be treated with IV lidocaine for 48 hours under the management of a qualified pain service (Acute Pain Service, Inpatient Chronic Pain Service, Inpatient Palliative Care Service). Low dose IV lidocaine infusions are being used intraoperatively and postoperatively as part of a multimodal approach to decrease pain and reduce opioid requirements. Abstract This systematic review evaluates the safety and efficacy of intravenous (IV) lidocaine for the treatment of acute pain in adult patients.