Continuous low-dose intravenous lidocaine is effective for visceral pain secondary to peritoneal carcinomatosis in terminal cancer patients

Abstract

8533 Background: Lidocaine, a local anesthetic, is often used as an anti-arrhythmic and as an analgesic of best support care (BSC) for patients with neuropathic pain. However, little is known about the effect of low-dose lidocaine on the abdominal pain of terminally-ill patients with peritoneal carcinomatosis. Aim: To evaluate whether visceral pain is controlled and activities of daily life (ADL) are improved during continuous lidocaine infusion. Methods: 28 terminally ill patients with peritoneal carcinomatosis due to the gastrointestinal (26) and gynecologic (2) cancers were studied. Despite aggressive pain management with opiates, non-steroidal anti-inflammatory drugs and other adjuvants, debilitating pain persisted. After a test dose of 2mg/kg intravenously, lidocaine was administered at low-doses (0.4 and/or 0.8mg/kg-h) through a vein and continued for more than 24 hours. Pain was quantitated on a faces rating scale from the level 0 (no pain) to 5 (severe pain); doses of opiates, amounts of oral intake, side effects, and ADL were measured before and after lidocaine. Results: Age (mean±SE) was 62±2, and percentage of males was 54%. Patients were not hypercalcemia but were slightly malnutrished (albumin 2.9±0.1g/dl) and anemic (hemoglobin 10.3±0.4g/dl). The duration of lidocaine administration in hospital was 18±3days. Abdominal symptoms improved within 1.2±0.1days after beginning lidocaine, and pain scale decreased from 2.7±0.2 to 0.6±0.2; p<0.001. In 68% of patients, the pain level became zero. Blood concentration of lidocaine at 0.8mg/kg-h was 3.0±0.4μg/ml 1 week later. 68% of patients needed no increase in opiate dosage during lidocaine administration. Waist size did not decrease, however, oral intake increased (p=0.002) during lidocaine administration. No obvious side effects, such as perioral numbness, were seen except for emotional lability noted in 4 patients. 43% patients were able to be discharged for continued end-of-life comfort care with home parenteral nutrition and continuation of lidocaine administration. Conclusions: We suggest that continuous, low-dose intravenous lidocaine is BSC and is a very effective approach for analgesia and improvement of ADL in patients with peritoneal carcinomatosis. No significant financial relationships to disclose.