A Rare Case of Drug-Induced Liver Injury Arising from Pain Balls: Case Report and Review of Literature

Abstract

Purpose: “Pain balls” are elastomeric pumps that provide continuous infusion of a local anesthetic directly into a surgical site for effective, non-narcotic postoperative pain relief [Dowling R, et al 2003]. Although it has excellent safety profile, it may cause rare complications. We present an unusual case of drug-induced liver injury (DILI) secondary to the use of bupivacaine pain ball with accompanying review of literature. Results: A 50 y.o. Caucasian male with recent bilateral inguinal hernia repair presented with a 3-day history of severe fatigue, nausea without vomiting, anorexia, jaundice, low grade fever, right upper quadrant (RUQ) abdominal pain and dark urine. He denies any high risk behavior or illicit drug use. He was using bupivacaine pain ball and ibuprofen only. On admission, he had scleral icterus, mild RUQ tenderness with no hepatosplenomegaly. There were no stigmata of chronic liver disease. Laboratory work-up showed Hct 45%, creatinine 0.9 mg/dl, total bilirubin 2.7 mg/dL (direct 1.9 mg/dL), AST 218 U/L, ALT 1018 U/L, Alk Phos 285 U/L, INR 1, and Lipase- 154 U/L. Further work-up for his hepatic dysfunction showed negative viral hepatitis panel except (+) Hepatitis B surface Ab and negative ANA, anti-mitochondrial and anti-smooth muscle, CMV and EBV antibodies. His acetaminophen level was <2 mcg/ml. Imaging included normal US abdomen with a non-dilated CBD of 3.3 mm. The patient underwent upper endoscopy that showed mild gastritis with normal biopsy results. Since workup had been non-revealing, a diagnosis of DILI from bupivacaine use was made. His pain ball was stopped. Shortly afterwards, his symptoms and liver enzymes improved and eventually normalized. Discussion: Pain ball usually uses local anesthetics such as ropivacaine, bupivacaine, or lidocaine to provide analgesia without causing significant systemic absorption. Bupivacaine undergoes hepatic metabolism once absorbed. We searched PubMed (inception to 2012) and found only four cases of DILI arising from locally given anesthetics [Yokoyama M, et al 2001]. Pathophysiologic mechanism remains unclear but these cases pointed to the development of allergic reaction or metabolic alteration as the cause. A recent trial of 48 mastectomy patients suggested the use of lower doses of locally given anesthetics to decrease overall systemic toxicity [Bhuvaneswari, et al. 2012]. Conclusion: Our case highlights a rare complication of locally given anesthetics. The pathophysiology remains unclear. Treatment involves withdrawal of the local anesthetic and all hepatotoxic drugs that leads to rapid clinical improvement.