{
  "abstract": "Background and Aims Pain management after liver surgery is challenging due to the nature of the procedure and postoperative metabolic changes. While epidural analgesia is considered the gold standard, liver dysfunction and coagulopathy limit its use. Superficial peripheral nerve catheters have emerged as potential alternatives. The external oblique intercostal (EOI) block targets T6-T10 intercostal nerves, offering upper abdominal analgesia. However, high systemic absorption of local anesthetics—especially in patients with impaired liver function—raises safety concerns.Methods Following Institutional Review Board approval (IRB32044), we retrospectively reviewed patients undergoing liver surgery with peripheral nerve blocks between January 2021 and October 2024. Of 115 screened, we included those who received EOI catheters. Data collected included demographics, block technique, local anesthetic regimen, postoperative pain scores (POD 0–2), and lidocaine plasma levels through POD4.Results Seven patients met inclusion criteria, including one pediatric case (<18 years). Mean age was 53 years (range 14–78), with five males and two females. Techniques included bilateral catheters (n=4), unilateral catheters (n=2), and one unilateral catheter with a contralateral rectus sheath block. All blocks were ultrasound-guided and primed with ropivacaine. Two patients received ropivacaine infusions; five received lidocaine programmed intermittent boluses (four with patient-controlled boluses). Mean pain scores were 3.4 on POD0, 3.2 on POD1, and 2.4 on POD2. Median lidocaine levels (IQR) were 1.6 mcg/mL (1.2–2) on POD1, 2.6 (1.9–2.9) on POD2, 2.4 (1.7–3) on POD3, and 4.5 (1.8–5.1) on POD4. Two patients peaked at 4.8 and 5.1 mcg/mL.Conclusions EOI catheters provide effective pain control after liver surgery and are associated with variable plasma lidocaine levels. High systemic absorption of local anesthetics is known after fascial plane blocks. While the EOI block offers uniquely favorable coverage for liver procedures—unlike other fascial plane techniques—its use requires careful monitoring to minimize the risk of local anesthetic systemic toxicity.",
  "authors": [
    {
      "affiliations": [
        "Anesthesiology, Stanford University, Stanford, USA"
      ],
      "name": "Claudia Denoue"
    },
    {
      "affiliations": [
        "Anesthesiology, Chinese University of Hong Kong, Shenzhen, China"
      ],
      "name": "Ban Tsui"
    },
    {
      "affiliations": [
        "Anesthesiology, Stanford University, Stanford, USA"
      ],
      "name": "Rakesh Sondekoppam"
    },
    {
      "affiliations": [
        "Anesthesiology, Stanford University, Stanford, USA"
      ],
      "name": "Jean Louis Horn"
    }
  ],
  "title": "EP017 Lidocaine levels during external oblique intercostal catheter infusions after liver surgery",
  "uid": "3ec8721e-3429-50a3-9152-2505a6c1a72b"
}