Background Chronic post-surgical pain (CPSP) has a negative impact on the recovery, quality of life, and physical functioning of elderly patients. This study aimed to test the superiority of parecoxib vs. placebo in preventing chronic post-hepatectomy pain in elderly patients under combined general-epidural anesthesia. Methods A total of 105 elderly patients undergoing hepatectomy under combined general-epidural anesthesia were randomized into the parecoxib or placebo group. The primary outcome was the proportion of patients with CPSP 3 months postoperatively. The secondary outcomes included the Short-Form McGill Pain Questionnaire score in CPSP-positive responders, acute pain intensity, postoperative analgesic demand, inflammatory markers change, and postoperative complications within 28 days. Results The parecoxib group provided a non-significant absolute 9.1% reduction in the rate of CPSP compared to the placebo group (P = 0.34). The average chronic pain visual analog scale in the parecoxib group was lower than that in the placebo group (P = 0.04). Significantly less moderate-to-severe acute pain at rest (P = 0.04) and with coughing (P < 0.001), less patient-controlled epidural analgesia (PCEA) consumption (P = 0.01), and less rescue analgesia (P < 0.001) were observed in the parecoxib group compared to the placebo group. Furthermore, no between-group difference was observed in inflammatory markers (P > 0.05) and postoperative complications (P = 0.65). Conclusions Parecoxib reduced the prevalence of CPSP in elderly patients after hepatectomy under combined general-epidural anesthesia from 44.4 to 35.3% with no statistical significance. Moreover, significantly alleviated CPSP intensity and improved acute pain management were observed. Trial registration This study was retrospectively registered in the Chinese Clinical Trial Registry (URL: http://www.chictr.org.cn/edit.aspx?pid=56961&htm=4) on August 3, 2020 (ChiCTR-2,000,035,198).

Background Gas embolism induced by CO2 pneumoperitoneum is commonly identified as a risk factor for morbidity, especially cardiopulmonary morbidity, after laparoscopic liver resection (LLR) in adults. Increasing pneumoperitoneum pressure (PP) contributes to gas accumulation following laparoscopy. However, few studies have examined the effects of PP in the context of LLR. In LLR, the PP-central venous pressure (CVP) gradient is increased due to hepatic vein rupture, hepatic sinusoid exposure, and low CVP management, which together increase the risk of CO2 embolization. The aim of this study is to primarily determine the role of low PP (10 mmHg) on the incidence of severe gas embolism. Methods Adult participants (n = 140) undergoing elective LLR will be allocated to either a standard (15 mmHg) or low (10 mmHg) PP group. Anesthesia management, postoperative care, and other processes will be performed similarly in both groups. The occurrence of severe gas embolism, which is defined as gas embolism ≥ grade 3 according to the Schmandra microbubble method, will be detected by transesophageal echocardiography (TEE) and recorded as the primary outcome. The subjects will be followed up until discharge and followed up by telephone 1 and 3 months after surgery. Postoperative outcomes, such as the Post-Operative Quality of Recovery Scale, pain severity, and adverse events, will be assessed. Serum cardiac markers and inflammatory factors will also be assessed during the study period. The correlation between intraoperative inferior vena cava-collapsibility index (IVC-CI) under TEE and central venous pressure (CVP) will also be explored. Discussion This study is the first prospective randomized clinical trial to determine the effect of low versus standard PP on gas embolism using TEE during elective LLR. These findings will provide scientific and clinical evidence of the role of PP. Trial status Protocol version: version 1 of 21-08-2020 Trial registration ChiCTR2000036396 (http://www.chictr.org.cn). Registered on 22 August 2020.