Objective:To evaluate the efficacy of bupivacaine pamoate for sciatic nerve block in rats.Methods:Forty-eight SPF healthy male Sprague-Dawley rats, weighing 300-400 g, were divided into 6 groups using a random number table method: bupivacaine pamoate vehicle group (group VE), bupivacaine HCl group (group BH), liposomal bupivacaine group (group BL), low-dose bupivacaine pamoate group (group HL), moderate-dose bupivacaine pamoate group (group HM) and high-dose bupivacaine pamoate group (group HH), with 8 animals in each group.In VE, BH, BL, HL, HM and HH groups, bupivacaine pamoate vehicle 0.4 ml, bupivacaine HCl solution 0.4 ml, liposomal bupivacaine suspension 0.4 ml, and 1, 3 and 10 mg/ml bupivacaine pamoate suspension 0.4 ml were injected around the left sciatic nerve, respectively.The thermal paw withdrawal latency were measured before administration (T 0) and at 0.5, 1.5, 3, 5, 8, 12, 16, 24 and 48 h after injection (T 1-9). The percentage of maximum possible effect (MPE) of thermal paw withdrawal latency was calculated, and motor function score was simultaneously performed to evaluate the efficacy of sensory and motor block.Five and three rats in each group were sacrificed at 2 and 7 days after administration (T 9, 10), respectively, and the sciatic nerve at the injection site and the surrounding muscle tissues were harvested for microscopic examination (with a light microscope) after Luxol fast blue and HE staining.Nerve damage and inflammatory responses were assessed and scored to evaluate neurotoxicity. Results:Compared with group VE, the MPE was significantly increased at T 1-4 in group HL, at T 1-8 in group HM and at T 1-8 in group HH, the motor function scores were decreased at T 1-4 in group HL, at T 1-5 in group HM and at T 1-7 in group HH ( P<0.05), and no significant change was found in inflammatory response scores for the sciatic nerve and surrounding muscles at each time point in HL, HM and HH groups ( P>0.05). Compared with group BH, the MPE was significantly increased at T 3-8, motor function scores were decreased at T 3-5, and inflammatory response scores for the muscles around the sciatic nerve were decreased at T 9 in group HM ( P<0.05). Compared with group BL, the MPE was significantly increased at T 3-7, motor function scores were decreased at T 4, 5, and inflammatory response scores for the sciatic nerve and surrounding muscles were decreased at T 9 in group HM ( P<0.05). The nerve damage score was 0 in the six groups. Conclusion:Bupivacaine pamoate can block the sciatic nerve of rats, the duration of block is prolonged with the increase in the concentration, and the duration of motor block is not longer than that of sensory block; compared with the same concentration and equal volume of bupivacaine HCl and liposomal bupivacaine, bupivacaine pamoate produces longer duration of sciatic nerve block and less neurotoxicity.

Objective:To investigate the clinical characteristics of cases with different congenital pulmonary airway malformations (CPAM) volume ratios (CVR) and the effect of maternal glucocorticoid treatment during pregnancy on CPAM.Methods:A retrospective study was conducted on 56 singleton pregnant women with fetal CPAM diagnosed prenatally in the Department of Obstetrics and Gynecology at Nanjing Drum Tower Hospital, Affiliated Hospital of Medical School, Nanjing University, from September 2020 to May 2023. Among these, three cases received maternal glucocorticoid treatment during pregnancy and clinical conditions were reported in detail. Statistical analyses were performed using independent sample t-tests, non-parametric tests, Chi-square tests, or Fisher's exact test. Results:(1) General information: The average age of the 56 pregnant women with CPAM fetuses was (32.0±0.7) years. All fetuses had unilateral lesions, with 25 cases (44.6%) on the left side. Types Ⅰ, Ⅱ, and Ⅲ CPAM accounted for 5.4% (3/56), 50.0% (28/56), and 44.6% (25/56), respectively. Fetal hydrops occurred in two cases, and the maximum CVR during the fetal period for the other 54 non-hydropic fetuses was 0.79±0.66. (2) The CVR threshold for the risk of fetal hydrops was set as the mean maximum CVR of non-hydropic CPAM fetuses plus 2 standard deviations (0.79+2×0.66=2.1). The subjects were divided into two groups based on the maximum CVR during the fetal period: CVR≤2.0 group ( n=50) and CVR>2.0 group ( n=6). Comparison between the CVR>2.0 group and CVR≤2.0 group: The CVR>2.0 group had significantly higher rates of fetal hydrops [2/6 vs. 0.0% (0/50), Fisher's exact test], mediastinal shift [5/6 vs. 32.0% (16/50), χ 2=4.03], polyhydramnios [6/6 vs. 4.0% (2/50), Fisher's exact test], and postnatal surgery [4/5 vs. 22.2% (10/45), continuity correction χ 2=4.86] (all P<0.05). None of the fetuses with CVR≤2.0 had hydrops or received intrauterine intervention. The overall live birth rate was 89.3% (50/56). (3) Maternal glucocorticoid treatment during pregnancy: three of six fetuses with CVR>2.0 were treated with maternal glucocorticoid during pregnancy, and all were delivered alive at term after the intervention with resolution of edema and/or reduction in mass size. Two of them were treated with postnatal thoracoscopic surgery and were followed up to 5 and 14 months of age, respectively, with no abnormalities in feeding and development; the other was not treated surgically until 3 months of age, with no respiratory-related symptoms and no abnormalities in feeding and development. Conclusions:Prenatal ultrasound indicating CVR>2.0 is associated with increased rates of fetal hydrops, mediastinal shift, and polyhydramnios. Maternal glucocorticoid treatment during pregnancy may lead to favorable pregnancy outcomes for these CPAM fetuses.