The Median Effective Concentration (EC50) of Epidural Ropivacaine With Different Doses of Oxycodone During Limb Surgery in Elderly Patients.

BACKGROUND: Oxycodone can be used both intravenously and epidurally in elderly patients because of its strong analgesic effect and more slight respiratory inhibition compared with other opioids at the same effect. In this study, we determined the median effective concentration (EC50) of epidural ropivacaine required for great saphenous vein surgery in elderly patients in order to describe its pharmacodynamic interaction with oxycodone. METHODS: One hundred forty-one elderly patients scheduled for high ligation and stripping of the great saphenous vein surgery were allocated into three groups in a randomized, double-blinded manner as follows: Q2.5 group (2.5 mg oxycodone), Q5.0 group (5.0 mg oxycodone), and C group (normal saline). Anesthesia, was achieved with epidural ropivacaine and oxycodone. The EC50 of ropivacaine for surgery with different doses of oxycodone was adjusted by using an up-and-down sequential methods with an adjacent concentration gradient at a factor of 0.9 to inhibit analgesia. Anesthesia associated adverse events and recovery, characteristics were also recorded. RESULTS: The EC50 of ropivacaine for the great saphenous vein surgery in elderly patients was 0.399% (95% CI, 0.371-0.430%) in the Q2.5 group, 0.396% (95% CI, 0.355-0.441%) in the Q5.0 group, and 0.487% (95% CI, 0.510-0.465%) in the C group, respectively (P < 0.05). Specially, the EC50 of ropivacaine in the Q2.5 and Q5.0 groups was lower than that in the C group (P < 0.01), But the difference between the Q2.5 group and the Q5.0 group was not significant (P > 0.05). There was no significant difference in the Bromage score from the motor block examination, heart rate (HR) or mean arterial pressure (MAP) at each observation time point after epidural administration among the three groups (P > 0.05). No serious adverse reactions occurred in any of the three groups. CONCLUSION: Oxycodone combined with ropivacaine epidural anesthesia can reduce the EC50 of ropivacaine required for elderly patients undergoing the great saphenous vein surgery. There was no significant difference in anesthesia associated adverse events among the three groups. The recommended dose of oxycodone is 2.5 mg.

New species and new synonyms of Macromotettixoides (Orthoptera: Tetrigidae) with an updated key.

The genus Macromotettixoides Zheng, Wei Jiang, 2005 is reviewed. Four new species of the genus, M. daiyunshanensis Deng, sp. nov., M. curvicarina Deng, sp. nov., M. convexa Deng, sp. nov. and M. shengtangshanensis Deng, sp. nov. are described with detailed illustrations of external morphology. Two new synonyms are established: M. jinggangshanensis, syn. nov. is synonymized with M. jiuwanshanensis Zheng, Wei Jiang, 2005; M. parvula Zha Wen, 2017, syn. nov. is synonymized with M. undulatifemura Deng, Zheng Yang, 2012. Additionally, an updated key to species of the genus is given.

Can Dexmedetomidine Improve Arterial Oxygenation and Intrapulmonary Shunt during One-lung Ventilation in Adults Undergoing Thoracic Surgery? A Meta-analysis of Randomized, Placebo-controlled Trials.

BACKGROUND: One-lung ventilation (OLV) is a common ventilation technology during thoracic surgery that can cause serious clinical problems. We aimed to conduct a meta-analysis to compare oxygenation and intrapulmonary shunt during OLV in adults undergoing thoracic surgery with dexmedetomidine (Dex) versus placebo to assess the influence and safety of using Dex. METHODS: Randomized controlled trials comparing lung protection in patients who underwent thoracic surgery with Dex or a placebo were retrieved from PubMed, EMBASE, MEDLINE, Cochrane Library, and China CNKI database. The following information was extracted from the paper: arterial oxygen partial pressure (PaO2), PaO2/inspired oxygen concentration (PaO2/FiO2, oxygenation index [OI]), intrapulmonary shunt (calculated as Qs/Qt), mean arterial pressure (MAP), heart rate (HR), tumor necrosis factor-α (TNF-α), interleukin (IL)-6, superoxide dismutase (SOD), and malondialdehyde (MDA). RESULTS: Fourteen randomized controlled trials were included containing a total of 625 patients. Compared with placebo group, Dex significantly increased PaO2/FiO2(standard mean difference [SMD] = 0.98, 95% confidence interval [CI] [0.72, 1.23], P < 0.00001). Besides, Qs/Qt (SMD= -1.22, 95% CI [-2.20, -0.23], P = 0.020), HR (SMD= -0.69, 95% CI [-1.20, 0.17], P = 0.009), MAP (SMD= -0.44, 95% CI [-0.84, 0.04], P = 0.030), the concentrations of TNF-α (SMD = -1.55, 95% CI [-2.16, -0.95], P <0.001), and IL-6 (SMD = -1.53, 95% CI [-2.37, -0.70], P = 0.0003) were decreased in the treated group, when compared to placebo group. No significant difference was found in MDA (SMD = -1.14, 95% CI [-3.48, 1.20], P = 0.340) and SOD (SMD = 0.41, 95% CI [-0.29, 1.10], P = 0.250) between the Dex group and the placebo group. Funnel plots did not detect any significant publication bias. CONCLUSIONS: Dex may improve OI and reduce intrapulmonary shunt during OLV in adults undergoing thoracic surgery. However, this conclusion might be weakened by the limited number of pooled studies and patients.

Do the lungs contribute to propofol elimination in patients during orthotopic liver transplantation without veno-venous bypass?

BACKGROUND: The clearance of propofol is very rapid, and its transformation takes place mainly in the liver. Some reports indicated extrahepatic clearance of the drug and that the lungs are the likely place where the process occurs. This study was undertaken to compare the plasma concentrations of propofol both in the pulmonary and radial arteries after constant infusion during the dissection, anhepatic and reperfusion phases of orthotopic liver transplantation (OLT) without veno-venous bypass, attempting to investigate extrahepatic clearance and to determine whether the human lungs take part in the elimination of propofol. METHODS: Fifteen patients undergoing OLT without veno-venous bypass were enrolled in the study, and propofol was infused via a forearm vein at a rate of 2 mg x kg-1 x h-1. Blood samples were simultaneously collected from pulmonary and radial arteries at the end of the first hepatic portal dissection (T0), at the clamping of the portal vein (T1), 30, and 60 minutes after the beginning of the anhepatic phase (T2, T3), and 30, 60, and 120 minutes after the unclamping of the new liver (T4, T5, T6). Plasma propofol concentrations were measured using a reversed-phase, high-performance liquid chromatographic method with fluorescence detection. RESULTS: The concentrations of plasma propofol in the pulmonary and radial arteries at T2 and T3 rose significantly compared with T0 and T1 (P<0.01) respectively. After reperfusion, the drug concentrations at T4, T5 and T6 decreased significantly compared with T2, T3 (P<0.01) respectively. There were no significant differences in plasma propofol concentrations between the pulmonary and radial arteries at any time points. CONCLUSIONS: Propofol is eliminated mainly by the liver, and also by extrahepatic organs. The lungs seem to be not a major site contributing to the extrahepatic metabolism of propofol in humans.

Plasma levels of tumor necrotic factor-alpha and interleukin-6, -8 during orthotopic liver transplantation and their relations to postoperative pulmonary complications.

BACKGROUND: Pulmonary complications after orthotopic liver transplantation (OLT) include high morbidity and mortality. Experimental data have suggested hepatic ischemia and reperfusion are induced by pro-inflammatory cytokines. The high level of inflammatory cytokines might additionally influence pulmonary capillary fluid filtration. The objectives of this study were to measure the concentrations of tumor necrotic factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) during OLT and to investigate the relationship between these cytokines and postoperative pulmonary complications. METHODS: Twenty-two patients undergoing OLT were divided into two groups according to whether they had postoperative pulmonary complications: group A consisting of 8 patients with postoperative pulmonary complications, and group B consisting of 14 patients without postoperative pulmonary complications. Enzyme-linked immunoassay (ELISA) was used to determine serum TNF-alpha, IL-6 and IL-8. Blood samples were taken at the beginning of operation (T0), clamping and cross-clamping of the inferior cava and portal vein (T1, T2), 90 minutes and 3 hours after reperfusion (T3, T4) and 24 hours after operation (T5). RESULTS: The level of PaO2/FiO2 in group A was lower than that in group B (P<0.05). The concentrations of TNF-alpha, IL-6 and IL-8 in the two groups increased rapidly at T2, peaked at T3, decreased rapidly after T3 until 24 hours after operation. The concentrations of TNF-alpha, IL-6 and IL-8 in group A were higher than those in group B at T2, T3, and T4 (P<0.05). CONCLUSION: After un-clamping of the inferior cava and portal vein, the serum concentrations of TNF-alpha, IL-6 and IL-8 increased may be related to pulmonary injury after hepatic ischemic reperfusion.

The influence of the severity of chronic virus-related liver disease on propofol requirements during propofol-remifentanil anesthesia.

PURPOSE: The purpose of this study was to investigate the influence of chronic virus- related liver disease severity on propofol requirements. MATERIALS AND METHODS: In this study, 48 male patients with chronic hepatitis B infection were divided into three groups according to Child-Turcotte-Pugh classification of liver function (groups A, B, and C with mild, moderate and severe liver disease, respectively). After intubation, propofol concentration was adjusted by ± 0.3 µg/mL increments to maintain bispectral index in the range of 40-60. Target propofol concentrations at anesthesia initiation, pre-intubation and pre-incision were recorded. RESULTS: The initial concentration used in group C was significantly lower than that used in group A or B (p<0.05), whereas no difference was observed between groups A and B. At pre-intubation, the actual required concentration of propofol increased significantly (3.2 µg/mL) in group A (p<0.05), which lead to significant differences between the groups (p<0.05). At pre-incision, the requirements for propofol decreased significantly in both groups A and B (3.0 µg/mL and 2.7 µg/mL, respectively) compared with those at pre-intubation (p<0.05), and were significantly different for all three groups (p<0.05), with group C demonstrating the lowest requirement (2.2 µg/mL). The required concentrations of propofol at pre-incision were similar to those at induction. CONCLUSION: In this study, propofol requirements administered by target-controlled infusion to maintain similar depths of hypnosis were shown to depend on the severity of chronic virus-related liver dysfunction. In other words, patients with the most severe liver dysfunction required the least amount of propofol.