Comparison of the effects of general and local anesthesia in lumbar interlaminar endoscopic surgery.

BACKGROUND: Percutaneous endoscopic lumbar discectomy (PELD) with an interlaminar approach is a technique used to treat lumbar disc hernia. It has not yet been established whether general or local anesthesia (LA) is preferable for lumbar interlaminar endoscopic surgery. METHODS: Between October, 2012 and June, 2016, 60 patients were recruited and randomly divided into 2 groups: the general anesthesia (GA) group and the LA group. The patients' basic clinical data, intraoperative patient experience, Oswestry disability index (ODI), visual analog scale (VAS) score, and the postoperative patient satisfaction rate were assessed. RESULTS: Statistically significant differences were found between the two groups in operative time and length of hospital stay. There were no significant differences in postoperative ODI or VAS scores between the two groups during follow-up at 3, 6, and 12 months. One patient in the GA group sustained a nerve root injury intraoperatively. Two patients in the LA group suffered adverse reactions, as did six patients in the GA group. However, 50% of the patients expressed fear about undergoing the surgery with LA, while all patients felt they could undergo the same surgery with GA. CONCLUSIONS: General and LA are both suitable for use in lumbar interlaminar endoscopic surgery. However, GA makes a positive intraoperative surgical experience more likely for the patient.

Pharmacokinetics of Intranasally Administered Dexmedetomidine in Chinese Children.

Background: Intranasal application is a comfortable, effective, nearly non-invasive, and easy route of administration in children. To date, there is, however, only one pharmacokinetic study on intranasal dexmedetomidine in pediatric populations and none in Chinese children available. Therefore, this study aimed to characterize the pharmacokinetics of intranasally administered dexmedetomidine in Chinese children. Methods: Thirteen children aged 4 to 10 years undergoing surgery received 1 µg/kg dexmedetomidine intranasally. Arterial blood samples were drawn at various time points until 180 min after dose. Dexmedetomidine plasma concentrations were measured with high performance liquid chromatography (HPLC) and mass spectrometry. Pharmacokinetic modeling was performed by population analysis using linear compartment models with first-order absorption. Results: An average peak plasma concentration of 748 ± 30 pg/ml was achieved after 49.6 ± 7.2 min. The pharmacokinetics of dexmedetomidine was best described by a two-compartment model with first-order absorption and an allometric scaling with estimates standardized to 70-kg body weight. The population estimates (SE) per 70 kg bodyweight of the apparent pharmacokinetic parameters were clearance CL/F = 0.32 (0.02) L/min, central volume of distribution V1/F = 34.2 (4.9) L, intercompartmental clearance Q2/F = 10.0 (2.2) L/min, and peripheral volume of distribution V2/F = 34.9 (2.3) L. The estimated absorption rate constant was Ka = 0.038 (0.004) min-1. Conclusions: When compared with studies in Caucasians, Chinese children showed a similar time to peak plasma concentration after intranasal administration, but the achieved plasma concentrations were about three times higher. Possible reasons are differences in age, ethnicity, and mode of administration.

Intravenous dexmedetomidine pre-medication reduces the required minimum alveolar concentration of sevoflurane for smooth tracheal extubation in anesthetized children: a randomized clinical trial.

BACKGROUND: It has been known that Dexmedetomidine pre-medication enhances the effects of volatile anesthetics, reduces the need of sevoflurane, and facilitates smooth extubation in anesthetized children. This present study was designed to determine the effects of different doses of intravenous dexmedetomidine pre-medication on minimum alveolar concentration of sevoflurane for smooth tracheal extubation (MACEX) in anesthetized children. METHODS: A total of seventy-five pediatric patients, aged 3-7 years, ASA physical status I and II, and undergoing tonsillectomy were randomized to receive intravenous saline (Group D0), dexmedetomidine 1 µg∙kg-1 (Group D1), or dexmedetomidine 2 µg∙kg-1 (Group D2) approximately 10 min before anesthesia start. Sevoflurane was used for anesthesia induction and anesthesia maintenance. At the end of surgery, the initial concentration of sevoflurane for smooth tracheal extubation was determined according to the modified Dixon's "up-and-down" method. The starting sevoflurane for the first patient was 1.5% in Group D0, 1.0% in Group D1, and 0.8% in Group D2, with subsequent 0.1% up or down in next patient based on whether smooth extubation had been achieved or not in current patient. The endotreacheal tube was removed after the predetermined concentration had been maintained constant for ten minutes. All responses ("smooth" or "not smooth") to tracheal extubation and respiratory complications were assessed. RESULTS: MACEX values of sevoflurane in Group D2 (0.51 ± 0.13%) was significantly lower than in Group D1 (0.83 ± 0.10%; P < 0.001), the latter being significantly lower than in Group D0 (1.40 ± 0.12%; P < 0.001). EC95 values of sevoflurane were 0.83%, 1.07%, and 1.73% in Group D2, Group D1, and Group D0, respectively. No patient in the current study had laryngospasm. CONCLUSION: Dexmedetomidine decreased the required MACEX values of sevoflurane to achieve smooth extubation in a dose-dependent manner. Intravenous dexmedetomidine 1 µg∙kg-1 and 2 µg∙kg-1 pre-medication decreased MACEX by 41% and 64%, respectively. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR): ChiCTR-IOD-17011601 , date of registration: 09 Jun 2017, retrospectively registered.

Tracheal extubation in deeply anesthetized pediatric patients after tonsillectomy: a comparison of high-concentration sevoflurane alone and low-concentration sevoflurane in combination with dexmedetomidine pre-medication.

BACKGROUND: Dexmedetomidine can facilitate a smooth extubation process and reduce the requirement of sevoflurane and emergence agitation when administrated perioperatively. We aimed to observe the extubation process and the recovery characteristics in pediatric patients undergoing tonsillectomy while anesthetized with either high-concentration sevoflurane alone or low-concentration sevoflurane combined with pre-medication of single dose of intravenous dexmedetomidine. METHODS: Seventy-five patients (ASA I or II, aged 3-7 years) undergoing tonsillectomy were randomized into three equal groups: to receive intravenous saline (Group D0), dexmedetomidine 1 µg/kg (Group D1), or dexmedetomidine 2 µg/kg (Group D2) approximately 10 min before anesthesia. Before the end of surgery, sevoflurane were adjusted to 1.5 times, 1.0 time and 0.8 times the minimal effective concentration in groups D0, D1 and D2, respectively. The sevoflurane concentration for each group was maintained for at least 10 min before the tracheal deep-extubation was performed. The extubation event, recovery characteristics and post-op respiratory complications were recorded. RESULTS: All tracheal tubes in three groups were removed successfully during deep anesthesia. Nine patients in Group D0, three patients in Group D1, and two patients in Group D2 required oral airway to maintain a patent airway after extubation. The frequency of oral airway usage in groups D1 and D2 were significantly lower than that in Group D0. The percentages of patients with ED and the requirements of fentanyl in groups D1 and D2 were also significantly lower than those in Group D0. The time from extubation to spontaneous eye opening in Group D2 was longer than that in groups D0 and D1. The times of post-anesthesia care unit discharge in groups D0 and D2 were longer than that in Group D1. No other respiratory complications and vomiting were observed. CONCLUSION: A single dose of intravenous dexmedetomidine as pre-medication in combination with low-concentration sevoflurane at the end of surgery provided safe and smooth deep extubation condition and it also lowered the emergence agitation in sevoflurane-anaesthetized children undergoing tonsillectomy. Preoperative dexmedetomidine at 1 µg/kg did not prolong postoperative recovery time. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR): ChiCTR-IOR-16008423 , date of registration: 06 may 2016.

Differential general anesthetic effects on microglial cytokine expression.

Post-operative cognitive dysfunction has been widely observed, especially in older patients. An association of post-operative cognitive dysfunction with the neurodegenerative diseases, such as Alzheimer's disease, has been suggested. Neuroinflammation contributes to Alzheimer pathology, through elevated pro-inflammatory cytokines and microglial activation in the CNS leading to neuronal damage, synaptic disruption and ultimately cognitive dysfunction. We compare the effects of three different, clinically-used, anesthetics on microglial activation with, and without, the prototypical inflammatory trigger, lipopolysaccharide (LPS). Microglial BV-2 cell cultures were first exposed to isoflurane, sevoflurane (each at 2 concentrations) or propofol for 6 h, and cytokine levels measured in lysates and media. The same experiments were repeated after 1 h LPS pre-treatment. We found; 1) anesthetics alone have either no or only a small effect on cytokine expression; 2) LPS provoked a large increase in microglia cytokine expression; 3) the inhaled anesthetics either had no effect on LPS-evoked responses or enhanced it; 4) propofol nearly eliminated the LPS pro-inflammatory cytokine response and improved cell survival as reflected by lactate dehydrogenase release. These data suggest that propofol may be a preferred anesthetic when it is desirable to minimize neuroinflammation.

[Tumor-selective replication, cytotoxicity and GM-CSF production of oncolytic recombinant adenovirus in KH901 injection].

OBJECTIVE: To study the tumor-selective replication, cytotoxicity and GM-CSF production of the recombinant virus in KH901 injection used to infect the cells cultured in vitro. METHODS: A panel of tumor and normal cells was infected with recombinant adenovirus in KH901 and wild-type adenovirus type 5 at a MOI of 2 PPC, the cells were harvested at 72 hours after infection and made a titer after three cycles of freeze/thaw; A panel of tumor and normal cells was infected with recombinant adenovirus KH901 at MOI of 1 or 10 PPC. For 24 hours after infection the medium was harvested to determine the biological activity of GM-CSF; A panel of tumor and normal cells was infected with KH901 of recombinant adenovirus and wild-type adenovirus type 5 at MOIs of 0, 0.1, 1, 10, 100, and 1000 PPC. At 7 days after infection, cell viability was determined by the MTT assay, and ECso was determined too. RESULTS: The data showed that wild-type adenovirus type 5 replicated efficiently in and killed both the tumor and normal cells, however, the recombinant adenovirus in KH901 replicated hugely in tumor cells [(2526.4+/-136.8)-(2796.6+/-104.6) TCID50/cell), and produced significant amount of GM-CSF [(1177. 793 +/-6.62)-(3924.497+/-17.79) IU/(10(6) cell x 24h)] and killed the tumor cells [EC50: (0.31+/-0.06)-(0.19+/- 0.01) pfu/cell] while was replicating poorly in non-permissive human normal cells [(56.8+/-9.2)-(90.1+/-14.4) TCID50/ cell], and producing very small amount of GM-CSF [(13.397+/-0.82) IU/(10(6)cell x 24 h)] and attenuating human primary cells killed [EC50: (92.33 +/- 9.12)-(121.20 +/- 19.94) pfu/cell], with which there was statistically a significant difference between wild-type adenovirus type 5 and recombinant adenovirus in KH901 (P<0.05). CONCLUSION: In vitro studies show that the tumor-selective replication, cytotoxicity, GM-CSF production of recombinant adenovirus lead the injection KH901 containing the recombinant adenovirus, as oncolytic agent, to have a potential utility for the treatment of solid tumors.