Leonurine Preconditioning Attenuates Ischemic Acute Kidney Injury in Rats by Promoting Nrf2 Nuclear Translocation and Suppressing TLR4/NF-κB Pathway.

Despite the precise mechanisms for renal ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) are poorly understood, nuclear factor erythroid 2 related factor 2 (Nrf2) and Toll-like receptor 4 (TLR4) pathways were considered as the important targets. Leonurine (LEO) is a special alkaloid extracted from Chinese motherwort (Leonurus japonicus Houtt), which has an anti-inflammatory effect and reduces oxidative stress. We conducted the study to explore the efficacy of LEO against I/R-induced AKI in rats and further investigated the underlying mechanisms. Ischemic renal injury was induced by temporary vascular clamping for 45 min. We have measured the levels of inflammation-related biomarkers and antioxidative stress markers. Next, Western blot analysis and Real-time PCR were performed to analyze whether the Nrf2 and TLR4/nuclear factor-kappaB (NF-κB) pathways were involved in this process. We found that LEO pretreatment remarkably decreased serum creatinine and blood urea nitrogen (BUN) in I/R rats and attenuated acute tubular damage. In addition, LEO markedly increased the expression of antioxidant proteins and decreased the levels of inflammatory factors. Further study revealed that LEO promoted Nrf2 into the nucleus, promoted the expression of heme oxygenase-1 (HO-1) and quinone oxidoreductase 1 (NQO-1), and suppressed the TLR4/NF-κB signal pathway in kidney tissues of ischemic AKI rats. The study reveals that LEO has a protective effect to prevent ischemic AKI through activation of Nrf2 nuclear translocation resisting oxidative stress injury and inhibition of the TLR4/NF-κB pathway mediated inflammatory gene expression.

Chloral hydrate as a sedating agent for neurodiagnostic procedures in children.

BACKGROUND: This is an updated version of a Cochrane Review published in 2017. Paediatric neurodiagnostic investigations, including brain neuroimaging and electroencephalography (EEG), play an important role in the assessment of neurodevelopmental disorders. The use of an appropriate sedative agent is important to ensure the successful completion of the neurodiagnostic procedures, particularly in children, who are usually unable to remain still throughout the procedure. OBJECTIVES: To assess the effectiveness and adverse effects of chloral hydrate as a sedative agent for non-invasive neurodiagnostic procedures in children. SEARCH METHODS: We searched the following databases on 14 May 2020, with no language restrictions: the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 12 May 2020). CRS Web includes randomised or quasi-randomised controlled trials from PubMed, Embase, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials (CENTRAL), and the specialised registers of Cochrane Review Groups including Cochrane Epilepsy. SELECTION CRITERIA: Randomised controlled trials that assessed chloral hydrate agent against other sedative agent(s), non-drug agent(s), or placebo. DATA COLLECTION AND ANALYSIS: Two review authors independently evaluated studies identified by the search for their eligibility, extracted data, and assessed risk of bias. Results were expressed in terms of risk ratio (RR) for dichotomous data and mean difference (MD) for continuous data, with 95% confidence intervals (CIs). MAIN RESULTS: We included 16 studies with a total of 2922 children. The methodological quality of the included studies was mixed. Blinding of the participants and personnel was not achieved in most of the included studies, and three of the 16 studies were at high risk of bias for selective reporting. Evaluation of the efficacy of the sedative agents was also underpowered, with all the comparisons performed in small studies. Fewer children who received oral chloral hydrate had sedation failure compared with oral promethazine (RR 0.11, 95% CI 0.01 to 0.82; 1 study; moderate-certainty evidence). More children who received oral chloral hydrate had sedation failure after one dose compared to intravenous pentobarbital (RR 4.33, 95% CI 1.35 to 13.89; 1 study; low-certainty evidence), but there was no clear difference after two doses (RR 3.00, 95% CI 0.33 to 27.46; 1 study; very low-certainty evidence). Children with oral chloral hydrate had more sedation failure compared with rectal sodium thiopental (RR 1.33, 95% CI 0.60 to 2.96; 1 study; moderate-certainty evidence) and music therapy (RR 17.00, 95% CI 2.37 to 122.14; 1 study; very low-certainty evidence). Sedation failure rates were similar between groups for comparisons with oral dexmedetomidine, oral hydroxyzine hydrochloride, oral midazolam and oral clonidine. Children who received oral chloral hydrate had a shorter time to adequate sedation compared with those who received oral dexmedetomidine (MD -3.86, 95% CI -5.12 to -2.6; 1 study), oral hydroxyzine hydrochloride (MD -7.5, 95% CI -7.85 to -7.15; 1 study), oral promethazine (MD -12.11, 95% CI -18.48 to -5.74; 1 study) (moderate-certainty evidence for three aforementioned outcomes), rectal midazolam (MD -95.70, 95% CI -114.51 to -76.89; 1 study), and oral clonidine (MD -37.48, 95% CI -55.97 to -18.99; 1 study) (low-certainty evidence for two aforementioned outcomes). However, children with oral chloral hydrate took longer to achieve adequate sedation when compared with intravenous pentobarbital (MD 19, 95% CI 16.61 to 21.39; 1 study; low-certainty evidence), intranasal midazolam (MD 12.83, 95% CI 7.22 to 18.44; 1 study; moderate-certainty evidence), and intranasal dexmedetomidine (MD 2.80, 95% CI 0.77 to 4.83; 1 study, moderate-certainty evidence). Children who received oral chloral hydrate appeared significantly less likely to complete neurodiagnostic procedure with child awakening when compared with rectal sodium thiopental (RR 0.95, 95% CI 0.83 to 1.09; 1 study; moderate-certainty evidence). Chloral hydrate was associated with a higher risk of the following adverse events: desaturation versus rectal sodium thiopental (RR 5.00, 95% 0.24 to 102.30; 1 study), unsteadiness versus intranasal dexmedetomidine (MD 10.21, 95% CI 0.58 to 178.52; 1 study), vomiting versus intranasal dexmedetomidine (MD 10.59, 95% CI 0.61 to 185.45; 1 study) (low-certainty evidence for aforementioned three outcomes), and crying during administration of sedation versus intranasal dexmedetomidine (MD 1.39, 95% CI 1.08 to 1.80; 1 study, moderate-certainty evidence). Chloral hydrate was associated with a lower risk of the following: diarrhoea compared with rectal sodium thiopental (RR 0.04, 95% CI 0.00 to 0.72; 1 study), lower mean diastolic blood pressure compared with sodium thiopental (MD 7.40, 95% CI 5.11 to 9.69; 1 study), drowsiness compared with oral clonidine (RR 0.44, 95% CI 0.30 to 0.64; 1 study), vertigo compared with oral clonidine (RR 0.15, 95% CI 0.01 to 2.79; 1 study) (moderate-certainty evidence for aforementioned four outcomes), and bradycardia compared with intranasal dexmedetomidine (MD 0.17, 95% CI 0.05 to 0.59; 1 study; high-certainty evidence). No other adverse events were significantly associated with chloral hydrate, although there was an increased risk of combined adverse events overall (RR 7.66, 95% CI 1.78 to 32.91; 1 study; low-certainty evidence). AUTHORS' CONCLUSIONS: The certainty of evidence for the comparisons of oral chloral hydrate against several other methods of sedation was variable. Oral chloral hydrate appears to have a lower sedation failure rate when compared with oral promethazine. Sedation failure was similar between groups for other comparisons such as oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam. Oral chloral hydrate had a higher sedation failure rate when compared with intravenous pentobarbital, rectal sodium thiopental, and music therapy. Chloral hydrate appeared to be associated with higher rates of adverse events than intranasal dexmedetomidine. However, the evidence for the outcomes for oral chloral hydrate versus intravenous pentobarbital, rectal sodium thiopental, intranasal dexmedetomidine, and music therapy was mostly of low certainty, therefore the findings should be interpreted with caution. Further research should determine the effects of oral chloral hydrate on major clinical outcomes such as successful completion of procedures, requirements for an additional sedative agent, and degree of sedation measured using validated scales, which were rarely assessed in the studies included in this review. The safety profile of chloral hydrate should be studied further, especially for major adverse effects such as oxygen desaturation.

Nrf2 Antioxidative System is Involved in Cytochrome P450 Gene Expression and Activity: A Delay in Pentobarbital Metabolism in Nrf2-Deficient Mice.

NF-E2-related factor 2 (Nrf2) is a transcriptional regulator of biologic defense proteins, such as antioxidant proteins and phase II detoxification enzymes. Cytochrome P450 (P450) enzymes have been shown to regulate phase I metabolism of various drugs and are partially regulated by Nrf2; however, the influence of Nrf2 on drug pharmacokinetics is not known. Here, we showed that Nrf2 depletion prolonged the effect of pentobarbital, a sleep-promoting drug. Pretreatment with phenobarbital, a P450 inducer, shortens the sleeping time associated with pentobarbital-induced sedation in wild-type (WT) mice; however, this effect was not observed in Nrf2-/- mice. Furthermore, the blood pentobarbital concentration was higher in Nrf2-/- mice than in WT mice at 30-60 minutes, and the phenobarbital-induced enhancement of its clearance was attenuated in Nrf2-/- mice compared with WT mice. Total P450 content was decreased in Nrf2-/- mouse livers, and the phenobarbital-induced increase in P450 content was lower in Nrf2-/- mice than WT mice. Cyp1a2, Cyp2a5, Cyp2c29, and Cyp2e1 gene expression levels under physiologic conditions and Cyp1a2, Cyp2a5, and Cyp2b10 gene expression levels under phenobarbital-treated conditions were lower in Nrf2-/- mice compared with WT mice. Additionally, pentobarbital metabolism in liver microsomes was attenuated by Nrf2 depletion. Taken together, these findings suggested that Nrf2 influenced pentobarbital pharmacokinetics through the regulation of drug metabolism and P450 gene expression. Thus, Nrf2-mediated regulation of P450 may contribute to the biologic defense against increased reactive oxygen species production. SIGNIFICANCE STATEMENT: NF-E2-related factor 2 (Nrf2) plays a critical role in the cellular defense against oxidative stress. Nrf2-/- mice with reduced ability to eliminate reactive oxygen species (ROS) showed a significant delay in emergence from pentobarbital-induced sleep, which was associated with decreased P450 activities and gene expression. Our findings provide that Nrf2 dysfunction or ROS that exceed a threshold level of the eliminating ability of the Nrf2 system may reduce P450 activity.

Perfused murine heart optical transmission spectroscopy using optical catheter and integrating sphere: Effects of ischemia/reperfusion.

Tissue transmission optical absorption spectroscopy provides dynamic information on metabolism and function. Murine genetic malleability makes it a major model for heart research. The diminutive size of the mouse heart makes optical transmission studies challenging. Using a perfused murine heart center mounted in an integrating sphere for light collection with a ventricular cavity optical catheter as an internal light source provided an effective method of optical data collection in this model. This approach provided high signal to noise optical spectra which when fit with model spectra provided information on tissue oxygenation and redox state. This technique was applied to the study of cardiac ischemia and ischemia reperfusion which generates extreme heart motion, especially during the ischemic contracture. The integrating sphere reduced motion artifacts associated with a fixed optical pickup and methods were developed to compensate for changes in tissue thickness. During ischemia, rapid decreases in myoglobin oxygenation occurred along with increases in cytochrome reduction levels. Surprisingly, when ischemic contracture occurred, myoglobin remained fully deoxygenated, while the cytochromes became more reduced consistent with a further, and critical, reduction of mitochondrial oxygen tension during ischemic contraction. This optical arrangement is an effective method of monitoring murine heart metabolism.

Taurine potentiates the anticonvulsive effect of the GABAA agonist muscimol and pentobarbital in the immature mouse hippocampus.

OBJECTIVE: The high incidence of epileptic seizures in neonates and their frequent refractoriness to pharmacologic therapies require identification of new therapeutical options. Therefore, we investigated whether the modulatory effect of taurine on γ-aminobutyric acid (GABA)A receptors can enhance the anticonvulsive potential of the GABAA receptor agonist muscimol and of the barbiturate pentobarbital. METHODS: We performed field potential recordings in in toto hippocampus preparations of immature (postnatal days 4-7) C57Bl/6 mouse pups. Spontaneous epileptiform activity was induced by the continuous presence of the potassium channel blocker 4-aminopyridine and the glycinergic antagonist strychnine in Mg2+ -free solutions. RESULTS: Bath application of 0.1 µmol/L muscimol increases the occurrence of recurrent epileptiform discharges, whereas they are significantly attenuated in a dose-dependent manner by muscimol in concentrations between 0.5 and 5 µmol/L. Taurine at concentrations between 0.1 and 0.5 mmol/L induces a proconvulsive effect, but upon coapplication, it significantly augments the anticonvulsive effect of moderate muscimol doses (0.5-1 µmol/L). In addition, the anticonvulsive effect of 100 and 200 µmol/L pentobarbital is increased significantly in the presence of 0.5 µmol/L taurine. SIGNIFICANCE: These observations demonstrate that taurine can indeed enhance the anticonvulsive effects of muscimol and pentobarbital, suggesting that taurine may act as a positive modulator on GABAA receptors. Thus, interfering with the modulatory taurine binding site of GABAA receptors or the interstitial taurine concentration may provide new therapeutical options for anticonvulsive therapies in neonates.

Palmatine plays a role in sedation and hypnosis by increasing 5-hydroxytryptamine.

Objective of this study was to investigate the sedative and hypnotic effects of palmatine and to observe whether its mechanism is related to 5-hydroxytryptamine (5-HT) and GABA. The sedative and hypnotic effects of palmatine on mice were observed with mouse autonomic activity test, direct sleep test, pentobarbital sodium in suprathreshold and subthreshold dose sleep test. The content of GABA and 5-HT in brain homogenate was determined by ELISA  method. Mouse brain specimens were observed by immunohistochemistry for 5-HT expression in the nucleus of mouse brain. Palmatine could reduce spontaneous activities of mice, prolong the sleep time of mice induced by pentobarbital sodium in suprathreshold dose and shorten the sleep latency.  And it could increase the number of mice falling asleep induced by pentobarbital sodium in subthreshold dose and the incidence of falling asleep, but with no direct sleep effect. In addition, it enhanced the 5-HT content in brain, but had no effect on GABA content, and had no toxicity to PC12 cells. Palmatine plays a significant role in sedation and hypnosis, which may be associated with the increase of intra-cerebral 5-HT.

Comparison of chloral hydrate and pentobarbital sedation for pediatric echocardiography.

BACKGROUND: In 2013, outpatient use of chloral hydrate (CH) was limited and other alternatives such as oral pentobarbital (PB) were explored to achieve conscious sedation in young children for transthoracic echocardiography (TTE). We aimed to assess efficacy and safety of the two medications. METHODS: Clinical information, from a computerized database, about children who received sedation with either CH or PB for TTE at our center (2008-2015) was reviewed, and the two groups were compared for sedation effectiveness and complications. RESULTS: Three thousand eight hundred fifty one pediatric patients (median age 8 months) underwent conscious sedation during TTE (mean doses CH 50 mg/kg, PB 4 mg/kg). Demographic characteristics of the two groups were similar. Sedation failure rate (CH 2.4%, PB 2.9%, P = NS), need for supplemental doses (CH 17.9%, PB 16.2%, P = NS), and overall adverse event rate (PB 1.4%, CH 1.9%; P = NS) were similar in the two groups. There were fewer episodes of respiratory depression with PB (0.3% vs 1.6%, P < 0.05). The rate of paradoxical reactions was higher with PB (1% vs 0.03%, P < 0.05). Increasing age predicted the need for supplemental doses and for sedation failure in both groups. Neonates (7.5% vs 0%) and infants (2% vs 0.6%) given CH were more likely to develop adverse reactions. CONCLUSION: Chloral hydrate and PB are equally effective. However, CH is associated with an increased incidence of transient desaturation, while PB is associated with an increased incidence of a paradoxical reaction. Increasing age is predictive of the need for supplemental doses and for failure of sedation in both groups.

GABA Type A Receptor Activation in the Allosteric Coagonist Model Framework: Relationship between EC50 and Basal Activity.

The concerted transition model for multimeric proteins is a simple formulation for analyzing the behavior of transmitter-gated ion channels. We used the model to examine the relationship between the EC50 for activation of the GABA type A (GABAA) receptor by the transmitter GABA and basal activity employing concatemeric ternary GABAA receptors expressed in Xenopus oocytes. Basal activity, reflecting the receptor function in the absence of the transmitter, can be changed either by mutation to increase constitutive activity or by the addition of a second agonist (acting at a different site) to increase background activity. The model predicts that either mechanism for producing a change in basal activity will result in identical effects on the EC50 We examined receptor activation by GABA while changing the level of basal activity with the allosterically acting anesthetics propofol, pentobarbital, or alfaxalone. We found that the relationship between EC50 and basal activity was well described by the concerted transition model. Changes in the basal activity by gain-of-function mutations also resulted in predictable changes in the EC50 Finally, we altered the number of GABA-binding sites by a mutation and again found that the relationship could be well described by the model. Overall, the results support the idea that interactions between the transmitter GABA and the allosteric agonists propofol, pentobarbital, or alfaxalone can be understood as reflecting additive and independent free energy changes, without assuming any specific interactions.

Comparison of Intranasal Dexmedetomidine and Oral Pentobarbital Sedation for Transthoracic Echocardiography in Infants and Toddlers: A Prospective, Randomized, Double-Blind Trial.

BACKGROUND: Acquisition of transthoracic echocardiographic (TTEcho) images in children often requires sedation. The optimal sedative for TTEcho has not been determined. Children with congenital heart disease are repeatedly exposed to sedatives and anesthetics that may affect brain development. Dexmedetomidine, which in animals alters brain structure to a lesser degree, may offer advantages in this vulnerable population. METHODS: A prospective, randomized, double-blind trial enrolled 280 children 3-24 months of age undergoing outpatient TTEcho, comparing 2.5 µg·kg intranasal dexmedetomidine to 5 mg·kg oral pentobarbital. Rescue sedation, for both groups, was intranasal dexmedetomidine 1 µg·kg. The primary outcome was adequate sedation within 30 minutes without rescue sedation, assessed by blinded personnel. Secondary outcomes included number of sonographer pauses, image quality in relation to motion artifacts, and parental satisfaction. RESULTS: Success rates with a single dose were not different between sedation techniques; 85% in the pentobarbital group and 84% in the dexmedetomidine group (P = .8697). Median onset of adequate sedation was marginally faster with pentobarbital (16.5 [interquartile range, 13-21] vs 18 [16-23] minutes for dexmedetomidine [P = .0095]). Time from drug administration to discharge was not different (P = .8238) at 70.5 (64-83) minutes with pentobarbital and 70 (63-82) minutes with dexmedetomidine. Ninety-five percent of sedation failures with pentobarbital and 100% of dexmedetomidine failures had successful rescue sedation with intranasal dexmedetomidine. CONCLUSIONS: Intranasal dexmedetomidine was comparable to oral pentobarbital sedation for TTEcho sedation in infants and did not increase the risk of clinically important adverse events. Intranasal dexmedetomidine appears to be an effective "rescue" sedative for both failed pentobarbital and dexmedetomidine sedation. Dexmedetomidine could be a safer option for repeated sedation in children, but further studies are needed to assess long-term consequence of repeated sedation in this high-risk population.

Outcomes in Children Treated with Pentobarbital Infusion for Refractory and Super-Refractory Status Epilepticus.

BACKGROUND: Functional neurologic outcome for children with refractory and super-refractory status epilepticus has not been well defined. METHODS: Retrospective chart review including children age 0-17 years who received pentobarbital infusion from 2003 to 2016 for status epilepticus. Outcomes were defined in terms of mortality, need for new medical technology assistance at hospital discharge and functional neurologic outcome determined by pediatric cerebral performance category score (PCPC). Potential patient characteristics associated with functional neurologic outcome including age, sex, ethnicity, etiology of the status epilepticus, and duration of pentobarbital infusion were evaluated. RESULTS: Forty children met inclusion criteria. In-hospital mortality was 30% (12/40). Of survivors, 21% (6/28) returned to baseline PCPC while half (14/28) declined in function ≥ 2 PCPC categories at hospital discharge. 25% (7/28) of survivors required tracheostomy and 27% (7/26) required new gastrostomy. Seizures persisted at discharge for most patients with new onset status epilepticus while the majority of patients with known epilepsy returned to baseline seizure frequency. Etiology (p = 0.015), PCPC at admission (p = 0.0006), new tracheostomy (p = 0.012), and new gastrostomy tube (p = 0.012) were associated with increase in PCPC score ≥ 2 categories in univariable analysis. Duration of pentobarbital infusion (p = 0.005) and length of hospital stay (p = 0.056) were longer in patients who demonstrated significant decline in neurologic function. None of these variables maintained statistical significance when multiple logistic regression model adjusting for PCPC score at admission was applied. At long-term follow-up, 36% (8/22) of children demonstrated improvement in PCPC compared to discharge and 23% (5/22) showed deterioration including three additional deaths. CONCLUSIONS: Mortality in this population was high. The majority of children experienced some degree of disability at discharge. Despite prolonged pentobarbital infusion, there were cases of survival with good neurologic outcome.

Oral pentobarbital suspension for children sedation during MR imaging.

OBJECTIVES: The efficacy and safety of an oral pentobarbital suspension for sedation during pediatric MR imaging were assessed. METHODS: Data were recorded from October 2016 to January 2017. The exact dose of oral pentobarbital suspension was given for each child with an oral syringe. Parameters recorded included the patient's age and weight, the time required to sedate, the duration of sedation, the time required to discharge, and quality of MR imaging. The adverse effects were recorded. RESULTS: Oral pentobarbital suspension was administered to 81 children aged from 8 months to 8 years at a dose of 5mg/kg of body weight. The mean time required to sedate was 30±21min, a mean time of sedation of 47±23min, and a mean time to discharge of 77±32min. Sedation occurred a satisfied quality of MR imaging in 67% of patients. The failure of examination was essentially due to bad taste of the drug suspension. The overall success rate of sedation in patients less than 12 months was 100%. For ages 1 to 3 years, the success rate decreased to 76% and for ages 4 to 8 years, it decreased to 42%. CONCLUSIONS: Oral pentobarbital suspension used in MR imaging demonstrated its high rate of successful sedation in infants less than 12 months with no adverse effects during the study period.

Refinement of intraperitoneal injection of sodium pentobarbital for euthanasia in laboratory rats (Rattus norvegicus).

BACKGROUND: The Canadian Council on Animal Care and American Veterinary Medical Association classify intraperitoneal (IP) pentobarbital as an acceptable euthanasia method in rats. However, national guidelines do not exist for a recommended dose or volume and IP euthanasia has been described as unreliable, with misinjections leading to variable success in ensuring a timely death. The aims of this study were to assess and improve efficacy and consistency of IP euthanasia. In a randomized, blinded study, 51 adult female Sprague-Dawley rats (170-495 g) received one of four treatments: low-dose low-volume (LL) IP pentobarbital (n = 13, 200 mg/kg pentobarbital), low-dose high-volume (LH) IP pentobarbital (n = 14, 200 mg/kg diluted 1:3 with phosphate buffered saline), high-dose high-volume (HH, n = 14, 800 mg/kg pentobarbital), or saline. Times to loss of righting reflex (LORR) and cessation of heartbeat (CHB) were recorded. To identify misinjections, necropsy examinations were performed on all rats. Video recordings of LL and HH groups were analyzed for pain-associated behaviors. Between-group comparisons were performed with 1-way ANOVA and Games-Howell post hoc tests. Variability in CHB was assessed by calculating the coefficient of variation (CV). RESULTS: The fastest euthanasia method (CHB) was HH (283.7 ± 38.0 s), compared with LL (485.8 ± 140.7 s, p = 0.002) and LH (347.7 ± 72.0 s, p = 0.039). Values for CV were: HH, 13.4%; LH, 20.7%; LL, 29.0%. LORR time was longest in LL (139.5 ± 29.6 s), compared with HH (111.6 ± 19.7 s, p = 0.046) and LH (104.2 ± 19.3 s, p = 0.01). Misinjections occurred in 17.0% (7/41) of euthanasia attempts. Pain-associated behavior incidence ranged from 36% (4/11, LL) to 46% (5/11, HH). CONCLUSIONS: These data illustrate refinement of the IP pentobarbital euthanasia technique. Both dose and volume contribute to speed of death, with a dose of 800 mg/kg (HH) being the most effective method. An increase in volume alone does not significantly reduce variability. The proportion of misinjections was similar to that of previous studies.

Chloral hydrate as a sedating agent for neurodiagnostic procedures in children.

BACKGROUND: Paediatric neurodiagnostic investigations, including brain neuroimaging and electroencephalography (EEG), play an important role in the assessment of neurodevelopmental disorders. The use of an appropriate sedative agent is important to ensure the successful completion of the neurodiagnostic procedures, particularly in children, who are usually unable to remain still throughout the procedure. OBJECTIVES: To assess the effectiveness and adverse effects of chloral hydrate as a sedative agent for non-invasive neurodiagnostic procedures in children. SEARCH METHODS: We used the standard search strategy of the Cochrane Epilepsy Group. We searched MEDLINE (OVID SP) (1950 to July 2017), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, Issue 7, 2017), Embase (1980 to July 2017), and the Cochrane Epilepsy Group Specialized Register (via CENTRAL) using a combination of keywords and MeSH headings. SELECTION CRITERIA: We included randomised controlled trials that assessed chloral hydrate agent against other sedative agent(s), non-drug agent(s), or placebo for children undergoing non-invasive neurodiagnostic procedures. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the studies for their eligibility, extracted data, and assessed risk of bias. Results were expressed in terms of risk ratio (RR) for dichotomous data, mean difference (MD) for continuous data, with 95% confidence intervals (CIs). MAIN RESULTS: We included 13 studies with a total of 2390 children. The studies were all conducted in hospitals that provided neurodiagnostic services. Most studies assessed the proportion of sedation failure during the neurodiagnostic procedure, time for adequate sedation, and potential adverse effects associated with the sedative agent.The methodological quality of the included studies was mixed, as reflected by a wide variation in their 'Risk of bias' profiles. Blinding of the participants and personnel was not achieved in most of the included studies, and three of the 13 studies had high risk of bias for selective reporting. Evaluation of the efficacy of the sedative agents was also underpowered, with all the comparisons performed in single small studies.Children who received oral chloral hydrate had lower sedation failure when compared with oral promethazine (RR 0.11, 95% CI 0.01 to 0.82; 1 study, moderate-quality evidence). Children who received oral chloral hydrate had a higher risk of sedation failure after one dose compared to those who received intravenous pentobarbital (RR 4.33, 95% CI 1.35 to 13.89; 1 study, low-quality evidence), but after two doses there was no evidence of a significant difference between the two groups (RR 3.00, 95% CI 0.33 to 27.46; 1 study, very low-quality evidence). Children who received oral chloral hydrate appeared to have more sedation failure when compared with music therapy, but the quality of evidence was very low for this outcome (RR 17.00, 95% CI 2.37 to 122.14; 1 study). Sedation failure rates were similar between oral chloral hydrate, oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam.Children who received oral chloral hydrate had a shorter time to achieve adequate sedation when compared with those who received oral dexmedetomidine (MD -3.86, 95% CI -5.12 to -2.6; 1 study, moderate-quality evidence), oral hydroxyzine hydrochloride (MD -7.5, 95% CI -7.85 to -7.15; 1 study, moderate-quality evidence), oral promethazine (MD -12.11, 95% CI -18.48 to -5.74; 1 study, moderate-quality evidence), and rectal midazolam (MD -95.70, 95% CI -114.51 to -76.89; 1 study). However, children with oral chloral hydrate took longer to achieve adequate sedation when compared with intravenous pentobarbital (MD 19, 95% CI 16.61 to 21.39; 1 study, low-quality evidence) and intranasal midazolam (MD 12.83, 95% CI 7.22 to 18.44; 1 study, moderate-quality evidence).No data were available to assess the proportion of children with successful completion of neurodiagnostic procedure without interruption by the child awakening. Most trials did not assess adequate sedation as measured by specific validated scales, except in the comparison of chloral hydrate versus intranasal midazolam and oral promethazine.Compared to dexmedetomidine, chloral hydrate was associated with a higher risk of nausea and vomiting (RR 12.04 95% CI 1.58 to 91.96). No other adverse events were significantly associated with chloral hydrate (including behavioural change, oxygen desaturation) although there was an increased risk of adverse events overall (RR 7.66, 95% CI 1.78 to 32.91; 1 study, low-quality evidence). AUTHORS' CONCLUSIONS: The quality of evidence for the comparisons of oral chloral hydrate against several other methods of sedation was very variable. Oral chloral hydrate appears to have a lower sedation failure rate when compared with oral promethazine for children undergoing paediatric neurodiagnostic procedures. The sedation failure was similar for other comparisons such as oral dexmedetomidine, oral hydroxyzine hydrochloride, and oral midazolam. When compared with intravenous pentobarbital and music therapy, oral chloral hydrate had a higher sedation failure rate. However, it must be noted that the evidence for the outcomes for the comparisons of oral chloral hydrate against intravenous pentobarbital and music therapy was of very low to low quality, therefore the corresponding findings should be interpreted with caution.Further research should determine the effects of oral chloral hydrate on major clinical outcomes such as successful completion of procedures, requirements for additional sedative agent, and degree of sedation measured using validated scales, which were rarely assessed in the studies included in this review. The safety profile of chloral hydrate should be studied further, especially the risk of major adverse effects such as bradycardia, hypotension, and oxygen desaturation.

Assessment of renal function in the anaesthetised rat following injection of superparamagnetic iron oxide nanoparticles.

A recent study showed that a significant fall in mean arterial pressure (MAP) occurred following intravenous injection of two novel superparamagnetic iron oxide nanoparticles (SPIONs), MF66 and OD15. To assess if this was caused by excessive glomerular clearance, the effect of both particles on renal function was studied. Experiments were performed on sodium pentobarbital anaesthetised male Wistar rats (250-350 g). Twenty-minute urine clearances were taken followed by an i.v. bolus of MF66, OD15 (2 mg·kg-1), or dH2O (0.4 mL·kg-1). MF6 or OD15 injection resulted in a significant transient drop in MAP and renal blood flow by approximately 33% and 50% (P < 0.05). The absolute excretion of sodium was significantly increased (P < 0.05) by almost 80% and 70% following OD15 and MF66, respectively. Similarly, fractional excretion of sodium was increased by almost 80% and 60% following OD15 and MF66, respectively. The glomerular filtration rate was not significantly affected, but urine flow increased nonsignificantly by approximately 50% and 66% following i.v. injection of OD15 and MF66, respectively. SPIONs produce a decrease in blood pressure and a natriuresis; however, the rate of fluid filtration in the kidney was not significantly affected.

Alveolar formation is dysregulated by restricted nutrition but not excess sedation in preterm lambs managed by noninvasive support.

BACKGROUND: Preterm birth and respiratory support with invasive mechanical ventilation frequently leads to bronchopulmonary dysplasia (BPD). A hallmark feature of BPD is alveolar simplification. For our preterm lamb model of BPD, invasive mechanical ventilation is associated with postnatal feeding intolerance (reduced nutrition) and sedation. In contrast, preterm lambs managed by noninvasive support (NIS) have normal alveolar formation, appropriate postnatal nutrition, and require little sedation. We used the latter, positive-outcome group to discriminate the contribution of reduced nutrition vs. sedation on alveolar simplification. We hypothesized that, restricted nutrition, but not sedation with pentobarbital, contributes to impaired indices of alveolar formation in preterm lambs managed by NIS. METHODS: Preterm lambs managed by NIS for 21d were randomized into three groups: NIS control, NIS plus restricted nutrition, and NIS plus excess sedation with pentobarbital. We quantified morphological and biochemical indices of alveolar formation, as well as mesenchymal cell apoptosis and proliferation. RESULTS: Restricted nutrition impaired morphological and biochemical indices of alveolar formation, and reduced mesenchymal cell apoptosis and proliferation. Excess sedation with pentobarbital did not alter these indices, although mesenchymal cell apoptosis was less. CONCLUSION: Our results demonstrate that restricted nutrition, but not excess sedation, contributes to impaired alveolar formation during the evolution of BPD in chronically ventilated preterm lambs.

A suicide involving intraperitoneal injection of pentobarbital.

We present an unusual case of suicide by intraperitoneal injection of pentobarbital, an overdose of zolpidem and the intake of diazepam, ethanol and other psychoactive substances. The autopsy and specimen collection were conducted in a 10 to 18 h postmortem interval. The toxicological analysis revealed a significantly higher pentobarbital concentration in femoral blood compared to cardiac blood (36 vs. 15 mg/L). On the contrary, zolpidem and diazepam concentrations in cardiac blood (2700 and 590 µg/L) were found to be significantly higher than in femoral blood (1500 and 230 µg/L). These findings point to a postmortem redistribution with a distinct gradient from areas of high drug concentrations in the gastrointestinal tract (zolpidem and diazepam) and the injection site (pentobarbital) to peripheral tissue. Ethanol concentration was 0.95 ‰ which amplified the CNS depression. The choice of this unusual suicide method was associated with the deceased's former job as a veterinarian's assistant. In veterinary medicine, the intraperitoneal injection of a lethal dose of pentobarbital is quite commonly performed to euthanise small animals. Intraperitoneal injection is rare as route of administration in humans.

Theanine enhanced both the toxicity of strychnine and anticonvulsion of pentobarbital sodium.

CONTEXT: Theanine, an additive, holds several effects on the central nervous system without toxicity and affects CNS drugs. Theanine bilaterally alters ß wave of the EEG with or without caffeine and pentobarbital-induced locomotor activity. Theanine also enhances hypnosis of pentobarbital sodium (PB) and antidepression of midazolam, suggesting there are complicated interactions between theanine and CNS drugs. On the other side, theanine induces glycine release. Glycine potentiates the strychnine toxicity via NMDA receptor activation. Moreover, PB facilitates GABAA receptor activation by GABA, and it is commonly prescribed for strychnine poison. However, what the role that theanine plays in the anticonvulsion of PB against strychnine poison is still unknown. MATERIALS AND METHODS: Theanine, pentobarbital sodium or strychnine was injected intraperitoneally. EEG was monitored by BIOPAC 16 EEG amplifiers. LD50 of strychnine and hypnotic ED50 of pentobarbital sodium with or without theanine for mice were tested according to Bliss' case. RESULTS: (1) Theanine enhanced the strychnine toxicity. Both theanine and strychnine 1.0 mg/kg increased the power of the ß wave. Theanine aggravated that of strychnine 1.0 mg/kg. Theanine attenuated the LD50 of strychnine. (2) Theanine enhanced the anticonvulsion of PB. Theanine increased the power of α, ß wave and decreased hypnotic ED50 of PB; PB attenuated strychnine-induced EEG excitation and mortality with or without theanine, and theanine enhanced the effects of PB. Further, theanine enhanced the anticonvulsion of PB dose-dependently against the strychnine toxicity but not the lethal toxicity of strychnine. DISCUSSION AND CONCLUSIONS: These results indicated theanine interacted with PB and strychnine. Theanine enhanced both the strychnine toxicity and anticonvulsion of PB against strychnine poison.

Vancomycin pharmacokinetic parameters in patients with acute brain injury undergoing controlled normothermia, therapeutic hypothermia, or pentobarbital infusion.

BACKGROUND: Therapeutic strategies that cause an alteration in patient temperature, such as controlled normothermia (CN), therapeutic hypothermia (TH), and pentobarbital infusion (PI), are often used to manage complications caused by acute brain injury. The purpose of this study was to evaluate pharmacokinetic (PK) parameters of vancomycin in patients with acute brain injury undergoing temperature modulation. METHODS: This was a retrospective cohort study of adult patients with acute brain injury admitted between May 2010 and March 2014 who underwent CN, TH, or PI and received vancomycin. Predicted PK parameters based on population data were compared with calculated PK parameters based on serum concentrations. RESULTS: Seventeen CN patients and 10 TH/PI patients met inclusion criteria. Traumatic brain injury and aneurysmal subarachnoid hemorrhage accounted for the majority of admitting diagnoses. In the CN group, the median dose was 16.7 (15.5-18.4) mg/kg. The median calculated elimination rate constant [0.155 (0.108-0.17) vs. 0.103 (0.08-0.142) hr(-1); p = 0.04] was significantly higher than the predicted value. The median measured trough concentration [8.9 (7.7-11.1) vs. 17.1 (10.8-22.3) υg/mL; p = 0.004] was significantly lower than predicted. In the TH/PI group, the median dose was 15.4 (14.7-17.2) mg/kg. No significant differences were found between the median calculated and predicted elimination rate constant [0.107 (0.097-0.109) vs. 0.112 (0.102-0.127) hr(-1); p = 0.41] and median measured and predicted trough concentration [14.2 (12.7-17.1) vs. 13.1 (11-17.8) υg/mL; p = 0.71]. CONCLUSION: Patients who underwent TH/PI did not exhibit PK alterations when compared to predicted PK parameters based on population data, while patients who underwent CN experienced PK alterations favoring an increased elimination of vancomycin.

Is pentobarbital safe and efficacious in the treatment of super-refractory status epilepticus: a cohort study.

INTRODUCTION: Seizures refractory to third-line therapy are also labeled super-refractory status epilepticus (SRSE). These seizures are extremely difficult to control and associated with poor outcome. We aimed to characterize efficacy and side-effects of continuous infusions of pentobarbital (cIV-PTB) treating SRSE. METHODS: We retrospectively reviewed continuous electroencephalography (cEEG) reports for all adults with RSE treated with cIV-PTB between May 1997 and April 2010 at our institution. Patients with post-anoxic SE and those receiving cIV-PTB for reasons other than RSE were excluded. We collected baseline information, cEEG findings, side-effects and functional outcome at discharge and one year. RESULTS: Thirty one SRSE patients treated with cIV-PTB for RSE were identified. Mean age was 48 years old (interquartile range (IQR) 28,63), 26% (N = 8) had a history of epilepsy. Median SE duration was 6.5 days (IQR 4,11) and the mean duration of cIV-PTB was 6 days (IQR 3,14). 74% (N = 23) presented with convulsive SE. Underlying etiology was acute symptomatic seizures in 52% (N = 16; 12/16 with encephalitis), remote 30% (N = 10), and unknown 16% (N = 5). cIV-PTB controlled seizures in 90% (N = 28) of patients but seizures recurred in 48% (N = 15) while weaning cIV-PTB, despite the fact that suppression-burst was attained in 90% (N = 28) of patients and persisted >72 hours in 56% (N = 17). Weaning was successful after adding phenobarbital in 80% (12/15 of the patients with withdrawal seizures). Complications during or after cIV-PTB included pneumonia (32%, N = 10), hypotension requiring pressors (29%, N = 9), urinary tract infection (13%, N = 4), and one patient each with propylene glycol toxicity and cardiac arrest. One-third (35%, N = 11) had no identified new complication after starting cIV-PTB. At one year after discharge, 74% (N = 23) were dead or in a state of unresponsive wakefulness, 16% (N = 5) severely disabled, and 10% (N = 3) had no or minimal disability. Death or unresponsive wakefulness was associated with catastrophic etiology (p = 0.03), but none of the other collected variables. CONCLUSIONS: cIV-PTB effectively aborts SRSE and complications are infrequent; outcome in this highly refractory cohort of patients with devastating underlying etiologies remains poor. Phenobarbital may be particularly helpful when weaning cIV-PTB.