Use of Dexamethasone to Prevent Extubation Failure in Pediatric Intensive Care Unit: A Randomized Controlled Clinical Trial

Extubation failure is a common event in intensive care units. Corticosteroids are effective in preventing failure in adults, but no consensus has been reached on this matter in pediatrics. We assessed the efficacy of intravenous dexamethasone in mechanically ventilated children and adolescents for more than 48 hours, with at least one risk factor for failure. Extubations were scheduled 24 hours in advance when possible, and patients were randomly assigned into two groups: one group received a loading dose followed by up to four doses of dexamethasone, and the other group received no corticosteroids. Need for reintubation and length of stay in the pediatric intensive care unit were similar in both groups, and frequency of reintubation was 12.9%.

Diagnosis and treatment of streptococcal toxic shock syndrome in the pediatric intensive care unit: case report

Among the infections caused by Streptococcus β hemolyticus from the Lancefield serogroup A, toxic shock syndrome is perhaps the most severe, and its mortality rate is high. Its clinical similarity to other forms of shock, especially septic shock, can often confuse the evaluator and interfere with the selection of the most appropriate therapy. This report aims to inform readers of the need to add this syndrome as a differential diagnosis in cases of shock, especially those with no well-defined clinical manifestations. For this purpose, we present the case of an infant with common flu-like symptoms who progressed rapidly with a rash, a reduced level of consciousness and clinical and laboratory signs of shock that required intensive support. In addition to cultures indicating the etiological agent, the appearance of exanthema and necrotizing fasciitis led to the diagnosis. However, less than 50% of cases present classic clinical signs of this entity. Penicillins combined with aminoglycosides are still the therapy of choice and are supported by a high level of evidence. Despite the severity of this patient's presentation, the progression was satisfactory.

Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

Protective effects of the dipeptidyl peptidase IV inhibitor sitagliptin in the blood-retinal barrier in a type 2 diabetes animal model

AIM

The aim of this study was to evaluate the efficacy of sitagliptin, a dipeptidyl peptidase IV inhibitor (DPP-IV), in preventing the deleterious effects of diabetes on the blood-retinal barrier in male Zucker Diabetic Fatty (ZDF) rats.

METHODS

ZDF rats at 20 weeks of age were treated with sitagliptin (10 mg/kg/day) during 6 weeks. The effect of the drug on glycaemia was assessed by evaluating glycated haemoglobin (HbA1c). The content and/or distribution of tight junction (TJ) proteins occludin and claudin-5, as well as nitrotyrosine residues, interleukin (IL)-1β, BAX and Bcl-2 was evaluated in the retinas by western blotting and/or immunohistochemistry. Retinal cell apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay. The number of CD34+ cells present in peripheral circulation was assessed by flow cytometry, and endothelial progenitor cells (EPC) adhesion ability to the retinal vessels was evaluated by immunohistochemistry.

RESULTS

Sitagliptin improved glycaemic control as reflected by a significant decrease in HbA1c levels by about 1.2%. Treatment with sitagliptin prevented the changes in the endothelial subcellular distribution of the TJ proteins induced by diabetes. Sitagliptin also decreased the nitrosative stress, the inflammatory state and cell death by apoptosis in diabetic retinas. Diabetic animals presented decreased levels of CD34+ cells in the peripheral circulation and decreased adhesion ability of EPC to the retinal vessels. Sitagliptin allowed a recovery of the number of CD34+ cells present in the bloodstream to levels similar to their number in controls and increased the adhesion ability of EPC to the retinal vessels.

CONCLUSIONS

Sitagliptin prevented nitrosative stress, inflammation and apoptosis in retinal cells and exerted beneficial effects on the blood-retinal barrier integrity in ZDF rat retinas.

Antibiotic treatment schemes for very severe community-acquired pneumonia in children: a randomized clinical study

OBJECTIVE

To compare clinical response to initial empiric treatment with oxacillin plus ceftriaxone and amoxicillin plus clavulanic acid in hospitalized children diagnosed with very severe community-acquired pneumonia (CAP).

METHODS

A prospective randomized clinical study was conducted among children 2 months to 5 years old with a diagnosis of very severe CAP in the pediatric ward of São Paulo State University Hospital in Botucatu, São Paulo, Brazil, from April 2007 to May 2008. Patients were randomly divided into two groups by type of treatment: an oxacillin/ceftriaxone group (OCG, n = 48) and an amoxicillin/clavulanic acid group (ACG, n = 56). Analyzed outcomes were: time to clinical improvement (fever and tachypnea), time on oxygen therapy, length of stay in hospital, need to widen antimicrobial spectrum, and complications (including pleural effusion).

RESULTS

The two groups did not differ statistically for age, sex, symptom duration before admission, or previous antibiotic treatment. Time to improve tachypnea was less among ACG patients than OCG patients (4.8 ± 2.2 versus 5.8 ± 2.4 days respectively; P = 0.028), as was length of hospital stay (11.0 ± 6.2 versus 14.4 ± 4.5 days respectively; P = 0.002). There were no statistically significant differences between the two groups for fever improvement time, time on oxygen therapy, need to widen antimicrobial spectrum, or frequency of pleural effusion.

CONCLUSIONS

Both treatment plans are effective in treating very severe CAP in 2-month-to 5-year-old hospitalized children. The only analyzed outcome that favored amoxicillin/clavulanic acid treatment was time required to improve tachypnea.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT01166932.

Causality assessment of adverse drug reactions: comparison of the results obtained from published decisional algorithms and from the evaluations of an expert panel, according to different levels of imputability

OBJECTIVES

To evaluate agreement between causality assessments of reported adverse drug reactions (ADRs) obtained from decisional algorithms, with those obtained from an expert panel using the WHO global introspection method (GI), according to different levels of imputability and to evaluate the influence of confounding variables.

METHOD

Two hundred reports were included in this study. An independent researcher used decisional algorithms, while an expert panel assessed the same ADR reports using the GI, both aimed at evaluating causality. Reports were divided according to the presence, absence or lack of information on confounding variables.

RESULTS

The rates of concordance between assessments made using the algorithms and GI according to levels of imputability were: 45% for 'certain', 61% for 'probable', 46% for 'possible' and 17% for drug unrelated terms. When confounding variables were taken into account, the rates of concordance for the 'absence of information', 'lack of information' and 'presence of confounding variables' in the 'certain' group were 49, 69 and 7%, respectively. The corresponding values for the 'probable' group were 80, 68 and 24% and 30, 51 and 51%, respectively for the 'possible' group.

CONCLUSION

Full agreement with global introspection was not found for any level of causality assessment. Confounding variables were found to be associated with low levels of agreement between decision algorithms and the GI method compromising the algorithms' sensitivity and specificity.

Acute changes in dopamine release and turnover in rat caudate nucleus following a single dose of methamphetamine

Acute changes in dopamine (DA) turnover were studied in the caudate nucleus (CN) of adult male rats between 0-24 h after a single injection of Methamphetamine (20 mg/kg, ip). A single dose of METH-induced an increase in DA turnover [(DOPAC + HVA)/DA] concomitant with an acute DA release followed by transient DA and DOPAC depletion in the rat CN.

In vitro study on the interaction of Valeriana officinalis L. extracts and their amino acids on GABAA receptor in rat brain

This work studied in vitro the interaction of aqueous and hydroalcoholic extracts of Valeriana officinalis L. and compounds that are present in the extracts (amino acids and valerenic acid) with the GABAA (gamma-aminobutyric acid) receptor, using the [3H] muscimol binding technique to crude synaptic membranes from rat brain cortices. Both extracts displaced [3H]muscimol bound and this effect is probably due only to their amino acid content, specially GABA. This fact explains the in vitro effect of valerian extracts on GABAA receptor but not their sedative effect.

Synaptosomal GABA release as influenced by valerian root extract--involvement of the GABA carrier

The effect of an aqueous extract obtained from the roots of Valeriana officinalis was investigated on the uptake and release of GABA in synaptosomes isolated from rat brain cortex. Aqueous extract of valerian inhibited the uptake and stimulated the release of [3H]GABA, either in the absence or in the presence of K+ depolarization. The release was Na(+)-dependent and independent of the presence of Ca2+ in the external medium. It is concluded that valerian extract releases [3H]GABA by reversal of the GABA carrier, which is Na(+)-dependent and Ca(2+)-independent. This increase in [3H]GABA release appears to be independent from Na(+)-K(+)-ATPase activity and the membrane potential.

Monoamine oxidase activity in blood platelets of migraine patients

Biochemical changes in platelets of migraine patients during the attacks have been reported before, however there are some conflicting results. In an attempt to define the biochemical lesion in the platelets, we have carried out a survey of platelets monoamine oxidase in migraine patients with and without aura. Platelet MAO activity in platelets from migraine patients was significantly reduced when compared with normal platelets.