Pediatric research
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Newborn resuscitation with pure oxygen may be associated with long-term detrimental effects. Due to the change in attitude toward use of less oxygen upon resuscitation, there is a need to study effects of intermediate hyperoxia. The aim was to study dose-response correlation between inspiratory fraction of oxygen used for resuscitation and urinary markers of oxidative damage to DNA and amino acids. ⋯ Quotient of 8-oxo-dG/2dG and o-Tyr/Phe ratios were significantly and dose-dependant higher in piglets resuscitated with supplementary oxygen. 8-oxodG/dG: Mean (SD) 5.76 (1.81) versus 22.44 (12.55) p < 0.01 and o-Tyr/Phe: 19.07 (10.7) versus 148.7 (59.8)for 21% versus 100%, p < 0.001. Hypoxia and subsequent resuscitation for 15 min with graded inspiratory fraction of oxygen causes increased oxidative stress and a dose-dependant oxidation of DNA and Phenylalanine. The increase in the hydroxyl attack may lead to a pro-oxidative status and risk for genetic instability.
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Comparative Study
Monocyte mRNA phenotype and adverse outcomes from pediatric multiple organ dysfunction syndrome.
Impairment of the ability to mount an inflammatory response is associated with death from adult critical illness. This phenomenon, characterized by reduced monocyte production of proinflammatory mediators such as tumor necrosis factor alpha (TNF-alpha), is poorly understood in children. We hypothesized that differential expression of inflammation-related genes would be seen in monocytes from children with adverse outcomes from multiple organ dysfunction syndrome (MODS). ⋯ Among survivors, high mRNA levels for IL-10, IRAK-M, pyrin, IRAK1, or TLR4 were associated with longer durations of pediatric intensive care unit (PICU) stay and mechanical ventilation (p < or = 0.02). These data suggest that adverse outcomes from pediatric MODS are associated with an anti-inflammatory monocyte mRNA phenotype. Future studies are warranted to explore mechanisms of immunodepression in pediatric critical illness.
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Few data exist regarding resuscitation of hypovolemic shock in infants, and alternative strategies such as vasopressor therapy merit further evaluation. However, the effects of norepinephrine on cerebral perfusion and oxygenation during hemorrhagic shock in the pediatric population are still unclear. Eight anesthetized piglets were subjected to hypotension by blood withdrawal of 25 mL/kg. ⋯ Following norepinephrine, cerebral perfusion pressure (CPP) could be restored immediately, whereas TOI and Ptio2 did not increase significantly. In contrast, following retransfusion, TOI and Ptio2 increased to 68+/-3% and 27+/-7 mm Hg reaching baseline values, respectively. In conclusion, while norepinephrine increased CPP immediately, cerebral oxygenation as reflected by TOI and Ptio2 could not be improved by norepinephrine, but only by retransfusion.
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The upper airway wall motion may be responsible for significant error when measuring respiratory resistance (Rrs) with the forced oscillation technique (FOT), particularly in young children with airway obstruction. Assessing the response to methacholine from the change in respiratory admittance (Ars, the reciprocal of respiratory impedance, Zrs) avoids the artifact. The aim of the study was to explore the possibility of assessing the response to a bronchodilator from the change in Ars. ⋯ The relative change in Ars was not significantly different with SG and HG. Both estimates were significantly correlated (p < 0.0001). The change in Ars may thus be useful to avoid the upper airway artefact when assessing the response to salbutamol using the FOT in young children.
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Sensorineural hearing loss (SNHL) is the most common sequel of bacterial meningitis (BM) and is observed in up to 30% of survivors when the disease is caused by Streptococcus pneumoniae. BM is the single most important origin of acquired SNHL in childhood. Anti-inflammatory dexamethasone holds promises as potential adjuvant therapy to prevent SNHL associated with BM. ⋯ Three weeks after the infection, the averaged number of type I neurons per square millimeter of the Rosenthal's canal dropped from 0.3019 +/- 0.0252 in controls to 0.2227 +/- 0.0635 in infected animals receiving saline (p < 0.0005). Dexamethasone was not more effective than saline in preventing neuron loss (0.2462 +/- 0.0399; p > 0.05). These results suggest that more efficient adjuvant therapies are needed to prevent SNHL associated with pediatric PM.