Administration of Tumescence in Pediatric Burn Patients Causes Significant Hypertension.

The effects of injecting tumescence containing phenylephrine in pediatric burn patients are unknown, but anecdotally our clinicians note a high incidence of hypertension requiring treatment. This study sought to determine whether tumescence with phenylephrine was associated with hypertension requiring treatment in our pediatric burn patients. This was a retrospective cohort study of pediatric burn patients who underwent tangential excision with split-thickness autografting, excision alone, or autografting alone from 2013 to 2017. Records were reviewed for hypertensive episodes, defined as ≥2 consecutive blood pressure readings that were >2 SD above normal. Published intraoperative age- and sex-adjusted standards were used to define reference values. Parametric and nonparametric tests were used when appropriate. In total, 258 operations were evaluated. Mean patient age was 7.6 ± 5.2 years, and 64.7% were male. Patients were predominately white (69.8%). Overall, there was a 62.8% incidence of hypertension. On univariate logistic regression analysis, duration of operation, estimated blood loss, treated TBSA, and weight-adjusted volume of tumescence were significant predictors of intraoperative hypertension (P < .01). On multivariate analysis, weight-adjusted volume of tumescence alone was significantly associated with the presence of hypertension with an odds ratio of 2.0 (95% confidence interval: 1.33-3.04). Of the 162 operations which exhibited at least one episode of significant hypertension, 128 cases (79%) were treated. Intraoperative administration of phenylephrine-containing tumescence in pediatric burn patients is associated with clinically significant hypertension requiring treatment. This practice should be conducted with caution in pediatric burn operations until its clinical implications are defined.

The Double-Strand Break Landscape of Meiotic Chromosomes Is Shaped by the Paf1 Transcription Elongation Complex in Saccharomyces cerevisiae.

Histone modification is a critical determinant of the frequency and location of meiotic double-strand breaks (DSBs), and thus recombination. Set1-dependent histone H3K4 methylation and Dot1-dependent H3K79 methylation play important roles in this process in budding yeast. Given that the RNA polymerase II associated factor 1 complex, Paf1C, promotes both types of methylation, we addressed the role of the Paf1C component, Rtf1, in the regulation of meiotic DSB formation. Similar to a set1 mutation, disruption of RTF1 decreased the occurrence of DSBs in the genome. However, the rtf1 set1 double mutant exhibited a larger reduction in the levels of DSBs than either of the single mutants, indicating independent contributions of Rtf1 and Set1 to DSB formation. Importantly, the distribution of DSBs along chromosomes in the rtf1 mutant changed in a manner that was different from the distributions observed in both set1 and set1 dot1 mutants, including enhanced DSB formation at some DSB-cold regions that are occupied by nucleosomes in wild-type cells. These observations suggest that Rtf1, and by extension the Paf1C, modulate the genomic DSB landscape independently of H3K4 methylation.