Sinus Arrest Related to Dexmedetomidine Infusion in an Infant; a Case Report and Review of Current Literature.

Background: Dexmedetomidine, an alpha 2 agonist, has emerged as a desirable sedative agent in the pediatric intensive care unit due to its minimal effect on respiratory status and reduction in delirium. Bradycardia and hypotension are common side effects, however there are emerging reports of more serious cardiovascular events, including sinus arrest and asystole. These case reports have been attributed to high vagal tone or underlying cardiac conduction dysfunction. Objectives: To describe the development of sinus arrest during sedation with dexmedetomidine in a patient without clinical features of high vagal tone, underlying cardiac conduction dysfunction, or intervening episodes of bradycardia. Case Presentation: An 11 month-old patient requiring sedation during mechanical ventilation for acute respiratory failure secondary to Adenovirus. To facilitate sedation, a dexmedetomidine infusion was initiated at .5 mcg/kg/hr and increased to maximum 1 mcg/kg/hr. Within 8 hours of initiating therapy, the patient had three episodes of sinus arrest. There was no intervening bradycardia between episodes and no further episodes occurred following discontinuation of dexmedetomidine. The patient did not have any clinical features associated with high vagal tone or underlying cardiac conduction dysfunction. Conclusions: As result of these findings, understanding risk factors for bradycardia, or more serious hemodynamic instability with dexmedetomidine infusions, is important to help identify high risk patients and weigh the associated risks and benefits of its administration.

Results from a prospective longitudinal survey of employment and work outcomes in newly diagnosed cancer patients during and after curative-intent chemotherapy: A Wisconsin Oncology Network study.

BACKGROUND: Postcancer work limitations may affect a substantial proportion of patients and contribute to the "financial toxicity" of cancer treatment. The degree and nature of work limitations and employment outcomes are poorly understood for cancer patients, particularly in the immediate period of transition after active treatment. We prospectively examined employment, work ability, and work limitations during and after treatment. METHODS: A total of 120 patients receiving curative therapy who were employed prior to their cancer diagnosis and who intended to work during or after end of treatment (EOT) completed surveys at baseline (pretreatment), EOT, and 3, 6, and 12 months after EOT. Surveys included measures of employment, work ability, and work limitations. Descriptive statistics (frequencies, percentages, means with standard deviations) were calculated. RESULTS: A total of 111 participants completed the baseline survey. On average, participants were 48 years of age and were mostly white (95%) and female (82%) with a diagnosis of breast cancer (69%). Full-time employment decreased during therapy (from 88% to 50%) and returned to near prediagnosis levels by 12-month follow-up (78%). Work-related productivity loss due to health was high during treatment. CONCLUSIONS: This study is the first to report the effects of curative intent cancer therapy on employment, work ability, and work limitations both during and after treatment. Perceived work ability was generally high overall 12 months after EOT, although a minority reported persistent difficulty. A prospective analysis of factors (eg, job type, education, symptoms) most associated with work limitations is underway to assist in identifying at-risk patients.

Plk1 protects kinetochore-centromere architecture against microtubule pulling forces.

During mitosis, sister chromatids attach to microtubules which generate ~ 700 pN pulling force focused on the centromere. We report that chromatin-localized signals generated by Polo-like kinase 1 (Plk1) maintain the integrity of the kinetochore and centromere against this force. Without sufficient Plk1 activity, chromosomes become misaligned after normal condensation and congression. These chromosomes are silent to the mitotic checkpoint, and many lag and mis-segregate in anaphase. Their centromeres and kinetochores lack CENP-A, CENP-C, CENP-T, Hec1, Nuf2, and Knl1; however, CENP-B is retained. CENP-A loss occurs coincident with secondary misalignment and anaphase onset. This disruption occurs asymmetrically prior to anaphase and requires tension generated by microtubules. Mechanistically, centromeres highly recruit PICH DNA helicase and PICH depletion restores kinetochore disruption in pre-anaphase cells. Furthermore, anaphase defects are significantly reduced by tethering Plk1 to chromatin, including H2B, and INCENP, but not to CENP-A. Taken as a whole, this demonstrates that Plk1 signals are crucial for stabilizing centromeric architecture against tension.