Neuraxial Anesthesia in Parturients with Thrombocytopenia: A Multisite Retrospective Cohort Study.

BACKGROUND: The primary aim of this study was to estimate the risk of neuraxial hematoma associated with neuraxial anesthetic procedures in thrombocytopenic parturients. METHODS: A multicenter retrospective cohort study design was used to estimate the risk for spinal-epidural hematoma in parturients with a platelet count of <100,000/mm receiving neuraxial anesthesia and the risk of complications in thrombocytopenic parturients who receive general anesthesia. RESULTS: No cases of spinal hematoma were observed in 102 thrombocytopenic parturients receiving epidural analgesia or 71 receiving spinal anesthesia. Including data from the previous published series (total n = 499), the exact binomial 95% confidence interval for the risk of spinal-epidural hematoma was 0% to 0.6%. Given the small number of patients at each specific platelet count, the theoretical risks at individual platelet count strata are presented. Overall aggregate serious morbidity rate in women who received general anesthesia secondary to thrombocytopenia was 6.5% (95% confidence interval, 2.1%-14.5%). CONCLUSIONS: Our work supports the relative maternal safety of neuraxial anesthesia in parturients with mild thrombocytopenia and estimates the maternal complication rate associated with the avoidance of neuraxial anesthesia. Remaining uncertainties at lower platelet counts make a national "low platelet" registry critical to a more accurate assessment of the risk of epidural hematoma and would aid in standardization of anesthesia practice.

Large-scale functional annotation and expanded implementations of the P{wHy} hybrid transposon in the Drosophila melanogaster genome.

Whole genome sequencing of the model organisms has created increased demand for efficient tools to facilitate the genome annotation efforts. Accordingly, we report the further implementations and analyses stemming from our publicly available P{wHy} library for Drosophila melanogaster. A two-step regime-large scale transposon mutagenesis followed by hobo-induced nested deletions-allows mutation saturation and provides significant enhancements to existing genomic coverage. We previously showed that, for a given starting insert, deletion saturation is readily obtained over a 60-kb interval; here, we perform a breakdown analysis of efficiency to identify rate-limiting steps in the process. Transrecombination, the hobo-induced recombination between two P{wHy} half molecules, was shown to further expand the P{wHy} mutational range, pointing to a potent, iterative process of transrecombination-reconstitution-transrecombination for alternating between very large and very fine-grained deletions in a self-contained manner. A number of strains also showed partial or complete repression of P{wHy} markers, depending on chromosome location, whereby asymmetric marker silencing allowed continuous phenotypic detection, indicating that P{wHy}-based saturational mutagenesis should be useful for the study of heterochromatin/positional effects.

Selective Intraoperative Vasopressor Use Is Not Associated with Increased Risk of DIEP Flap Complications.

BACKGROUND: During deep inferior epigastric perforator (DIEP) flap cases, anesthesiologists commonly avoid intravenous vasopressor administration because of the theoretical concern of inducing vasospasm, thrombosis, or congestion in the vessels of the anastomosis, potentially resulting in poor flap perfusion and ischemia and necessitating revision. In the setting of hypotension, however, vasopressor administration may actually improve outcomes by augmenting flap perfusion by means of increased mean arterial pressure. METHODS: The authors reviewed 475 consecutive DIEP flap cases in 333 patients at a single large academic medical center over a 3-year period, addressing potential confounders using univariate analyses. RESULTS: Ephedrine administration was significantly associated with decreased risk of intraoperative flap complications (OR, 0.88), including vasospasm, thrombosis, and congestion requiring revision, compared with controls, after controlling for the severity and duration of hypotension. Phenylephrine had no significant association with complication rates. Vasopressor administration was not associated with an increased risk of reoperation in the setting of necrosis within 60 days. CONCLUSIONS: Ephedrine treatment for hypotension during DIEP flap cases is associated with decreased intraoperative flap complication rates compared with controls who did not receive vasopressors, whereas phenylephrine has no significant association. The common clinical practice of complete abstinence from vasopressors out of concern for worsening DIEP flap outcomes is not supported by this study. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

The relationship of cigarette smoking to peripheral arterial disease.

Cigarette smoking is one of the most important risk factors for peripheral arterial disease (PAD). Smoking increases the risk of PAD by several fold and is a more influential risk factor for PAD than for coronary artery disease. Multiple pathophysiologic mechanisms may account for the prevalence of atherosclerosis in cigarette smokers. These include abnormalities of endothelial function, lipoprotein metabolism, coagulation, and platelet function. Smoking cessation decreases the risk of cardiovascular morbidity and mortality, and may improve functional capacity in patients with PAD. Therapies to promote smoking cessation include counseling, nicotine replacement, and bupropion. Healthcare providers must enhance their efforts and target smoking cessation as a modifiable risk factor in patients with PAD and other manifestations of atherosclerosis.

Perioperative management of partial face transplantation involving a heparin antibody-positive donor.

Heparin-induced thrombocytopenia (HIT) is an immunologic condition that may lead to thrombosis. We present a case of face transplantation from a donor who had suffered a severe stroke, possibly from HIT, during cardiac surgery. The procedure was planned to include full heparinization. The anesthesia team was involved in the early planning phase and had detailed access to the donor's medical history; alternative anticoagulation for the donor and recipient was suggested so as to avoid a possible complication.

A deletion-generator compound element allows deletion saturation analysis for genomewide phenotypic annotation.

With the available eukaryotic genome sequences, there are predictions of thousands of previously uncharacterized genes without known function or available mutational variant. Thus, there is an urgent need for efficient genetic tools for genomewide phenotypic analysis. Here we describe such a tool: a deletion-generator technology that exploits properties of a double transposable element to produce molecularly defined deletions at high density and with high efficiency. This double element, called P[wHy], is composed of a "deleter" element hobo, bracketed by two genetic markers and inserted into a "carrier" P element. We have used this P[wHy] element in Drosophila melanogaster to generate sets of nested deletions of sufficient coverage to discriminate among every transcription unit within 60 kb of the starting insertion site. Because these two types of mobile elements, carrier and deleter, can be found in other species, our strategy should be applicable to phenotypic analysis in a variety of model organisms.