Return to Duty Following Exertional Heat Stroke: A Review.

INTRODUCTION: Exertional heat stroke (EHS), which presents with extreme hyperthermia and alteration to the central nervous system, disproportionately affects the military, where warfighters are expected to perform in all types of environmental conditions. Because of an incomplete understanding of individualized recovery from EHS, there are several shortcomings with the current guidance on return to duty (RTD) following an EHS. The purpose of this manuscript is to provide an updated literature review of best practices for return to duty following EHS to guide decision making regarding EHS and explore areas of future research for medical staff who work with warfighters. MATERIALS AND METHODS: A literature review related to EHS in both athlete and military populations, as well as any existing guidelines for RTD, was conducted using PubMed and Covidence. RESULTS: Twenty-one articles were identified for this updated review on EHS and RTD, with recommendations focused during and after an EHS event, as well as the role of heat tolerance testing (HTT). CONCLUSIONS: EHS has a high morbidity and mortality rate if not treated rapidly. Because the extent of end-organ damage is dependent on the amount of time that the individual is hyperthermic, rapid diagnosis via rectal thermometry, and efficient cooling methods are imperative to the wellbeing of EHS patients. Following EHS, gradual RTD recommendations within the limits of operational demand should be implemented to reduce the risk for a subsequent heat injury event. While many versions of HTT, most notably the Israeli Defense Force (IDF) protocol, have been created to guide RTD recommendations, a universal assessment for heat tolerance has yet to be adopted. As such, medical personnel should apply a multifactorial approach to ensure safe RTD.

Structure Determination of Lipid A with Multiple Glycosylation Sites by Tandem MS of Lithium-Adducted Negative Ions.

FLATn is a tandem mass spectrometric technique that can be used to rapidly generate spectral information applicable for structural elucidation of lipids like lipid A from Gram-negative bacterial species from a single bacterial colony. In this study, we extend the scope and capability of FLATn by tandem MS fragmentation of lithium-adducted molecular lipid A anions and fragments (FLATn-Li) that provides additional structural and diagnostic data from FLATn samples allowing for the discrimination of terminal phosphate modifications in a variety of pathogenic and environmental species. Using FLATn-Li, we elucidated the lipid A structure from several bacterial species, including novel structures from arctic bacterioplankton of the Duganella and Massilia genera that favor 4-amino-4-deoxy-l-arabinopyranose (Ara4N) modification at the 1-phosphate position and that demonstrate double glycosylation with Ara4N at the 1 and 4' phosphate positions simultaneously. The structures characterized in this work demonstrate that some environmental psychrophilic species make extensive use of this structural lipid A modification previously characterized as a pathogenic adaptation and the structural basis of resistance to cationic antimicrobial peptides. This observation extends the role of phosphate modification(s) in environmental species adaptation and suggests that Ara4N modification can functionally replace the positive charge of the phosphoethanolamine modification that is more typically found attached to the 1-phosphate position of modified lipid A.