Introduction Hemorrhage is the leading threat to the survival of battlefield casualties. This study aims to investigate the types of fluids and blood products administered in prehospital trauma encounters to discover the effectiveness of Tactical Combat Casualty Care (TCCC) recommendations. Materials and Methods This is a secondary analysis of a previously described dataset from the Department of Defense Trauma Registry with a focus on prehospital fluid and blood administration in conjunction with changes in the TCCC guidelines. We collected demographic information on each patient. We categorized receipt of each fluid type and blood product as a binary variable for each casualty and evaluated trends over 2007–2020 both unadjusted and controlling for injury severity and mechanism of injury. Results Our original dataset comprised 25,897 adult casualties from January 1, 2007 through March 17, 2020. Most (97.3%) of the casualties were male with a median age of 25. Most (95.5%) survived to hospital discharge, and 12.2% of the dataset received fluids of any kind. Medical personnel used crystalloids in 7.4% of encounters, packed red blood cells in 2.0%, and whole blood in 0.5% with very few receiving platelets or freeze-dried plasma. In the adjusted model, we noted significant year-to-year increases in intravenous fluid administration from 2014 to 2015 and 2018 to 2019, with significant decreases noted in 2008–2009, 2010–2012, and 2015–2016. We noted no significant increases in Hextend used, but we did note significant decreases in 2010–2012. For any blood product, we noted significant increases from 2016 to 2017, with decreases noted in 2009–2013, 2015–2016, and 2017–2018. Overall, we noted a general spike in all uses in 2011–2012 that rapidly dropped off 2012–2013. Crystalloids consistently outpaced the use of blood products. We noted a small upward trend in all blood products from 2017 to 2019. Conclusions Changes in TCCC guidelines did not immediately translate into changes in prehospital fluid administration practices. Crystalloid fluids continue to dominate as the most commonly administered fluid even after the 2014 TCCC guidelines changed to use of blood products over crystalloids. There should be future studies to investigate the reasons for delay in guideline implementation and efforts to improve adherence.

In this review five older and lesser known clinical concepts which have weathered decades of clinical practice are presented along with the best supportive evidence that is currently available. Parenteral diarrhea is defined as diarrhea due to infections outside the gastrointestinal tract; and specifically, urinary tract infections are often associated with concomitant diarrhea. The otitis-conjunctivitis syndrome is a clinical observation that for specific infectious agents otitis media and conjunctivitis will commonly occur together. The concept of double-sickening; a potentially useful clinical presentation that commonly forecasts a secondary bacterial infection is also reviewed. Another lesser known topic discussed is the evidence that Candida species frequently colonize the skin in many diaper rashes and the early and more liberal administration of antifungal medications may be appropriate. Finally, in contrast to the common practice of aggressively treating fever, there is new and growing evidence suggesting that fever is actually beneficial to the patient. While these five older clinical concepts have variable degrees of supporting evidence, their longevity and usefulness over decades of clinical practice cannot be denied.