Clinical Applications of Heart Rate Variability in the Triage and Assessment of Traumatically Injured Patients

Heart rate variability (HRV) is a method of physiologic assessment which uses fluctuations in the RR intervals to evaluate modulation of the heart rate by the autonomic nervous system (ANS). Decreased variability has been studied as a marker of increased pathology and a predictor of morbidity and mortality in multiple medical disciplines. HRV is potentially useful in trauma as a tool for prehospital triage, initial patient assessment, and continuous monitoring of critically injured patients. However, several technical limitations and a lack of standardized values have inhibited its clinical implementation in trauma. The purpose of this paper is to describe the three analytical methods (time domain, frequency domain, and entropy) and specific clinical populations that have been evaluated in trauma patients and to identify key issues regarding HRV that must be explored if it is to be widely adopted for the assessment of trauma patients

Practices for Protecting and Enhancing Fish and Wildlife on Coal Mined Land in the Uinta-Southwestern Utah Region

This handbook contains information on the best current practices to minimize disturbances and adverse impacts of surface mining on fish and wildlife resources. Current state and federal legislation was reviewed to determine those practices which were most compatible with the best technology currently available, fish and wildlife plans, and reclamation plans for the Uinta-Southwestern region of the U.S. The information presented includes risks, limitations, approximate costs, and maintenance and management requirements of each practice. Plans for the restoration of specific habitats, according to the best current practices, are also included

Clotting Changes, Including Disseminated Intravascular Coagulation, during Rapid Renal-Homograft Rejection

One of two patients in whom early homograft rejection developed after renal transplantation had many antidonor antibodies before operation. By the measurement of gradients across intracorporeal and extracorporeal homografts in this patient, the new kidneys were shown to sequester host immunoglobulins, platelets, white cells and clotting factors. Moreover, the renal venous blood then contained fibrinolytic activity. This presensitized recipient, as well as a second patient who did not have detectable preformed humoral antibodies, gave evidence from clinical observation and from the various clotting tests of disseminated intravascular coagulation with fibrinolysis and a severe bleeding diathesis. Immunofluorescent and histologic studies revealed a laying down of fibrin in the homograft vessels that continued in some cases to cortical necrosis of the transplanted kidneys or, alternatively, receded at the time fibrinolysis occurred. The variety of rejection seen in these patients has been characterized as an immunologically induced coagulopathy. © 1970, Massachusetts Medical Society. All rights reserved

Crowdsourcing hypothesis tests: Making transparent how design choices shape research results

To what extent are research results influenced by subjective decisions that scientists make as they design studies? Fifteen research teams independently designed studies to answer fiveoriginal research questions related to moral judgments, negotiations, and implicit cognition. Participants from two separate large samples (total N > 15,000) were then randomly assigned to complete one version of each study. Effect sizes varied dramatically across different sets of materials designed to test the same hypothesis: materials from different teams renderedstatistically significant effects in opposite directions for four out of five hypotheses, with the narrowest range in estimates being d = -0.37 to +0.26. Meta-analysis and a Bayesian perspective on the results revealed overall support for two hypotheses, and a lack of support for three hypotheses. Overall, practically none of the variability in effect sizes was attributable to the skill of the research team in designing materials, while considerable variability was attributable to the hypothesis being tested. In a forecasting survey, predictions of other scientists were significantly correlated with study results, both across and within hypotheses. Crowdsourced testing of research hypotheses helps reveal the true consistency of empirical support for a scientific claim.</div

Tissue oxygenation during management of cerebral perfusion pressure with phenylephrine or vasopressin

Phenylephrine is often used for management of cerebral perfusion pressure after traumatic brain injury, but can have undesirable actions. Few studies have evaluated alternatives. The hypothesis was that arginine vasopressin was as effective as phenylephrine for maintaining tissue oxygenation during cerebral perfusion pressure management. Prospective randomized, blinded animal study. University laboratory. Thirty-five anesthetized swine (46 +/- 1 kg). Blunt trauma to the head and bilateral chests (estimated injury severity score was 25-32) was followed by hypoventilation. Resuscitation was divided into phases to simulate treatment in a typical prehospital, emergency room, and intensive care unit. For 30-45 mins postinjury, 1 L of normal saline was administered. For 45-120 mins, normal saline maintained systolic blood pressure >100 mm Hg plus mannitol for intracranial hypertension. After 120 mins, phenylephrine or arginine vasopressin was titrated to cerebral perfusion pressure >70 mm Hg (randomized and blinded) plus normal saline to maintain filling pressure >12 mm Hg plus glucose to maintain normoglycemia. Mortality rate was 37% (13 of 35) within 2 hrs. Before resuscitation, mean arterial pressure was 61 +/- 5 mm Hg, heart rate was 110 +/- 6 beats/min, PaO2 was 46 +/- 2 mm Hg, and lactate was 5.0 +/- 0.4 mM. Intracranial pressure increased from 8 +/- 1 mm Hg to 20 +/- 1 mm Hg and brain tissue PO2 decreased from 19 +/- 1 mm Hg to 8 +/- 1 mm Hg. Resuscitation corrected most variables, as well as mixed venous, renal, portal, and muscle oxygen saturations, but 90% (20 of 22) required pressor support. After 6 hrs with either pressor, hemodynamics were stable. However, with phenylephrine vs. arginine vasopressin, intracranial pressure averaged >10 mm Hg higher and brain tissue PO2 was 6 mm Hg lower, whereas tissue oxygen saturations were >10% higher in the shoulder and hindlimb muscles (all p < 0.05). Arginine vasopressin was as effective as phenylephrine for maintaining cerebral perfusion pressure, but intracranial pressure and brain tissue oxygenation were improved at the expense of the periphery