Management of the pregnant trauma patient in the emergency department.

This supplement reviews the evidence regarding important considerations in pregnant trauma patients, including the primary and secondary survey as well as the possibility for Rh exposure, placental abruption, uterine rupture, and the need for a prompt perimortem cesarean section in the moribund patient. Because ionizing radiation is a concern in pregnancy, the circumstances in which benefits of testing outweigh risks to the fetus are discussed. Emergency clinicians are encouraged to advocate for trauma prevention, including proper use of safety restraints in motor vehicles and screening for domestic violence, as these measures have been shown to be effective in reducing morbidity and mortality in this patient population. Recommendations for monitoring, admission, discharge, and follow-up are also provided.

A preprocedural checklist improves the safety of emergency department intubation of trauma patients.

OBJECTIVES: Endotracheal intubation of trauma patients is a vital and high-risk procedure in the emergency department (ED). The hypothesis was that implementation of a standardized, preprocedural checklist would improve the safety of this procedure. METHODS: A preprocedural intubation checklist was developed and then implemented in a prospective pre-/postinterventional study in an academic trauma center ED. The proportions of trauma patients older than 16 years who experienced intubation-related complications during the 6 months before checklist implementation and 6 months after implementation were compared. Intubation-related complications included oxygen desaturation, emesis, esophageal intubation, hypotension, and cardiac arrest. Additional outcomes included time from paralysis to intubation and adherence to safety process measures. RESULTS: During the study, 141 trauma patients were intubated, including 76 in the prechecklist period and 65 in the postchecklist period. A lower proportion of patients experienced intubation-related complications in the postchecklist period (1.5%) than the prechecklist period (9.2%), representing a 7.7% (95% confidence interval = 0.5% to 14.8%) absolute risk reduction. Paralysis-to-intubation time was also lower in the postchecklist period (median = 82 seconds, interquartile range [IQR] = 68 to 101 seconds) compared to the prechecklist period (median = 94 seconds, IQR = 78 to 115 seconds; p = 0.02). Adherence to safety process measures also improved, with all safety measures performed in 69.2% in the postchecklist period compared to 17.1% before the checklist (p < 0.01). CONCLUSIONS: Implementation of a preintubation checklist for ED intubation of trauma patients was associated with a reduction in intubation-related complications, decreased paralysis-to-intubation time, and improved adherence to recognized safety measures.

Trauma in the pregnant patient: an evidence-based approach to management.

The management of acute trauma in the pregnant patient relies on a thorough understanding of the underlying physiology of pregnancy. This issue reviews the evidence regarding important considerations in pregnant trauma patients, including the primary and secondary survey as well as the possibility for Rh exposure, placental abruption, uterine rupture, and the need for a prompt perimortem cesarean section in the moribund patient. Because ionizing radiation is always a concern in pregnancy, the circumstances where testing provides benefits that outweigh risks to the fetus are discussed. Emergency clinicians are encouraged to advocate for trauma prevention, including proper safety restraints for motor vehicles and screening for domestic violence, as these measures have been shown to be effective in reducing morbidity and mortality in this population. Recommendations for monitoring, admission, discharge, and follow-up are also noted.

Individualized guidelines: the potential for increasing quality and reducing costs.

BACKGROUND: Current guidelines focus on a particular risk factor and specify criteria for categorizing persons into a small number of treatment groups. OBJECTIVE: To compare current guidelines with individualized guidelines (that use readily available characteristics from each person to calculate the risk reduction expected from treatment and to identify persons for treatment in ranked order of decreasing expected benefit), in the context of blood pressure management. DESIGN: Analysis of person-specific, longitudinal data. SETTING: The ARIC (Atherosclerosis Risk in Communities) Study. PARTICIPANTS: Persons aged 45 to 64 years without preexisting cardiovascular disease who currently do not receive antihypertensive treatment. INTERVENTION: Treatment according to the criteria of the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7 guidelines); individualized guidelines, or treatment in decreasing order of expected benefit; and random care, or treatment of persons selected at random. MEASUREMENTS: Number of myocardial infarctions (MIs) and strokes and medical costs. RESULTS: Compared with treating people according to random care, individualized guidelines could prevent the same number of MIs and strokes as JNC 7 guidelines at savings that are 67% greater than using JNC 7 guidelines, or it could prevent 43% more MIs and strokes for the same cost as treatment according to JNC 7 guidelines. The superiority of individualized guidelines was not sensitive to a wide range of assumptions about costs, treatment effectiveness, level of risk for cardiovascular disease in the population, or effects on workflow. The degree of superiority was sensitive to the accuracy of the method used to rank patients and to its span (the proportion of the population for whom all of the outcomes of interest can be calculated). LIMITATIONS: Specific results apply to the effects of blood pressure management on MI and stroke in the ARIC Study population. The methods for calculating individual benefits require quantitative evidence about the relationships among risk factors, long-term outcomes, and treatment effects. CONCLUSION: Use of individualized guidelines can help to increase the quality and reduce the cost of care.

To keep an incessant watch.

Medical residency is an educational enterprise directed toward producing clinicians who recognize and correctly manage disease. While formal graduate medical education provides didactics and bedside teaching to improve knowledge, individual learning efforts are essential to the educational experience. Keeping track of patient outcomes after disposition from the emergency department (ED) is a useful exercise in reviewing gaps in knowledge of the individual and deficiencies in systems-based care. In reviewing the agreement between admission and discharge diagnoses of a single resident over 4 years of residency, significant improvement in diagnostic accuracy was observed. This method of self-correction has potential to supplement formal residency education in emergency medicine.

Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans.

CONTEXT: Millions of individuals habitually expose themselves to room light in the hours before bedtime, yet the effects of this behavior on melatonin signaling are not well recognized. OBJECTIVE: We tested the hypothesis that exposure to room light in the late evening suppresses the onset of melatonin synthesis and shortens the duration of melatonin production. DESIGN: In a retrospective analysis, we compared daily melatonin profiles in individuals living in room light (<200 lux) vs. dim light (<3 lux). PATIENTS: Healthy volunteers (n = 116, 18-30 yr) were recruited from the general population to participate in one of two studies. SETTING: Participants lived in a General Clinical Research Center for at least five consecutive days. INTERVENTION: Individuals were exposed to room light or dim light in the 8 h preceding bedtime. OUTCOME MEASURES: Melatonin duration, onset and offset, suppression, and phase angle of entrainment were determined. RESULTS: Compared with dim light, exposure to room light before bedtime suppressed melatonin, resulting in a later melatonin onset in 99.0% of individuals and shortening melatonin duration by about 90 min. Also, exposure to room light during the usual hours of sleep suppressed melatonin by greater than 50% in most (85%) trials. CONCLUSIONS: These findings indicate that room light exerts a profound suppressive effect on melatonin levels and shortens the body's internal representation of night duration. Hence, chronically exposing oneself to electrical lighting in the late evening disrupts melatonin signaling and could therefore potentially impact sleep, thermoregulation, blood pressure, and glucose homeostasis.

Designing synthetic vesicles that engulf nanoscopic particles.

We examine the interaction of a lipid bilayer membrane with a spherical particle in solution using dissipative particle dynamics, with the aim of controlling the passage of foreign objects into and out of vesicles. Parameters are chosen such that there is a favorable adhesive interaction between the membrane and the particle. Under these conditions, the membrane wraps the particle in a process resembling phagocytosis in biological cells. We find that, for a homogeneous membrane with a uniform attraction to the particle, the membrane is unable to fully wrap the particle when the adhesion strength is below a certain value. This is observed even in the limit of zero membrane tension. When the adhesion strength is increased above the threshold value, the membrane fully wraps the particle. However, the wrapped particle remains tethered to the larger membrane. We next consider an adhesive domain, or raft, in an otherwise nonadhesive membrane. We find that, when the particle is wrapped by the raft, the line tension at the raft interface promotes fission, allowing the wrapped particle to detach from the larger membrane. This mechanism could be used to allow particles to cross a vesicle membrane.

Shear-driven release of a bud from a multicomponent vesicle.

The authors study the response of a multicomponent budded vesicle to an imposed shear flow using dissipative particle dynamics. Under certain circumstances, phase separation in the vesicle membrane leads to the formation of a minority domain which deforms into a nearly spherical bud in order to reduce its interfacial energy. The authors show that an imposed shear force has a varying effect on the vesicle, tending either to separate the bud from the vesicle or to stretch the bud open, depending on the vesicle orientation. The authors examine the interplay of membrane bending rigidity, line tension, and shear in determining the behavior of the vesicle. With the appropriate design, vesicles can be made to release buds in a controlled manner in response to shear. The authors outline a regime in which bud release is favorable.

Designing a simple ratcheting system to sort microcapsules by mechanical properties.

Using computational modeling, we analyze the fluid-driven motion of compliant particles over a rigid, saw-toothed surface. The particles are modeled as fluid-filled elastic shells and, thus, simulate ex vivo biological cells or polymeric microcapsules. Through the model, we demonstrate how the patterned surface and an oscillatory shear flow can be combined to produce a ratcheting motion, yielding a straightforward method for sorting these capsules by their relative stiffness. Since the approach exploits the capsule's inherent response to the substrate, it does not involve explicit measurement and assessment. Because the process utilizes an oscillatory shear, the sorting can be accomplished over a relatively short portion of the substrate. Due to these factors, this sorting mechanism can prove to be both efficient and relatively low-cost.

Adaptation of human pineal melatonin suppression by recent photic history.

The human circadian pacemaker controls the timing of the release of the pineal hormone melatonin, which promotes sleep, decreases body temperature, and diminishes cognitive performance. Abnormal melatonin secretion has been observed in psychiatric and circadian disorders. Although melatonin secretion is directly suppressed by exposure to light in a nonlinear intensity-dependent fashion, little research has focused on the effect of prior photic history on this response. We examined eight subjects in controlled laboratory conditions using a within-subjects design. Baseline melatonin secretion was monitored under constant routine conditions and compared with two additional constant routines with a fixed light stimulus for 6.5 h of 200 lux (50 microW/cm(2)) after approximately 3 d of photic exposure during the subjective day of either about 200 lux (50 microW/cm(2)) or about 0.5 lux (0.15 microW/cm(2)). We found a significant increase in melatonin suppression during the stimulus after a prior photic history of approximately 0.5 lux compared with approximately 200 lux, revealing that humans exhibit adaptation of circadian photoreception. Such adaptation indicates that translation of a photic stimulus into drive on the human circadian pacemaker involves more complex temporal dynamics than previously recognized. Further elucidation of these properties could prove useful in potentiating light therapies for circadian and affective disorders.