Early hemostatic responses to trauma identified with hierarchical clustering analysis.

BACKGROUND: Trauma-induced coagulopathy is a complex multifactorial hemostatic response that is poorly understood. OBJECTIVES: To identify distinct hemostatic responses to trauma and identify key components of the hemostatic system that vary between responses. PATIENTS/METHODS: A cross-sectional observational study of adult trauma patients at an urban level I trauma center emergency department was performed. Hierarchical clustering analysis was used to identify distinct clusters of similar subjects according to vital signs, injury/shock severity, and comprehensive assessment of coagulation, clot formation, platelet function, and thrombin generation. RESULTS: Among 84 total trauma patients included in the model, three distinct trauma clusters were identified. Cluster 1 (N = 57) showed platelet activation, preserved peak thrombin generation, plasma coagulation dysfunction, a moderately decreased fibrinogen concentration and normal clot formation relative to healthy controls. Cluster 2 (N = 18) showed platelet activation, preserved peak thrombin generation, and a preserved fibrinogen concentration with normal clot formation. Cluster 3 (N = 9) was the most severely injured and shocked, and showed a strong inflammatory and bleeding phenotype. Platelet dysfunction, thrombin inhibition, plasma coagulation dysfunction and a decreased fibrinogen concentration were present in this cluster. Fibrinolytic activation was present in all clusters, but was particularly increased in cluster 3. Trauma clusters were most noticeably different in their relative fibrinogen concentration, peak thrombin generation, and platelet-induced clot contraction. CONCLUSIONS: Hierarchical clustering analysis identified three distinct hemostatic responses to trauma. Further insights into the underlying hemostatic mechanisms responsible for these responses are needed.

Vestibular influences on cat lumbar paravertebral muscles.

Recordings were made from nerves innervating ventral lumbar paravertebral muscles (quadratus lumborum) during natural vestibular stimulation in vertical planes. The best direction of vestibular stimulation for producing an increase in nerve activity was near nose-up pitch in two-thirds of the animals, but was near nose-down pitch in the others. The response gain (re. position) was flat across the frequency range of 0.05-1 Hz, and the responses persisted throughout 11-s static tilts. These data suggest that otolith organs activated by pitch influence activity in the lumbar paravertebral muscles. These responses may serve to stabilize the vertebral column during movements involving body pitch, such as vertical climbing.

Adjunctive rifampin therapy for central nervous system staphylococcal infections.

OBJECTIVE: To review the published clinical data assessing the role of adjunctive rifampin therapy for the treatment of staphylococcal central nervous system (CNS) infections. DATA SOURCES: A MEDLINE search (January 1966-March 2000) of English-language literature pertaining to CNS staphylococcal infections and rifampin was performed; tertiary sources were also used. DATA EXTRACTION: Human data and case reports were included, as no clinical trials have been published. DATA SYNTHESIS: Retrospective reviews of rifampin used in combination with other antibiotics for serious bacterial infections show conflicting results. Few case reports have described clinical successes with adjunctive rifampin therapy for CNS infections. CONCLUSIONS: The routine use of adjunctive rifampin for CNS infections cannot be justified.

Multidisciplinary management of sedation and analgesia in critical care.

Management of sedation and analgesia in critical care medicine is a multidisciplinary process that involves physicians, nurses, pharmacists, and other healthcare providers. Optimal management of these common issues includes recognition of the importance of predisposing and causative conditions that contribute to the sensations of pain and discomfort, anxiety, and delirium. Treatment includes pharmacological intervention, correction of predisposing factors, and use of other preventative and nonpharmacological measures. It is increasingly clear that, although necessary for patient comfort, sedative and analgesic medications can have adverse consequences, including side-effects as well as prolonged mechanical ventilation and ICU length of stay. Optimal use of sedative and analgesic medications involves matching unique properties of specific medications with individual patient characteristics. Guidelines that minimize unnecessary variability in practice, prevent excessive medication, and emphasize management based on individual patient characteristics improve the effective utilization of these medications.