89 resultados para General Society of Mayflower Descendants
Resumo:
BACKGROUND: Physiological data obtained with the pulmonary artery catheter (PAC) are susceptible to errors in measurement and interpretation. Little attention has been paid to the relevance of errors in hemodynamic measurements performed in the intensive care unit (ICU). The aim of this study was to assess the errors related to the technical aspects (zeroing and reference level) and actual measurement (curve interpretation) of the pulmonary artery occlusion pressure (PAOP). METHODS: Forty-seven participants in a special ICU training program and 22 ICU nurses were tested without pre-announcement. All participants had previously been exposed to the clinical use of the method. The first task was to set up a pressure measurement system for PAC (zeroing and reference level) and the second to measure the PAOP. RESULTS: The median difference from the reference mid-axillary zero level was - 3 cm (-8 to + 9 cm) for physicians and -1 cm (-5 to + 1 cm) for nurses. The median difference from the reference PAOP was 0 mmHg (-3 to 5 mmHg) for physicians and 1 mmHg (-1 to 15 mmHg) for nurses. When PAOP values were adjusted for the differences from the reference transducer level, the median differences from the reference PAOP values were 2 mmHg (-6 to 9 mmHg) for physicians and 2 mmHg (-6 to 16 mmHg) for nurses. CONCLUSIONS: Measurement of the PAOP is susceptible to substantial error as a result of practical mistakes. Comparison of results between ICUs or practitioners is therefore not possible.
Resumo:
In bacterial meningitis, several pharmacodynamic factors determine therapeutic success-when defined as sterilization of the CSF: (1) Local host defense deficits in the CNS require the use of bactericidal antibiotics to sterilize the CSF. (2) CSF antibiotic concentrations that are at least 10-fold above the MBC are necessary for maximal bactericidal activity. Protein binding, low pH, and slow bacterial growth rates are among the factors that may explain the high antibiotic concentrations necessary in vivo. (3) High CSF peak concentrations that lead to rapid bacterial killing appear more important than prolonged suprainhibitory concentrations, probably because very low residual levels in the CSF prevent bacterial regrowth, even during relatively long dosing intervals. (4) Penetration of antibiotics into the CSF is significantly impaired by the blood-brain barrier and thus, very high serum levels are necessary to achieve the CSF concentrations required for optimal bactericidal activity. Beyond these principles, recent data suggests that rapid lytic killing of bacteria in the CSF may have harmful effects on the brain because of the release of biologically active products from the lysed bacteria. Since rapid CSF sterilization remains a key therapeutic goal, the harmful consequences of bacterial lysis present a major challenge in the therapy of bacterial meningitis. Currently, dexamethasone represents that only clinically beneficial approach to reduce the harmful effects of bacterial lysis, and novel approaches are required to improve the outcome of this serious infection.