BackgroundDelirium is a common condition in hospitalized seniors that nonetheless often goes undetected by nurses or is delayed in being detected which negatively impacts quality of care and outcomes. We sought to develop a new screening tool for delirium, The Sour Seven Questionnaire, a 7-item questionnaire suitable to be completed from informal or untrained caregiver observation. The study aimed to develop the scoring criteria for a positive delirium screen and assess concurrent validity of the questionnaire against a geriatric psychiatrist’s assessment.MethodsA pilot study of 80 hospitalized seniors over age 65 recruited from three units (2 medical, 1 orthopedic). Participants were assessed using the Confusion Assessment Method (CAM) with a brief cognitive screen and the Sour Seven Questionnaire posed to the appointed informal caregiver (family member) or untrained nurse for up-to 7 days. Subjects testing positive on the CAM and a random sample of negatively CAM screened subjects were assessed by the geriatric psychiatrist.ResultsFrom 80 participants, 21 screened positive for delirium on the CAM. 18 of the 21 CAM positive screens were diagnosed to have delirium by the geriatric psychiatrist, and 17 of the 18 randomly assigned negative CAM screens were confirmed as not having delirium. From the questionnaires on these 39 participants, weighted scoring for each of the 7 questions of the Sour Seven Questionnaire was developed based on their relative risks for correctly predicting delirium when compared to the geriatric psychiatrist’s clinical assessment. Total scoring of the questionnaire resulted in the following positive predictive values for delirium: 89 % with a total score of 4 (sensitivity 89.5 %, specificity 90 %), and 100 % with a total score of 9 (sensitivity 63.2 %, specificity 100 %). Comparison between scoring on questionnaires posed to informal caregivers versus untrained nurses showed no differences.ConclusionA weighted score of 4 in the Sour Seven Questionnaire has concurrent validity as a screening tool for delirium and a score of 9 is diagnostic for delirium. The Sour Seven Questionnaire is the first screening tool for delirium shown to be suitable for use by informal caregivers and untrained nurses in hospitalized seniors.Electronic supplementary materialThe online version of this article (doi:10.1186/s12877-016-0217-2) contains supplementary material, which is available to authorized users.

Local measurements of vapor phase residence time fraction, vapor bubble size distribution, bubble axial velocity, and vapor and liquid temperatures were performed in turbulent boiling flow of Refrigerant-113. The dissolved air content of the experimental fluid was minimized. Data are reported for three wall heat fluxes, two fluid mass velocities, and three subcoolings at test section inlet. Local time-averaged interfacial area concentrations were estimated. The measuring devices, viz., dual-sensor fiber-optic probe for the vapor bubble measurements and phase-compensated chromel-alumel microthermocouple for the fluid temperature measurement, provided more complete and accurate data compared with our earlier work. The data should be helpful in the development and validation of multidimensional turbulent boiling flow models. Further work is needed, however, before the local interfacial area concentration can be determined with confidence.

The velocity field was measured in turbulent subcooled boiling flow of Refrigerant-113 through a vertical annular channel whose inner wall was heated. A two-component laser Doppler velocimeter was used. Measurements are reported in the boiling layer adjacent to the inner wall as well as in the outer all-liquid layer for two fluid mass velocities and four wall heat fluxes. The turbulence was found to be inhomogeneous and anisotropic and the turbulent kinetic energy significantly higher than in single-phase liquid flow at the same mass velocity. A marked shift toward the inner wall was observed of the zero location of the axial Reynolds shear stress in the liquid phase, and the magnitude of the shear stress increased sharply close to the inner wall. The near-wall liquid velocity field was quite different from that in single-phase liquid flow at a similar Reynolds number. Comparison of the measurements with the predictions of a three-dimensional two-fluid model of turbulent subcooled boiling flow show reasonably good agreement for some quantities and a need for further development of certain aspects of the model.

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