Postoperative cognitive dysfunction: a concept analysis.

BACKGROUND: Post-operative cognitive dysfunction (POCD) is a concern for clinicians that often presents post-surgery where generalized anesthesia has been used. Its prevalence ranges from 36.6% in young adults to 42.4% in older individuals. Conceptual clarity for POCD is lacking in the currently body literature. Our two-fold purpose of this concept analysis was to (1) critically appraise the various definitions, while also providing the best definition, of POCD and (2) narratively synthesize the attributes, surrogate or related terms, antecedents (risk factors), and consequences of the concept. METHOD: The reporting of our review was guided by the PRISMA statement and the 6-step evolutionary approach to concept analysis developed by Rodgers. Three databases, including Medline, CINAHL, and Web of Science, were searched to retrieve relevant literature on the concept of POCD. Two independent reviewers conducted abstract and full-text screening, data extraction, and appraisal. The review process yielded a final set of 86 eligible articles. RESULT: POCD was defined with varying severities ranging from subtle-to-extensive cognitive changes (1) affecting single or multiple cognitive domains that manifest following major surgery (2), is transient and reversible, and (3) may last for several weeks to years. The consequences of POCD may include impaired quality of life, resulting from withdrawal from the labor force, increased patients' dependencies, cognitive decline, an elevated risk of dementia, rising healthcare costs, and eventual mortality. CONCLUSION: This review resulted in a refined definition and comprehensive analysis of POCD that can be useful to both researchers and clinicians. Future research is needed to refine the operational definitions of POCD so that they better represent the defining attributes of the concept.

Correction to: The effect of zinc supplementation on blood pressure: a systematic review and dose-response meta-analysis of randomized-controlled trials.

The original version of this article unfortunately contained a mistake. The family name of "Israel Júnior Borges do Nascimento" was incorrect.

The effect of zinc supplementation on blood pressure: a systematic review and dose-response meta-analysis of randomized-controlled trials.

PURPOSE: Despite previous investigations on the effects of zinc supplementation on blood pressure, inconsistent findings are available in this regard. Therefore, we conducted a systematic review and meta-analysis of randomized clinical trials on the effects of zinc supplementation on blood pressure (BP) in adults. METHODS: Relevant studies published up to September 2019 were searched through PubMed/Medline, Scopus, ISI Web of Science, and Google Scholar using suitable keywords. All randomized clinical trials (RCTs) that examined the effect of oral zinc supplementation on systolic blood pressure (SBP) or diastolic blood pressure (DBP) in adults were included. RESULTS: Overall, nine trials were included in our study. Zinc supplementation significantly reduced SBP compared to the control [weighted mean differences (WMD) - 1.49 mmHg; 95% CI - 2.85 to - 0.13; P = 0.03]. However, zinc supplementation had no significant effects on DBP (WMD - 0.88 mmHg; 95% CI - 2.04 to 0.29; P = 0.14). Nonlinear analysis failed to indicate a significant influence of supplementation dosage or duration on both SBP and DBP. Sensitivity analysis showed that no individual study had a significant impact on our final results. In addition, we found no evidence for the presence of small-study effects among studies for both SBP and DBP. CONCLUSION: We found a significant reduction in SBP following zinc supplementation. However, zinc supplementation had no significant effect on DBP. In addition, no nonlinear association was found between supplementation dosage and duration with changes in both SBP and DBP. Further RCTs using different dosages of zinc in various durations are required to confirm our conclusion.

Metformin Therapy Reduces Obesity Indices in Children and Adolescents: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

Purpose: Few studies have summarized findings for the effect of metformin on obesity indices. Therefore, we aimed to conduct a systematic review and meta-analysis on the effect of metformin on obesity indices among children and adolescents. Methods: Relevant articles published up to September 2018 were searched in SCOPUS, Medline, and Google Scholar using appropriate keywords. All clinical trials that examined the effect of metformin on obesity indices in children and adolescents were included. Results: Overall, 38 studies, including 2199 participants (39.75% male and 60.25% female), were included. The pooled results indicated that metformin significantly reduced BMI [weighted mean difference (WMD): -1.07 kg/m2; 95% confidence interval (CI): -1.43 to -0.72]. Same findings were found for waist circumference (WC) (WMD: -1.93 cm; 95% CI: -2.69 to -1.16). Metformin also reduced body weight in all participants (WMD: -2.51 kg; 95% CI: -3.14 to -1.89). Moreover, it reduced body fat mass in patients with overweight or obesity (WMD: -1.90%; 95% CI: -3.25 to -0.56) and chronic diseases (WMD: -1.41%; 95% CI: -2.23 to -0.58), but not among those with growth problems. Metformin therapy did not affect lean body mass (LBM) in patients with overweight or obesity and growth problems; however, it reduced LBM in patients with chronic diseases (WMD: -1.49 kg; 95% CI: -2.69 to -0.30). Conclusions: We found a significant reduction in BMI, body weight, WC, and fat mass following administration with metformin. However, the effect of metformin on LBM was not significant. Further studies are required to confirm these findings.

Piloting Me and My Wishes-Videos of Nursing Home Residents' Preferences.

CONTEXT: A key challenge in nursing homes (NHs) is how to attain and clarify resident preferences for care and then communicate these preferences to family members and staff. OBJECTIVES: We evaluated the feasibility and acceptability of Me & My Wishes-person-centered videos of residents discussing their preferences for daily and end-of-life (EOL) care. METHODS: For this descriptive study, Me & My Wishes videos were created with residents in three NHs in the Pacific Northwest. Feasibility was evaluated by tracking resident enrollment, completing and sharing their video, and conducting debriefing interviews to ascertain residents' impressions of the recording process and personalized conversation. After viewing the video, staff and family assessed communication quality via survey-the extent to which they perceived messages from the video (e.g., preferences for EOL) to be timely, accurate, adequate, complete, and credible and items on resident preferences for daily and EOL care. RESULTS: Twenty of 33 residents approached created videos; 18 of these residents shared their videos with family or staff. Residents reported that they liked the opportunity to express their wishes. On a scale of 1-7 (lower is better), mean ratings were 2.0 (family) and 1.3 (staff) for communicating preferences for daily care; 1.9 (family) and 1.2 (staff) for communicating preferences for EOL. Both family and staff reported increased knowledge about resident preferences for daily and EOL care. CONCLUSION: This research supports the feasibility and acceptability of a videotaping approach (Me & My Wishes) for viewing, listening, and discussing residents' preferences for daily and EOL care.

Controlling interfacial film formation in mixed polymer-surfactant systems by changing the vapor phase.

Here we show that transport-generated phase separation at the air-liquid interface in systems containing self-assembling amphiphilic molecules and polymers can be controlled by the relative humidity (RH) of the air. We also show that our observations can be described quantitatively with a theoretical model describing interfacial phase separation in a water gradient that we published previously. These phenomena arises from the fact that the water chemical potential corresponding to the ambient RH will, in general, not match the water chemical potential in the open aqueous solution. This implies nonequilibrium conditions at the air-water interface, which in turn can have consequences on the molecular organization in this layer. The experimental setup is such that we can control the boundary conditions in RH and thereby verify the predictions from the theoretical model. The polymer-surfactant systems studied here are composed of polyethylenimine (PEI) and hexadecyltrimethylammonium bromide (CTAB) or didecyldimethylammonium bromide (DDAB). Grazing-incidence small-angle X-ray scattering results show that interfacial phases with hexagonal or lamellar structure form at the interface of dilute polymer-surfactant micellar solutions. From spectroscopic ellipsometry data we conclude that variations in RH can be used to control the growth of micrometer-thick interfacial films and that reducing RH leads to thicker films. For the CTAB-PEI system, we compare the phase behavior of the interfacial phase to the equilibrium bulk phase behavior. The interfacial film resembles the bulk phases formed at high surfactant to polymer ratio and reduced water contents, and this can be used to predict the composition of interfacial phase. We also show that convection in the vapor phase strongly reduces film formation, likely due to reduction of the unstirred layer, where diffusive transport is dominating.

Evanescent-wave dynamic light scattering at an oil-water interface: diffusion of interface-adsorbed colloids.

A light-scattering goniometer for evanescent-wave dynamic light scattering (EWDLS) measurements at a liquid-fluid interface is introduced, and used for measurements on two charge-stabilized polystyrene colloid systems adsorbed to alkane-water interfaces. The goniometer allows an independent variation of the penetration depth and the scattering vector components parallel and perpendicular to a liquid-fluid interface. The possible illumination geometries are compared. Ellipsometry at the liquid-fluid interface is implemented as a complementary tool. In EWDLS measurements, the absence of diffusive motion perpendicular to the interface is demonstrated, which confirms the adsorption of the particles. The two-step decay of the autocorrelation function is interpreted in terms of diffusion within a two-dimensional interface lattice of colloidal particles, stabilized by repulsive electrostatic interactions, and a desorption process. A significant slowing down of the in-plane diffusion of the colloids as compared to the bulk diffusion is observed.

The effect of shear on colloidal aggregation and gelation studied using small-angle light scattering.

In situ light scattering measurements were performed to investigate the effect of low shear rates (0.13-3.56 s(-1)) on an aggregating colloidal system made of 20 nm polystyrene particles. The aggregating system was subjected to a shear for a short period (ca. 33 s) and only once at various times after the onset of aggregation. The effect of shear (aggregation kinetics and morphology) was studied both in a cluster dilute and in a cluster dense regime (see introduction). Our results have shown that shear can enhance the aggregation and gelation. Shear induced growth can yield hybrid superaggregates when the system is dense.

Multiple-scattering effects on static light-scattering optical structure factor measurements.

We show that the extent and effect of multiple scattering on angularly resolved light-scattering intensity measurements, the optical structure factor, can be quantitatively described by a single parameter, the average number of scattering events along the scattering volume. This quantity is easily measured or calculated and hence provides a useful experimental indicator of multiple scattering, which is a hindrance to accurate structure factor measurements.