RESUMEN
BACKGROUND: Cerebrospinal fluid (CSF) flow is crucial for brain homeostasis and its dysfunction is highly associated with neurodegenerative diseases. Restoring CSF circulation is proposed as a key strategy for the treatment of the diseases. Among the methods to improve CSF circulation, focused ultrasound (FUS) stimulation has emerged as a promising non-invasive brain stimulation technique, with effectiveness evidenced by ex vivo studies. However, due to technical disturbances in in vivo imaging combined with FUS, direct evidence of real-time in vivo CSF flow enhancement by FUS remains elusive. OBJECTIVE: To investigate whether FUS administered through the skull base can enhance CSF influx in living animals with various real-time imaging techniques. METHODS: We demonstrate a novel method of applying FUS through the skull base, facilitating cortical CSF influx, evidenced by diverse in vivo imaging techniques. Acoustic simulation confirmed effective sonication of our approach through the skull base. After injecting fluorescent CSF tracers into cisterna magna, FUS was administered at the midline of the jaw through the skull base for 30 min, during which imaging was performed concurrently. RESULTS: Enhanced CSF influx was observed in macroscopic imaging, demonstrated by the influx area and intensity of the fluorescent dyes after FUS. In two-photon imaging, increased fluorescence was observed in the perivascular space (PVS) after stimulation. Moreover, particle tracking of microspheres showed more microspheres entering the imaging field, with increased mean speed after FUS. CONCLUSION: Our findings provide direct real-time in vivo imaging evidence that FUS promotes CSF influx and flow in the PVS.
RESUMEN
OBJECTIVE: To compare pressure injury (PI) incidence based on repositioning intervals and support surfaces in acute care settings. METHODS: This pragmatic, quasi-experimental trial recruited a total of 251 critically ill patients who were at low or moderate risk for PI development. Participants were assigned to three interventions: a 2-hour repositioning interval using an air mattress, a 2-hour repositioning interval using a foam mattress, or a 3-hour repositioning interval using a foam mattress. Data were collected by nurses every shift over the course of 14 days. Pressure injury incidence was analyzed using a χ2 test. RESULTS: There were no statistically significant differences in PI incidence between the groups with a 2-hour repositioning interval. However, the PI incidence in the group using a foam mattress with a 3-hour repositioning interval was significantly lower than in the group using an air mattress with a 2-hour repositioning interval (odds ratio, 0.481; 95% confidence interval, 0.410-0.565). CONCLUSIONS: The findings showed that PIs decreased when the repositioning interval was extended from every 2 hours to every 3 hours while using foam mattresses. This study suggests that a 3-hour repositioning interval using a foam mattress could be applied to reduce the risk of PI development for patients at low or moderate risk.
