[Diaries for intensive care unit patients reduce the risk for psychological sequelae : Systematic literature review and meta-analysis]. / Intensivtagebücher senken Risiko für psychische Folgestörungen : Systematische Literaturrecherche und Metaanalyse.

BACKGROUND: Diaries are written for patients on intensive care units (ICU) by clinicians and relatives to reduce the risk of psychological complications such as posttraumatic stress disorder (PTSD), anxiety, and depression. The authors of a Cochrane Review on this topic published in 2015, included studies with PTSD diagnoses based on interviews carried out by qualified personnel, and concluded that there is inadequate evidence to support the thesis that ICU diaries reduce the risk of psychological complications. METHODS: The present study replicated the design of the Cochrane Review with identical search algorithms, but included additional outcomes data from validated methods of diagnosing psychological complications that were not considered in the original Cochrane Review. The primary outcome was PTSD in patients or relatives with ICU diaries. Secondary outcomes were anxiety and/or depression symptoms. Study quality was evaluated using the Cochrane risk of bias assessment. RESULTS: The replicated search produced 3179 citations, of which there were 6 eligible studies from which 605 patients and 145 relatives could be included in the meta-analysis. Studies ratings ranged from low to good. The meta-analyses of the PTSD outcome demonstrated the following: (a) for ICU patients (4 studies, n = 569 patients) a non-significant reduction (odds ratio [OR] 0.58, 95% confidence interval [CI]: 0.24-1.42, p = 0.23), and (b) for relatives' PTSD (2 studies, n = 145 relatives) a significant reduction (OR 0.17, 95%CI: 0.08-0.38, p < 0.0001). The symptoms anxiety and depression in ICU patients (2 studies each, n = 88 patients) were significantly reduced (OR 0.23, 95%CI: 0.07-0.77, p = 0.02; OR 0.27, 95%CI: 0.09-0.77, p = 0.01, respectively). Heterogeneity was between 0 and 54%. CONCLUSION: ICU diaries may reduce the risk of psychological complications in patients and relatives after ICU stays.

Some physico-chemical parameters that influence proteinase K resistance and the infectivity of PrPSc after high pressure treatment.

Crude brain homogenates of terminally diseased hamsters infected with the 263 K strain of scrapie (PrP Sc) were heated and/or pressurized at 800 MPa at 60 degrees C for different times (a few seconds or 5, 30, 120 min) in phosphate-buffered saline (PBS) of different pH and concentration. Prion proteins were analyzed on immunoblots for their proteinase K (PK) resistance, and in hamster bioassays for their infectivity. Samples pressurized under initially neutral conditions and containing native PrP Sc were negative on immunoblots after PK treatment, and a 6-7 log reduction of infectious units per gram was found when the samples were pressurized in PBS of pH 7.4 for 2 h. A pressure-induced change in the protein conformation of native PrP Sc may lead to less PK resistant and less infectious prions. However, opposite results were obtained after pressurizing native infectious prions at slightly acidic pH and in PBS of higher concentration. In this case an extensive fraction of native PrP Sc remained PK resistant after pressure treatment, indicating a protective effect possibly due to induced aggregation of prion proteins in such buffers.

Some physico-chemical parameters that influence proteinase K resistance and the infectivity of PrP Sc after high pressure treatment

Crude brain homogenates of terminally diseased hamsters infected with the 263 K strain of scrapie (PrP Sc) were heated and/or pressurized at 800 MPa at 60°C for different times (a few seconds or 5, 30, 120 min) in phosphate-buffered saline (PBS) of different pH and concentration. Prion proteins were analyzed on immunoblots for their proteinase K (PK) resistance, and in hamster bioassays for their infectivity. Samples pressurized under initially neutral conditions and containing native PrP Sc were negative on immunoblots after PK treatment, and a 6-7 log reduction of infectious units per gram was found when the samples were pressurized in PBS of pH 7.4 for 2 h. A pressure-induced change in the protein conformation of native PrP Sc may lead to less PK resistant and less infectious prions. However, opposite results were obtained after pressurizing native infectious prions at slightly acidic pH and in PBS of higher concentration. In this case an extensive fraction of native PrP Sc remained PK resistant after pressure treatment, indicating a protective effect possibly due to induced aggregation of prion proteins in such buffers.