A Novel Approach to Managing Thirst and Dry Mouth in Palliative Care: A Prospective Randomized Cross-Over Trial.

CONTEXT: Thirst and xerostomia are significant and highly distressing symptoms experienced by patients receiving palliative and end-of-life care. OBJECTIVES: Determine a reduction of thirst intensity and perceptions of dry mouth on a numerical scale following both the experimental intervention (mini mint ice cubes) and control (plain ice chips). METHODS: Cross-over Randomized Controlled Trial (RCT) to assess the effectiveness of novel intervention in the treatment of dry mouth and the sensation of thirst in palliative care patients. RESULTS: Patients rated the severity of their symptoms of dry mouth and thirst using a numeric rating scale (NRS). On commencing the study and preintervention, all patients suffered severe dry mouth and thirst (≥5/10). Mint and plain ice cubes produced improvement of symptoms immediately after interventions. Results from dry mouth ratings show, a decrease of 1.6 points for plain ice cubes (P < 0.0001), on average, ratings for mint ice cubes decreased 3.7 (P < 0.0001). For the sensation of thirst, the plain ice cube intervention group rating decreased 1.7 points (P < 0.006), ratings for mint ice cubes decreased 3.4 points (P < 0.0001). The average decrease in dry mouth and thirst intensity scores from preintervention to postintervention were significantly greater for mint ice cubes (P < 0.05) and 86.6% of patients preferred mint ice cubes. CONCLUSION: This trial found that while usual mouth care and the intervention were both able to reduce the intensity of dry mouth and the sensation of thirst, the mint intervention had a greater response.

Relieving Perception of Thirst and Xerostomia in Patients with Palliative and End-of-life Care Needs: A Rapid Review.

CONTEXT: Thirst and dry mouth are interlinked symptoms that frequently cause significant distress for patients with life-limiting conditions. OBJECTIVES: The objective of this rapid review was to identify and synthesize effective interventions that relieve perceptions of thirst and dry mouth of patients with palliative care and end-of-life care needs. METHODS: Eligible studies were undertaken in clinical settings, with patients experiencing thirst-related distress and/or dry mouth. This review of peer-reviewed literature was conducted following aspects of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. The main outcomes of interest were: 1) efficacy of thirst and dry mouth interventions for patient, and 2) patient, caregiver, and staff acceptability and satisfaction of the interventions. Scientific journal articles were retrieved through searches in electronic databases of MEDLINE (Ovid), CINAHL (EBSCO), and AgeLine (EBSCO). RESULTS: Eleven studies were included for analysis and synthesis of the results. Most studies either focused on a dry mouth intervention or reported dry mouth outcomes within a broader thirst intervention (n = 9/11 studies). Standard oral care was the common intervention type (n = 5/11). All but one dry mouth intervention reported statistical improvement in outcomes of interest. All studies that reported on thirst were conducted in an Intensive Care Unit (ICU) setting (n = 4/4). No studies specifically addressed thirst in patients in specialist palliative care settings. CONCLUSION: Evidence from this review suggests that thirst interventions established within the ICU setting may prove effective for treatment of terminally ill patients receiving specialist palliative care.

Investigating tryptophan quenching of fluorescein fluorescence under protolytic equilibrium.

Fluorescein is one of most used fluorescent labels for characterizing biological systems, such as proteins, and is used in fluorescence microscopy. However, if fluorescein is to be used for quantitative measurements involving proteins then one must account for the fact that the fluorescence of fluorescein-labeled protein can be affected by the presence of intrinsic amino acids residues, such as tryptophan (Trp). There is a lack of quantitative information to explain in detail the specific processes that are involved, and this makes it difficult to evaluate quantitatively the photophysics of fluorescein-labeled proteins. To address this, we have explored the fluorescence of fluorescein in buffered solutions, in different acidic and basic conditions, and at varied concentrations of tryptophan derivatives, using steady-state absorption and fluorescence spectroscopy, combined with fluorescence lifetime measurements. Stern-Volmer analyses show the presence of static and dynamic quenching processes between fluorescein and tryptophan derivatives. Nonfluorescent complexes with low association constants (5.0-24.1 M(-1)) are observed at all pH values studied. At low pH values, however, an additional static quenching contribution by a sphere-of-action (SOA) mechanism was found. The possibility of a proton transfer mechanism being involved in the SOA static quenching, at low pH, is discussed based on the presence of the different fluorescein prototropic species. For the dynamic quenching process, the bimolecular rate constants obtained (2.5-5.3 x 10(9) M(-1)s(-1)) were close to the Debye-Smoluchowski diffusion rate constants. In the encounter controlled reaction mechanism, a photoinduced electron transfer process was applied using the reduction potentials and charges of the fluorophore and quencher, in addition to the ionic strength of the environment. The electron transfer rate constants (2.3-6.7 x 10(9) s(-1)) and the electronic coupling values (5.7-25.1 cm(-1)) for fluorescein fluorescence quenching by tryptophan derivatives in the encounter complex were then obtained and analyzed.

Patterning of wettability for controlling capillary-driven flow in closed channels.

Glass capillaries are prepared with well-defined regions of tuneable wettability on the interior walls using an inexpensive and simple approach. A homogeneous layer of hydrophilic TiO2 nanoparticles is adsorbed on the capillary wall and chemically hydrophobized using octadecyltrihydrosilane (OTHS). The hydrophobic OTHS monolayer is then patterned by spatially-selective removal of the OTHS via TiO2-catalysed decomposition by ultraviolet irradiation. By patterning the capillaries with hydrophilic-hydrophobic rings, modulated penetration of a liquid (glycerol, in this study) can be achieved. For given wettability contrast, the penetration dynamics and equilibrium rise heights are very sensitive to the characteristic length-scale of the pattern, and may offer greater, time-dependent sampling control in fluidic devices.