COVID-19 vaccination acceptability in the UK at the start of the vaccination programme: a nationally representative cross-sectional survey (CoVAccS - wave 2).

OBJECTIVES: Investigate factors associated with the intention to have the COVID-19 vaccination following initiation of the UK national vaccination programme. STUDY DESIGN: An online cross-sectional survey completed by 1500 adults (13th-15th January 2021). METHODS: Linear regression analyses were used to investigate associations between intention to be vaccinated for COVID-19 and sociodemographic factors, previous influenza vaccination, attitudes and beliefs about COVID-19 and COVID-19 vaccination and vaccination in general. Participants' main reasons for likely vaccination (non-)uptake were also solicited. RESULTS: 73.5% of participants (95% CI 71.2%, 75.7%) reported being likely to be vaccinated against COVID-19, 17.3% (95% CI 15.4%, 19.3%) were unsure, and 9.3% (95% CI 7.9%, 10.8%) reported being unlikely to be vaccinated. The full regression model explained 69.8% of the variance in intention. Intention was associated with: having been/intending to be vaccinated for influenza last winter/this winter; stronger beliefs about social acceptability of a COVID-19 vaccine; the perceived need for vaccination; adequacy of information about the vaccine; and weaker beliefs that the vaccine is unsafe. Beliefs that only those at serious risk of illness should be vaccinated and that the vaccines are just a means for manufacturers to make money were negatively associated with vaccination intention. CONCLUSIONS: Most participants reported being likely to get the COVID-19 vaccination. COVID-19 vaccination attitudes and beliefs are a crucial factor underpinning vaccine intention. Continued engagement with the public with a focus on the importance and safety of vaccination is recommended.

Predicting energy needs in ventilator-dependent critically ill patients: effect of adjusting weight for edema or adiposity.

Predicting energy needs in critical illness can be difficult because of uncertainties about the influence of multiple factors on energy expenditure. Understanding these components is important to avoid limiting optimal outcome by underfeeding and to avoid complications of overfeeding. Prediction strategies often use a patient's weight to estimate needs. For overweight patients, there is controversy as to whether actual or modified weight should be used in predictions. This study was designed to evaluate a proposed technique to improve the accuracy of predicting energy needs in critically ill, overweight subjects. Subjects' energy needs were predicted [with Harris-Benedict equation (HBE) and kilojoules per kilogram (KPK) strategies] by using both actual weight and an adjusted weight developed to attempt to more accurately reflect lean mass. Results were compared with measured energy expenditure determined by indirect calorimetry. Results indicated that use of actual weights in predictions for overweight subjects may lead to overfeeding. Use of adjusted weights led to more accurate energy predictions with the KPK than with the HBE strategy. Adjusted-weight strategies could explain > 45% of the variability of resting energy expenditure in subjects 130-159% of ideal body weight. Results of this study suggest that using adjusted weights with the KPK prediction strategy may be preferable for this population, particularly for patients > or = 130% of ideal body weight. This study also indicated that multiple diagnoses may not lead to increased energy requirements.

Transfusion requirements during continuous veno-venous haemofiltration: -the importance of filter life.

OBJECTIVE: To investigate the relationship between loss of haemofilter circuits due to blood clots and requirement for blood transfusion in intensive care patients. DESIGN: Retrospective case note review. SETTING: A British, nine-bed, tertiary, medical and surgical intensive care unit (ICU) serving a 950-bed university teaching hospital. PATIENTS: Thirty-three ICU patients requiring haemofiltration for more than 48 h. Thirty-three comparison patients requiring 7 or more days of intensive care, without haemofiltration. METHODS: ICU, haemofiltration and haematology records were examined retrospectively. Note was taken of demographic data, daily haemoglobin concentrations and the dates and numbers of blood transfusions and haemofilter clots. RESULTS: The study groups did not differ significantly in terms of age, sex and length of ICU stay. Haemofiltered patients had higher APACHE II scores (21 vs 15, p = 0.006), lower haemoglobin concentrations (102 vs 110 g/l, p = 0.0001) and higher blood transfusion rates (1.1 vs 0.3 units/day, p < 0.0001) when compared to the non-haemofiltered group. There was a positive correlation between haemofilter blood clot rate and blood transfusion rate (r = 0.48). More blood was transfused on days when haemofilter blood clots occurred than on days when no haemofilter clot occurred (1.0 vs 0.59 units, p = 0.03). CONCLUSION: Haemofiltration is associated with an increased requirement for transfusion of blood. The temporal relationship between occurrence of haemofilter blood clots and transfusion of blood suggests that haemofilter lifespan may be an important determinant of this.

Glycoproteins Ib and IIb/IIIa in the quality assessment of platelet concentrates during storage.

We have previously shown that levels of soluble glycocalicin (GC) in plasma supernatants derived from units of platelet concentrates (PC) increase progressively during storage. We now report further studies which show that the levels of both microparticle-bound and soluble GC in PC during storage are influenced by exposure of PC samples to EDTA and treatment of PC packs with ultraviolet B (UVB) irradiation. EDTA leads to a significant increase in the release of microvesicle-bound and soluble GC, while UVB irradiation leads to a dose- and rate-dependent increase in GC release. Paradoxically, UVB leads to an unexpected decrease in supernatant levels of von Willebrand factor (vWf) during storage which contrasts with its increase in untreated, stored PC. Moreover, an increase in GC release during storage is associated with a corresponding decrease in platelet size as determined by measurement of mean platelet volume (MPV) in citrated PC. The GC release is significantly correlated with standard platelet functional tests and other new generation tests such as dMPV and supernatant levels of vWf. In addition, preliminary results show the presence of microparticle-bound and soluble glycoprotein (Gp) IIb/IIIa in the supernatant plasma of stored PC. Our results suggest that supernatant levels of GpIb, GpIIb/IIIa, and vWf, together with alteration in MPV, provide essential new informative parameters for quality assessment of PC.

Characteristics of platelet concentrates, with particular reference to Autopheresis C Plateletcell: correlation between dMPV and other tests for platelet function.

The quality of platelet concentrates (PC) collected by the Autopheresis C cell separator was assessed in two Regional Transfusion Centres taking part in a multicentre study. This study also enabled the assessment of a new simple, rapid test of platelet function and comparison with more established tests, such as aggregation to adenosine diphosphate, as a tool for the quality testing of PC. The new test, based upon the measurement of mean platelet volume using automated haematological cell analysers, is rapid and uses the same samples as those used to estimate the platelet and leucocyte content of the concentrates. The high correlation between this test and the other tests of platelet function used in the study suggests that it is an ideal tool in the quality testing of platelet concentrates.

Quality of platelet concentrates irradiated with UVB light: effect of UV dose and dose rate on glycocalicin release and correlation with other markers of the platelet storage lesion.

The amount of membrane-associated glycoprotein Ib in platelet concentrates (PCs) irradiated with a high dose of UVB light has been shown to be significantly reduced after 48 h storage. We recently corroborated this finding when we noted an increase in the supernatant levels of glycocalicin (GC, a major segment of glycoprotein Ib) in UVB-treated PCs during storage. The aim of the present study was to determine whether GC release was related to both the UV dose and the rate of dose delivery. Plateletpheresis concentrates obtained from five donors were pooled and split into five equal parts. Four of these were treated with 7500 and 15,000 mJ/cm2 UVB using two prototype UV sources with differing rates of dose delivery; namely, Baxter (BAT) and British Aerospace (BAC) cabinets, with the latter having the slower rate of delivery. On days 1 and 5 of storage, GC levels in the supernatants of PCs were determined by ELISA. Moreover, the following parameters were also assessed: platelet and WBC count; hypotonic shock response (HSR) and platelet aggregation response to ADP, ADP+collagen, ADP+arachidonic acid and ristocetin; pH; supernatant levels of lactate, glucose, von Willebrand factor (vWf) and beta-thromboglobulin (beta TG). The results revealed an association of GC release with UVB dose using both UV sources, although this was more apparent in the BAC system, in which glycocalicin release at day 5 of storage was as follows (microgram/ml, mean +/- SD): 4.8 +/- 0.3 and 9.5 +/- 3.6 at 7500 and 15,000 mJ/cm2 respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet concentrates irradiated with ultraviolet light retain satisfactory in vitro storage characteristics and in vivo survival.

We have previously reported that platelet concentrates (PC) may be irradiated with ultraviolet light (UVL) in a cryostorage pack such that mixed lymphocyte reactions (MLR) are abolished whilst satisfactory platelet function is retained during subsequent storage using Fenwal PL-1240 containers. We have now studied both platelet structure and function after irradiation in DuPont Stericell bags which are both UV-permeable and biocompatible. The irradiation dosage was 3000 Joules/m2 of UVL at a mean wavelength of 310 nm; a dose previously shown to abolish MLR. No detriment to platelet function was observed when compared to control as measured by aggregation responses to adenosine diphosphate (ADP), collagen and ristocetin, hypotonic shock response and pH during 5 d of storage. Lactate levels were significantly higher (P less than 0.01) and glucose levels lower (P less than 0.01) in UV-treated PC, although in the majority the lactate level did not exceed 20 mmol/l. Betathromboglobulin and platelet factor 4 levels were higher during storage in the UV group, the latter reaching significance (P less than 0.05). When whole platelets and platelet membranes were stained with Coomassie blue or Periodic Acid-Schiff's reagent after electrophoresis in polyacrylamide gels no obvious alterations to major membrane constituents were observed on days 1 and 5 of storage. Paired in vivo autologous studies in healthy volunteers using 111Indium-labelling were performed at the end of 5 d of storage. The UV-treated platelets gave satisfactory and equivalent results for recovery, half life and survival when compared to controls. We conclude that PC irradiated with UVL and stored for 5 d in DuPont Stericell containers appear suitable for transfusion and may prove to be nonimmunogenic. Further in vivo studies of haemostatic efficacy and recipient alloimmunization are now warranted.