Seven-step framework to enhance practitioner explanations and parental understandings of research without prior consent in paediatric emergency and critical care trials.

BACKGROUND: Alternatives to prospective informed consent enable the conduct of paediatric emergency and critical care trials. Research without prior consent (RWPC) involves practitioners approaching parents after an intervention has been given and seeking consent for their child to continue in the trial. As part of an embedded study in the 'Emergency treatment with Levetiracetam or Phenytoin in Status Epilepticus in children' (EcLiPSE) trial, we explored how practitioners described the trial and RWPC during recruitment discussions, and how well this information was understood by parents. We aimed to develop a framework to assist trial conversations in future paediatric emergency and critical care trials using RWPC. METHODS: Qualitative methods embedded within the EcLiPSE trial processes, including audiorecorded practitioner-parent trial discussions and telephone interviews with parents. We analysed data using thematic analysis, drawing on the Realpe et al (2016) model for recruitment to trials. RESULTS: We analysed 76 recorded trial discussions and conducted 30 parent telephone interviews. For 19 parents, we had recorded trial discussion and interview data, which were matched for analysis. Parental understanding of the EcLiPSE trial was enhanced when practitioners: provided a comprehensive description of trial aims; explained the reasons for RWPC; discussed uncertainty about which intervention was best; provided a balanced description of trial intervention; provided a clear explanation about randomisation and provided an opportunity for questions. We present a seven-step framework to assist recruitment practice in trials involving RWPC. CONCLUSION: This study provides a framework to enhance recruitment practice and parental understanding in paediatric emergency and critical care trials involving RWPC. Further testing of this framework is required.

Opt-out screening for HIV, hepatitis B and hepatitis C: observational study of screening acceptance, yield and treatment outcomes.

BACKGROUND: We initiated an emergency department (ED) opt-out screening programme for HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) at our hospital in Dublin, Ireland. The objective of this study was to determine screening acceptance, yield and the impact on follow-up care. METHODS: From July 2015 through June 2018, ED patients who underwent phlebotomy and could consent to testing were tested for HIV, HBV and HCV using an opt-out approach. We examined acceptance of screening, linkage to care, treatment and viral suppression using screening programme data and electronic health records. The duration of follow-up ranged from 1 to 36 months. RESULTS: Over the 36-month study period, there were 140 550 ED patient visits, of whom 88 854 (63.2%, 95% CI 63.0% to 63.5%) underwent phlebotomy and 54 817 (61.7%, 95% CI 61.4% to 62.0%) accepted screening for HIV, HBV and HCV, representing 41 535 individual patients. 2202 of these patients had a positive test result. Of these, 267 (12.1%, 95% CI 10.8% to 13.6%) were newly diagnosed with an infection and 1762 (80.0%, 95% CI 78.3% to 81.7%) had known diagnoses. There were 38 new HIV, 47 new HBV and 182 new HCV diagnoses. 81.5% (95% CI 74.9% to 87.0%) of known patients who were not linked were relinked to care after screening. Of the new diagnoses, 86.2% (95% CI 80.4 to 90.8%) were linked to care. CONCLUSION: Although high proportions of patients had known diagnoses, our programme was able to identify many new infected patients and link them to care, as well as relink patients with known diagnoses who had been lost to follow-up.

Oral nitroglycerin solution for oesophageal food impaction: a prospective single-arm pilot study.

BACKGROUND: Thirteen episodes of oesophageal food impaction (EFI) per 100 000 people present to a medical setting each year. Several pharmacological interventions meant to relieve such impactions have been explored; none have proven superior. OBJECTIVES: Perform a single-arm feasibility study of oral nitroglycerin solution for EFI. METHODS: Twenty adult patients presenting to a single urban tertiary medical centre thought to have EFI were given up to three doses of 0.4 mg nitroglycerin solution orally and evaluated for resolution of symptoms, new symptoms and vital signs. Patients with intractable vomiting, haemodynamic instability, airway compromise, oesophageal perforation, coronary ischaemia or presentation delayed greater than 12 hours were excluded. RESULTS: 17 of 20 enrolled subjects received the intervention. The average duration of symptoms prior to intervention was 285 min (SD=187). Four subjects did not tolerate the intervention (inability to swallow or headache). Two of 17 (11.8%) subjects obtained temporally proximal symptom resolution: 11 min after the second dose, and 7 min after the third dose. Seven also received glucagon during their visit, with 0% temporally proximal symptom resolution. Fifteen underwent endoscopy, with food bolus identified in 12. One subject had brief and mild hypotension with spontaneous resolution. Two subjects developed a headache after nitroglycerin administration. The median length of stay for those who found relief without endoscopy was 195 min (range 129-261) vs 374 min (range 122-525) among those with endoscopy. CONCLUSION: The observed rate of relief after oral nitroglycerin solution for EFI is disappointing but comparable to previous glucagon, benzodiazepines and effervescent beverage studies, and that of placebo. Oral nitroglycerin solution appears to be well tolerated among those able to swallow, although in our sample several subjects were unable to tolerate swallowing entirely.

Clinical outcomes stratified by baseline functional class after initial combination therapy for pulmonary arterial hypertension.

BACKGROUND: Initial combination therapy with ambrisentan and tadalafil reduced the risk of clinical failure events for treatment-naïve participants with pulmonary arterial hypertension (PAH) as compared to monotherapy. Previous studies in PAH have demonstrated greater treatment benefits in more symptomatic participants. METHODS: AMBITION was an event-driven, double-blind study in which participants were randomized 2:1:1 to once-daily initial combination therapy with ambrisentan 10 mg plus tadalafil 40 mg, ambrisentan 10 mg plus placebo, or tadalafil 40 mg plus placebo. In this pre-specified subgroup analysis, we compared the efficacy data between those with functional class (FC) II vs. FC III symptoms at baseline. RESULTS: This analysis included 500 participants in the previously defined primary analysis set (n = 155 FC II, n = 345 FC III). Comparing combination therapy to pooled monotherapy, the risk of clinical failure events was reduced by 79% (hazard ratio, 0.21 [95% confidence interval: 0.071, 0.63]) for FC II patients and 42% (hazard ratio, 0.58 [95% confidence interval: 0.39, 0.86]) for FC III patients. In a post-hoc analysis, the risk of first hospitalization for worsening PAH was also reduced by combination therapy, particularly for FC II patients (0 combination vs. 11 [14%] pooled monotherapy). Adverse events were frequent but comparable between the subgroups. CONCLUSIONS: Treatment benefit from initial combination therapy appeared at least as great for FC II as for FC III participants. Hospitalizations for worsening PAH were not observed in FC II participants assigned to combination. The present data support an initial combination strategy for newly diagnosed patients even when symptoms are less severe. Funded by Gilead Sciences, Inc. and GlaxoSmithKline; AMBITION ClinicalTrials.gov number, NCT01178073.

Phenomenological study exploring ethics in prehospital research from the paramedic's perspective: experiences from the Paramedic-2 trial in a UK ambulance service.

OBJECTIVES: We set out to investigate paramedics' views of ethics and research, drawing on experiences from Paramedic-2, a randomised controlled trial comparing epinephrine and placebo in out-of-hospital cardiac arrest (OHCA). METHODS: An interpretative phenomenological approach was adopted. A purposive sample of paramedics (n=6) from North East Ambulance Service NHS Foundation Trust were invited to a semi-structured, in-depth interview. RESULTS: Three superordinate themes emerged: (1) morality, (2) emotion and (3) equipoise. Some viewed Paramedic-2 as an opportunity to improve OHCA outcomes for the many, viewing participation as a moral obligation; others viewed the study as unethical, equating participation with immoral behaviour. Morality was a motivator to drive individual action. Positive and negative emotions were exhibited by the paramedics involved reflecting the wider view each paramedic held about trial participation. Those morally driven to participate in Paramedic-2 discussed their pride in being associated with the trial, while those who found participation unethical, discussed feelings of guilt and regret. Individual experience and perceptions of epinephrine guided each paramedic's willingness to accept or reject equipoise. Some questioned the role of epinephrine in OHCA; others believed withholding epinephrine was synonymous to denying patient care. CONCLUSION: A paucity of evidence exists to support any beneficial role of epinephrine in OHCA. Despite this, some paramedics were reluctant to participate in Paramedic-2 and relied on their personal perceptions and experiences of epinephrine to guide their decision regarding participation. Failure to acknowledge the importance of individual perspectives may jeopardise the success of future out-of-hospital trials.

Understanding the management of patients with head injury taking warfarin: who should we scan and when? Lessons from the AHEAD study.

Anticoagulated patients represent an important and increasing proportion of the patients with head trauma attending the ED, but there is no international consensus for their appropriate investigation and management. International guidelines vary and are largely based on a small number of studies, which provide poor-quality evidence for the management of patients taking warfarin. This article provides an overview of the clinical research evidence for CT scanning head-injured patients taking warfarin and a discussion of interpretation of risk and acceptable risk. We aim to provide shop floor clinicians with an understanding of the limitations of the evidence in this field and the limitations of applying 'one-size-fits-all' guidelines to individual patients. There is good evidence for a more selective scanning approach to patients with head injuries taking warfarin than is currently recommended by most guidelines. Specifically, patients without any head injury-related symptoms and GCS score 15 have a reduced risk of adverse outcome and may not need to be scanned. We argue that there is evidence to support an individualised approach to decision to CT scan in mild head injuries on warfarin and that clinicians should feel able to discuss risks with patients and sometimes decide not to scan.

Canadian and UK/Ireland practice patterns in lumbar puncture performance in febrile neonates with bronchiolitis.

BACKGROUND: Serious bacterial infections in young infants with bronchiolitis are rare. Febrile infants <1 month old with bronchiolitis often receive a lumbar puncture (LP), despite limited data for this practice and lack of clinical practice guidelines for this population. The primary objective was to investigate practice patterns in performance of LPs in the ED management of febrile infants aged ≤30 days with bronchiolitis. METHODS: A cross-sectional survey of two national paediatric emergency research networks (PediatricEmergency Research Canada (PERC) and the PediatricEmergency Research UK/Ireland (PERUKI)) was conducted January to November 2017 using a modified Dillman technique. The survey was preceded by a clinical vignette describing a well appearing, 21-day-old infant with low-grade fever, respiratory findings typical of bronchiolitis and no perinatal serious bacterial infection (SBI) risk features. RESULTS: The response rate from PERC was 169/250 (68%) and 172/201 (86%) from PERUKI. Nine physicians in training were excluded, leaving 332 eligible participants. Although most physicians believe that neonates with bronchiolitis rarely have meningitis (PERC 141/161 (87.6%); PERUKI 154/171 (90%)) and feel comfortable diagnosing bronchiolitis in this group (PERC 136/161 (84.5%); PERUKI 143/171 (83.6%)), there was significant variation in the proportion who would be likely/very likely to perform an LP (PERC 100/161 (62.1%); PERUKI 15/171 (8.8%)) (p<0.0001). Practice in Canada, <10 years in practice and lack of comfort with diagnosing bronchiolitis represent multivariable predictors of LP; OR 23.7 (95% CI 11.7 to 47.9), 2.3 (95% CI 1.2 to 4.2) and 2.5 (95% CI 1.1 to 5.0), respectively. Rapid knowledge of respiratory syncytial virus positivity would decrease LP probability from 35.4% to 20.2%. CONCLUSION: Estimated probability of performing LPs and other interventions in otherwise healthy febrile neonates with bronchiolitis is highly variable between emergency physicians in Canada and the UK/Ireland. Network, <10 years in ED practice and comfort level with diagnosing bronchiolitis in newborns constitute independent predictors of the likelihood of LP performance.

Implant-associated gene expression in the jaw bone of smokers and nonsmokers: A human study using quantitative qPCR.

OBJECTIVES: This study aimed to compare the molecular events in implant-adherent cells and in peri-implant bone during the osseointegration of machined and oxidized titanium implants in smokers and nonsmokers. MATERIALS AND METHODS: Twenty-four smokers and 24 nonsmokers each received machined and anodically oxidized mini-implants. The mini-implants and the surrounding bone were retrieved after 1, 7, and 28 days, for gene expression analysis of selected factors using quantitative polymerase chain reaction (qPCR). RESULTS: Differences between machined and oxidized implants were more evident in the implant-adherent cells than the peri-implant bone. The machined implants revealed higher expression of proinflammatory cytokines, interleukin-8 (IL-8) (in nonsmokers), and tumor necrosis factor-alpha (in nonsmokers and smokers), compared with the oxidized implants. Conversely, the expression of bone formation genes, alkaline phosphatase and osteocalcin, was generally higher at the oxidized implants. In smokers, the temporal pattern revealed the delayed and initial inhibition of osteoblastic and osteoclastic gene expression, respectively, mainly at the machined implants. In contrast, oxidized implants revealed higher expression of bone remodeling, cathepsin K (CatK) and calcitonin receptor, and coupling, receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin, genes after 7 day in smokers. CONCLUSIONS: The implant-adherent cells are more sensitive to surface properties and smoking conditions than the cells in the peri-implant bone. Smoking imposes inhibitory effects on the initial molecular events of osseointegration in the human bone-implant interface. The surface properties of oxidized implants appear to have a beneficial effect on osseointegration by mitigating the smoking-induced negative effects.

Why sample size estimates?

Sample size estimates are critical to the planning and interpretation of clinical studies, whether they are descriptive or analytical. Too small a sample size will result in imprecise estimates in a descriptive study and failure to achieve 'statistical significance' in an analytic or comparative study. Here we discuss what both researchers and readers should understand about the reasons for sample size estimates, how they are done and how achieving or not achieving the desired sample size can affect the interpretation of the outcomes.

What is positionality and should it be expressed in quantitative studies?

Although we are increasingly reaping the benefits of qualitative studies, their approach and that of quantitative studies remain rather separate. Emergency medicine practitioners thrive off research in context as we deal with such an undifferentiated population however quantitative 'hard-science' work is conspicuous for its absence of positionality. This contrasts strongly with the way in which qualitative research, within the domain of so-called soft-science literature, uses positionality as an integral element of the research process. Without contextualising the researcher and research environment in qualitative studies, often the meaning of any research output is lost. What follows is that positionality does not undermine the truth of such research, instead it defines the boundaries within which the research was produced. ​ The absence of positionality when considered alongside the notion of bias, may challenge the quantitative idea of validity.

Reasons and evolution of non-thrombolysis in acute ischaemic stroke.

INTRODUCTION: Despite increasing evidence of its efficacy in advanced age or in mild or severe strokes, intravenous thrombolysis remains underused for acute ischaemic stroke (AIS). Our aim was to obtain an updated view of reasons for non-thrombolysis and to identify its changing patterns over time. METHODS: This is a retrospective study of prospectively collected data from the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) from the years 2003-2011. Patients admitted with acute stroke in the past 24 hours who had not had thrombolysis were identified; reasons for non-thrombolysis documented in the prospectively entered data were tabulated and analysed for the group as a whole. Data were analysed for the years 2003-2006 and 2007 forward because of changes in contraindications. A subgroup of patients who arrived within the treatment window ≤180 min was separately analysed for reasons for non-thrombolysis. Predictors of non-thrombolysis were investigated via multivariate regression analyses. RESULTS: In the 2019 non-thrombolysed patients the most frequent reasons for non-thrombolysis were admission delays (66.3%), stroke severity (mostly mild) (47.9%) and advanced age (14.1%); 55.9% had more than one exclusion criterion. Among patients arriving ≤180 min after onset, the main reasons were stroke severity and advanced age. After 2006, significantly fewer patients were excluded because of age (OR 2.65, p<0.001) or (mostly mild) stroke severity (OR 10.56, p=0.029). Retrospectively, 18.7% of all non-thrombolysed patients could have been treated because they only had relative contraindications. CONCLUSION: Onset-to-admission delays remain the main exclusion criterion for thrombolysis. Among early arrivals, relative contraindications such as minor stroke severity and advanced age were frequent. Thrombolysis rate increased with the reduction of thrombolysis restrictions (eg, age and stroke severity).

Understanding How Bereaved Parents Cope With Their Grief to Inform the Services Provided to Them.

Our objective was to develop a rich description of how parents experience their grief in the first year after the death of their child, and how various bereavement follow-up and support services helped them during this time, with the aim of informing follow-up and support services offered to bereaved parents. Our findings situated parents' individual experiences of coping within the social and institutional contexts in which they grieved. In the first year after the death of their child, parents regulated their intense feelings of grief through loss-oriented, restoration-oriented, and/or meaning reconstruction strategies. Often, parents' relationships with others and many of the bereavement follow-up and support services helped them in this regard. This article also explores how the results may aid service providers in accompanying parents in a way that optimizes outcomes for these parents.

Human factors in prehospital research: lessons from the PARAMEDIC trial.

BACKGROUND: There is an urgent need to develop prehospital research capability in order to improve the care of patients presenting to emergency medical services (EMS). The Prehospital Randomised Assessment of a Mechanical compression Device In Cardiac arrest trial, a pragmatic cluster randomised trial evaluating the LUCAS-2 device, represents the largest randomised controlled trial conducted by UK ambulance services to date. The aim of this study was to identify and analyse factors that may influence paramedic attitudes to, and participation in, clinical trials. METHODS: Personal and organisational experience from this trial was assessed by feedback from a workshop attended by collaborators from participating EMS and a survey of EMS personnel participating in the trial. A work systems model was used to explain the impact of five interwoven themes-person, organisation, tasks, tools & technology and environment-on trial conduct including gathering of high-quality data. RESULTS: The challenge of training a geographically diverse EMS workforce required development of multiple educational solutions. In order to operationalise the trial protocol, internal organisational relationships were perceived as essential. Staff perceptions of the normalisation of participation and ownership of the trial influenced protocol compliance rates. Undertaking research was considered less burdensome when additional tasks were minimised and more difficult when equipment was unavailable. The prehospital environment presents practical challenges for undertaking clinical trials, but our experience suggests these are not insurmountable and should not preclude conducting high-quality research in this setting. CONCLUSIONS: Application of a human factors model to the implementation of a clinical trial protocol has improved understanding of the work system, which can inform the future conduct of clinical trials and foster a research culture within UK ambulance services. TRIAL REGISTRATION NUMBER: ISRCTN08233942.

How do patients feel about taking part in clinical trials in emergency care?

BACKGROUND: There is little in-depth research into how patients feel about emergency medical trials, and what influences these feelings. OBJECTIVES: To investigate patients' feelings on taking part in emergency medical research, particularly trials conducted without prospective consent. METHODS: Seventeen inpatients, all recently admitted with a medical emergency, were interviewed. Questions focused on feelings on taking part in hypothetical trials, particularly trials conducted with deferred consent. RESULTS: Five main themes were identified. Level of trust in the medical profession-high levels of trust tended to correlate with willingness to participate in trials. Previous bad healthcare experiences tended to diminish trust. Concerns for personal well-being-patients identified a conflict between aversion to unknown side effects and desire for access to newer and potentially better treatments. Some would be less inclined to participate in research if they were severely unwell, some more so. Altruism-many cited the importance of helping to advance medical knowledge and of 'giving back to the health service'. Concerns over autonomy-some felt that deferred consent was a violation of personal autonomy. Uncertainty-many patients seemed to struggle to understand the more complex concepts discussed. CONCLUSIONS: Patients are broadly trusting, and open to participating in emergency medical trials, but want to be kept as informed as possible throughout the process. Willingness may be improved by providing more complete explanations, although this may be limited by the complexity of relevant concepts. Good communication and improved public understanding of clinical trials would likely increase acceptance of emergency care research.

Implementing a Systematic Voiding Program for Patients With Urinary Incontinence After Stroke.

We explored health professionals' views of implementing a systematic voiding program (SVP) in a multi-site qualitative process evaluation in stroke services recruited to the intervention arms of a cluster randomized controlled feasibility trial during 2011-2013. We conducted semi-structured group or individual interviews with 38 purposively selected nursing, managerial, and care staff involved in delivering the SVP. Content analysis of transcripts used normalization process theory (NPT) as a pre-specified organization-level exploratory framework. Barriers to implementing the SVP included perceived lack of suitability for some patient groups, patient fear of extending hospital stay, and difficulties with SVP enactment, scheduling, timing, recording, and monitoring. Enablers included the guidance provided by the SVP, patient and relative involvement, extra staff, improved nursing skill and confidence, and experience of success. Three potential mechanisms of consistency, visibility, and individualization linked the SVP process with improvements in outcome, and should be emphasized in SVP implementation.

Establishing the research priorities of paediatric emergency medicine clinicians in the UK and Ireland.

OBJECTIVE: Paediatric Emergency Research in the UK and Ireland (PERUKI) is a collaborative clinical studies group established in August 2012. It consists of a network of 43 centres from England, Ireland, Northern Ireland, Scotland and Wales, and aims to improve the emergency care of children through the performance of robust collaborative multicentre research within emergency departments. A study was conducted regarding the research priorities of PERUKI, to establish the research agenda for paediatric emergency medicine in the UK and Ireland. METHODS: A two-stage modified Delphi survey was conducted of PERUKI members via an online survey platform. Stage 1 allowed each member to submit up to 12 individual questions that they identified as priorities for future research. In stage 2, the shortlisted questions were each rated on a seven-point Likert scale of relative importance. PARTICIPANTS: Members of PERUKI, including clinical specialists, academics, trainees and research nurses. RESULTS: Stage 1 surveys were submitted by 46/91 PERUKI members (51%). A total of 249 research questions were generated and, following the removal of duplicate questions and shortlisting, 60 questions were carried forward for stage 2 ranking. Stage 2 survey responses were submitted by 58/95 members (61%). For the 60 research questions that were rated, the mean score of 'relative degree of importance' was 4.70 (range 3.36-5.62, SD 0.55). After ranking, the top 10 research priorities included questions on biomarkers for serious bacterial illness, major trauma, intravenous bronchodilators for asthma and decision rules for fever with petechiae, head injury and atraumatic limp. CONCLUSIONS: Research priorities of PERUKI members have been identified. By sharing these results with clinicians, academics and funding bodies, future research efforts can be focused to the areas of greatest need.

ABG needle study: a randomised control study comparing 23G versus 25G needle success and pain scores.

OBJECTIVE: To determine whether a narrower gauge needle used in ABG sampling is associated with lower pain scores and complication rates without increasing the level of difficulty of the procedure. METHODS: We performed a prospective single-blinded randomised control study of patients from a tertiary-level emergency department in Sydney who required an ABG analysis over the period of June 2010-July 2012. Patients were randomised to either a 23G or 25G needle and the primary outcome that included pain experienced by these patient were recorded as pain scores on a 10 cm hatched visual analogue scale. The difficulty scores and complications were also noted from the operator. RESULTS: Data for 119 consenting eligible patients were included in the analysis. 63 patients were allocated to the 23G needle group and 56 to the 25G needle group. The mean pain score was 3.5 (SD=2.7) for the 23G group and 3.4 (SD=2.7) for the 25G group with a mean difference between the pain scores of 0.1 (95% CI -0.9 to 1.1, p=0.83). The 23G and 25G mean difficulty score was 3.4 (SD=2.6) and 4.3 (SD=2.4), respectively, with a mean difference of 0.9 (95% CI -0.03 to 1.7, p=0.06). 21.6% of patient in the 23G needle group experienced some complication with regard to the sampling in the form of haematoma, tenderness or paraesthesia in comparison to 5.4% of patients in the 25G needle group (p=0.03). CONCLUSIONS: There was no significant difference in pain scores experienced by patients undertaking ABG sampling with either a 23G or 25G needle. TRIAL REGISTRATION NUMBER: ACTRN12609000957291.

Emergency department malnutrition screening and support model improves outcomes in a pilot randomised controlled trial.

OBJECTIVE: To trial malnutrition screening in older adults presenting to an emergency department (ED) and compare two service delivery models of nutritional support on nutritional status, quality of life, falls and unplanned hospital admissions. DESIGN: Participants (>60 years) presenting to ED screened at malnutrition risk were randomly allocated to either the control group (receiving regular treatment from community hospital interface programme nursing staff) or intervention group (receiving dietetic assessment, nutrition intervention and follow-up in addition to regular community hospital interface programme support). Outcome measures including body weight, quality of life, depression, falls history and days of hospital admissions were collected at baseline and 12 weeks. RESULTS: Of 703 patients screened, 84 (12%) were identified at malnutrition risk. 24 consented to the intervention study, with 88% (21/24) confirmed to be malnourished. Clinically important but not statistically significant differences were found over the 12-week trial; the intervention group (n=9) gained 0.8 kg (±3.7) while the control group (n=10) lost -1.1 kg (±4.6). The intervention group also had better quality of life, less depression and shorter hospital admissions. CONCLUSIONS: Malnutrition screening appears feasible in ED. This pilot suggests a model of care providing nutrition support to older adults identified at nutritional risk may lead to improved patient outcomes but further research in a larger sample is required to confirm these findings.

Identification of the optimum vagal manoeuvre technique for maximising vagal tone.

OBJECTIVES: This study sought to determine the most effective technique for Valsalva Manoeuvre (VM) and Human Dive Reflex Manoeuvre (HDR) generation of vagal tone. METHODS: We conducted a repeated-measures trial of healthy adult volunteers from a university campus, aged 18-56 years, in sinus rhythm. Participants were randomised to VM (in supine or Trendelenberg postures) and HDR (supine or sitting postures) sequentially. Participants performed three trials of each technique, in random order, with a continuous ECG recording. Single-blinded analysis of ECG data was conducted. Mean differences between premanoeuvre and postmanoeuvre R-R intervals and heart rates were calculated for each posture within and between vagal manoeuvres. RESULTS: Seventy-two participants were enrolled. The difference between VM (supine) and VM (Trendelenberg) was not significant at 0.008 s (-0.023 to 0.038). The difference in mean R-R intervals for HDR (supine) was greater than HDR (sitting) 0.062 (0.031 to 0.093), although this significance was not reflected in a heart-rate change of -0.87 (-3.00 to 1.26). VM supine generated greatest overall mean R-R interval difference, while HDR (sitting) provided the smallest change in R-R interval. The VM (supine) provided a significant maximum effectiveness over the HDR (supine) of 0.102 s (0.071 to 0.132). CONCLUSIONS: This study demonstrates that VM (supine) generates the greatest vagal tone producing the largest transient heart rate decrease in healthy volunteers. No advantage was identified in Trendelenberg posturing for the VM in this study. These results may assist in the standardisation of vagal manoeuvre technique for the range of therapeutic and diagnostic applications.