Does patient activation matter? An examination of the relationships between patient activation and healthcare use in older adults with mild frailty after discharge from an emergency department.

ObjectivePatient engagement, as measured by the Patient Activation Measure (PAM®), has been used to assess patients' ability to manage their own care. This study aimed to determine whether the PAM® could predict healthcare use in older adults aged >70years, living independently in the community with mild frailty, within 30days after emergency department (ED) discharge.MethodsA prospective single-centre observational cohort study was completed including older adults who presented to an ED. The 13-item PAM® and selected International Consortium for Health Outcomes Measures were completed prior to ED discharge.ResultsTwo hundred patients were recruited with a mean age of 84.8years (s.d. 6.9). The mean PAM® score was 58.6 (s.d. 13.3), with 12.5% at Level 1 (n=25), 40% at Level 2 (n=80), 34.5% at Level 3 (n=69) and 13.0% at Level 4 (n=26). The PAM® level was significantly associated with ED presentations in the past 6months (P=0.030). The PAM® level did not predict healthcare use within 30days of discharge consisting of time until ED representation (P=0.557), number of ED representations (P=0.560), number of hospital admissions (P=0.499), length of stay in hospital (P=0.254) and number of post-discharge contacts (P=0.667).ConclusionsOverall, the PAM® did not predict prospective short-term healthcare use. However, the PAM® was significantly associated with 6-month previous ED use. With more than 50% of patients at Level 1 or 2, indicating lower capacity for self-management, tailored interventions are required to assist mildly frail patients to manage discharge care plans and engage in preventative strategies.

Delirium detection in the emergency department: A diagnostic accuracy meta-analysis of history, physical examination, laboratory tests, and screening instruments.

INTRODUCTION: Geriatric emergency department (ED) guidelines emphasize timely identification of delirium. This article updates previous diagnostic accuracy systematic reviews of history, physical examination, laboratory testing, and ED screening instruments for the diagnosis of delirium as well as test-treatment thresholds for ED delirium screening. METHODS: We conducted a systematic review to quantify the diagnostic accuracy of approaches to identify delirium. Studies were included if they described adults aged 60 or older evaluated in the ED setting with an index test for delirium compared with an acceptable criterion standard for delirium. Data were extracted and studies were reviewed for risk of bias. When appropriate, we conducted a meta-analysis and estimated delirium screening thresholds. RESULTS: Full-text review was performed on 55 studies and 27 were included in the current analysis. No studies were identified exploring the accuracy of findings on history or laboratory analysis. While two studies reported clinicians accurately rule in delirium, clinician gestalt is inadequate to rule out delirium. We report meta-analysis on three studies that quantified the accuracy of the 4 A's Test (4AT) to rule in (pooled positive likelihood ratio [LR+] 7.5, 95% confidence interval [CI] 2.7-20.7) and rule out (pooled negative likelihood ratio [LR-] 0.18, 95% CI 0.09-0.34) delirium. We also conducted meta-analysis of two studies that quantified the accuracy of the Abbreviated Mental Test-4 (AMT-4) and found that the pooled LR+ (4.3, 95% CI 2.4-7.8) was lower than that observed for the 4AT, but the pooled LR- (0.22, 95% CI 0.05-1) was similar. Based on one study the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is the superior instrument to rule in delirium. The calculated test threshold is 2% and the treatment threshold is 11%. CONCLUSIONS: The quantitative accuracy of history and physical examination to identify ED delirium is virtually unexplored. The 4AT has the largest quantity of ED-based research. Other screening instruments may more accurately rule in or rule out delirium. If the goal is to rule in delirium then the CAM-ICU or brief CAM or modified CAM for the ED are superior instruments, although the accuracy of these screening tools are based on single-center studies. To rule out delirium, the Delirium Triage Screen is superior based on one single-center study.

A streamlined Emergency Department approach to moderate risk chest pain in patients with no pre-existing coronary artery disease: A pilot study.

OBJECTIVE: Moderate risk patients with chest pain and no previously diagnosed coronary artery disease (CAD) who present to ED require further risk stratification. We hypothesise that management of these patients by ED physicians can decrease length of stay (LOS), without increasing patient harm. METHODS: A prospective pilot study with comparison to a pre-intervention control group was performed on patients presenting with chest pain to an ED in Perth, Australia between May and October 2021, following the introduction of a streamlined guideline consisting of ED led decision making and early follow up. Patients had no documented CAD and were at moderate risk of major adverse cardiac events (MACE). Electronic data was used for comparison. Primary outcomes were total LOS and LOS following troponin. RESULTS: One hundred eighty-six patients were included. Median total LOS was reduced by 62 min, but this change was not statistically significant (482 [360-795] vs 420 [360-525] min, P = 0.06). However, a significant 60 min decrease in LOS was found following the final troponin (240 (120-571) vs 180 (135-270) min, P = 0.02). There was no difference in the rate of MACE (0% vs 2%, P = 0.50), with no myocardial infarction or death. CONCLUSIONS: Our study suggests that patients with no pre-existing CAD can be safely managed by emergency physicians streamlining their ED management and decreasing LOS. This pathway could be used in other centres following confirmation of the results by a larger study.

Applications of natural language processing at emergency department triage: A narrative review.

INTRODUCTION: Natural language processing (NLP) uses various computational methods to analyse and understand human language, and has been applied to data acquired at Emergency Department (ED) triage to predict various outcomes. The objective of this scoping review is to evaluate how NLP has been applied to data acquired at ED triage, assess if NLP based models outperform humans or current risk stratification techniques when predicting outcomes, and assess if incorporating free-text improve predictive performance of models when compared to predictive models that use only structured data. METHODS: All English language peer-reviewed research that applied an NLP technique to free-text obtained at ED triage was eligible for inclusion. We excluded studies focusing solely on disease surveillance, and studies that used information obtained after triage. We searched the electronic databases MEDLINE, Embase, Cochrane Database of Systematic Reviews, Web of Science, and Scopus for medical subject headings and text keywords related to NLP and triage. Databases were last searched on 01/01/2022. Risk of bias in studies was assessed using the Prediction model Risk of Bias Assessment Tool (PROBAST). Due to the high level of heterogeneity between studies and high risk of bias, a metanalysis was not conducted. Instead, a narrative synthesis is provided. RESULTS: In total, 3730 studies were screened, and 20 studies were included. The population size varied greatly between studies ranging from 1.8 million patients to 598 triage notes. The most common outcomes assessed were prediction of triage score, prediction of admission, and prediction of critical illness. NLP models achieved high accuracy in predicting need for admission, triage score, critical illness, and mapping free-text chief complaints to structured fields. Incorporating both structured data and free-text data improved results when compared to models that used only structured data. However, the majority of studies (80%) were assessed to have a high risk of bias, and only one study reported the deployment of an NLP model into clinical practice. CONCLUSION: Unstructured free-text triage notes have been used by NLP models to predict clinically relevant outcomes. However, the majority of studies have a high risk of bias, most research is retrospective, and there are few examples of implementation into clinical practice. Future work is needed to prospectively assess if applying NLP to data acquired at ED triage improves ED outcomes when compared to usual clinical practice.

Caring for persons with Dementia: a qualitative study of the needs of carers following care recipient discharge from hospital.

BACKGROUND: A randomised clinical trial titled the Carer End of Life Planning Intervention (CELPI) in people dying with dementia evaluated the effect of carer education and support about palliative care on care recipient outcomes. We present a pre-planned qualitative analysis of data collected during the CELPI trial in which needs of carers randomised to the study intervention group were assessed using a novel instrument (Carer Needs Directed Assessment in Dementia (CANDID). This tool aimed to identify carers' perceptions of their own and their care-recipients' needs and is an important step in identifying support provision for dementia-specific, palliative cares services upon hospital discharge. METHODS: The CANDID tool was designed to identify the needs and experiences of primary carers and of their care recipients during the last twelve months of the care recipient's life. The tool consisted of 33 open-ended questions evaluating: symptom management, emergency contacts, advance care planning, carer's perception of the care recipient's future needs, carer's current needs, and a proposed current and future care plan. The researcher's philosophical assumption of interpretative phenomenology informed the study and approach to data collection and analysis. Qualitative data collected during interviews using this tool were thematically analysed in five steps: compiling, disassembling, reassembling, interpreting and concluding. An interpretation of participants' reality emerged from their common experiences and the subjective meanings assigned to actions attached to the phenomena studied. RESULTS: Thirty carer participants were included. Analysis identified three major themes: Carers' perceived stressors, systemic barriers to care provision, and future planning. Issues identified included barriers to accessing supports, carer health and division between roles, financial burden, familial conflicts, adquate care in hospital and aged care facilities, concern about future needs, and end-of-life discussions. CONCLUSION: The CANDID tool enabled an evaluation of carer needs and concerns. Identifying those needs may inform a referral to palliative care services where the level of management required may be benenficial for both the person living with dementia and their primary carer. TRIAL REGISTRATION: Australian Clinical Trials Registration: (ACTRN12619001187134).

Effect of intravenous fluid volume on biomarkers of endothelial glycocalyx shedding and inflammation during initial resuscitation of sepsis.

PURPOSE: To investigate the effect of IV fluid resuscitation on endothelial glycocalyx (EG) shedding and activation of the vascular endothelium and inflammation. MATERIALS AND METHODS: A planned biomarker sub-study of the REFRESH trial in which emergency department (ED) patients) with suspected sepsis and hypotension were randomised to a restricted fluid/early vasopressor regimen or IV fluid resuscitation with later vasopressors if required (usual care). Blood samples were collected at randomisation (T0) and at 3 h (T3), 6 h (T6)- and 24 h (T24) for measurement of a range of biomarkers if EG shedding, endothelial cell activation and inflammation. RESULTS: Blood samples were obtained in 95 of 99 enrolled patients (46 usual care, 49 restricted fluid). Differences in the change in biomarker over time between the groups were observed for Hyaluronan (2.2-fold from T3 to T24, p = 0.03), SYN-4 (1.5-fold from T3 to T24, P = 0.01) and IL-6 (2.5-fold from T0 to T3, p = 0.03). No difference over time was observed between groups for the other biomarkers. CONCLUSIONS: A consistent signal across a range of biomarkers of EG shedding or of endothelial activation or inflammation was not demonstrated. This could be explained by pre-existing EG shedding or overlap between the fluid volumes administered in the two groups in this clinical trial. Trial registration Australia New Zealand Clinical Trials Registry ACTRN126160000006448 Registered 12 January 2016.

Review article: Prehospital telehealth for emergency care: A scoping review.

Telehealth has been successfully implemented in the prehospital setting to expedite emergency care, although applications are still in their infancy. With recent advances in technologies, it is not described how prehospital telehealth has evolved over the past decade. This scoping review aimed to answer the research question 'what telehealth platforms have been used to facilitate communication between prehospital healthcare providers and emergency clinicians in the past decade?'. The review was guided by Joanna Briggs Institute scoping review methodology and reported in accordance with the PRISMA checklist for scoping reviews. A systematic search of five databases and Google Scholar was undertaken using key terms 'prehospital', 'ambulance', 'emergency care' and 'telehealth', and results were limited to research articles published in English language between 2011 and 2021. Articles were included if they related to the research question and reported quantitative, qualitative, mixed-method or feasibility studies. A total of 28 articles were included in the review that reported feasibility (n = 13), intervention (n = 7) or observational studies (n = 8) involving 20 telehealth platforms. Platforms were commonly implemented to provide prehospital staff with medical support for general emergency care and involved a range of devices that were used to transmit video, audio and biomedical data. The benefits of prehospital telehealth to patients, clinicians and organisations were identified. Challenges to telehealth involved technical, clinical and organisational issues. Few facilitators of prehospital telehealth were identified. Telehealth platforms to facilitate prehospital to ED communication continue to develop but require technological advances and improved network connectivity to support implementation in the prehospital environment.

Descriptive Study of Ambulance Attendances for Older Adults with and without Dementia in Western Australia.

OBJECTIVE: To describe and compare characteristics of ambulance attendances for older adults with and without dementia. METHODS: A retrospective cohort study was conducted using electronic patient care records from the main ambulance service in Western Australia. All attendances for people aged 65 years or older in the years 2019-21 were included. Dementia status was adjudicated from the clinical history and medication lists. Patient and case characteristics of those with and without dementia were compared and stratified by type of residence. RESULTS: There were 277,996 emergency ambulance attendances made by 124,711 older adults, of whom 23.5% had dementia. The mean number of attendances per person was 3.3 in the dementia cohort vs 2.0 in those without dementia. Falls were the leading reason for ambulance attendance. People with dementia were significantly frailer, required longer at-scene intervals, were less likely to be transported as the highest priority, and had lower 30-day survival. CONCLUSIONS: Dementia is common amongst older adults attended by paramedics and is associated with higher ambulance utilization per person. People with dementia attended by paramedics have stronger signals of vulnerability, such as increased frailty. As the number of people living with dementia increases in the future, there are implications for workforce training and service planning. There are opportunities for developing alternatives to emergency department transportation for some people with dementia.

Genes involved in platelet aggregation and activation are downregulated during acute anaphylaxis in humans.

Objective: Mechanisms underlying the anaphylactic reaction in humans are not fully understood. Here, we aimed at improving our understanding of anaphylaxis by investigating gene expression changes. Methods: Microarray data set GSE69063 was analysed, describing emergency department (ED) patients with severe anaphylaxis (n = 12), moderate anaphylaxis (n = 6), sepsis (n = 20) and trauma (n = 11). Samples were taken at ED presentation (T0) and 1 h later (T1). Healthy controls were age and sex matched to ED patient groups. Gene expression changes were determined using limma, and pathway analysis applied. Differentially expressed genes were validated in an independent cohort of anaphylaxis patients (n = 31) and matched healthy controls (n = 10), using quantitative reverse transcription-polymerase chain reaction. Results: Platelet aggregation was dysregulated in severe anaphylaxis at T0, but not in moderate anaphylaxis, sepsis or trauma. Dysregulation was not observed in patients who received adrenaline before T0. Seven genes (GATA1 (adjusted P-value = 5.57 × 10-4), TLN1 (adjusted P-value = 9.40 × 10-4), GP1BA (adjusted P-value = 2.15 × 10-2), SELP (adjusted P-value = 2.29 × 10-2), MPL (adjusted P-value = 1.20 × 10-2), F13A1 (adjusted P-value = 1.39 × 10-2) and SPARC (adjusted P-value = 4.06 × 10-2)) were significantly downregulated in severe anaphylaxis patients who did not receive adrenaline before ED arrival, compared with healthy controls. One gene (TLN1 (adjusted P-value = 1.29 × 10-2)) was significantly downregulated in moderate anaphylaxis patients who did not receive adrenaline before ED arrival, compared with healthy controls. Conclusion: Downregulation of genes involved in platelet aggregation and activation is a unique feature of the early anaphylactic reaction not previously reported and may be associated with reaction severity.

Review article: Roles of activities of daily living and frailty assessments for residents of residential aged care services in emergency department transfers: A scoping review.

Residents from residential aged care services (RACS) (i.e. nursing homes) many of whom are frail or disabled, are frequently transferred to ED for treatment of acute episodes of illness or injury. This review scoped the research related to the ways in which frailty or activities of daily living (ADL) measures are used for clinical purposes, either prior to the transfer of patients to ED or in ED themselves. A search for original studies up to June 2021 that included participants aged 65 years or over was conducted across four databases. Abstracts were first reviewed, leading to full text screening and article selection. Thirty-four studies were included in the scoping review. Most of the ADL and frailty assessments were conducted in residential aged care settings. In seven studies, ADL or frailty assessments in the aged care setting contributed to reduced transfer rates to ED. No results were found that associated the assessment of ADL or frailty with decisions related to treatment in the ED. A single ED study involved specialist emergency nursing in an ED as an intervention which included frailty assessment and led to decreased hospitalisation. This scoping review confirms an opportunity for further research into the ways frailty and ADL assessments are used for decision making in relation to the transfer of frail older people to ED, including how these assessments influence their treatment.

No association between intravenous fluid volume and endothelial glycocalyx shedding in patients undergoing resuscitation for sepsis in the emergency department.

Endothelial glycocalyx (EG) shedding is associated with septic shock and described following intravenous (IV) fluid administration. To investigate the possible impact of IV fluids on the pathobiology of septic shock we investigated associations between biomarkers of EG shedding and endothelial cell activation, and relationships with IV fluid volume. Serum samples were obtained on admission (T0) and at 24 h (T24) in patients undergoing haemodynamic resuscitation for suspected septic shock in the emergency department. Biomarkers of EG shedding-Syndecan-1 (Syn-1), Syndecan-4 (Syn-4), Hyaluronan, endothelial activation-Endothelin-1 (ET-1), Angiopoeitin-2 (Ang-2), Vascular Endothelial Growth Factor Receptor-1(VEGF-1) and leucocyte activation/inflammation-Resistin, Neutrophil Gelatinase Associated Lipocalin (NGAL) and a marker of cardiac stretch-Pro-Atrial Natriuretic Peptide (Pro-ANP) were compared to the total IV fluid volume administered using Tobit regression. Data on 86 patients (52 male) with a mean age of 60 (SD 18) years were included. The mean fluid volume administered to T24 was 4038 ml (SD 2507 ml). No significant association between fluid volume and Pro-ANP or any of the biomarkers were observed. Syn-1 and Syn-4 were significantly correlated with each other (Spearman Rho 0.43, p < 0.001) but not with Hyaluronan. Syn-1 and Syn-4 both correlated with VEGFR-1 (Rho 0.56 and 0.57 respectively, p < 0.001) whereas Hyaluronan correlated with ET-1 (Rho 0.43, p < 0.001) and Ang-2 (Rho 0.43, p < 0.001). There was no correlation between Pro-ANP and any of the EG biomarkers. Distinct patterns of association between biomarkers of EG shedding and endothelial cell activation were observed among patients undergoing resuscitation for sepsis. No relationship between IV fluid volume and Pro-ANP or any of the other biomarkers was observed.

Behavioural drivers influencing emergency department attendance in Victoria during the 2020 COVID-19 pandemic: A mixed methods investigation.

OBJECTIVE: To identify behavioural drivers and barriers that may have contributed to changes in ED attendance during the first 10 months of the coronavirus disease 2019 (COVID-19) pandemic in Victoria. METHODS: We conducted a mixed methods analysis of patients who attended one of eight participating EDs between 1 November 2019 and 31 December 2020. A random sample of patients were chosen after their visit and invited to participate in an online survey assessing behavioural drivers and barriers to attendance. The study timespan was divided into four periods based on local and world events to assess changes in attitudes and behaviours over this period. RESULTS: A total of 5600 patients were invited to complete the survey and 606 (11%) submitted sufficient information for analysis. There were significant differences in participants' attitudes towards healthcare and EDs, levels of concern about contracting and spreading COVID-19 and the influence of mask wearing. Patients expressed more concern about the safety of an ED during the largest outbreak of COVID-19 infections than they did pre-COVID, but this difference was not sustained once community infection numbers dropped. General concerns about hospital attendance were higher after COVID than they were pre-COVID. A total of 27% of patients specifically stated that they had delayed their ED attendance. CONCLUSION: Patients expressed increased concerns around attending ED during the first 10 months of the 2020 COVID-19 pandemic and frequently cited COVID-19 as a reason for delaying their presentation. These factors would be amenable to mitigation via focussed public health messaging.

Can we improve delirium prevention and treatment in the emergency department? A systematic review.

BACKGROUND: This systematic review was conducted to evaluate any interventions to prevent incident delirium, or shorten the duration of prevalent delirium, in older adults presenting to the emergency department (ED). METHODS: Health sciences librarian designed electronic searches were conducted from database inception through September 2021. Two authors reviewed studies, and included studies that evaluated interventions for the prevention and/or treatment of delirium and excluded non-ED studies. The risk of bias (ROB) was evaluated by the Cochrane ROB tool or the Newcastle-Ottawa (NOS) scale. Meta-analysis was conducted to estimate a pooled effect of multifactorial programs on delirium prevention. RESULTS: Our search strategy yielded 11,900 studies of which 10 met study inclusion criteria. Two RCTs evaluated pharmacologic interventions for delirium prevention; three non-RCTs employed a multi-factorial delirium prevention program; three non-RCTs evaluated regional anesthesia for hip fractures; and one study evaluated the use of Foley catheter, medication exposure, and risk of delirium. Only four studies demonstrated a significant impact on delirium incidence or duration of delirium-one RCT of melatonin reduced the incidence of delirium (OR 0.19, 95% CI 0.06 to 0.62), one non-RCT study on a multi-factorial program decreased inpatient delirium prevalence (41% to 19%) and the other reduced incident delirium (RR 0.37, 95% CI 0.22 to 0.61). One case-control study on the use of ED Foley catheters in the ED increased the duration of delirium (proportional OR 3.1, 95% CI 1.3 to 7.4). A pooled odds ratio for three multifactorial programs on delirium prevention was 0.46 (95% CI 0.31-0.68, I2  = 0). CONCLUSION: Few interventions initiated in the ED were found to consistently reduce the incidence or duration of delirium. Delirium prevention and treatment trials in the ED are still rare and should be prioritized for future research.

Prehospital continuous positive airway pressure (CPAP) for acute respiratory distress: a randomised controlled trial.

OBJECTIVE: To compare the efficacy of continuous positive airway pressure (CPAP) versus usual care for prehospital patients with severe respiratory distress. METHODS: We conducted a parallel group, individual patient, non-blinded randomised controlled trial in Western Australia between March 2016 and December 2018. Eligible patients were aged ≥40 years with acute severe respiratory distress of non-traumatic origin and unresponsive to initial treatments by emergency medical service (EMS) paramedics. Patients were randomised (1:1) to usual care or usual care plus CPAP. The primary outcomes were change in dyspnoea score and change in RR at ED arrival, and hospital length of stay. RESULTS: 708 patients were randomly assigned (opaque sealed envelope) to usual care (n=346) or CPAP (n=362). Compared with usual care, patients randomised to CPAP had a greater reduction in dyspnoea scores (usual care -1.0, IQR -3.0 to 0.0 vs CPAP -3.5, IQR -5.2 to -2.0), median difference -2.0 (95% CI -2.5 to -1.6); and RR (usual care -4.0, IQR -9.0 to 0.0 min-1 vs CPAP -8.0, IQR -14.0 to -4.0 min-1), median difference -4.0 (95% CI -5.0 to -4.0) min-1. There was no difference in hospital length of stay (usual care 4.2, IQR 2.1 to 7.8 days vs CPAP 4.8, IQR 2.5 to 7.9 days) for the n=624 cases admitted to hospital, median difference 0.36 (95% CI -0.17 to 0.90). CONCLUSIONS: The use of prehospital CPAP by EMS paramedics reduced dyspnoea and tachypnoea in patients with acute respiratory distress but did not impact hospital length of stay. TRIAL REGISTRATION NUMBER: ACTRN12615001180505.

Neurological outcome in adult out-of-hospital cardiac arrest - Not all doom and gloom!

AIMS: To describe neurological and functional outcomes among out-of-hospital cardiac arrest (OHCA) patients who survived to hospital discharge; to determine the association between neurological outcome at hospital discharge and 12-month survival. METHODS: Our cohort comprised adult OHCA patients (≥18 years) attended by St John WA (SJWA) paramedics in Perth, Western Australia (WA), who survived to hospital discharge, between 1st January 2004 and 31st December 2019. Neurological and functional status at hospital discharge (and before the arrest) was determined by medical record review using the five-point 'Cerebral Performance Category (CPC)' and 'Overall Performance Category (OPC)' scores. Adjusted multivariable logistic regression analysis was used to estimate the association of CPC score at hospital discharge with 12-month survival, adjusted for prognostic variables. RESULTS: Over the study period, SJWA attended 23,712 OHCAs. Resuscitation was attempted in 43.4% of cases (n = 10,299) with 2171 subsequent admissions, 99.4% (n = 2158) of these were admitted to a study hospital. Of the 1062 hospital survivors, 71.3% (n = 757) were CPC1 (highest category of neurological performance), 21.4% (n = 227) CPC2, 6.3% (n = 67) CPC3 and 1.0% (n = 11) CPC4. OPC scores followed a similar distribution. Of the 1,011 WA residents who survived to hospital discharge, 92.3% (n = 933) survived to 12-months. A CPC1-2 at hospital discharge was significantly associated with 12-month survival (adjusted odds ratio 3.28, 95% confidence interval 1.69-6.39). CONCLUSION: Whilst overall survival is low, most survivors of OHCA have a good neurological outcome at hospital discharge and are alive at 12-months.

Small nucleolar RNA networks are up-regulated during human anaphylaxis.

BACKGROUND: Anaphylaxis is a severe, potentially life-threatening allergic reaction driven primarily by the activation of mast cells. We still fail to understand factors underlying reaction severity. Furthermore, there is currently no reliable diagnostic test to confirm anaphylaxis in the emergency department (ED). OBJECTIVE: This study sought to explore gene expression changes associated with anaphylaxis severity in peripheral blood leucocytes and evaluate biomarker potential. METHODS: Microarray analysis (total RNA) was performed using peripheral blood samples from ED patients with moderate (n = 6) or severe (n = 12) anaphylaxis and sepsis (n = 20) at presentation (T0) and one hour later (T1). Results were compared between groups and healthy controls (n = 10 and n = 11 matched to anaphylaxis and sepsis patients, respectively). Changes in gene expression were determined using R programming language, and pathway analysis applied to explore biological processes and pathways associated with genes. Differentially expressed genes were validated in an independent cohort of anaphylaxis (n = 30) and sepsis (n = 20) patients, and healthy controls (n = 10), using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: Significant up-regulation of small nucleolar RNAs (snoRNAs) was demonstrated in anaphylaxis compared to sepsis patients in the microarray cohort, at T0 and T1. qRT-PCR analysis of the validation cohort showed five genes: SNORD61, SNORD8, SNORD69, SNORD119 and HIST1H1D to be significantly up-regulated (adjusted p < 0.05) in severe anaphylaxis compared to sepsis. Seven genes (SNORD61, SNORD8, SCARNA21, SNORD69, SNORD110, SNORD119 and SNORD59A) were significantly up-regulated (adjusted p < 0.05) in severe anaphylaxis compared to healthy controls. CONCLUSION: This study demonstrates for the first time the unique involvement of snoRNAs in the pathogenesis of anaphylaxis and suggests they are not a general feature of systemic inflammation. Further investigation of snoRNA expression in anaphylaxis could provide insights into disease pathogenesis. CLINICAL RELEVANCE: SnoRNAs are up-regulated during acute anaphylaxis in humans and could potentially be used as biomarkers of severe anaphylaxis.