Determining the Effectiveness of Counterpressure Maneuvers in Pediatric Patients Presenting With Syncope to the Emergency Department

Knowledge Gaps and Objectives The typical presentation and management for paediatric syncope is poorly understood. From research in adults, it is known that obtaining a detailed history of prodromal symptoms and the circumstance of a syncopal event is important for diagnosis, risk stratification, and determining patient prognosis. However, research in paediatric patients is lacking, with recommendations often disputed and based on a paucity of direct evidence, assuming that children will respond similarly to adults; however, this may not be the case. The investigators will (stage I) catalogue the syncopal symptoms observed in paediatric patients presenting to the emergency department (ED) with transient loss of consciousness, and (stage II) assess the efficacy of counter pressure maneuver (CPM) training in preventing recurrent syncope for paediatric patients.

Methods, Stage I; Presentation of syncope in paediatric patients Ethical approval for this study was granted by the University of British Columbia's Clinical Research Ethics Board. The investigators will recruit paediatric patients (age 7-19 years) presenting to the ED with resolved transient loss of consciousness in the last week. Research assistants will identify potential participants based on exclusion criteria, and a clinician will later gather a brief medical history and perform a screen for study eligibility. Exclusion criteria: suspected or confirmed cardiac arrhythmia diagnosis; traumatic head injury; new presentation of a seizure disorder or epilepsy; structural heart disease; hypoglycemia; physical and/or psychological disability associated with vasovagal syncope (VVS).

Consenting patients will complete a survey detailing the nature of their episodes in terms of the provocative situation, their signs and symptoms, and history of syncope or presyncope alongside a brief medical history (age, self-reported Tanner stage, age at onset of female menarche if applicable).

The primary outcome is to document the typical presentation of syncope and presyncope in paediatric patients identified as having experienced VVS. Additional outcomes include predictive factors for uncomplicated syncope in this population, including the influence of pubertal stage on the onset of paediatric syncope. Secondary outcomes include identifying the incidence of syncope, determining typical causes for syncope, and reporting on predictive factors for syncope secondary to other causes in this population. Bivariate analyses assessing possible associations between presenting prodromes and syncopal diagnoses will be conducted using either Fisher or Chi-square tests for categorical variables, and univariate multinomial models for continuous variables. These analyses will also be conducted adjusting for age and sex (either through regression or matching). The incidence and subtype of syncope presented will be calculated using an appropriate reference population. Qualitative data will be analyzed using a thematic approach, to identify trends in chosen variables based on patient responses.

Methods, Stage II; Paediatric counterpressure manoeuvres trial Stage I patients with a confirmed diagnosis of VVS from a clinician will be referred to stage II. Patients will be followed for one year while they implement either usual care for syncope (behavioural interventions and avoidance measures) or usual care alongside CPM use (leg crossing, hand grip, crouching). The primary outcome measure will be the time to syncopal reoccurrence over the 1-year follow up period, while secondary outcome measures include history of syncope in the prior 2 years, frequency of presyncopal episodes, preferred management strategies (CPM, or usual care), and barriers to implementing CPM. The predicted risk of syncopal reoccurrence will be identified using a logistic regression model with a covariate for treatment arm (CPM, standard of care). Outcomes will be compared between groups using the estimated risk ratio and risk difference. The Wald test for the log-odds coefficient from the logistic model will be used to test for treatment effect (level of 0.05). The investigators will also perform a Kaplan-Meier survival analysis (time to syncope recurrence), using a log-rank test and Cox proportional hazards analysis to compare curves. Qualitative follow-up call data will again be analyzed using a thematic approach.