Competing interests T.P.Saltzherr is a research fellow at the Trauma Unit Department of Surgery, employed by the AMC Medical Research B.V. and supported by an unrestricted grant from Siemens Medical Solutions, Den Haag, the Netherlands. Authors’ contributions JCG was the admitting specialist during initial assessment and trauma care of this patient. All four authors drafted, read and approved Inhibitors,research,lifescience,medical the final manuscript. Pre-publication history

The pre-publication history for this paper can be accessed here: http://www.biomedcentral.com/1471-227X/9/24/prepub
The management of haemodynamically stable supraventricular tachycardia (SVT) in the form of atrioventricular nodal re-entry tachycardia (AVNRT) or atrioventricular re-entry tachycardia (AVRT) by Melbourne Mobile Intensive Care Ambulance (MICA) Paramedics has traditionally involved the use of vagal manoeuvres as a primary intervention, followed by pharmacological interventions. Recent changes to Victorian Ambulance clinical practice guidelines, which Inhibitors,research,lifescience,medical effectively

inhibit pharmacological interventions (GSK2118436 cost unless greater than 30 minutes from hospital), have created reliance upon the Valsalva Manoeuvre (VM) as the sole management method for these patients in the prehospital setting. Historically, VM education within the MICA paramedic course has been somewhat informal, and ongoing education relies heavily on cultural practice and individual learning. A comprehensive Inhibitors,research,lifescience,medical literature Inhibitors,research,lifescience,medical review revealed no standardised prehospital VM method in clinical practice use. [1] This review did however highlight a number of studies which supported technique, performance and a biomechanical basis of the VM for the treatment of SVT. However, these studies were confounded by a plethora of definitions that inhibited clarity of either defined practice or efficiency. The literature gave rise to the three elements of an evidence-based model of VM performance Inhibitors,research,lifescience,medical (Posture, Pressure and Duration).

[2-7] Six identified clinical studies compared clinical efficacy of VM against other vagal manoeuvres, and highlighted the safety of the VM for prehospital use, whilst also suggesting not that early intervention improves clinical outcome. [8,3,4-12] Biomechanics of the VM The VM is characterised by four distinct phases of action, precipitated by onset of strain due to the generation of an increased intrathoracic pressure. Traditionally this has been against a closed glottis, but evidence suggests that an open glottis assists in prevention of potential deleterious side effects. [11,4,13] The four Phases of effect are as follows [6,11,2,13]: • Phase 1: Transient increase in aortic pressure with compensatory decrease in heart rate due to increased Intrathoracic pressure. • Phase 2: End of transient period, with decreasing aortic pressure and increasing heart rate. • Phase 3: Decreasing aortic pressure and compensatory rise in heart rate (end of strain phase).