Waveform Analysis–Guided Treatment Versus a Standard Shock-First Protocol for the Treatment of Out-of-Hospital Cardiac Arrest Presenting in Ventricular Fibrillation

© Gary Wilson/ Pre-hospital Research Forum

Circulation. 2013; 128: 995-1002

Ventricular fibrillation (VF) waveform properties have been shown to predict defibrillation success and outcomes among patients treated with immediate defibrillation. We postulated that a waveform analysis algorithm could be used to identify VF unlikely to respond to immediate defibrillation, allowing selective initial treatment with cardiopulmonary resuscitation in an effort to improve overall survival.

Methods and Results In a multicenter, double-blind, randomized study, out-of-hospital cardiac arrest patients in 2 urban emergency medical services systems were treated with automated external defibrillators using either a VF waveform analysis algorithm or the standard shock-first protocol. The VF waveform analysis used a predefined threshold value below which return of spontaneous circulation (ROSC) was unlikely with immediate defibrillation, allowing selective treatment with a 2-minute interval of cardiopulmonary resuscitation before initial defibrillation. The primary end point was survival to hospital discharge. Secondary end points included ROSC, sustained ROSC, and survival to hospital admission. Of 6738 patients enrolled, 987 patients with VF of primary cardiac origin were included in the primary analysis. No immediate or long-term survival benefit was noted for either treatment algorithm (ROSC, 42.5% versus 41.2%, P=0.70; sustained ROSC, 32.4% versus 33.4%, P=0.79; survival to admission, 34.1% versus 36.4%, P=0.46; survival to hospital discharge, 15.6% versus 17.2%, P=0.55, respectively).

Conclusions Use of a waveform analysis algorithm to guide the initial treatment of out-of-hospital cardiac arrest patients presenting in VF did not improve overall survival compared with a standard shock-first protocol. Further study is recommended to examine the role of waveform analysis for the guided management of VF.

http://circ.ahajournals.org/content/128/9/995.abstract.html?etoc

Death in the Field: Teaching Paramedics to Deliver Effective Death Notifications Using the Educational Intervention “GRIEV_ING”

© Gary Wilson/ Pre-hospital Research Forum

Prehospital Emergency Care. October-December 2013, Vol. 17, No. 4 , Pages 501-510

Emergency medical services (EMS) personnel are rarely trained in death notification despite frequently terminating resuscitation in the field. As research continues to validate guidelines for the termination of resuscitation (TOR) and reputable organizations such as NAEMSP lend support to such protocols, death notification in the field will continue to increase. The authors sought to test the hypothesis that a learning module, GRIEV_ING, which teaches a structured method for death notification, will improve the confidence, competency, and communication skills of EMS personnel in death notification.

Methods. The GRIEV_ING didactic session consisted of a 90-minute education session composed of a didactic lecture, small group breakout session, and role-plays. This was both preceded and followed by a 15-minute case role-play using trained standardized survivors. To assess performance we used a pre–post design with 3 quantitative measures: confidence, competency, and, communication. Paramedics from the local EMS agency participated in the education as a part of continuing education. Pre–post differences were measured using a paired t-test and McNemar’s test.

Results. Thirty EMS personnel consented and participated. Confidence and competency demonstrated statistically significant improvements: confidence (percent change in scores = 11.4%, p < 0.0001) and competency (percent change in scores = 13.9%, p = 0.0001). Communication skill scores were relatively unchanged in pre–post test analysis (percent change in scores = 0.4, p = 0.9).

Conclusion. This study demonstrated that educating paramedics to use a structured communication model based on the GRIEV_ING mnemonic improved confidence and competence of EMS personnel delivering death notification.

http://informahealthcare.com/doi/abs/10.3109/10903127.2013.804135

Wilderness Medical Society Practice Guidelines for Treatment of Exercise-Associated Hyponatremia

© Gary Wilson/ Pre-hospital Research Forum

Wilderness & Environmental Medicine. Volume 24, Issue 3 , Pages 228-240, September 2013

Exercise-associated hyponatremia (EAH) typically occurs during or up to 24 hours after prolonged physical activity, and is defined by a serum or plasma sodium concentration below the normal reference range of 135 mEq/L. It is also reported to occur in individual physical activities or during organized endurance events conducted in austere environments in which medical care is limited or often not available, and patient evacuation to definitive care is often greatly delayed. Rapid recognition and appropriate treatment are essential in the severe form to ensure a positive outcome. Failure in this regard is a recognized cause of event-related fatality.

In an effort to produce best practice guidelines for EAH in the austere environment, the Wilderness Medical Society convened an expert panel. The panel was charged with the development of evidence-based guidelines for management of EAH. Recommendations are made regarding the situations when sodium concentration can be assessed in the field and when these values are not known. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians.

http://www.wemjournal.org/article/S1080-6032(13)00063-X/fulltext (full text)

Wilderness Medical Society Practice Guidelines for Spine Immobilisation in the Austere Environment

© Gary Wilson/ Pre-hospital Research Forum

Wilderness & Environmental Medicine. Volume 24, Issue 3 , Pages 241-252, September 2013

In an effort to produce best-practice guidelines for spine immobilization in the austere environment, the Wilderness Medical Society convened an expert panel charged with the development of evidence-based guidelines for management of the injured or potentially injured spine in an austere (dangerous or compromised) environment. Recommendations are made regarding several factors related to spinal immobilisation. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks or burdens for each factor according to the methodology stipulated by the American College of Chest Physicians. A treatment algorithm based on the guidelines is presented.

http://www.wemjournal.org/article/S1080-6032(13)00071-9/fulltext (full text)

A Prospective Evaluation of the Utility of the Prehospital 12-lead Electrocardiogram to change patient management in the Emergency Department

© Gary Wilson/ Pre-hospital Research Forum

Prehospital Emergency Care. Posted online on September 12, 2013. 

Retrospective research has shown that 19% of 12-lead prehospital electrocardiograms (prehospital ECGs) had clinically significant abnormalities that were not captured on the initial emergency department (ED) ECG and had the potential to change medical management. The purpose of this study was to prospectively determine how many prehospital ECGs had clinically significant abnormalities not present on the initial ED ECG and determine how many prehospital ECGs changed physician management.

Methods. We conducted a 3-month, prospective cohort study of patients who had a 12-lead prehospital ECG completed by EMS prior to arriving at one of two tertiary care EDs. STEMI bypass patients were excluded. Physicians reviewed the prehospital ECG to determine whether there were any clinically significant abnormalities present on the prehospital ECG not captured on the initial ED ECG. Physicians recorded if and how the prehospital ECG changed their management.

Results. A total of 281 patients were enrolled. Thirty-five (12.5%; 95% CI: 9.1%, 16.8%) prehospital ECGs showed changes that were not captured on the initial ED ECG (11 ST depression, 5 T-wave inversion [TWI], 2 ST depression and TWI, 12 arrhythmia, 2 arrhythmia with ST depression, 2 ST elevation, 1 unknown). Fifty-two (18.5%; 95% CI: 14.4%, 23.5%) prehospital ECGs influenced physician management. There were 30 (10.7%) instances where physicians were willing to refer the patient to an inpatient service based on information captured on the prehospital ECG, regardless if the initial ED ECG was normal.

Conclusions. Prehospital ECGs show clinically significant abnormalities that are not always captured on the initial ED ECG. Prehospital ECGs have the potential to change the management of patients in the ED.

http://informahealthcare.com/doi/abs/10.3109/10903127.2013.825350

Beta-Adrenergic Antagonists Improve Oxygen Saturation in Acute Pulmonary Oedema: A Case Series in the Prehospital Setting

Prehospital Emergency Care. July-September 2013, Vol. 17, No. 3 , Pages 421-423 

© Gary Wilson/ Pre-hospital Research Forum

The use of beta-adrenergic antagonists in acute heart failure is controversial. In this case series, the authors report the use of intravenous atenolol, a short-acting cardioselective beta-adrenergic antagonist, to treat acute pulmonary oedema in the prehospital setting. Four patients with a documented history of cardiac disease and one patient with unknown cardiac issues experienced severe respiratory distress and presented with pulmonary oedema; the local emergency medical service was utilized.

In all of the patients, the saturation of peripheral oxygen (SpO2) was severely low, and the patients were rapidly treated with oxygen, diuretics, morphine, and nitrates. However, only a small increase in oxygen saturation was observed. Intravenous atenolol was administered and led to a dramatic increase in SpO2. In the case series, the authors observed the positive effect of early treatment with short-acting beta-adrenergic antagonists on the recovery of rapid oxygen delivery in severely hypoxemic patients.

http://informahealthcare.com/doi/abs/10.3109/10903127.2013.785621

Prehospital Use of Tranexamic Acid for Haemorrhagic Shock in Primary and Secondary Air Medical Evacuation

Air Medical Journal. Volume 32, Issue 5 , Pages 289-292, September 2013

© Gary Wilson/ Pre-hospital Research Forum

Major haemorrhage remains a leading cause of death in both military and civilian trauma. The authors report the use of tranexamic acid (TXA) as part of a trauma exanguination/massive transfusion protocol in the management of haemorrhagic shock in a civilian primary and secondary air medical evacuation (AME) helicopter EMS program.

Methods
TXA was introduced into the CCP flight paramedic program in June 2011. Indications for use include age > 16 years, major trauma (defined a priori based on mechanism of injury or findings on primary survey), and heart rate (HR) > 110 beats per minute (bpm) or systolic blood pressure (SBP) < 90 mmHg. The protocol, which includes 24-hour online medical oversight, emphasizes rapid initiation of transport, permissive hypotension in select patients, early use of blood products (secondary AME only), and infusion of TXA while en route to a major trauma centre.

Results

Over a 4-month period, the CCP flight crews used TXA a total of 13 times. Patients had an average HR of 111 bpm [95% CI 90.71–131.90], SBP of 91 mmHg [95% CI 64.48–118.60], and Glascow Coma Score of 7 [95% CI 4.65–9.96]. For primary AME, average response time was 33 minutes [95% CI 19.03–47.72], scene time 22 minutes [95% CI 20.23–24.27], and time to TXA administration 32 minutes [95% CI 25.76–38.99] from first patient contact. There were no reported complications with the administration of TXA in any patient.

Conclusion
The authors report the successful integration of TXA into a primary and secondary AME program in the setting of major trauma with confirmed or suspected hemorrhagic shock. Further studies are needed to assess the effect of such a protocol in this patient population.

http://www.airmedicaljournal.com/article/S1067-991X(13)00113-2/abstract?elsca1=etoc&elsca2=email&elsca3=1067-991X_201309_32_5&elsca4=emergency_medicine

An evaluation of a new prehospital pre-alert guidance tool

Emerg Med J 2013;30:820-823

Background The requirement for guidance regarding ambulance crews pre-alerting patients into hospital emergency departments (ED) has been well established, but a clear guidance tool that supports a decision to pre-alert a receiving hospital is lacking.

Aims To investigate the impact of a new pre-alert tool on current alerting practice and evaluate its ability to take the place of a pre-hospital early warning system. The study evaluated a newly introduced pre-alert guidance tool which was developed in conjunction with the JRCALC guidelines.

Methods Data were collected for a sample of patients brought by ambulance to the resuscitation area of Aberdeen Royal Infirmary ED over a 7-week period. Basic demographic information plus alert status and guidance prompt status was collected and compared with a pragmatic alert requirement. Analysis of ambulance crew alert decisions and the pre-alert guidance prompt advice was undertaken and compared.

Results Ambulance crew decisions to alert had a sensitivity of 72% (CI 62% to 80%), specificity of 50% (CI 27% to 73%), positive predictive value (PPV) of 90% and negative predictive value (NPV) of 22%. The pre-alert guidance alert prompt had a sensitivity of 99% (CI 94% to 100%), specificity of 64% (CI 39% to 84%), PPV of 95% and NPV of 90%. 28% of patients were under-alerted by ambulance crews, mostly medical patients presenting with chest pain.

Conclusions The pre-alert guidance tool shows face validity and superior ability to advise a pre-alert than ambulance crew decisions. It supplements a practitioners’ clinical decision-making and has been regarded as having a positive impact on ED triage and utilisation of resources. It proved to have superior sensitivity and specificity to that of ambulance crew decisions; the latter having a significant level of under-alerts.  However, these values were considerably less than those in the literature, suggesting the tool may have prompted an increased number of appropriate alerts by the ambulance crews involved. The findings support the use and development of such a tool that complements the autonomous decision -making skills of ambulance crews in the present pre-hospital environment. The core strengths of the tool are its simple structure and no requirement for calculations to be done. One major predicted weakness of the tool was that it may have prompted many over-alerts in order to eliminate any under-alerts, but this was not found to be the case. Further levels of validity are expected to be achieved with continued audit and ongoing use of this tool.

http://emj.bmj.com/content/30/10/820?etoc

The accuracy of existing pre-hospital triage tools for injured children in England – An analysis using trauma registry and emergency department data

Emerg Med J 2013;30:867 

© Gary Wilson/ Pre-hospital Research Forum

Objectives & Background Pre-hospital triage is becoming increasingly important as Regional Trauma Networks for children are implemented in England. The low incidence of trauma in children makes pre-hospital assessment of injury severity and where to send an injured child challenging. Currently there are few validated pre-hospital triage tools for children’s trauma and no consensus on which to use. We investigate performance characteristics of pre-hospital paediatric triage tools currently in use in England for identifying injured children.

Methods The authors identified a total of eight pre-hospital paediatric triage tools (six in current usage in England). Each tool was interrogated using 701 retrospective clinical episodes from the Trauma Audit and Research Network (TARN–representing severely injured children) and from 2934 patient records in four English Emergency Departments (representing moderate to minor injuries). Target rates for under– and over-triage were set as <5% and <25–50% respectively.

Results From TARN data, two triage tools demonstrated acceptable under-triage rates (3% and 4%) for severe injuries but unacceptable over-triage of moderate injuries (83% and 72%). Two tools demonstrated acceptable over-triage (7% and 16%) with unacceptable under-triage (61% and 63%). Four tools demonstrated unacceptable under- and over-triage.

For moderate and minor injuries, three tools demonstrated acceptable under- and over-triage rates (all 0%). The other five tools had unacceptable under-triage rates (25–100%). All eight tools had acceptable over-triage rates (1%–21%).

Conclusion For severe injuries, none of the pre-hospital triage tools for injured children currently used in England meet recommended criteria for over- and under-triage rates. For moderate to minor injuries, all tools achieved acceptable over-triage rates but tended to under-triage. There is an urgent need for development of triage tools to accurately risk-stratify injured children in the pre-hospital setting.

http://emj.bmj.com/content/30/10/867.1?etoc

Performance of the i-gel™ during pre-hospital cardiopulmonary resuscitation

Resuscitation. Volume 84, Issue 9, September 2013, Pages 1229–1232

© Gary Wilson/ Pre-hospital Research Forum

Current cardiopulmonary resuscitation (CPR) guidelines recommend airway management and ventilation whilst minimising interruptions to chest compressions. We have assessed i-gel™ use during CPR.

Methods
In an observational study of i-gel™ use during CPR we assessed the ease of i-gel™ insertion, adequacy of ventilation, the presence of a leak during ventilation, and whether ventilation was possible without interrupting chest compressions.

Results
We analysed i-gel™ insertion by paramedics (n = 63) and emergency physicians (n = 7) in 70 pre-hospital CPR attempts. There was a 90% first attempt insertion success rate, 7% on the second attempt, and 3% on the third attempt. Insertion was reported as easy in 80% (n = 56), moderately difficult in 16% (n = 11), and difficult in 4% (n = 3). Providers reported no leak on ventilation in 80% (n = 56), a moderate leak in 17% (n = 12), and a major leak with no chest rise in 3% (n = 2). There was a significant association between ease of insertion and the quality of the seal (r = 0.99, p = 0.02). The i-gel™ enabled continuous chest compressions without pauses for ventilation in 74% (n = 52) of CPR attempts. There was no difference in the incidence of leaks on ventilation between patients having continuous chest compressions and patients who had pauses in chest compressions for ventilation (83% versus 72%, p = 0.33, 95% CI [−0.1282, 0.4037]). Ventilation during CPR was adequate during 96% of all CPR attempts.

Conclusions
The i-gel™ is an easy supraglottic airway device to insert and enables adequate ventilation during CPR.

http://www.sciencedirect.com/science/article/pii/S0300957213002578