Deon Brink

Induction of therapeutic hypothermia during out-of-hospital cardiac arrest using a rapid infusion of cold saline: The RINSE Trial (Rapid Infusion of Cold Normal Saline)

Background: Patients successfully resuscitated by paramedics from out-of-hospital cardiac arrest often have severe neurologic injury. Laboratory and observational clinical reports have suggested that induction of therapeutic hypothermia during cardiopulmonary resuscitation (CPR) may improve neurologic outcomes. One technique for induction of mild therapeutic hypothermia during CPR is a rapid infusion of large-volume cold crystalloid fluid. Methods: In this multicenter, randomized, controlled trial we assigned adults with out-of-hospital cardiac arrest undergoing CPR to either a rapid intravenous infusion of up to 2 L of cold saline or standard care. The primary outcome measure was survival at hospital discharge; secondary end points included return of a spontaneous circulation. The trial was closed early (at 48% recruitment target) due to changes in temperature management at major receiving hospitals. Results: A total of 1198 patients were assigned to either therapeutic hypothermia during CPR (618 patients) or standard prehospital care (580 patients). Patients allocated to therapeutic hypothermia received a mean (SD) of 1193 (647) mL cold saline. For patients with an initial shockable cardiac rhythm, there was a decrease in the rate of return of a spontaneous circulation in patients who received cold saline compared with standard care (41.2% compared with 50.6%, P=0.03). Overall 10.2% of patients allocated to therapeutic hypothermia during CPR were alive at hospital discharge compared with 11.4% who received standard care (P=0.71). Conclusions: In adults with out-of-hospital cardiac arrest, induction of mild therapeutic hypothermia using a rapid infusion of large-volume, intravenous cold saline during CPR may decrease the rate of return of a spontaneous circulation in patients with an initial shockable rhythm and produced no trend toward improved outcomes at hospital discharge. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01173393.

Incidence, characteristics and survival outcomes of out‐of‐hospital cardiac arrest in children and adolescents between 1997 and 2014 in Perth, Western Australia

The present study was to describe the trends in the incidence, characteristics and survival of paediatric out‐of‐hospital cardiac arrest (OHCA) over an 18 year period.

Association between ambulance dispatch priority and patient condition

To compare chief complaints of the Medical Priority Dispatch System in terms of the match between dispatch priority and patient condition.

Lower chest compression fraction associated with ROSC in OHCA patients with longer downtimes

AIM To investigate the relationship between chest compression fraction (CCF) and survival outcomes in OHCA, including whether the relationship varied based upon downtime from onset of arrest to provision of cardiopulmonary resuscitation (CPR) by emergency medical services (EMS). METHODS Data from resuscitations performed by St John Ambulance Western Australia (SJA-WA) paramedics between July 2014 and June 2016 was captured using the Q-CPR feedback device. Logistic regression analysis was used to study the relationship between CCF and return of spontaneous circulation (ROSC). Various lengths of Q-CPR data were used ranging from the first 3min to all available episode data. Cases were subsequently divided into groups based upon downtime; ≤15min, >15min and unknown. Univariate and multivariable logistic regression analyses were performed in each group. RESULTS There were 341 cases eligible for inclusion. CCF >80% was significantly associated with decreased odds of ROSC compared to CCF≤80% (aOR: 0.49, 95%CI: 0.28-0.87). This relationship remained significant whether the first 3min of data was used, the first 5min or all available episode data. Among the group with a downtime >15min, CCF was significantly lower for those who achieved ROSC compared to those who did not (mean (SD): 73.01 (12.99)% vs. 83.05 (9.38)% p=0.002). The adjusted odds ratio for achieving ROSC in this group was significantly less with CCF>80% compared to CCF≤80% (aOR: 0.06, 95%CI: 0.01-0.38). CONCLUSION We demonstrated an inverse relationship between CCF and ROSC that varied depending upon the time from arrest to provision of EMS-CPR.

The linguistic and interactional factors impacting recognition and dispatch in emergency calls for out-of-hospital cardiac arrest: a mixed-method linguistic analysis study protocol

Introduction Emergency telephone calls placed by bystanders are crucial to the recognition of out-of-hospital cardiac arrest (OHCA), fast ambulance dispatch and initiation of early basic life support. Clear and efficient communication between caller and call-taker is essential to this time-critical emergency, yet few studies have investigated the impact that linguistic factors may have on the nature of the interaction and the resulting trajectory of the call. This research aims to provide a better understanding of communication factors impacting on the accuracy and timeliness of ambulance dispatch. Methods and analysis A dataset of OHCA calls and their corresponding metadata will be analysed from an interdisciplinary perspective, combining linguistic analysis and health services research. The calls will be transcribed and coded for linguistic and interactional variables and then used to answer a series of research questions about the recognition of OHCA and the delivery of basic life-support instructions to bystanders. Linguistic analysis of calls will provide a deeper understanding of the interactional dynamics between caller and call-taker which may affect recognition and dispatch for OHCA. Findings from this research will translate into recommendations for modifications of the protocols for ambulance dispatch and provide directions for further research. Ethics and dissemination The study has been approved by the Curtin University Human Research Ethics Committee (HR128/2013) and the St John Ambulance Western Australia Research Advisory Group. Findings will be published in peer-reviewed journals and communicated to key audiences, including ambulance dispatch professionals.

15 The importance of staying on the call: recognition of cardiac arrest after initial dispatch

Aim We compared survival in out-of-hospital cardiac arrest (OHCA) cases recognised at initial dispatch (“primary recognition”) with those subsequently recognised as OHCA ?(“secondary recognition”) and those not recognised as OHCA (“non-recognition”). Methods We analysed cases of paramedic-confirmed OHCA in Perth, Western Australia (WA), from January 2014 to December 2015. We excluded traumatic OHCA, paramedic-witnessed arrests, and cases where paramedics did not attempt resuscitation. Emergency ambulance calls in WA are processed using the Medical Priority Dispatch System, via ProQA software. We analysed the ProQA data of each call for the presence of OHCA-specific dispatch codes (including code revisions) and call-taker instructions for cardiopulmonary resuscitation (CPR). Results Among 1430 cases of OHCA, 84% (n=1195) were recognised by call-takers as OHCA. Of the 1195 recognised cases, 32% (n=386) were identified through secondary recognition. Survival to 30 days was significantly higher among cases with secondary recognition (13.2%) than among cases with primary recognition (7.9%) and non-recognised cases (7.7%) (p=0.008). More than half of all cases of secondary recognition were initially dispatched as Unconscious/Fainting patient. Conclusion Nearly one third of call-taker recognition of OHCA occurs after initial dispatch. The higher survival probability of patients recognised by secondary recognition is consistent with those patients arresting more recently relative to the timing of the call. For many cases of OHCA, the call-taker’s ability to stay on the call and remain alert to the possibility of OHCA may strengthen the chain of survival. Conflict of interest A. Whiteside and D. Brink receive full salary support, and P. Bailey, M. Inoue and J. Finn receive partial salary support from St John Ambulance. Funding Funding for this research was received from an Australian NHMRC (National Health and Medical Research Centre) Partnership Project: #1076949 ‘Improving ambulance dispatch to time-critical emergencies’. J. Finn. and J. Bray receive partial salary support from the NHMRC ‘Aus-ROC’ Centre for Research Excellence #1029983. J. Bray receives salary support from an NHMRC/NHF (National Heart Foundation) Early Career Fellowship.

14 Initial prehospital vital signs to predict subsequent adverse hospital outcomes

Aim There is growing interest to improve identification of the critically ill patient in the prehospital setting.1–3 We aimed to assess whether initial vital physiological signs in the prehospital setting can predict subsequent adverse hospital outcomes, defined as intensive care (ICU) admission or death in the emergency department (ED). Methods The initial prehospital physiological data of all adult patients, transported by the St John Ambulance Service to the metropolitan public EDs were linked to the ED information system in this retrospective cohort study. Cardiac arrest unwitnessed by paramedics, rural, inter-hospital, non-emergency, and air transfers were excluded. Area under receiver operating characteristic curve (AUROC) was assessed. Logistic regression with a restricted cubic spline function was used to assess the ability of four physiological variables: systolic blood pressure (BP), heart rate (HR), respiratory rate (RR) and Glasgow Coma Score (GCS) to predict adverse hospital outcomes. Results Of the 1 79 374 patients, 2268 (1.3%) were subsequently admitted to ICU or died in the ED. AUROC was 0.829 (95% confidence interval 0.820–0.839). The GCS was the most important vital sign, and explained about 56% of the variability of the outcome compared to <11% by each of the other vital signs. A strong non-linearity between initial BP and adverse hospital outcomes was also observed but not with GCS, HR or RR. Conclusion Initial prehospital vital signs, in particular GCS, may predict subsequent adverse hospital outcomes. Non-linear associations between initial physiological signs and subsequent outcomes should be considered in developing prehospital alert systems. References Royal College of physicians. National Early Warning Score (NEWS): Standardising the assessment of acute illness severity in the NHS. Report of a working party. London: RCP. 2012. Silcock DJ, Corfield AR, Gowens PA, Rooney KD. Validation of the National Early Warning Score in the prehospital setting. Resuscitation2015;89:31–5. Williams TA, Tohira H, Finn J, Perkins GD, Ho KM. The ability of early warning scores (EWS) to detect critical illness in the prehospital setting: A systematic review. Resuscitation2016;102:35–43. Conflict of interest P. Bailey is the Clinical Services Director of St John Ambulance-Western Australia. D. Brink is the Executive Manager Clinical Governance St John Ambulance-Western Australia. J. Finn receives partial salary support from St John Ambulance-Western Australia T.A. Williams, K.M. Ho, H. Tohira, D. M. Fatovich, P. Gowens, G. D. Perkins has no conflict of interest St John Ambulance Western Australia played no role in the study design, conduct or interpretation of the results. Funding None declared.

Induction of Therapeutic Hypothermia During Out-of-Hospital Cardiac Arrest Using a Rapid Infusion of Cold SalineClinical Perspective

Background: Patients successfully resuscitated by paramedics from out-of-hospital cardiac arrest often have severe neurologic injury. Laboratory and observational clinical reports have suggested that induction of therapeutic hypothermia during cardiopulmonary resuscitation (CPR) may improve neurologic outcomes. One technique for induction of mild therapeutic hypothermia during CPR is a rapid infusion of large-volume cold crystalloid fluid. Methods: In this multicenter, randomized, controlled trial we assigned adults with out-of-hospital cardiac arrest undergoing CPR to either a rapid intravenous infusion of up to 2 L of cold saline or standard care. The primary outcome measure was survival at hospital discharge; secondary end points included return of a spontaneous circulation. The trial was closed early (at 48% recruitment target) due to changes in temperature management at major receiving hospitals. Results: A total of 1198 patients were assigned to either therapeutic hypothermia during CPR (618 patients) or standard prehospital care (580 patients). Patients allocated to therapeutic hypothermia received a mean (SD) of 1193 (647) mL cold saline. For patients with an initial shockable cardiac rhythm, there was a decrease in the rate of return of a spontaneous circulation in patients who received cold saline compared with standard care (41.2% compared with 50.6%, P=0.03). Overall 10.2% of patients allocated to therapeutic hypothermia during CPR were alive at hospital discharge compared with 11.4% who received standard care (P=0.71). Conclusions: In adults with out-of-hospital cardiac arrest, induction of mild therapeutic hypothermia using a rapid infusion of large-volume, intravenous cold saline during CPR may decrease the rate of return of a spontaneous circulation in patients with an initial shockable rhythm and produced no trend toward improved outcomes at hospital discharge. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01173393.

Induction of Therapeutic Hypothermia During Out-of-Hospital Cardiac Arrest Using a Rapid Infusion of Cold SalineClinical Perspective: The RINSE Trial (Rapid Infusion of Cold Normal Saline)

Background: Patients successfully resuscitated by paramedics from out-of-hospital cardiac arrest often have severe neurologic injury. Laboratory and observational clinical reports have suggested that induction of therapeutic hypothermia during cardiopulmonary resuscitation (CPR) may improve neurologic outcomes. One technique for induction of mild therapeutic hypothermia during CPR is a rapid infusion of large-volume cold crystalloid fluid. Methods: In this multicenter, randomized, controlled trial we assigned adults with out-of-hospital cardiac arrest undergoing CPR to either a rapid intravenous infusion of up to 2 L of cold saline or standard care. The primary outcome measure was survival at hospital discharge; secondary end points included return of a spontaneous circulation. The trial was closed early (at 48% recruitment target) due to changes in temperature management at major receiving hospitals. Results: A total of 1198 patients were assigned to either therapeutic hypothermia during CPR (618 patients) or standard prehospital care (580 patients). Patients allocated to therapeutic hypothermia received a mean (SD) of 1193 (647) mL cold saline. For patients with an initial shockable cardiac rhythm, there was a decrease in the rate of return of a spontaneous circulation in patients who received cold saline compared with standard care (41.2% compared with 50.6%, P=0.03). Overall 10.2% of patients allocated to therapeutic hypothermia during CPR were alive at hospital discharge compared with 11.4% who received standard care (P=0.71). Conclusions: In adults with out-of-hospital cardiac arrest, induction of mild therapeutic hypothermia using a rapid infusion of large-volume, intravenous cold saline during CPR may decrease the rate of return of a spontaneous circulation in patients with an initial shockable rhythm and produced no trend toward improved outcomes at hospital discharge. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01173393.

Induction of Therapeutic Hypothermia During Out-of-Hospital Cardiac Arrest Using a Rapid Infusion of Cold Saline (The RINSE Trial)

Background: Patients successfully resuscitated by paramedics from out-of-hospital cardiac arrest often have severe neurologic injury. Laboratory and observational clinical reports have suggested that induction of therapeutic hypothermia during cardiopulmonary resuscitation (CPR) may improve neurologic outcomes. One technique for induction of mild therapeutic hypothermia during CPR is a rapid infusion of large-volume cold crystalloid fluid. Methods: In this multicenter, randomized, controlled trial we assigned adults with out-of-hospital cardiac arrest undergoing CPR to either a rapid intravenous infusion of up to 2 L of cold saline or standard care. The primary outcome measure was survival at hospital discharge; secondary end points included return of a spontaneous circulation. The trial was closed early (at 48% recruitment target) due to changes in temperature management at major receiving hospitals. Results: A total of 1198 patients were assigned to either therapeutic hypothermia during CPR (618 patients) or standard prehospital care (580 patients). Patients allocated to therapeutic hypothermia received a mean (SD) of 1193 (647) mL cold saline. For patients with an initial shockable cardiac rhythm, there was a decrease in the rate of return of a spontaneous circulation in patients who received cold saline compared with standard care (41.2% compared with 50.6%, P=0.03). Overall 10.2% of patients allocated to therapeutic hypothermia during CPR were alive at hospital discharge compared with 11.4% who received standard care (P=0.71). Conclusions: In adults with out-of-hospital cardiac arrest, induction of mild therapeutic hypothermia using a rapid infusion of large-volume, intravenous cold saline during CPR may decrease the rate of return of a spontaneous circulation in patients with an initial shockable rhythm and produced no trend toward improved outcomes at hospital discharge. Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01173393.