An armed assailant in our hospital: Are we prepared?

While armed assailant attacks are rare in the hospital setting, they pose a potential risk to healthcare staff, patients, visitors and the infrastructure. Singapore hospitals have well-developed disaster plans to respond to a mass casualty incident occurring outside the hospital. However, lack of an armed assailant incident response plan can significantly reduce the hospital's ability to appropriately respond to such an incident. The authors describe various strategies that can be adopted in the development of an armed assailant incident response plan. Regular staff training will increase staff resilience and capability to respond to a potential threat in the future. The aim of this article is to highlight the need for the emergency preparedness units of all hospitals to work together with various stakeholders to develop an armed assailant incident response plan. This will be of great benefit for keeping healthcare facilities safe, both for staff as well as for the community.

Inhaling muscle spray: A rising trend of abuse.

Ethyl chloride was popular as an inhalant recreational drug in the 1980s. It is easily available in pharmacies as well as sold online as a topical anesthetic spray for pain relief. In recent times, its use is gaining popularity again among the youth as an inhalant drug due to its neuro-stimulatory effects. To avoid the risks associated with use of illegal drugs, and ease of availability of ethyl chloride without restrictions, there is a rising trend to use it as a "substitute" drug of abuse. In this paper, we try to highlight to the critical care and emergency physicians that majority of these cases present with predominant neurological symptoms, with occasional involvement of the cardiovascular system. The diagnosis of ethyl chloride poisoning is primarily clinical and supportive care is the mainstay of treatment, along with subsequent counseling. Ethyl chloride abuse should be considered as a differential diagnosis in young patients presenting with predominant neurological symptoms. Alongside raising public awareness, the manufacturers and retail distributors of these products have an important role to play in reducing the risk of abuse.

A multicenter prospective randomized study comparing the efficacy of escalating higher biphasic versus low biphasic energy defibrillations in patients presenting with cardiac arrest in the in-hospital environment.

BACKGROUND: Biphasic defibrillation has been practiced worldwide for >15 years. Yet, consensus does not exist on the best energy levels for optimal outcomes when used in patients with ventricular fibrillation (VF)/pulseless ventricular tachycardia (VT). METHODS: This prospective, randomized, controlled trial of 235 adult cardiac arrest patients with VF/VT was conducted in the emergency and cardiology departments. One group received low-energy (LE) shocks at 150-150-150 J and the other escalating higher-energy (HE) shocks at 200-300-360 J. If return of spontaneous circulation (ROSC) was not achieved by the third shock, LE patients crossed over to the HE arm and HE patients continued at 360 J. Primary end point was ROSC. Secondary end points were 24-hour, 7-day, and 30-day survival. RESULTS: Both groups were comparable for age, sex, cardiac risk factors, and duration of collapse and VF/VT. Of the 118 patients randomized to the LE group, 48 crossed over to the HE protocol, 24 for persistent VF, and 24 for recurrent VF. First-shock termination rates for HE and LE patients were 66.67% and 64.41%, respectively (P=0.78, confidence interval: 0.65-1.89). First-shock ROSC rates were 25.64% and 29.66%, respectively (P=0.56, confidence interval: 0.46-1.45). The 24-hour, 7-day, and 30-day survival rates were 85.71%, 74.29%, and 62.86% for first-shock ROSC LE patients and 70.00%, 50.00%, and 46.67% for first-shock ROSC HE patients, respectively. Conversion rates for further shocks at 200 J and 300 J were low, but increased to 38.95% at 360 J. CONCLUSION: First-shock termination and ROSC rates were not significantly different between LE and HE biphasic defibrillation for cardiac arrest patients. Patients responded best at 150/200 J and at 360 J energy levels. For patients with VF/pulseless VT, consideration is needed to escalate quickly to HE shocks at 360 J if not successfully defibrillated with 150 or 200 J initially.

Role of peak current in conversion of patients with ventricular fibrillation

<p><b>INTRODUCTION</b>Peak currents are the final arbiter of defibrillation in patients with ventricular fibrillation (VF). However, biphasic defibrillators continue to use energy in joules for electrical conversion in hopes that their impedance compensation properties will address transthoracic impedance (TTI), which must be overcome when a fixed amount of energy is delivered. However, optimal peak currents for conversion of VF remain unclear. We aimed to determine the role of peak current and optimal peak levels for conversion in collapsed VF patients.</p><p><b>METHODS</b>Adult, non-pregnant patients presenting with non-traumatic VF were included in the study. All defibrillations that occurred were included. Impedance values during defibrillation were used to calculate peak current values. The endpoint was return of spontaneous circulation (ROSC).</p><p><b>RESULTS</b>Of the 197 patients analysed, 105 had ROSC. Characteristics of patients with and without ROSC were comparable. Short duration of collapse < 10 minutes correlated positively with ROSC. Generally, patients with average or high TTI converted at lower peak currents. 25% of patients with high TTI converted at 13.3 ± 2.3 A, 22.7% with average TTI at 18.2 ± 2.5 A and 18.6% with low TTI at 27.0 ± 4.7 A (p = 0.729). Highest peak current conversions were at < 15 A and 15-20 A. Of the 44 patients who achieved first-shock ROSC, 33 (75.0%) received < 20 A peak current vs. > 20 A for the remaining 11 (25%) patients (p = 0.002).</p><p><b>CONCLUSION</b>For best effect, priming biphasic defibrillators to deliver specific peak currents should be considered.</p>

Prompt use of mechanical cardiopulmonary resuscitation in out-of-hospital cardiac arrest: the MECCA study report

<p><b>INTRODUCTION</b>Early use of mechanical cardiopulmonary resuscitation (CPR) for out-of-hospital cardiac arrest (OHCA) may improve survival outcomes. Current evidence for such devices uses outcomes from an intention-to-treat (ITT) perspective. We aimed to determine whether early use of mechanical CPR using a LUCAS 2 device results in better outcomes.</p><p><b>METHODS</b>A prospective, randomised, multicentre study was conducted over one year with LUCAS 2 devices in 14 ambulances and manual CPR in 32 ambulances to manage OHCA. The primary outcome was return of spontaneous circulation (ROSC). Secondary outcomes were survival at 24 hours, discharge from hospital and 30 days.</p><p><b>RESULTS</b>Of the 1,274 patients recruited, 1,191 were eligible for analysis. 889 had manual CPR and 302 had LUCAS CPR. From an ITT perspective, outcomes for manual and LUCAS CPR were: ROSC 29.2% and 31.1% (odds ratio [OR] 1.09, 95% confidence interval [CI] 0.82-1.45; p = 0.537); 24-hour survival 11.2% and 13.2% (OR 1.20, 95% CI 0.81-1.78; p = 0.352); survival to discharge 3.6% and 4.3% (OR 1.20, 95% CI 0.62-2.33; p = 0.579); and 30-day survival 3.0% and 4.0% (OR 1.32, 95% CI 0.66-2.64; p = 0.430), respectively. By as-treated analysis, outcomes for manual, early LUCAS and late LUCAS CPR were: ROSC 28.0%, 36.9% and 24.5%; 24-hour survival 10.6%, 15.5% and 8.2%; survival to discharge 2.9%, 5.8% and 2.0%; and 30-day survival 2.4%, 5.8% and 0.0%, respectively. Adjusted OR for survival with early LUCAS vs. manual CPR was 1.47 after adjustment for other variables (p = 0.026).</p><p><b>CONCLUSION</b>This study showed a survival benefit with LUCAS CPR as compared to manual CPR only, when the device was applied early on-site.</p>

Termination of Resuscitation Rules to Predict Neurological Outcomes in Out-of-Hospital Cardiac Arrest for an Intermediate Life Support Prehospital System.

AIM: Futile resuscitation can lead to unnecessary transports for out-of-hospital cardiac arrest (OHCA). The Basic Life Support (BLS) and Advanced Life Support (ALS) termination of resuscitation (TOR) guidelines have been validated with good results in North America. This study aims to evaluate the performance of these two rules in predicting neurological outcomes of OHCA patients in Singapore, which has an intermediate life support Emergency Medical Services (EMS) system. METHODS: A retrospective cohort study was carried out on Singapore OHCA data collected from April 2010 to May 2012 for the Pan-Asian Resuscitation Outcomes Study (PAROS). The outcomes of each rule were compared to the actual neurological outcomes of the patients. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and predicted transport rates of each test were evaluated. RESULTS: A total of 2,193 patients had cardiac arrest of presumed cardiac etiology. TOR was recommended for 1,411 patients with the BLS-TOR rule, with a specificity of 100% (91.9, 100.0) for predicting poor neurological outcomes, PPV 100% (99.7, 100.0), sensitivity 65.7% (63.6, 67.7), NPV 5.6% (4.1, 7.5), and transportation rate 35.6%. Using the ALS-TOR rule, TOR was recommended for 587 patients, specificity 100% (91.9, 100.0) for predicting poor neurological outcomes, PPV 100% (99.4, 100.0), sensitivity 27.3% (25.4, 29.3), NPV 2.7% (2.0, 3.7), and transportation rate 73.2%. BLS-TOR predicted survival (any neurological outcome) with specificity 93.4% (95% CI 85.3, 97.8) versus ALS-TOR 98.7% (95% CI 92.9, 99.8). CONCLUSION: Both the BLS and ALS-TOR rules had high specificities and PPV values in predicting neurological outcomes, the BLS-TOR rule had a lower predicted transport rate while the ALS-TOR rule was more accurate in predicting futility of resuscitation. Further research into unique local cultural issues would be useful to evaluate the feasibility of any system-wide implementation of TOR.

Interventional strategies associated with improvements in survival for out-of-hospital cardiac arrests in Singapore over 10 years.

AIM: We aim to study if there has been an improvement in survival for Out-of-Hospital Cardiac Arrest (OHCA) in Singapore, the effects of various interventional strategies over the past 10 years, and identify strategies that contributed to improved survival. METHODS: Rates of OHCA survival were compared between 2001-2004 and 2010-2012, using nationwide data for all OHCA presenting to EMS and public hospitals. A multivariate logistic regression model for survival to discharge was constructed to identify strategies with significant impact. RESULTS: A total of 5453 cases were included, 2428 cases from 2001 to 2004 and 3025 cases from 2010 to 2012. There was significant improvement in Utstein (witnessed, shockable) survival to discharge from 2001-2004 (2.5%) to 2010-2012 (11.0%), adjusted odds ratio (OR) 9.6 [95% CI: 2.2-41.9]). Overall survival to discharge increased from 1.6% to 3.2% (adjusted OR 2.2 [1.5-3.3]). Bystander CPR rates increased from 19.7% to 22.4% (p=0.02). The multivariate regression model (adjusted for important non-modifiable risk factors) showed that response time <8min (OR 1.5 [1.0-2.3]), bystander AED (OR 5.8 [2.0-16.2]), and post-resuscitation hypothermia (OR 30.0 [11.5-78.0]) were significantly associated with survival to hospital discharge. Conversely, pre-hospital epinephrine (OR 0.6 [0.4-0.9]) was associated negatively with survival. CONCLUSIONS: OHCA survival has improved in Singapore over the past 10 years. Improvement in response time, public AEDs and post-resuscitation hypothermia appear to have contributed to the increase in survival. Singapore's experience might suggest that developing EMS systems should focus on reducing times to basic life support, including bystander defibrillation and post-resuscitation care.

Geographic factors are associated with increased risk for out-of hospital cardiac arrests and provision of bystander cardio-pulmonary resuscitation in Singapore.

BACKGROUND: Bystander Cardio-Pulmonary Resuscitation (BCPR) can improve survival for Out-of-Hospital Cardiac Arrest (OHCA). This study aimed to investigate the geographic variation of BCPR provision and survival to discharge outcomes among residential OHCA cases, evaluate this variation with individual and population characteristics and identify high-risk residential areas with low relative risk (RR) of BCPR and high RR of OHCA at the development guide plan (DGP) census tract levels in Singapore. METHODS: This was a retrospective, secondary analysis of two prospectively-collected registries in Singapore from 2001 to 2011. We used Bayesian conditional autoregressive spatial models to examine predictors at the DGP level and calculate smoothed RR to identify high-risk areas. We used multi-level mixed-effects logistic regression models to examine the independent effects of individual and neighborhood factors. RESULTS: We found a total of 3942 OHCA with a BCPR rate of 20.3% and a survival to discharge rate of 1.9% and 3578 cases eligible for BCPR. After adjusting for age, witnessed status, presumed cardiac etiology and longer response time, the risk of BCPR provision significantly increased by 0.02% for every 1% increase in the proportion of household size 5 and above in the DGP area (odds ratio 1.02, 95%CI=1.002-1.038, p<0.026). We identified 10 high-risk residential areas with low RR of BCPR and high RR of OHCA. CONCLUSION: This study informed that neighborhood household size could have played a significant role in the provision of BCPR and occurrence of high-risk areas. It demonstrates the public health potential of combining geospatial and epidemiological analysis for improving health.

Implications for public access defibrillation placement by non-traumatic out-of-hospital cardiac arrest occurrence in Singapore.

INTRODUCTION: The American Heart Association recommends automated external defibrillator placement in public areas with a high probability (>1) of out-of-hospital cardiac arrest (OHCA) occurring in 5 years. We aimed to determine the incidence rate of OHCA for different location categories in Singapore. METHODS: Cardiac arrest incidence was obtained from a national registry. Denominators for the actual number of sites per location category were obtained from public accessible sources, government officers and purchased statistics. Analysis was performed and expressed in terms of the corresponding 95% confidence interval (CI). RESULTS: From 1 October 2001 to 14 October 2004, 2254 non-trauma OHCA cases were included. Mean age for arrests was 62.2 years, with 67.5% men. The location category with the highest incidence of cardiac arrests per site per 5 years was Port/Airport/Immigration Checkpoints (5.24 CI [3.66-7.20]). Top individual site with high average incidence of cardiac arrests per 5 years was Changi Airport (25.0 CI [16.18-36.90]). Seventy-one per cent of arrests occurred in residential areas. The postal sector with the highest average incidence per 100 000 population was Bedok Reservoir (54.89), whereas that with the highest population density was Bukit Merah/Alexandra with 348.14 population per 100 km(2) . CONCLUSION: In this study, we found the categories and individual sites that clearly fulfilled the American Heart Association criteria of at least 1 OHCA per site per 5 years. This study provides a model of how cardiac arrest registry data can be used to guide local health policy on automated external defibrillator deployment.

Effect of location of out-of-hospital cardiac arrest on survival outcomes.

INTRODUCTION: This study aims to study how the effect of the location of patient collapses from cardiac arrest, in the residential and non-residential areas within Singapore, relates to certain survival outcomes. MATERIALS AND METHODS: A retrospective cohort study of data were done from the Cardiac Arrest and Resuscitation Epidemiology (CARE) project. Out-of- hospital cardiac arrest (OHCA) data from October 2001 to October 2004 (CARE) were used. All patients with OHCA as confirmed by the absence of a pulse, unresponsiveness and apnoea were included. All events had occurred in Singapore. Analysis was performed and expressed in terms of the odds ratio (OR) and the corresponding 95% confidence interval (CI). RESULTS: A total of 2375 cases were used for this analysis. Outcomes for OHCA in residential areas were poorer than in non-residential areas-1638 (68.9%) patients collapsed in residential areas, and 14 (0.9%) survived to discharge. This was significantly less than the 2.7% of patients who survived after collapsing in a non-residential area (OR 0.31 [0.16 - 0.62]). Multivariate logistic regression analysis showed that location alone had no independent effect on survival (adjusted OR 1.13 [0.32 - 4.05]); instead, underlying factors such as bystander CPR (OR 3.67 [1.13 - 11.97]) and initial shockable rhythms (OR 6.78 [1.95 - 23.53]) gave rise to better outcomes. CONCLUSION: Efforts to improve survival from OHCA in residential areas should include increasing CPR by family members, and reducing ambulance response times.

Improving door-to-balloon times in primary percutaneous coronary intervention for acute ST-elevation myocardial infarction: the value of an audit-driven quality initiative.

INTRODUCTION: The study was designed to reduce door-to-balloon times in primary percutaneous coronary intervention for patients presenting to the Emergency Department with acute ST-elevation myocardial infarction, using an audit as a quality initiative. MATERIALS AND METHODS: A multidisciplinary work group performed a pilot study over 3 months, then implemented various process and work-flow strategies to improve overall door-to-balloon times. RESULTS AND CONCLUSION: We developed a guideline-based, institution-specific written protocol for triaging and managing patients who present to the Emergency Department with symptoms suggestive of STEMI, resulting in shortened median door-to-balloon times from 130.5 to 109.5 minutes (P<0.001).

Should a benzodiazepine antagonist be used in unconscious patients presenting to the emergency department?

UNLABELLED: Patients in coma with suspected drug poisoning are commonly encountered in the emergency department. Benzodiazepines are one of the most commonly used drugs in self-poisoning. Flumazenil, a benzodiazepine antagonist has been suggested as a diagnostic and treatment tool in suspected poisoning of unclear cause, but caution is required due to potential side effects. No systemic review of this literature has been done on this topic. OBJECTIVES: The aim of this study is to examine if flumazenil should be used in patients with coma from suspected drug poisoning. SEARCH STRATEGY: Randomised controlled trials were identified from the Cochrane Library, Pubmed and EMBASE. Bibliographies from included studies, known reviews and texts were searched. Content experts were contacted. SELECTION CRITERIA: Randomised controlled trials were eligible for inclusion. Studies were included if patients who presented with altered mental state from suspected drug poisoning were treated with intravenous flumazenil as compared to placebo. DATA COLLECTION AND ANALYSIS: Data were extracted and methodological quality was assessed independently by two reviewers. MAIN RESULTS: Seven randomised controlled trials were included. A total of 466 patients were involved. Flumazenil was found to reverse coma from suspected drug poisoning with a relative benefit of 4.45 (95% CI 2.65, 7.45). In terms of major side effects, there was no statistical difference between flumazenil and placebo (RR 2.86, 95% CI 0.12-69.32). However, in terms of minor side effects, flumazenil was associated with a higher incidence of anxiety (RR 2.84, 95% CI 1.28-6.30) and other side effects (RR 3.73, 95% CI 2.078-6.73). There was no difference in the incidence of vomiting (RR 4.28, 95% CI 0.95-19.35). CONCLUSION: Current evidence shows that flumazenil may be effective in the reversal of coma in patients presenting to the emergency department with coma from suspected drug poisoning.

Headache: an unusual presentation of aortic dissection.

The most common presenting symptom of aortic dissection is chest pain - headache as the initial manifestation is rare. We report a patient with a history of hypertension who presented with severe bifrontal headache, and was found to have an acute aortic dissection in the absence of carotid artery dissection. A discussion of the atypical presentation and possible pathophysiology follows.

Occult hypoglycemia in a diabetic patient on peritoneal dialysis.

In a patient with diabetes mellitus undergoing icodextrin continuous ambulatory peritoneal dialysis, the interference caused by icodextrin metabolites in bedside glucose analyzers led to an overestimation of capillary glucose levels and the potential for inappropriate therapy. We report this case to raise an awareness of this among emergency care providers who are at the front-line treating diabetes emergencies.

Not just gastroenteritis: thyroid storm unmasked.

Establishing the diagnosis of thyroid storm is difficult in the ED, especially where there is no antecedent history of thyroid disease or clinical clues like goitre, exophthalmos or altered mentation, yet early recognition and treatment are essential in reducing mortality and morbidity from this endocrine emergency. We present a case where suspected infective gastroenteritis in a newly diagnosed diabetic masked the major symptomatology of thyroid storm, and review the diagnosis and management of thyrotoxic crisis.