Inter-hospital trends of post-resuscitation interventions and outcomes of out-of-hospital cardiac arrest in Singapore

INTRODUCTION@#Hospital-based resuscitation interventions, such as therapeutic temperature management (TTM), emergency percutaneous coronary intervention (PCI) and extracorporeal membrane oxygenation (ECMO) can improve outcomes in out-of-hospital cardiac arrest (OHCA). We investigated post-resuscitation interventions and hospital characteristics on OHCA outcomes across public hospitals in Singapore over a 9-year period.@*METHODS@#This was a prospective cohort study of all OHCA cases that presented to 6 hospitals in Singapore from 2010 to 2018. Data were extracted from the Pan-Asian Resuscitation Outcomes Study Clinical Research Network (PAROS CRN) registry. We excluded patients younger than 18 years or were dead on arrival at the emergency department. The outcomes were 30-day survival post-arrest, survival to admission, and neurological outcome.@*RESULTS@#The study analysed 17,735 cases. There was an increasing rate of provision of TTM, emergency PCI and ECMO (P<0.001) in hospitals, and a positive trend of survival outcomes (P<0.001). Relative to hospital F, hospitals B and C had lower provision rates of TTM (≤5.2%). ECMO rate was consistently <1% in all hospitals except hospital F. Hospitals A, B, C, E had <6.5% rates of provision of emergency PCI. Relative to hospital F, OHCA cases from hospitals A, B and C had lower odds of 30-day survival (adjusted odds ratio [aOR]<1; P<0.05 for hospitals A-C) and lower odds of good neurological outcomes (aOR<1; P<0.05 for hospitals A-C). OHCA cases from academic hospitals had higher odds ratio (OR) of 30-day survival (OR 1.3, 95% CI 1.1-1.5) than cases from hospitals without an academic status.@*CONCLUSION@#Post-resuscitation interventions for OHCA increased across all hospitals in Singapore from 2010 to 2018, correlating with survival rates. The academic status of hospitals was associated with improved survival.

Clinical evaluation of the use of laryngeal tube versus laryngeal mask airway for out-of-hospital cardiac arrest by paramedics in Singapore

INTRODUCTION@#It remains unclear which advanced airway device has better placement success and fewer adverse events in out-of-hospital cardiac arrests (OHCAs). This study aimed to evaluate the efficacy of the VBM laryngeal tube (LT) against the laryngeal mask airway (LMA) in OHCAs managed by emergency ambulances in Singapore.@*METHODS@#This was a real-world, prospective, cluster-randomised crossover study. All OHCA patients above 13 years of age who were suitable for resuscitation were randomised to receive either LT or LMA. The primary outcome was placement success. Per-protocol analysis was performed, and the association between outcomes and airway device group was compared using multivariate binomial logistic regression analysis.@*RESULTS@#Of 965 patients with OHCAs from March 2016 to January 2018, 905 met the inclusion criteria, of whom 502 (55.5%) were randomised to receive LT while 403 (44.5%) were randomised to receive LMA. Only 174 patients in the LT group actually received the device owing to noncompliance. Placement success rate for LT was lower than for LMA (adjusted odds ratio [OR] 0.52, 95% confidence interval [CI] 0.31-0.90). Complications were more likely when using LT (OR 2.82,0 95% CI 1.64-4.86). Adjusted OR for prehospital return of spontaneous circulation (ROSC) was similar in both groups. A modified intention-to-treat analysis showed similar outcomes to the per-protocol analysis between the groups.@*CONCLUSION@#LT was associated with poorer placement success and higher complication rates than LMA. The likelihood of prehospital ROSC was similar between the two groups. Familiarity bias and a low compliance rate to LT were the main limitations of this study.

Simplified instructional phrasing in dispatcher-assisted cardiopulmonary resuscitation - when 'less is more'

INTRODUCTION@#In our national emergency dispatch centre, the standard protocol for dispatcher-assisted cardiopulmonary resuscitation (DACPR) in out-of-hospital cardiac arrests (OHCAs) involves the instruction 'push 100 times a minute 5 cm deep'. As part of quality improvement, the instruction was simplified to 'push hard and fast'.@*METHODS@#We analysed all dispatcher-diagnosed OHCAs over four months in 2018: January to February ('push 100 times a minute 5 cm deep') and August to September ('push hard and fast'). We also performed secondary per-protocol analysis based on the protocol used: (a) standard (n = 48); (b) simplified (n = 227); and (c) own words (n = 231).@*RESULTS@#A total of 506 cases were included: 282 in the 'before' group and 224 in the 'after' group. Adherence to the protocol was 15.2% in the 'before' phase and 72.8% in the 'after' phase (p < 0.001). The mean time between instruction and first compression for the 'before' and 'after' groups was 34.36 seconds and 26.83 seconds, respectively (p < 0.001). Time to first compression was 238.62 seconds and 218.83 seconds in the 'before' and 'after' groups, respectively (p = 0.016). In the per-protocol analysis, the interval between instruction and compression was 37.19 seconds, 28.31 seconds and 32.40 seconds in the standard protocol, simplified protocol and 'own words' groups, respectively (p = 0.005). The need for paraphrasing was 60.4% in the standard protocol group and 81.5% in the simplified group (p < 0.001).@*CONCLUSION@#Simplified instructions were associated with a shorter interval between instruction and first compression. Efforts should be directed at simplifying DACPR instructions.

Comparison of inhalational methoxyflurane (Penthrox®) and intramuscular tramadol for prehospital analgesia

INTRODUCTION@#Treatment of pain is an important component of prehospital care. Inhalational analgesia agents have attractive strengths, but there is a paucity of studies comparing these with more conventional agents. We aimed to compare inhalational methoxyflurane and intramuscular (IM) tramadol as first-contact analgesia in the Singapore national ambulance service.@*METHODS@#Ambulances were randomised to carry either methoxyflurane or IM tramadol for the first six months and crossed over to the other arm after six months. Patients aged ≥ 16 years, with acute pain arising from musculoskeletal trauma with Numerical Rating Scale (NRS) score ≥ 3 were enrolled. Variables included NRS reduction, time variables, adverse effects, Ramsay Sedation Scores, and patient and paramedic satisfaction scores on a Likert scale.@*RESULTS@#A total of 369 patients were enrolled into this study, but 26 patients were excluded due to missing data. The methoxyflurane arm had a shorter median time taken from arrival at the scene to drug administration (9.0 [interquartile range 6.0-14.0] minutes vs. 11.0 [interquartile range 8.0-15.0] minutes). For patients who achieved reduction in NRS ≥ 3 within 20 minutes, those in the methoxyflurane arm took a shorter time. However, the methoxyflurane (46.7%) arm experienced lower proportion of patients not achieving NRS reduction ≥ 3 when compared to the tramadol (71.6%) arm after over 20 minutes. The methoxyflurane arm had significantly higher paramedic and patient satisfaction scores.@*CONCLUSION@#For the doses of medication used in this implementation study, methoxyflurane was superior in efficacy, speed of onset and administration, but had more minor adverse effects when compared to IM tramadol.

Impact of dispatcher-assisted cardiopulmonary resuscitation and myResponder mobile app on bystander resuscitation

INTRODUCTION@#Bystander cardiopulmonary resuscitation (B-CPR) is associated with improved out-of hospital cardiac arrest survival. Community-level interventions including dispatcher-assisted CPR (DA-CPR) and myResponder were implemented to increase B-CPR. We sought to assess whether these interventions increased B-CPR.@*METHODS@#The Singapore out-of-hospital cardiac arrest registry captured cases that occurred between 2010 and 2017. Outcomes occurring in 3 time periods (Baseline, DA-CPR, and DA-CPR plus myResponder) were compared. Segmented regression of time-series data was conducted to investigate our intervention impact on the temporal changes in B-CPR.@*RESULTS@#A total of 13,829 out-of-hospital cardiac arrest cases were included from April 2010 to December 2017. Higher B-CPR rates (24.8% versus 50.8% vs 64.4%) were observed across the 3 time periods. B-CPR rates showed an increasing but plateauing trend. DA-CPR implementation was significantly associated with an increased B-CPR (level odds ratio [OR] 2.26, 95% confidence interval [CI] 1.79-2.88; trend OR 1.03, 95% CI 1.01-1.04), while no positive change was detected with myResponder (level OR 0.95, 95% CI 0.82-1.11; trend OR 0.99, 95% CI 0.98-1.00).@*CONCLUSION@#B-CPR rates in Singapore have been increasing alongside the implementation of community-level interventions such as DA-CPR and myResponder. DA-CPR was associated with improved odds of receiving B-CPR over time while the impact of myResponder was less clear.

Nation-Wide Observational Study of Cardiac Arrests Occurring in Nursing Homes and Nursing Facilities in Singapore

INTRODUCTION@#Nursing home (NH) residents with out-of-hospital cardiac arrests (OHCA) have unique resuscitation priorities. This study aimed to describe OHCA characteristics in NH residents and identify independent predictors of survival.@*MATERIALS AND METHODS@#OHCA cases between 2010-16 in the Pan-Asian Resuscitation Outcomes Study were retrospectively analysed. Patients aged <18 years old and non-emergency cases were excluded. Primary outcome was survival at discharge or 30 days. Good neurological outcome was defined as a cerebral performance score between 1-2.@*RESULTS@#A total of 12,112 cases were included. Of these, 449 (3.7%) were NH residents who were older (median age 79 years, range 69-87 years) and more likely to have a history of stroke, heart and respiratory diseases. Fewer NH OHCA had presumed cardiac aetiology (62% vs 70%, <0.01) and initial shockable rhythm (8.9% vs 18%, <0.01), but had higher incidence of bystander cardiopulmonary resuscitation (74% vs 43%, <0.01) and defibrillator use (8.5% vs 2.8%, <0.01). Non-NH (2.8%) residents had better neurological outcomes than NH (0.9%) residents ( <0.05). Factors associated with survival for cardiac aetiology included age <65 years old, witnessed arrest, bystander defibrillator use and initial shockable rhythm; for non-cardiac aetiology, these included witnessed arrest (adjusted odds ratio [AOR] 3.8, <0.001) and initial shockable rhythm (AOR 5.7, <0.001).@*CONCLUSION@#Neurological outcomes were poorer in NH survivors of OHCA. These findings should inform health policies on termination of resuscitation, advance care directives and do-not-resuscitate orders in this population.

Knowledge and attitudes of Singapore schoolchildren learning cardiopulmonary resuscitation and automated external defibrillator skills

<p><b>INTRODUCTION</b>Victims of out-of-hospital cardiac arrests require timely cardiopulmonary resuscitation (CPR) and early defibrillation. Callers to emergency medical services are asked to provide dispatcher-guided responses until an ambulance arrives. Knowing what to expect in such circumstances should reduce both delay and confusion.</p><p><b>METHODS</b>This study was conducted among schoolchildren aged 11-17 years using ten-item pre- and post-training surveys. We aimed to observe any knowledge and attitude shifts regarding CPR and automated external defibrillator (AED) use subsequent to the training.</p><p><b>RESULTS</b>A total of 1,196 students across five schools completed the pre- and post-training surveys. Survey questions tested basic CPR knowledge and attitudes towards CPR and AED use. The overall response rate was 80.8% and 81.5% in the pre- and post-training surveys, respectively. There was a statistically significant improvement in the students' CPR knowledge. The number of students who selected all the correct answers for the knowledge-based questions in the post-training survey increased by 64.7% (95% confidence interval 61.9%-67.5%; p < 0.001). There was also an improvement in their willingness to administer CPR (likely/very likely to administer CPR pre-training vs. post-training: 13.0% vs. 71.0%; p < 0.001) and use AED (likely/very likely to administer AED pre-training vs. post-training: 11.7% vs. 78.0%; p < 0.001) after training.</p><p><b>CONCLUSION</b>The training programme imparted new information and skills, and improved attitudes towards providing CPR and using AED. However, some concerns persisted about hurting the victim while performing CPR.</p>

Drowning in swimming pools: clinical features and safety recommendations based on a study of descriptive records by emergency medical services attending to 995 calls

<p><b>INTRODUCTION</b>This study was a descriptive analysis of national ambulance case records and aimed to make practical safety recommendations in order to reduce the incidence of drowning in swimming pools.</p><p><b>METHODS</b>A search was performed of a national database of descriptive summaries by first-responder paramedics of all 995 calls made to the Singapore Civil Defence Force between 1 January 2012 and 31 December 2014. We included all cases of submersion in both public and private pools for which emergency medical services were activated.</p><p><b>RESULTS</b>The highest proportion of drowning cases occurred in the age group of 0-9 years. Males accounted for 57.0% (61/107) of cases. Bystander cardiopulmonary resuscitation (CPR) was performed in 91.3% (21/23) and 68.6% (48/70) of cases of cardiac/respiratory arrest from drowning in public and private pools, respectively; the rate of bystander CPR was higher when a lifeguard was present (88.5%, 23/26 vs. 68.7%, 46/67). The majority (72.0%, 77/107) of drowning incidents occurred in private pools, most of which had no lifeguards present.</p><p><b>CONCLUSION</b>To our knowledge, this study was the first in Singapore to examine data from emergency medical services. Since the majority of incidents occurred in private pools without lifeguards, it is recommended that a lifeguard be present at every pool. For pools that are too small to justify mandatory lifeguard presence, safety measures, such as guidelines for pool design and pool fencing with latched gates, may be considered. As strict enforcement may not be possible, public education and parental vigilance remain vital.</p>

Singapore Defibrillation Guidelines 2016

The most common initial rhythm in a sudden cardiac arrest is ventricular fibrillation or pulseless ventricular tachycardia. This is potentially treatable with defibrillation, especially if provided early. However, any delay in defibrillation will result in a decline in survival. Defibrillation requires coordination with the cardiopulmonary resuscitation component for effective resuscitation. These two components, which form the key links in the chain of survival, have to be brought to the cardiac victim in a timely fashion. An effective chain of survival is needed in both the institution and community settings.

The role of dispatch in resuscitation

The role of the dispatch centre has increasingly become a focus of attention in cardiac arrest resuscitation. The dispatch centre is part of the first link in the chain of survival because without the initiation of early access, the rest of the chain is irrelevant. The influence of dispatch can also extend to the initiation of bystander cardiopulmonary resuscitation, early defibrillation and the rapid dispatch of emergency ambulances. The new International Liaison Committee on Resuscitation, the American Heart Association and, especially, the European Resuscitation Council 2015 guidelines have been increasing their emphasis on dispatch as the key to improving out-of-hospital cardiac arrest survival.

The Little India riot: experience of an emergency department in Singapore

<p><b>INTRODUCTION</b>Singapore experienced its second riot in 40 years on 8 December 2013, in the area known as Little India. A retrospective review of 36 casualties treated at the emergency department was conducted to evaluate injury patterns.</p><p><b>METHODS</b>Characteristics including the rate of arrival, injury severity, type and location, and disposition of the casualties were analysed.</p><p><b>RESULTS</b>The injuries were predominantly mild (97.2%), with the most common injuries involving the head (50.0%) and limbs (38.9%). 97.2% of the casualties were managed as outpatient cases.</p><p><b>CONCLUSION</b>The majority of the injuries in this incident were mild and could be managed as outpatient cases. Important lessons were learnt from the incident about the utilisation of manpower and safety of staff in the emergency department.</p>

Recognition and treatment of out-of-hospital cardiac arrests by non-emergency ambulance services in Singapore

<p><b>INTRODUCTION</b>Prompt recognition of cardiac arrest and initiation of cardiopulmonary resuscitation (CPR) and defibrillation is necessary for good outcomes from out-of-hospital cardiac arrest (OHCA). This study aims to describe the recognition and treatment of OHCA in patients conveyed by non-emergency ambulance services (EAS) in Singapore.</p><p><b>MATERIALS AND METHODS</b>This is a multi-centre, retrospective chart review, of cases presenting to public emergency departments (EDs), conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. The study was from October 2002 to August 2009. The following variables were examined: ability to recognise cardiac arrest, whether CPR was carried out by the ambulance crew and whether an automated external defibrillator (AED) was applied.</p><p><b>RESULTS</b>Eighty-six patients were conveyed by non-EAS and found to be in cardiac arrest upon ED arrival. Mean age was 63 years (SD 21.8), 70.9% were males. A total of 53.5% of arrests occurred in the ambulance while 70.9% were found to be asystolic upon ED arrival. Seven patients had a known terminal illness. Survival to discharge was 3.5%. Cardiac arrest went unrecognised by the ambulance crew in 38 patients (44.2%). CPR was performed in 35 patients (40.7%) of the 86 patients and AED was applied in only 10 patients (11.6%).</p><p><b>CONCLUSION</b>We found inadequate recognition and delayed initiation of treatment for OHCA. Possible reasons include a lack of training in patient monitoring and detection of cardiac arrest, lack of CPR training, lack of confidence in performing CPR, lack of AEDs on ambulances and lack of training in their use.</p>

Modelling the utility of body temperature readings from primary care consults for SARS surveillance in an army medical centre

<p><b>INTRODUCTION</b>There is interest in surveillance systems for outbreak detection at stages where clinical presentation would still be undifferentiated. Such systems focus on detecting clusters of syndromes in excess of baseline levels, which may indicate an outbreak. We model the detection limits of a potential system based on primary care consults for the detection of an outbreak of severe acute respiratory syndrome (SARS).</p><p><b>MATERIALS AND METHODS</b>Data from an averaged-sized medical centre were extracted from the Patient Care Enhancement System (PACES) [the electronic medical records system serving the Singapore Armed Forces (SAF)]. Thresholds were set to 3 or more cases presenting with particular syndromes and a temperature reading of >or=38oC (T >or=38). Monte Carlo simulation was used to insert simulated SARS outbreaks of various sizes onto the background incidence of febrile cases, accounting for distribution of SARS incubation period, delay from onset to first consult, and likelihood of presenting with T >or=38 to the SAF medical centre.</p><p><b>RESULTS</b>Valid temperature data was available for 2,012 out of 2,305 eligible syndromic consults (87.2%). T >or=38 was observed in 166 consults (8.3%). Simulated outbreaks would peak 7 days after exposure, but, on average, signals at their peak would consist of 10.9% of entire outbreak size. Under baseline assumptions, the system has a higher than 90% chance of detecting an outbreak only with 20 or more cases.</p><p><b>CONCLUSIONS</b>Surveillance based on clusters of cases with T >or=38 helps reduce background noise in primary care data, but the major limitation of such systems is that they are still only able to confidently detect large outbreaks.</p>