Susan Yap

Reducing ambulance response times using geospatial-time analysis of ambulance deployment.

OBJECTIVES This study aimed to determine if a deployment strategy based on geospatial-time analysis is able to reduce ambulance response times for out-of-hospital cardiac arrests (OOHCA) in an urban emergency medical services (EMS) system. METHODS An observational prospective study examining geographic locations of all OOHCA in Singapore was conducted. Locations of cardiac arrests were spot-mapped using a geographic information system (GIS). A progressive strategy of satellite ambulance deployment was implemented, increasing ambulance bases from 17 to 32 locations. Variation in ambulance deployment according to demand, based on time of day, was also implemented. The total number of ambulances and crews remained constant over the study period. The main outcome measure was ambulance response times. RESULTS From October 1, 2001, to October 14, 2004, a total of 2,428 OOHCA patients were enrolled into the study. Mean ± SD age for arrests was 60.6 ± 19.3 years with 68.0% male. The overall return of spontaneous circulation (ROSC) rate was 17.2% and survival to discharge rate was 1.6%. Response time decreased significantly as the number of fire stations/fire posts increased (Pearson χ(2) = 108.70, df = 48, p < 0.001). Response times for OOHCA decreased from a monthly median of 10.1 minutes at the beginning to 7.1 minutes at the end of the study. Similarly, the proportion of cases with response times < 8 minutes increased from 22.3% to 47.3% and < 11 minutes from 57.6% to 77.5% at the end of the study. CONCLUSIONS A simple, relatively low-cost ambulance deployment strategy was associated with significantly reduced response times for OOHCA. Geospatial-time analysis can be a useful tool for EMS providers.

Improved neurologically intact survival with the use of an automated, load-distributing band chest compression device for cardiac arrest presenting to the emergency department.

IntroductionIt has been unclear if mechanical cardiopulmonary resuscitation (CPR) is a viable alternative to manual CPR. We aimed to compare resuscitation outcomes before and after switching from manual CPR to load-distributing band (LDB) CPR in a multi-center emergency department (ED) trial.MethodsWe conducted a phased, prospective cohort evaluation with intention-to-treat analysis of adults with non-traumatic cardiac arrest. At these two urban EDs, systems were changed from manual CPR to LDB-CPR. Primary outcome was survival to hospital discharge, with secondary outcome measures of return of spontaneous circulation, survival to hospital admission and neurological outcome at discharge.ResultsA total of 1,011 patients were included in the study, with 459 in the manual CPR phase (January 01, 2004, to August 24, 2007) and 552 patients in the LDB-CPR phase (August 16, 2007, to December 31, 2009). In the LDB phase, the LDB device was applied in 454 patients (82.3%). Patients in the manual CPR and LDB-CPR phases were comparable for mean age, gender and ethnicity. The mean duration from collapse to arrival at ED (min) for manual CPR and LDB-CPR phases was 34:03 (SD16:59) and 33:18 (SD14:57) respectively. The rate of survival to hospital discharge tended to be higher in the LDB-CPR phase (LDB 3.3% vs Manual 1.3%; adjusted OR, 1.42; 95% CI, 0.47, 4.29). There were more survivors in LDB group with cerebral performance category 1 (good) (Manual 1 vs LDB 12, P = 0.01). Overall performance category 1 (good) was Manual 1 vs LDB 10, P = 0.06.ConclusionsA resuscitation strategy using LDB-CPR in an ED environment was associated with improved neurologically intact survival on discharge in adults with prolonged, non-traumatic cardiac arrest.

Knowledge of Signs and Symptoms of Heart Attack and Stroke among Singapore Residents

Aim. To determine the level of knowledge of signs and symptoms of heart attack and stroke in Singapore resident population, in comparison to the global community. Methods. A population based, random sample of 7,840 household addresses was selected from a validated national sampling frame. Each participant was asked eight questions on signs and symptoms of heart attack and 10 questions on stroke. Results. The response rate was 65.2% with 4,192 respondents. The level of knowledge for preselected, common signs and symptoms of heart attack and stroke was 57.8% and 57.1%, respectively. The respondents scored a mean of 5.0 (SD 2.4) out of 8 for heart attack, while they scored a mean of 6.8 (SD 2.9) out of 10 for stroke. Respondents who were ≥50 years, with lower educational level, and unemployed/retired had the least knowledge about both conditions. The level of knowledge of signs and symptoms of heart attack and stroke in Singapore is comparable to USA and Canada. Conclusion. We found a comparable knowledge of stroke and heart attack signs and symptoms in the community to countries within the same economic, educational, and healthcare strata. However older persons, those with lower educational level and those who are unemployed/retired, require more public health education efforts.

Retrospective study of elderly frequent attenders presenting with chest pain at emergency department

BackgroundThe aims of the study were to identify the characteristics of elderly frequent attenders to the emergency department (ED) presenting with chest pain and to assess the 1-year prognosis for developing adverse cardiac events.FindingsPatients over 75 years old, with four or more attendances to the ED between 1 January 2010 and 31 December 2010 with at least one attendance due to chest pain, were selected from a database. Data was collected on demographic details, visit history, disposition and admission outcomes. Each patient was followed up for 12 months after the index episode via the hospital electronic registry for adverse cardiac outcome. Adverse cardiac outcomes included death from cardiac event, acute myocardial infarction (ST elevation myocardial infarction (STEMI)/non-ST elevation myocardial infarction (NSTEMI)) or unstable angina. A total of 158 patients with 4 or more visits to the ED accounted for 290 visits with chest pain during 2010. There is a high prevalence of coronary risk factors in this cohort (hypertension 92.4%, hyperlipidaemia 65.2%, diabetes 49.4% and smoking 26.6%). The hospital admission rate was also high at 83.5%. Over the ensuing 12 months, 8 patients died of a primary cardiac event and a further 29 patients developed 36 non-fatal cardiac events. We could not establish any significant relationship between increase in adverse cardiac outcome and individual risk factors or even two or more risk factors (P = 0.0572). Patients with two or more attendances with chest pain were more likely to develop adverse cardiac outcome (P = 0.0068).ConclusionsElderly frequent attenders to the ED, who present with chest pain, have more cardiac risk factors and are more likely to develop adverse coronary outcomes if they re-attend with chest pain.

Hair apposition technique for scalp laceration repair: a randomized controlled trial comparing physicians and nurses (HAT 2 study)

OBJECTIVES The hair apposition technique (HAT) is a new method of closing scalp lacerations in which hairs on either side of the wound are twisted together and secured with a tissue adhesive. We aimed to compare the effectiveness, complications, and benefits of HAT performed by nurses or doctors in a randomized, prospective trial. METHODS We conducted the study in the ED from November 2002 to February 2005. Subjects were randomized to receive HAT either by doctors or nurses. All wounds were evaluated 7 days later. The outcomes wound infection, wound healing, bleeding, and overall complications were measured, setting +/-5% in the differences of the outcomes between the doctors and nurses as equivalence. RESULTS There were 88 and 76 patients in the doctor and nurse groups, respectively. There were no significant differences in all short-term outcomes between the doctors and nurses except for length of the procedure. The doctors had a shorter mean duration of procedure than the nurses (9.0 +/- 5.6 vs 12.8 +/- 7.5 minutes, P = .001). CONCLUSION The HAT can be safely performed by trained nurses with equivalent outcomes as doctors.

Frequent attenders to the ED: patients who present with repeated asthma exacerbations.

BACKGROUND Asthma has been reported as one of the main causes of frequent attendance to the emergency department (ED), and many of those visits are potentially preventable. Understanding the characteristics of frequent attender (FA) patients with asthmatic exacerbations will help to identify factors associated with frequent attendance and improve case management. The aim of this study is to describe the characteristics of FA who present multiple times to the ED for asthma exacerbations. METHODS This study was a retrospective review of cases presented to Singapore General Hospital ED in 2010. Patients who attended the ED for 4 times or more with at least 1 visit attributable to asthma exacerbations in 2010 were included. They were then categorized as FA with multiple exacerbations (FAME) and those with fewer exacerbations. RESULTS Of 105616 ED patients, 155 patients attending the ED in 2010 were identified as FA with asthma, and 26 (17%) of these patients were classified as FAME, resulting in 213 visits (45% of total visits). Compared with FA with fewer exacerbations group, FAME were more likely to be men (P = .002), unemployed (P < .000), bad debtors (P = .045), substance abusers (P = .022), previously known to medical social workers (P = .002), and were found to spend a longer amount of time in the ED (>6 hours) (P = .03). CONCLUSION We found that a small number of FAME patients accumulated a large number of ED visits and spent a significantly longer time in the ED. This group tended to be males with social, financial, and addiction problems.

Validation of the new Vancouver Chest Pain Rule in Asian chest pain patients presenting at the emergency department.

OBJECTIVES The new Vancouver Chest Pain (VCP) Rule recommends early discharge for chest pain patients who are at low risk of developing acute coronary syndrome (ACS), and thus can be discharged within 2 hours of arrival at the emergency department (ED). This study aimed to assess the performance of the new VCP Rule for Asian patients presenting with chest pain at the ED. METHODS This prospective cohort study involved patients attended to at the ED of a large urban centre. Patients of at least 25 years old, presenting with stable chest pain and a non-diagnostic ECG, and with no history of active coronary artery disease were included in the study. The main outcome measures were cardiac events, angioplasty, or coronary artery bypass within 30 days of enrolment. RESULTS The study included 1690 patients from 27 August 2000 to 1 May 2002, with 661 patients fulfilling the VCP criteria. Of those for early discharge, 24 had cardiac events and 13 had angioplasty or bypass at 30 days, compared to 91 and 41, respectively, for those unsuitable for discharge. This gave the rule a sensitivity of 78.1% for cardiac events, including angioplasty and bypass. Specificity was 41.0%, and negative predictive value (NPV) was 94.4%. CONCLUSION We found the new VCP Rule to have moderate sensitivity and poor specificity for adverse cardiac events in our population. With an NPV of less than 100%, this means that a small proportion of patients sent home with early discharge would still have adverse cardiac events.

Temporal variation of out-of-hospital cardiac arrests in an equatorial climate

Objective We aimed to determine whether there is a seasonal variation of out-of-hospital cardiac arrests (OHCA) in an equatorial climate, which does not experience seasonal environmental change. Methods We conducted an observational prospective study looking at the occurrence of OHCA in Singapore. Included were all patients with OHCA presented to Emergency Departments across the country. We examined the monthly, daily, and hourly number of cases over a three-year period. Data was analyzed using analysis of variance (ANOVA). Results From October, 1st 2001 to October, 14th 2004, 2428 patients were enrolled in the study. Mean age for cardiac arrests was 60.6 years with 68.0% male. Ethnic distribution was 69.5% Chinese, 15.0% Malay, 11.0% Indian, and 4.4% Others. There was no significant seasonal variation (spring/summer/fall/winter) of events (ANOVA P = 0.71), monthly variation (P = 0.88) or yearly variation (P = 0.26). We did find weekly peaks on Mondays and a circadian pattern with daily peaks from 9–10 am. Conclusions We did not find any discernable seasonal pattern of cardiac arrests. This contrasts with findings from temperate countries and suggests a climatic influence on cardiac arrest occurrence. We also found that sudden cardiac arrests follow a circadian pattern.

Knowledge and attitudes towards cardiopulmonary resuscitation and defibrillation amongst Asian primary health care physicians.

Objective To assess the knowledge and attitudes of local primary health care physicians in relation to cardiopulmonary resuscitation (CPR) and defibrillation. Methods We conducted a survey on general practitioners in Singapore by using a self-administered questionnaire that comprised 29 questions. Results The response rate was 80%, with 60 of 75 physicians completing the questionnaire. The average age of the respondents was 52 years. Sixty percent of them reported that they knew how to operate an automated external defibrillator (AED), and 38% had attended AED training. Only 36% were willing to perform mouth-to-mouth ventilation during CPR, and 53% preferred chest compression-only resuscitation (CCR) to standard CPR. We found those aged <50 years were more likely to be trained in basic cardiac life support (BCLS) (P < 0.001) and advanced cardiac life support (P = 0.005) or to have ever attended to a patient with cardiac arrest (P = 0.007). Female physicians tended to agree that all clinics should have AEDs (P = 0.005) and support legislation to make AEDs compulsory in clinics (P < 0.001). We also found that a large proportion of physicians who were trained in BCLS (P = 0.006) were willing to perform mouth-to-mouth ventilation. Conclusion Most local primary care physicians realize the importance of defibrillation, and the majority prefer CCR to standard CPR.

Characteristics of Frequent Users of Emergency Medical Services in Singapore

Abstract Objectives: This study aims to describe frequent users of Emergency Medical Services (EMS) conveyed to a Singapore tertiary hospital, focusing on a comparison between younger users (age <65) and older users in diagnoses and admission rates. Methods: All patients conveyed by EMS to a tertiary hospital 4 times or more over a 1-year period in 2015 had their EMS ambulance charts and Emergency Department (ED) electronic records retrospectively analyzed (n = 243), with admission the primary outcome. Results: The 243 frequent users were analyzed with a combined total of 1,705 visits, out of a total of 10,183 patients with 12,839 visits conveyed by EMS to Singapore General Hospital (SGH) in 2015. Younger frequent users (<65 years age) were found to be predominantly male (79.6%, p = 0.001) and were on average responsible for more visits than elderly frequent users (8.6 vs. 5.7, p = 0.004). Medical co-morbidities were significantly more prevalent in older users. Younger frequent users were more likely to be smokers (60.2% vs. 22.3%), heavy drinkers (51.3% vs. 8.5%), substance abusers (12.4% vs. 0.8%), and bad debtors (49.6% vs. 20.0%, p < 0.001). A larger proportion presented with altered mental states (11.7% vs. 5.4%, p < 0.001) and alcohol related diagnoses (34.7% vs. 5.3%, p < 0.001). Many were picked up from public areas (45.5% vs. 19.6%, p < 0.001), and had lower acuity triage scores at both EMS (p < 0.001) and ED (p = 0.001). They had lower admission rates (40.5% vs. 78.7%, p < 0.001) and shorter length of stay (4.3 vs. 5.9 days, p < 0.001). Univariable and multivariable analysis showed alcohol related diagnoses, history of alcohol abuse and lower triage scores were less likely to require admissions. Conclusion: Frequent EMS users consume a disproportionate amount of healthcare resources. Two broad subgroups of patients were identified: younger patients with social issues and older patients with multiple medical conditions. EMS usage by older patients was significantly associated with higher rates of admission