Early sepsis care with the National Early Warning Score 2-guided Sepsis Hour-1 Bundle in the emergency department: hybrid type 1 effectiveness-implementation pilot stepped wedge randomised controlled trial (NEWS-1 TRIPS) protocol

INTRODUCTION

Early sepsis treatment in the emergency department (ED) is crucial to improve patient survival. Despite international promulgation, the uptake of the Surviving Sepsis Campaign (SSC) Hour-1 Bundle (lactate measurement, blood culture, broad-spectrum antibiotics, 30 mL/kg crystalloid for hypotension/lactate ≥4 mmol/L and vasopressors for hypotension during/after fluid resuscitation within 1 hour of sepsis recognition) is low across healthcare settings. Delays in sepsis recognition and a lack of high-quality evidence hinder its implementation. We propose a novel sepsis care model (National Early Warning Score, NEWS-1 care), in which the SSC Hour-1 Bundle is triggered objectively by a high NEWS-2 (≥5). This study aims to determine the feasibility of a full-scale type 1 hybrid effectiveness-implementation trial on the NEWS-1 care in multiple EDs.

METHODS AND ANALYSIS

We will conduct a pilot type 1 hybrid trial and prospectively recruit 200 patients from 4 public EDs in Hong Kong cluster randomised in a stepped wedge design over 10 months. All study sites will start with an initial period of standard care and switch in random order at 2-month intervals to the NEWS-1 care unidirectionally. The implementation evaluation will employ mixed methods guided by the Reach, Effectiveness, Adoption, Implementation and Maintenance framework, which includes qualitative and quantitative data from focus group interviews, staff survey and clinical record reviews. We will analyse the 14 feasibility outcomes as progression criteria to a full-scale trial, including trial acceptability to patients and staff, patient and staff recruitment rates, accuracy of sepsis screening, protocol adherence, accessibility to follow-up data, safety and preliminary clinical impacts of the NEWS1 care, using descriptive statistics.

ETHICS AND DISSEMINATION

The institutional review boards of all study sites approved this study. This study will establish the feasibility of a full-scale hybrid trial. We will disseminate the findings through peer-reviewed publications, conference presentations and educational activities.

TRIAL REGISTRATION NUMBER

NCT05731349.

Exposure-response relationship between COVID-19 incidence rate and incidence and survival of out-of-hospital cardiac arrest (OHCA)

Aim

We aimed to report the epidemiology of OHCA, bystander CPR pattern and other Utstein factors in a region in Hong Kong during the COVID-19 pandemic. In particular, we studied the relationship between COVID-19 incidence, OHCA incidence and survival outcome.

Methods

This was a retrospective cohort study that used data from our registry to compare features of OHCA during pre-pandemic (Jan 2018 to Dec 2019), low-incidence pandemic (Jan 2020 to Dec 2021) and high-incidence pandemic (Jan to Mar 2022). We used multivariable logistic regression to identify survival predictors.

Results

Incidence of OHCA increased dramatically with surging COVID-19 incidence (65.9 vs 74.2 vs 159.2 per 100,000 population per year, p < 0.001). During the pandemic, there were more indoor OHCA (89.3% vs 92.6% vs 97.4%, p < 0.001), fewer witnessed arrest (38.5% vs 38.3% vs 29.6%, p = 0.001), and longer median time to basic life support upon receiving call (9 min vs 10 min vs 14 min, p < 0.001). There was a higher proportion of OHCA cases with bystander-CPR (26.1% vs 31.3% vs 35.3%, p < 0.001). The proportion of cases with survival to admission (STA) (30.8% vs 22.2% vs 15.4%, p < 0.001) and survival to discharge (STD) (2.2% vs 1.0% vs 0.2%, p = 0.001) were lowered. After controlling for confounders, the odds of STA was reduced by 33% and 55% during the low-incidence and high-incidence pandemic respectively.

Conclusion

The increase in COVID-19 incidence had an exposure-response relationship with an increased incidence of OHCA and worsened survival outcomes.

Effects of systemic antibiotics in early onset ventilator-associated pneumonia in trauma patients: A single-centre retrospective cohort study

Background:

Ventilator-associated pneumonia is one of the commonest complications encountered in intubated patients: its incidence ranges from 20% to 60%, with higher incidences seen in patients with polytrauma. Ventilator-associated pneumonia can result in poor neurological outcomes upon discharge, longer duration of mechanical ventilation and prolonged intensive care unit stays. The use of systemic antibiotics has been proposed as one method to reduce this complication. However, its effectiveness remains to be determined, and concerns about bacterial resistance hinder its use. This study aims to evaluate the effects of systemic antibiotics on early ventilator-associated pneumonia prevention.

Methods:

This is a single-centred retrospective cohort study, using data in the local trauma registry from 2015 to 2020. Patients aged ⩾18 years who suffered from injury to the head or trunk and were intubated within 12 h of hospitalization were evaluated for early ventilator-associated pneumonia to determine the effectiveness of systemic antibiotics on the incidence of ventilator-associated pneumonia and to identify other risk factors for ventilator-associated pneumonia in patients suffering from trauma.

Result:

A total of 250 patients were recruited; 59 of them met the criteria for early onset ventilator-associated pneumonia. Early use of broad-spectrum antibiotics with potent anaerobic coverage was found to be protective for early onset ventilator-associated pneumonia (adjusted odds ratio = 0.228, p = 0.044). Increasing age and severe thoracic or abdominal injury were also found to be strong non-modifiable predictors for the development of early onset ventilator-associated pneumonia.

Conclusion:

Use of systemic antibiotics with potent anaerobic coverage within 3 h of injury was found to prevent early onset ventilator-associated pneumonia in those intubated within 12 h of injury. However, a large-scale randomized control trial may be needed to further evaluate its benefit and its potential side effects, most notably the risk of antibiotic resistance.

Can mechanism of injury improve trauma diversion? A retrospective cross-sectional study

Objective:

The objective of this study was to determine the impact of adding selected mechanism of injury (MOI) to the existing trauma diversion criteria adopted in Hong Kong.

Method:

This is a cross-sectional study based on the trauma registry of New Territory West Cluster (NTWC) of Hospital Authority from January 2017 to December 2019. All adult patients aged 18 years or above were recruited if their injury occurred in the catchment area of Pok Oi Hospital (POH) or Tin Shui Wai Hospital (TSWH). Performance of the protocol before and after MOI criteria being added in terms of over-diversion and under-diversion rate was determined. Model discrimination was evaluated by plotting the receiver operating characteristic curve, and the area under the curve was compared before and after MOI criteria added. Net reclassification improvement and integrated discrimination improvement indices were evaluated.

Result:

A total of 502 patients were included for analysis. Before MOI criteria were added, the over-diversion rate and under-diversion rate were 31.1% and 54.7%, respectively. After MOI criteria were added, the over-diversion rate and under-diversion rate were 33.1% and 34.3%, respectively. The receiver operating characteristic curve of current primary trauma diversion (PTD) criteria had an area under the curve of 66.9% (95% confidence interval: 63%–71%). After adding MOI criteria, the new receiver operating characteristic curve yielded an area under the curve of 73.7% (95% confidence interval: 70%–78%), which is significantly better (p < 0.001). Net reclassification improvement and integrated discrimination improvement indices indicated that including MOI criteria would improve the model prediction.

Conclusion:

Adding mechanism of injury can improve trauma diversion protocol performance.

Clinical prediction rule of termination of resuscitation for out-of-hospital cardiac arrest patient with pre-hospital defibrillation given

OBJECTIVE

To derive a clinical prediction rule of termination of resuscitation (TOR) for out-of-hospital cardiac arrest (OHCA) with pre-hospital defibrillation given.

METHOD

This was a retrospective multicenter cohort study performed in three emergency departments (EDs) of three regional hospitals from 1/1/2012 to 31/12/2018. Patients of OHCA aged ≥18 years old were included. Those with post-mortem changes, return of spontaneous circulation and receiving no resuscitation in EDs were excluded. A TOR rule was derived by logistic regression analysis based on demographics and end-tidal carbon dioxide level of included subjects with pre-hospital defibrillation given.

RESULTS

There were 447 included patients had received pre-hospital defibrillation, in which 148 had return of spontaneous circulation (ROSC), with 22 survived to discharge (STD). Independent predictors for death on or before ED arrival (no ROSC) included EMS call to ED time >20 min and ETCO2 level <20 mmHg from first three sets. A 2-criteria rule predicting death on or before ED arrival by fulfilling both of the independent predictors had a specificity of 0.95 (95% CI 0.90-0.98) and positive predictive value (PPV) of 0.95 (95% CI 0.90-0.98), if 2nd set of ETCO2 was used. The positive likelihood ratio was 10.04 (95% CI 4.83-20.89).

CONCLUSION

The 2-criteria TOR rule for OHCA patients with pre-hospital defibrillation had a high specificity and PPV for predicting death on or before ED arrival.

Clinical, laboratory, and radiological features indicative of novel coronavirus disease (COVID-19) in emergency departments - a multicentre case-control study in Hong Kong

Objectives

Little is known about the value of routine clinical assessment in identifying patients with coronavirus disease 2019 (COVID‐19) in the emergency department (ED). We aimed to compare the exposure history, signs and symptoms, laboratory, and radiographic features of ED patients who tested positive and negative for COVID‐19.

Methods

This was a case‐control study in 7 EDs in Hong Kong from 20 January to 29 February 2020. Thirty‐seven patients with laboratory‐confirmed COVID‐19 were age‐ and sex‐matched to 111 controls. We compared the groups with univariate analysis and calculated the odds ratio (OR) of having COVID‐19 for each characteristic that was significantly different between the groups with adjustment for age and presumed location of acquiring the infection.

Results

There were no significant differences in patient characteristics and reported symptoms between the groups. A positive contact history within 14 days (adjusted OR 37.61, 95% CI: 10.86–130.19), bilateral chest radiograph shadow (adjusted OR 13.19, 95% CI: 4.66–37.35), having prior medical consultation (adjusted OR 7.43, 95% 2.89–19.09), a lower white blood cell count (adjusted OR 1.30, 95% CI: 1.11–1.51), and a lower platelet count (adjusted OR 1.07, 95% CI: 1.01–1.12) were associated with a higher odds of COVID‐19 separately. A higher neutrophil count was associated with a lower odds of COVID‐19 (adjusted OR 0.77, 95% CI: 0.65–0.91).

Conclusion

This study highlights a number of clinical features that may be useful in identifying high‐risk patients for early testing and isolation while waiting for the test result. Further studies are warranted to verify the findings.

Decision rule to predict pneumonia in children presented with acute febrile respiratory illness

BACKGROUND

It is a frequent challenge for physicians to identify pneumonia in patients with acute febrile respiratory symptoms, particularly in stable pediatric patients without respiratory distress. A decision rule is required to assist judgement on the need of ordering a chest radiograph.

METHOD

This was a multicenter prospective study in 3 emergency departments. Children younger than 6 years old with an acute onset of fever and respiratory symptoms were recruited. Split sample method was adopted for derivation and validation of the Pediatric Acute Febrile Respiratory Illness rule (PAFRI Rule). PAFRI was derived from logistic regression with weighting based on adjusted odds ratios.

RESULTS

Out of 967 children evaluated, 530 had taken chest radiograph examination, with 91 demonstrated evidence of pneumonia on radiograph. PAFRI Rule was derived from logistic regression with 5 weighed predictors: duration of fever <3 days (0 points), 3-4 days (2 points), 5-6 days (4 points), ≥7 days (5 points), chills (2 points), nasal symptoms (-2 points), abnormal chest examination (3 points), SpO₂ ≤96% or tachypnea (3 points). The Area under ROC curve of the PAFRI Rule, the Bilkis Decision Rule and Bilkis Simpler Rule were 0.733, 0.600 and 0.579 respectively. A PAFRI score of ≥0 gives a sensitivity of 91.7% and negative predictive value of 97.7%.

CONCLUSION

PAFRI rule can be used as a reference tool for guiding the need for taking Chest radiograph examination for pediatric patients. While promising, the PAFRI rule requires further validation.

WHAT'S KNOWN ON THIS SUBJECT

It is often a challenge for physicians to identify pneumonia in children acutely febrile with respiratory symptoms, particularly in those who are stable without respiratory distress. The decision to order chest radiograph was based on clinical assessment with heterogenous practice. A valid and verified clinical prediction rule for ordering chest radiograph examination for stable febrile children without signs of respiratory distress would therefore assist in management of this group of patients.

WHAT THIS STUDY ADDS

The PAFRI rule, based on parameters from clinical bedside assessment, can be used as a reference tool for guiding the need for referral to emergency department or taking use of chest radiograph for pediatric patients, and triaging for higher priority of clinical care.

Epidemiological study of major pelvic fracture in Hong Kong and analysis of predictors for mortality

Objectives and Background

Pelvic fracture causes significant mortality and morbidities. The purpose of this study is to identify the characteristics of patients with pelvic fracture in Hong Kong and to determine the factors predicting mortality. The result could help to identify high-risk patients who might benefit from more intensive evaluation and intervention.

Method:

Five hundred and eight patients (age > 12 years old) with pelvic fractures were identified from the trauma registries of four designated trauma centres in Hong Kong from 1 January 2005 to 31 December 2012. Patient baseline characteristics and outcomes were analysed. Stepwise logistic regression was performed to identify independent clinical predictors for mortality.

Result:

Mean age was 45.4 ± 19.2 years, 43.3% were female, mean length of hospital stay was 27.9 ± 42.4 days and mean length of intensive care unit stay was 4.8 ± 6.8 days. Injury severity score was 28.9 ± 18.7, revised trauma score was 7.2 ± 2 and 30-day mortality was 20.9%. Stepwise logistic regression identified patient’s age, presenting systolic blood pressure, initial Glasgow Coma Scale, injuries to the thoracic and abdominal regions, first base excess and the volume of red blood cell transfusion required within the first 6 h to be independent risk factors predicting mortality.

Conclusion:

Pelvic fracture is associated with significant risk of mortality in major trauma patients. Clinical characteristics obtained during emergency department resuscitation can help in selecting patients for timely aggressive interventions.

Hong Kong needs a territory-wide registry for out-of-hospital cardiac arrest

Out-of-hospital cardiac arrest (OHCA) is an urgent disease entity, and the outcomes of OHCA are poor. This causes a significant public health burden, with loss of life and productivity throughout society. Internationally, successful programmes have adopted various survival enhancement measures to improve outcomes of OHCA. A territory-wide organised survival enhancement campaign is required in Hong Kong to maintain OHCA survival rates that are comparable to those of other large cities. One key component is to establish an OHCA registry, such as those in Asia, the United States, Europe, Australia, and New Zealand. An OHCA registry can provide benchmarking, auditing, and surveillance for identification of weak points within the chain of survival and evaluation of the effectiveness of survival enhancement measures. In Hong Kong, digitisation of records in prehospital and in-hospital care provides the infrastructure for an OHCA registry. Resources and governance to maintain a sustainable OHCA registry are necessary in Hong Kong as the first step to improve survival and outcomes of OHCA.

Questionnaire survey on medical futility and termination of resuscitation in cardiac arrest patients among emergency physicians in Hong Kong

INTRODUCTION

The perceptions of medical futility and decisions about termination of resuscitation (TOR) for out-of-hospital cardiac arrest (OHCA) are highly heterogeneous and dependent on the practice of the attending emergency physicians. The objective of this study was to report and investigate the knowledge, attitudes, and practices regarding medical futility and TOR during management of OHCA in Hong Kong.

METHODS

A cross-sectional survey was conducted among emergency medicine physicians in Hong Kong. The questionnaire assessed participants' background, knowledge, attitudes, and behaviours concerning medical futility and TOR in management of OHCA. Composite scores were calculated to reflect knowledge, attitudes, and practices of OHCA treatment. Subgroup analysis and multiple regression analysis were used to explore the relationship between participants' background, knowledge, attitudes, and behaviours.

RESULTS

The response rate to this survey was 57% (140/247). Independent predictors of less aggressive resuscitation in OHCA patients included status as a Fellow of the Hong Kong College of Emergency Medicine (β= -0.314, P=0.028) and being an Advanced Cardiac Life Support instructor (β= -0.217, P=0.032). There was no difference in aggressiveness of resuscitation in terms of years of clinical experience (β=0.015, P=0.921), knowledge of TOR (β=0.057, P=0.509), or attitudes about TOR (β= -0.103, P=0.214). The correlation between knowledge and attitudes was low (Spearman's coefficient=0.02, P=0.795).

CONCLUSION

Clinical practice and behaviour of TOR was not demonstrated to have associations with knowledge or attitude. Status as a Fellow of the Hong Kong College of Emergency Medicine or Advanced Cardiac Life Support instructor were the only two parameters identified that had significant relationships with earlier TOR in medically futile patients with OHCA.

Validation and modification of the Ottawa subarachnoid haemorrhage rule in risk stratification of Asian Chinese patients with acute headache

OBJECTIVE

To validate the Ottawa subarachnoid haemorrhage (SAH) rule in an Asian Chinese cohort and to explore the roles of blood pressure and vomiting in prediction of SAH in patients with nontraumatic acute headache.

METHODS

A retrospective cohort study was conducted in two regional hospitals. All patients aged ≥16 years who presented with non-traumatic acute headache to the study centres from July 2013 to June 2016 were included. A logistic regression model was created for the variables of the Ottawa SAH rule and other potential predictors, including vomiting and systolic blood pressure (SBP) >160 mm Hg. Model discrimination was evaluated using the area under the receiver operating characteristic curve. Net reclassification improvement and integrated discrimination improvement indices were evaluated. The model's diagnostic characteristics, including sensitivities and specificities, were evaluated.

RESULTS

A total of 500 eligible headache cases were included, in 50 of which SAH was confirmed (10%). In addition to the predictors of the Ottawa SAH rule, vomiting and SBP >160 mm Hg were found to be significant independent predictors of SAH. Net reclassification improvement and integrated discrimination improvement indices indicated that including vomiting and SBP >160 mm Hg would improve the model prediction. The Ottawa SAH rule had 94% sensitivity and 32.9% specificity. The modified Ottawa SAH rule that included both vomiting and SBP >160 mm Hg as criteria improved sensitivity to 100%, specificity to 13.1%, positive predictive value to 11.3%, and negative predictive value to 100%.

CONCLUSIONS

The Ottawa SAH rule demonstrated high sensitivity. Addition of vomiting and SBP >160 mm Hg to the Ottawa SAH rule may increase its sensitivity.

A local review of child abuse in Hong Kong: From the perspective of emergency physicians

Background:

Child abuse occurs all over the world, including Hong Kong. The Accident and Emergency Department is one of the places in which cases of child abuse may present to.

Objectives:

As an emergency physician in the hospital, we need to understand the signs and symptoms and the risk factors of child abuse. We also need to perform risk assessment and formulate the plan of management.

Methods:

Databases in Hong Kong were searched to obtain the current situation of child abuse in Hong Kong. Literature about the nature of child abuse was also searched.

Results:

The epidemiology of child abuse in Hong Kong was reviewed. Signs and symptoms, risk factors, and management of child abuse were summarized in this review article. Conclusion: High vigilance is needed for emergency physicians to pick up cases of child abuse. Most cases of child abuse would finally need assessment from a multidisciplinary team.

Clinical prediction rule to predict pneumonia in adult presented with acute febrile respiratory illness

OBJECTIVE

To derive a clinical prediction rule to predict pneumonia in patients with acute febrile respiratory illness to emergency departments.

METHOD

This was a prospective multicentre study. 537 adults were recruited. Those requiring resuscitation or were hypoxaemic on presentation were excluded. Pneumonia was defined as new onset infiltrates on chest X-ray (CXR), or re-attendance within 7 days and diagnosed clinically as having pneumonia. A predictive model, the Acute Febrile Respiratory Illness (AFRI) rule was derived by logistic regression analysis based on clinical parameters. The AFRI rule was internally validated with bootstrap resampling and was compared with the Diehr and Heckerling rule.

RESULTS

In the 363 patients who underwent CXR, 100 had CXR confirmed pneumonia. There were 7 weighted factors within the ARFI rule, which on summation, gave the AFRI score: age ≥ 65 (1 point), peak temperature within 24 h ≥ 40 °C (2 points), fever duration ≥3 days (2 points), sore throat (-2 points), abnormal breath sounds (1 point), history of pneumonia (1 point) and SpO2 ≤ 96% (1 point). With the bootstrap resampling, the AFRI rule was found to be more accurate than the Diehr and Heckerling rule (area under ROC curve 0.816, 0.721 and 0.566 respectively, p < 0.001). At a cut-off of AFRI≥0, the rule was found to have 95% sensitivity, with a negative predictive value of 97.2%. Using the AFRI score, we found CXR could be avoided for patients having a score of <0.

CONCLUSION

AFRI score could assist emergency physicians in identifying pneumonia patients among all adult patients presented to ED for acute febrile respiratory illness.

Feasibility of predictive model by clinical and laboratory parameters for risk stratification of geriatric abdominal pain

Background:

Assessment of geriatric patients presented with abdominal pain had been challenge for emergency physicians with the ageing population. A rapid, reproducible risk stratification model for the assessment of the need for admission for geriatric abdominal pain would be required to identify low-risk patients to be managed as out-patient basis.

Objective:

Assess the feasibility of risk stratification model to predict the need of hospital admission based on readily available bedside parameters in emergency departments.

Methods:

This is a multicenter retrospective cohort study in four emergency departments. Patients aged at least 65 who presented with chief complaint of abdominal pain within the previous 7 days of attendance as the chief complaint were included. Chart review was performed for the included patients. The primary outcome was defined as a composite of mortality, abdominal surgery or endoscopic treatment, and other inpatient treatments for abdominal diseases within 14 days, surrogating the need of hospital admission. Logistic regression was modeled to identify independent predictors. The diagnostic accuracy of the risk model was evaluated with the receiver operating characteristic curve and compared with the clinical gestalt of decision for hospital admission by the attending physician.

Results:

In total, 553 patients were included. Symptoms of upper gastrointestinal bleeding, non-ambulatory presenting status, pain duration, focal abdominal tenderness, hyperglycemia, leukocytosis, and elevated creatinine were independent predictors of the outcome. The area under the receiver operating characteristic curve of the predicted probabilities of the logistic model was 0.741. In keeping for a low-risk criterion to achieve more than 90% sensitivity, the predictive model would only achieve 18.2% specificity which was inferior to clinical gestalt for hospital admission (sensitivity 99.3%, specificity 44.3%).

Conclusion:

Risk stratification model by clinical assessment and laboratory markers alone were inadequate and inferior to clinical gestalt for identification of the group of patients requiring inpatient treatment.

Public access defibrillation in Hong Kong in 2017

The concept of public access defibrillation was proposed more than 20 years ago. Since then, various programmes have been implemented in many major cities although not all have been successful. Fourteen years ago, the question of whether Hong Kong needed public access defibrillation was raised. This article aimed to answer this question based on the best available evidence. Over the years, the clinical effectiveness of public access defibrillation in out-of-hospital cardiac arrest has been proven. Nonetheless various studies have indicated that among others, cost-effectiveness, knowledge and attitudes of the public, and incidence of ventricular fibrillation are important factors that will affect the likelihood of success of such programmes. In Hong Kong, because of the long interval between recognition of arrest and first defibrillation, public access defibrillation is probably needed. To ensure the success of such a programme, careful planning in addition to the installation of more automated external defibrillators are essential.

Role of Sodium Bicarbonate in Resuscitation of out-of-Hospital Cardiac Arrest

Objective

To report the use of sodium bicarbonate (SB) in out-of-hospital cardiac arrest (OHCA) and to explore the role of sodium bicarbonate in resuscitation of OHCA in terms of restoration of spontaneous circulation (ROSC) and survival, and existence of dose-dependent relationship, especially in those with prolonged arrest.

Design

Retrospective cohort study.

Setting

Emergency department of two regional hospitals in a cluster of Hong Kong.

Methods

Adult patients aged at least 18 years old who presented to the study centres with non-traumatic OHCA in the period between March 2013 and December 2013 were included. Cases in which resuscitations were considered medically futile or not actually performed were excluded. Those with do-not-resuscitate (DNR) order or advance directives, those who were death before arrival with postmortem changes, and those who developed ROSC before or within 15 minutes of arrival were excluded from the study. Patients with known poisoning from tricyclic antidepressant or other sodium channel blockers were excluded from analysis if any. The primary outcome of this study was ROSC. Other outcome variables included survival to hospital admission (STA) and survival to hospital discharge (STD).

Results

A total of 489 patients were included during the study period for analysis. We found that patients who received sodium bicarbonate injection (SB group) during CPR had a higher percentage of ROSC than those who did not (no-SB group) (60.8% vs 22.5%; p<0.001). The survival-to-admission rate was higher in the SB group (56.8%) compared with the contrary (21.4%). The difference of survival-to-discharge between the two groups did not reach statistical significance (4.1% in SB group and 2.9% in the no-SB group; p=0.484). The rate of ROSC was found to be dose dependent, being higher in higher dose of SB administration. The ROSC rate increased from no-SB (22.4%) to 57.1% if given 50 ml SB, and further to 64.1% if given ≥100 ml SB.

Conclusions

Our study shows that the use of sodium bicarbonate in the CPR of OHCA is beneficial in ROSC. The effect is dose dependent, with better results in higher dose (>100 ml) of sodium bicarbonate; however, we fail to demonstrate its benefit for prolonged CPR cases (>30 minutes). (Hong Kong j.emerg. med. 2015;22:281-290)

Comparison of Clinical Prediction Rules for Termination of Resuscitation of Out-of-Hospital Cardiac Arrests on Arrival to Emergency Department

Objective

To compare the discriminative capacities of various termination of resuscitation (TOR) rules in the prediction of futile resuscitation in the emergency department (ED).

Design

Prospective cohort study.

Setting

2 public hospitals in a cluster in Hong Kong.

Methods

The data were obtained from a Cardiac Arrest Registry of the EDs of two hospitals, including consecutive adult patients suffering from non-traumatic out-of-hospital cardiac arrest from 1st August 2010 to 30th June 2012. Those with return of spontaneous circulation before ED arrival and cases without resuscitation in the EDs were excluded. The modified basic life support (BLS), modified advanced life support (ALS) and neurologic TOR rules were applied to the cohort. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value were calculated. The outcome measures were survival to hospital admission (STA) and survival to discharge (STD).

Results

Totally 1125 cases were included. The mean age was 72.4. Return of spontaneous circulation and STA occurred in 302 patients and 9 had STD. Regarding the outcome of STD, the modified ALS and neurologic TOR rules had outperformed the modified BLS rule. The specificity and PPV were 100% for both rules in predicting death when the rules suggested TOR. Regarding the outcome of STA, the neurologic TOR rule had the highest specificity [84.4%; 95% confident interval (CI): 79.7-88.2%] and PPV (84.5%; 95% CI: 79.8-88.3%).

Conclusions

The modified ALS and neurologic TOR rules have similar discriminative capacities to predict STD. The neurologic TOR rule has the highest ability to predict STA in the ED. (Hong Kong j.emerg.med. 2013;20:343-351)

Outcome and Prognostic Factors of Patients in Out-Of-Hospital Cardiac Arrests Presenting with Non-Shockable Rhythm in Hong Kong

Objective

To obtain the recent local epidemiological data and evaluate factors associated with outcomes of adult patients in non-traumatic non-shockable out-of-hospital-cardiac-arrest (OHCA) in Hong Kong.

Methods

It was a cross-sectional study lasting for nine months (from July 2009 to March 2010) in two emergency departments (ED) which served a population of 1.1 million. All non-traumatic OHCA patients aged equal or greater than 18 years presented with non-shockable cardiac rhythms to ED without postmortem changes were included. The pre-hospital factors, managements and outcomes were recorded in a standardised data entry form at the time of patient consultation. Logistic regression was used to evaluate the relationship between survival to admission (STA) and various prognostic factors.

Results

A total of 348 patients fulfilled the inclusion criteria. The mean age was 75.9 years old. Overall, there were 61 patients (17.5%) with restoration of spontaneous circulation and 58 patients (16.7%) had STA. The survival to hospital discharge (STD) rate was 0.86% (3 patients). Factors independently associated with better prognosis in terms of STA were initial pulseless electrical activity arrest (PEA) rhythm in ED (OR=4.72, 95% CI 2.30-9.69), witnessed arrest (OR=8.00, 95% CI 3.38-18.96) and non-cardiac cause of arrest (OR=2.17, 95% CI 1.00-4.67).

Conclusion

STA for adults presenting with non-traumatic non-shockable OHCA in our centre is 16.7%. Witnessed non-shockable OHCA patients presenting with initial PEA arrest rhythm and with a presumed non-cardiac in etiology are significantly associated with higher STA rate.

Predictors of Outcome in Out-Of-Hospital Cardiac Arrest Survived to Hospital Admission

Objective

To identify the independent predictors of survival to hospital discharge in the group of patients admitted to hospital with out-of-hospital cardiac arrest.

Design

Prospective cohort study.

Setting

Two public hospitals in a cluster in Hong Kong.

Methods

Data were reported to local Cardiac Arrest Registry using Utstein style template from 1st August 2010 to 31st October 2012. The post cardiac arrest care and outcome, premorbid mobility, activities of daily living (ADL) and medical illnesses were traced from medical records. Independent predictors were calculated using logistic regression model.

Results

A total of 323 patients were recruited in this study. Patients' age (Odds raio [OR]=0.966; 95% confidence interval [CI]=0.937-0.996), total down time (OR=0.897; 95% CI=0.858-0.938), pre-hospital defibrillation (OR=5.649; 95% CI=1.673-19.07), post-cardiac arrest intensive care (OR=3.674; 95% CI=1.001-13.951) were independent predictors of survival to hospital discharge.

Conclusions

Younger age, shorter down time, prehospital defibrillation for shockable rhythm, post-cardiac arrest intensive care are independent predictors of survival to discharge for patients admitted to hospital after out-of-hospital cardiac arrest. Premorbid health conditions, ADL and mobility are not predictors to patient's survival. (Hong Kong j.emerg.med. 2014;21:131-139)

Prevalence and Predictors of Under-Diversion in the Primary Trauma Diversion System in Hong Kong

Introduction

Primary trauma diversion (PTD) enables direct transfer of major trauma patients to trauma centres for definitive care. This study aimed to evaluate the performance of PTD in the New Territories West Cluster (NTWC) of Hospital Authority and to identify the predictors for under-diversion.

Methods

A cross-sectional study based on local trauma registry. All major trauma patients (defined as ISS>15 or requiring trauma team activation) in the catchment area of the local hospital from September 2007 to December 2011 were included. The appropriateness of diversion decision was independently evaluated by an expert team (a trauma nurse coordinator and an emergency medicine practitioner). The sensitivity, specificity, predictive values, agreement, over-diversion and under-diversion rates were calculated. Potential predictors for under-diversion including age, Glasgow Coma Scale, mechanism of injury, injured body part, and the distance from scene to the trauma centre/local hospital were employed for logistic regression analysis.

Results

There were 141 eligible cases identified. The sensitivity and specificity for PTD were 59.5% and 96.5% respectively. The over-diversion rate was 3.5% and the under-diversion rate was 40.5%. The overall accuracy was around 74.5%. Non-motor vehicle accident (OR 13, 95% confidence interval [CI]=3.5-48.0, p<0.01) and isolated head injury (OR 5.35, 95% CI=1.5-19.5, p=0.01) were 2 independent predictors for under-diversion in PTD.

Conclusions

The overall field triage compliance by the paramedics is satisfactory. Under-diversion rate in NTWC is high. Non-motor vehicle accident mechanism and isolated head injury are 2 significant predictors for under-diversion. Reinforcement in training to avoid potential pitfalls would improve the paramedics' trauma triage performance.

Is Poisoning by Oral Therapeutic Drugs more Severe? a Retrospective Study on Unintentional Paediatric Poisoning in a Local Emergency Hospital

Introduction

Paediatric unintentional poisoning is a common presenting problem in the emergency department. Our study aim to determine whether poisoning caused by oral therapeutic drugs was more severe and causing longer hospital stay. We also aim to review the recent local epidemiology of unintentional paediatric poisoning in Hong Kong.

Methods

We conducted a retrospective review on all consecutive cases of patients aged 0-9 who presented to the emergency department during a study period from 1st January 2006 to 31st December 2007 with unintentional poisoning. Demographic data, clinical presentation, poisoning agent involved, intervention performed and the clinical outcome were analysed. The clinical outcomes of poisoning due to oral therapeutic drugs versus other chemicals were compared.

Results

Sixty one poisoning episodes were included. The most common type of agents involved was oral therapeutic drugs (52.5%); followed by cleaning products and detergents (14.8%). Most cases were benign, 63.9% of the cases showed no clinical and biochemical poisoning effect without any treatment. Poisoning due to oral therapeutic drugs were more severe, 12.5% were classified as poisoning with major effect that required active treatment while no cases of severe poisoning were found in poisoning caused by other chemicals. Significantly fewer cases (40.6%) were classified as no or mild effect in the group caused by oral drugs, compared with those caused by other chemicals (86.2%) (p=0.001). The mean length of stay was also significantly longer in the group with oral drugs (1.7 days) compared with 0.9 days in other chemicals (p=0.047).

Conclusions

In our locality, severe unintentional poisonings were usually due to oral therapeutic drugs. For prevention planning, we should focus on the safety placement of oral medications of family members.

Impact of a Sepsis Guideline in Emergency Department on Outcome of Patients with Severe Sepsis

Objective

A dedicated program with guideline to enhance sepsis care was launched in July 2014 in Emergency Department (ED) of two regional hospitals. The study aimed to evaluate the effectiveness of the interventional program for severe sepsis patients, in antibiotic delivery rate and survival outcome.

Methods

It is a before-and-after interventional study with data from July to December 2013 and August 2014 to January 2015. A dedicated program for severe sepsis patients was introduced in July 2014. The outcome measures were blood culture rate, antibiotic administration rate in ED and mortality. Kaplan-Meier analysis and log-rank test was used for comparison of the survival. Multivariate Cox proportional hazards model was constructed to predict time to mortality adjusted for covariates.

Results

64 patients were included, 31 patients were in the pre-intervention group whereas 33 post-intervention. Both blood culture rate (29% vs 72.7%; p<0.001) and antibiotics administration in ED (38.7% vs 72.7%, p=0.0011) were significantly increased. Survival outcome was significantly improved in patients receiving timely antibiotics in ED (log-rank test p=0.016). Antibiotics administered in ED had hazard ratio of 0.178 (95% CI 0.053 to 0.595; p=0.005) in the Cox Proportional hazard regression model with adjustment of covariates. Age (adjusted odds ratio 1.06, 95% CI 1.01 to 1.12, p=0.033) and initial hypotension (adjusted odds ratio 0.97, 95% CI 0.95 to 0.99, p=0.005) were significant predictors of mortality.

Conclusion

A dedicated guideline for severe sepsis management could improve blood culture rate, early antibiotics administration in the emergency department. Patients received early antibiotic had better outcome and survival.

Outcome Predictors of Patients in Out-Of-Hospital Cardiac Arrests with Pre-Hospital Defibrillation in Hong Kong

Objective

To report the epidemiology, outcomes and the predictors of survival in patients with out-of-hospital cardiac arrest (OHCA) with pre-hospital shockable cardiac rhythms in Hong Kong.

Methods

It was a prospective study based on data from the cardiac arrest registry of emergency departments (ED) in two regional hospitals in Hong Kong from 1st August 2010 to 31st January 2012. All non-traumatic patients aged 18 years or above presented with OHCA with shockable pre-hospital cardiac rhythm and received pre-hospital defibrillation were included. The characteristics of patients, pre-hospital data, management and outcomes were recorded in a standardised form compatible with Utstein template at the time of patient consultation. Binominal logistic regression was applied to evaluate the relationship between survival to admission (STA) and patients' variables.

Results

A total of 135 patients fulfilled the inclusion criteria. The mean age was 67.0 years old. The STA rate was 34.8% and the survival to discharge (STD) rate was 6.7%. Factors independently associated with better prognosis in terms of STA were presence of bystander cardiopulmonary resuscitation (CPR) (OR 5.76, 95% CI=1.08-30.5), restoration of spontaneous circulation (ROSC) before arrival to ED (OR 43.94, 95% CI= 4.19-460.43) and short time from calling emergency medical services (EMS) to first defibrillation (OR 0.82, 95% CI=0.70-0.96).

Conclusion

STA rate for adults presenting with shockable OHCA in our study was 34.8%. Patients with shockable OHCA with bystander CPR, short call-to-shock time and achieved ROSC before arrival to ED are significantly associated with higher STA rate.

A Retrospective Study on Imperforate Hymen and Haematometrocolpos in a Regional Hospital

Objective

To find out the characteristics and presentations of imperforate hymen in the local population in Hong Kong and to assess if diagnosis of imperforate hymen made in the emergency department can reduce time to operation and length of hospital stay.

Design

Retrospective study.

Setting

A regional public hospital in Hong Kong.

Patients

We retrospectively collected data of all patients with the diagnosis of imperforate hymen (ICD 9 coding 752.42) from the period of January 1999 to June 2009. Demographics of the patients, their presenting symptoms and signs, the diagnostic process, investigation findings and time of operation were recorded and analysed.

Results

Fifteen cases of imperforate hymen were reported during that period. All were adolescent girls aged from 10 to 15 years. A total of 13 patients presented to the accident and emergency department (AED). Seven patients had the diagnosis made in the AED and 2 patients received bedside pelvic ultrasound. More than half of them (8 patients) presented with acute retention of urine. Other presentations included lower abdominal pain, constipation, lower abdominal mass, and protruding introital mass. Most cases diagnosed in the AED (5 out of 7) were admitted to the gynaecology ward while the others were admitted to the surgical or urology wards. Five out of the 7 cases diagnosed in the AED received operation within 24 hours; whereas only 1 out of the 6 cases with the diagnosis made after admission had operation within 24 hours. The difference was statistically significant (p=0.035, Fisher's exact test). The mean length of stay of the group diagnosed in the AED was 1.9 days while the mean length of stay for the group diagnosed after admission was 4.2 days.

Conclusion

Early diagnosis of imperforate hymen and haematometrocolpos in the AED for adolescent girls with primary amenorrhoea could have positive impact on proper admission to the gynaecology ward, prompt operation and shorter length of stay in hospital.

Comparison of the Accuracy of Local and International Prediction Models for Massive Transfusion in Major Trauma Patients

Objective

To validate a local prediction model (Rainer's score) for massive transfusion in trauma patients and compare its accuracy with international prediction models (TASH score and ABC score) using local trauma data.

Methods

Patients were recruited retrospectively from the trauma registry of a regional trauma centre during the period from January 2005 to December 2010. Patients with Injury Severity Score (ISS) ≥9 and aged ≥12 years were included. Burn and drowning patients, patients with known severe anemia (haemoglobin <7 g/dL) and renal failure were excluded. Massive transfusion was defined as delivery of ≥10 units of packed red blood cells within 24 hours. The sensitivity specificity positive and negative predictive values, positive and negative likelihood ratio and accuracy were calculated for different prediction models. The overall discriminatory capacities of models were compared using the area under the receiver operating characteristic (ROC) curve.

Results

A total of 1030 patents met the inclusion criteria and 27 patients required ≥10 units packed cells within 24 hours. The accuracy was the best in the TASH score (97.3%) when compared to the Rainer's score (96.5%) and ABC score (95.1%). Sensitivity was better in Rainer's score (33.3%) and ABC score (33.3%) than in the TASH score (25.9%). The area under ROC curve for TASH score, Rainer's score and ABC score were 0.911, 0.886 and 0.809 respectively.

Conclusions

We validate the prediction model (Rainer's score) by a set of local, non-university institution data. Rainer's score has high accuracy (97%) in predicting the need for massive transfusion and is comparable to TASH score and ABC score.

How Do Adult and Paediatric Intussusceptions Differ? a 10-Year Retrospective Study

Introduction

Intussusception in adult is considered to be an uncommon surgical condition. Our study aims to gather the epidemiology data of intussusception in local population and to compare the clinical characteristics, investigation and management between adult and paediatric intussusceptions.

Methods

This is a retrospective study of patients who were diagnosed intussusception from January 2001 to June 2011 in the study centre. Demographic data, clinical presentation, investigation and management were compared between adult and paediatric patients.

Results

There were 79 patients included in the study period. Twenty-two of them (27.8%) were adults (aged at least 18 years) while 57 (72.2%) of them were paediatrics patients (age <18 years). Forty-three (54.4%) of them were male and 36 (45.6%) of them were female. Mean age of intussusception in adult and paediatric groups were 56.1 years and 23.9 months respectively. The median duration of onset of the presentation of adult patient was 3.5 days which is longer than that of paediatrics group (1 day) (p<0.001), per-rectal bleeding occurred in 18.2% (4/22) of adult patients while 47.4% (27/57) of paediatric intussusception had per-rectal bleeding (p=0.017). There was also significantly more vomiting (78.9%, 45/57) in paediatric intussusception compared with 31.8% in adults (p<0.001). A total of 72.7% (16/22) of adult intussusception were diagnosed by CT scan while 94.7% (54/57) of paediatrics was diagnosed by ultrasound by radiology department. 77.3% (17/22) of the adult intussusceptions had a neoplastic leading point. All the adult intussusception required surgical management while only 21.1% (12/57) of the paediatrics group required surgical reduction with or without bowel resection. The median length of stay (LOS) of adult group was 9 days which is longer than that of the paediatrics group (4 days) (p<0.001).

Conclusions

Intussusception in adult patients lacks classical presentation of per-rectal bleeding and vomiting and the onset is commonly sub-acute when compared with paediatrics cases. Most of the adult intussusceptions have pathological leading points that warrant surgical management.

Shorter Symptoms Onset to Emergency Department Presentation Time Predicts Failure of Needle Aspiration in Primary Spontaneous Pneumothorax

Objective

To evaluate factors in predicting the failure of needle aspiration in primary spontaneous pneumothorax, in particular the interval between symptom onset and emergency department presentation.

Methods

This is a retrospective cohort study carried out from January 2010 to October 2012 in two public hospitals in Hong Kong. All consecutive adult patients aged 18 or more who attended the emergency departments in the study period with the diagnosis of primary spontaneous pneumothorax, where needle aspiration was performed as the primary treatment were recruited. Age, smoking status, previous pneumothorax, symptom interval, size of pneumothorax and aspirated gas volume were included in the analysis. The outcome was successful or failed needle aspiration. Logistic regression was used to identify independent predictors of failed needle aspiration.

Results

A total of 196 patients were included. Overall, 105 patients (53.6%) were treated successfully with no recurrence upon discharge. Among those failure patient, 30 patients (15.3%) failed as evidence by the chest X-ray taken immediately after the procedure while 61 patients (31.1%) failed upon subsequent chest X-ray. Multivariate logistic regression showed factors independently associated with failure of needle aspiration included size of pneumothorax (apex to cupola distance) (odds ratio [OR]=1.022, 95% confidence interval [CI]=1.009-1.039, p=0.001) and symptoms onset to emergency department presentation time (OR=0.987, 95% CI=0.976-0.999, p=0.028).

Conclusions

Large pneumothorax and shorter symptoms onset to emergency department presentation time were associated with higher failure rate of needle aspiration for primary spontaneous pneumothorax. (Hong Kong j.emerg. med. 2014;21:16-22)

Predictors of Outcomes of Pedestrian Casualties in Motor Vehicle Injuries Managed in Emergency Department

Introduction

Pedestrian injury is a major health care concern. This study aims to identify predictors of mortality and severe injury in pedestrian casualties in motor vehicle injury managed in emergency department in the local setting.

Methods

This is a retrospective cohort study of a linked hospital and police trauma registry (2004 to 2008). All pedestrian casualties treated in the emergency department (ED) of two regional hospitals in Hong Kong were included. Logistic regression was performed for potential predictor variables (age >65 years; injury patterns including head or face, thorax/abdomen/pelvis, neck/spine, extremities; existence of multiple injuries; heavy vehicles involved; body impact with the vehicles; injury at night and wet road surface) against mortality and severe injury, defined as Injury Severity Scale (ISS) >15.

Results

A total of 1542 pedestrian casualties were analysed. Age >65 was found to be an independent predictor of mortality in pedestrian casualties, with odds ratio (OR) of 5.15 (95% CI=2.21-12.00; p<0.001). Other independent predictors of mortality included injury to head/face (OR=4.52, 95% CI=1.75-11.7, p=0.002), injury to thorax/abdomen/pelvis (OR=13.36, 95% CI=5.64-31.6; p<0.001), multiple injuries (OR=4.0, 95% CI=1.06-15.1; p=0.041) and wet road surface (OR=3.27, 95% CI=1.31-8.17; p=0.011). These factors were also independent predictors for severe injury. Involvement of heavy vehicles and body impact with vehicles were not independent predictors of mortality. However, these were significant predictors of severe injury (OR=1.86 and 2.85 respectively).

Conclusion

Old age, injury to head/face or thorax/abdomen/pelvis, multiple injuries and wet road surface in accident scene are independent predictors for mortality in pedestrian casualties. In addition, involvement of heavy vehicles and body impact with vehicles are predictors of severe injury.

A Diabetic Patient with Abdominal Pain and Lactescent Serum

We present the case of a poorly controlled diabetic patient suffering from acute onset of abdominal pain and vomiting. A blood sample taken at the bedside revealed lactescent serum and provided an important clue to the patient's status of having severe hypertriglyceridaemia. The clinical diagnosis of hypertriglyceridaemia-induced acute pancreatitis was correctly made in the accident and emergency department. Clinical photos of the lactescent serum are shown. The incidence, risk factors and management of this particular type of acute pancreatitis are discussed.

Nuchal Pain Predicts Subarachnoid Haemorrhage in Severe Headache Patients

Objective

To find out predicting symptom(s) of non-traumatic subarachnoid haemorrhage in conscious patients without neurological deficit presenting with the primary complaint of severe headache.

Design

Case control study.

Setting

Regional public hospital, Hong Kong.

Subjects

Non-traumatic subarachnoid haemorrhage (ICD 9 coding 430) patients, who were conscious and with normal neurological examination, presenting to the accident and emergency department with severe headache between April 2005 to March 2007 were searched from the hospital database. The control group was recruited prospectively from the accident and emergency department during the period from November 2007 to April 2008.

Results

A total of 33 cases were compared to 57 controls to study on five selected symptoms and the likelihood to predict risk of subarachnoid haemorrhage. All five symptoms were significant by univariate analysis at significance level of 25%: nuchal pain (p<0.001), transient syncope (p=0.137), dizziness (p=0.026), vomiting (0=0.016) and presence of precipitating events (coitus, defecation or quarrel) (p=0.132). Only nuchal pain was statistically significant in the multivariate logistic regression analysis (OR=11.44; 95% CI=2.14 to 61.19) with age and gender controlled.

Conclusions

The presence of nuchal pain as a presenting symptom significantly increases the likelihood of non-traumatic subarachnoid haemorrhage by ten times among severe headache patients with normal neurological examination. Other symptoms like transient syncope, dizziness and vomiting are non-specific and do not predict a higher chance of occurrence of subarachnoid haemorrhage.

Prognosticating Clinical Prediction Scores Without Clinical Gestalt for Patients With Chest Pain in the Emergency Department

BACKGROUND

Assessment of patients with chest pain is a regular challenge in the emergency department (ED). Recent guidelines recommended quantitative assessment of ischemic risk by means of risk scores.

OBJECTIVE

Our aim was to assess the performance of Thrombosis in Myocardial Infarction (TIMI); Global Registry of Acute Coronary Events (GRACE); history, electrocardiogram, age, risk factors, and troponin (HEART) scores; and the North America Chest Pain Rule (NACPR) without components of clinical gestalt in predicting 30-day major adverse cardiac events (MACE).

METHODS

We performed a prospective cohort study in adult patients who attended the ED with undifferentiated chest pain. Clinical prediction rules were applied and calculated. The clinical prediction rules were modified from the original ones, excluding components requiring judgment by clinical gestalt. The primary outcome was MACE. Performance of the tests were evaluated by receive operating characteristic curves and the area under curves (AUC).

RESULTS

There were 1081 patients included in the study. Thirty-day MACE occurred in 164 (15.2%) patients. The AUC of the GRACE score was 0.756, which was inferior to the TIMI score (AUC 0.809) and the HEART score (AUC 0.845). A TIMI score ≥ 1 had a sensitivity of 97% and a specificity of 45.7%. A GRACE score ≥ 50 had a sensitivity of 99.4% and a specificity of 7.5%. A HEART score ≥ 1 had a sensitivity of 98.8% and a specificity of 11.7%. The NACPR had a sensitivity of 93.3% and a specificity of 51.5%.

CONCLUSIONS

Without clinical gestalt, the modified HEART score had the best discriminative capacity in predicting 30-day MACE.

Prescription practice of antihistamines for acute upper respiratory tract infections in pediatric patients in a local emergency department in Hong Kong

BACKGROUND

Currently there is very limited data in the literature assessing the prevalence of antihistamine prescription, and there is no local prevalence data about the prescription of antihistamine agents among primary practitioner and emergency physicians. The objectives are 1) to report the prevalence of antihistamine prescription for children less than 6 years old with acute upper respiratory infection and 2) to explore the associated factors for the prescription practice.

METHODS

This is a cross-sectional study. All consecutive cases of paediatric patients aged 6 or below who presented to the emergency department during a study period of one week from April 1 to July 4, 2009 with diagnosis of acute upper respiratory infection were included. Totally 162 patients were included.

RESULTS

Among the 162 cases, 141 (87%) patients were prescribed one antihistamine of any group. Sixty (37%) patients were prescribed two or more antihistamines. In multivariate logistic regression model, age was found to be significantly (P<0.001) associated with multiple antihistamine prescription (OR=1.042, 95%CI=1.02 to 1.06). Years of graduation of attending physician for more than 5 years was also a strong predictor of multiple antihistamine prescription (OR=4.654, 95%CI=2.20 to 9.84, P<0.001).

CONCLUSION

In the local emergency department, patients' age and the years of graduation from medical school of the attending physician were predictors of multiple antihistamine prescription for acute upper respiratory infections for children aged less than 6.

Abrupt rise of end tidal carbon dioxide level was a specific but non-sensitive marker of return of spontaneous circulation in patient with out-of-hospital cardiac arrest

OBJECTIVE

To evaluate the diagnostic accuracy of an abrupt and sustained increase in end-tidal carbon dioxide (ETCO2) to indicate return of spontaneous circulation (ROSC) during resuscitation of patient with out-of-hospital cardiac arrest.

DESIGN

Cross-sectional study.

SETTING

Emergency department of two regional hospitals.

METHODS

Patients with age ≥18 years old, suffered non-traumatic out-of-hospital cardiac arrest with active resuscitation and endotracheal intubation performed in emergency department, were included. ETCO2 value was charted throughout resuscitation. Time of ROSC was remarked. ETCO2 levels before and after ROSC were compared. Diagnostic accuracy of ETCO2 rise ≥10mmHg, ETCO2 rise ≥20mmHg, and ETCO2 rise to the level ≥40mmHg were evaluated for indicating ROSC.

RESULTS

ETCO2 level immediately after ROSC was higher as compared to the value before return of circulation (median ETCO2 was 32mmHg and 41mmHg respectively, p=0.033). With ETCO2 rise ≥10mmHg, the sensitivity was low (33%, 95% CI 22-47%), while specificity was 97% (95% CI 91-99%). Positive and negative predictive values were 83% (95% CI 62-95%) and 74% (95% CI 66-81%) respectively. The diagnostic accuracy was higher in cardiac arrest with presumed non-cardiac etiology (sensitivity 45%, specificity 100%) as compared to those with cardiac etiology (sensitivity 18%, specificity 97%).

CONCLUSIONS

The feature of an abrupt rise of ETCO2 was a specific but non-sensitive marker of ROSC in patient with out-of-hospital cardiac arrest.

Presenting hydrothorax predicts failure of needle aspiration in primary spontaneous pneumothorax

OBJECTIVE

The objective was to evaluate if existence of hydrothorax in initial chest radiograph predicts treatment outcome in patients with primary spontaneous pneumothorax who received needle thoracostomy.

METHODS

This is a retrospective cohort study carried out from January 2011 to August 2014 in 1 public hospital in Hong Kong. All consecutive adult patients aged 18years or above who attended the emergency department with the diagnosis of primary spontaneous pneumothorax with needle aspiration performed as primary treatment were included. Age, smoking status, size of pneumothorax, previous history of pneumothorax, aspirated gas volume and presence of hydropneumothorax in initial radiograph were included in the analysis. The outcome was success or failure of the needle aspiration. Logistic regression was used to identify the predicting factors of failure of needle aspiration.

RESULT

There were a total of 127 patients included. Seventy-three patients (57.5%) were successfully treated with no recurrence upon discharge. Among 54 failure cases, 13 patients (10.2%) failed immediately after procedure as evident by chest radiograph and required second treatment. Forty-one patients (32.3%) failed upon subsequent chest radiographs. Multivariate logistic regression showed factors independently associated with the failure of needle aspiration, which included hydropneumothorax in the initial radiograph (odds ratio [OR]=4.47 [1.56i12.83], P=.005), previous history of pneumothorax (OR=3.92 [1.57-9.79], P=.003), and large size of pneumothorax defined as apex-to-cupola distance ≥5cm (OR=2.75 [1.21-6.26], P=.016).

CONCLUSIONS

Hydropneumothorax, previous history of pneumothorax, and large size were independent predictors of failure of needle aspiration in treatment of primary spontaneous pneumothorax.

Prediction of en-route complications during interfacility transport by outcome predictive scores in ED

OBJECTIVE

The objective was to determine the accuracy of the outcome predictive scores (Modified Early Warning Score [MEWS]; Hypotension, Low Oxygen Saturation, Low Temperature, Abnormal ECG, Loss of Independence [HOTEL] score; and Simple Clinical Score [SCS]) in predicting en-route complications during interfacility transport (IFT) in emergency department.

DESIGN

This was a retrospective cohort study.

METHODS

All IFT cases by ambulances with either nurse-led or physician-led escort, occurring between 1 January 2011 and 31 December 2012, were included. Obstetric and pediatric cases (age < 18 years) were excluded. The condition of patients was quantified by using the predictive scores (MEWS, HOTEL, and SCS) at triage station and on ambulance departure. The accuracy of predictive scores was compared by the receiver operating characteristic (ROC) curves.

RESULTS

A total of 659 cases were included. Seventeen cases had en-route complications (2.6%). The complication rate in physician-escorted transport (2.2%) was similar to that in nurse-escorted transport (2.6%). None of the 57 intubated cases had en-route complications. The area under the ROC curve for MEWS was 0.662 (triage) and 0.479 (departure). The accuracy of MEWS at triage was better than that at departure (P = .049). The area under the ROC curve for HOTEL was 0.613 (triage) and 0.597 (departure), and that for SCS was 0.6 (triage) and 0.568 (departure). In general, the predictive scores at triage were better than those on departure.

CONCLUSION

None of the scores had good accuracy in prediction of en-route complications during IFT. MEWS at triage was among the best one already but was not ideal.

Utilization of the Accident & Emergency Departments by Chinese elderly in Hong Kong

BACKGROUND

The epidemiological data on elderly patients attending Accident and Emergency Departments (AEDs) in Hong Kong is lacking. The study aimed to examine the epidemiology of geriatric patient visits to AEDs in Hong Kong, including demographic data and predictors of life-saving interventions (LSI) and admission.

METHODS

A retrospective cross-sectional study of geriatric patients older than 64 years old attending three AEDs during the year 2012, with a sample of 1 200 patient visits recruited. The data were retrieved from the medical records of the respective hospitals. Descriptive characteristics of the visits were provided. Multivariate logistic regression was performed to evaluate the predictors of LSI and hospital admission.

RESULTS

The mean age of the patients was 79.1 years. Totally 49.7% of the patients were male. "Diseases of the respiratory system" was the commonest diagnosis in AEDs as well as that required admission. The admission rate was 56.8%. Logistic regression demonstrated that dependent activity of daily living (ADL), arrival by ambulance, and the higher number of co-morbidities were predictors of LSI, while advanced age, dependent ADL, institutionalized patients, arrival by ambulance, and higher number of co-morbidities were predictors of hospital admission.

CONCLUSIONS

Ageing population is creating an imminent burden on the emergency service in Hong Kong. Previously unavailable epidemiological information about geriatric attendance to AEDs was described. This forms the basis for development of future studies concerning the medical services on this specific group of patients.

Role of copeptin in dual-cardiac marker strategy for patients with chest pain presented to ED

OBJECTIVE

The objective of the study is to evaluate the role of copeptin in the diagnosis of acute coronary syndrome (ACS) and its role in dual-cardiac marker diagnostic strategy with troponin.

DESIGN

A prospective cohort study was carried out from May 2012 to October 2012.

SETTING

The study was conducted at the emergency department (ED) of a public hospital in a cluster of Hong Kong.

METHODS

Patients aged at least 18 years presented with chest pain to ED who have intermediate or high likelihood of ACS were included. All patients had blood taken in the ED for copeptin and troponin I. The adjudicated diagnoses of ACS were made by 2 independent physicians based on the universal definition. Diagnostic characteristics were calculated. Receiver operating characteristic curves were created. Areas under the curves were compared for copeptin, troponin I, and dual-marker strategy with copeptin and troponin I.

RESULTS

A total of 637 patients were recruited. Seventy-eight had been diagnosed to be ACS. The negative predictive value of copeptin for ACS was 0.881 (0.849-0.907) compared with troponin I, 0.937 (0.913-0.956). The areas under the receiver operating characteristic curves of copeptin, troponin I, and dual-marker strategy were 0.68, 0.859, and 0.880, respectively.

CONCLUSIONS

Addition of copeptin to troponin does not have significant improvement of the diagnostic accuracy of ACS in patients presented with chest pain.

Investigation of availability and accessibility of community automated external defibrillators in a territory in Hong Kong

OBJECTIVE

To evaluate the availability and accessibility of community automated external defibrillators in a territory in Hong Kong.

DESIGN

Cross-sectional study.

SETTING

Two public hospitals in New Territories West Cluster in Hong Kong.

PARTICIPANTS

Information about the locations of community automated external defibrillators was obtained from automated external defibrillator suppliers and through community search. Data on locations of out-of-hospital cardiac arrests from August 2010 to September 2013 were obtained from the local cardiac arrest registry of the emergency departments of two hospitals. Sites of both automated external defibrillators and out-of-hospital cardiac arrests were geographically coded and mapped. The number of out-of-hospital cardiac arrests within 100 m of automated external defibrillators per year and the proportion of out-of-hospital cardiac arrests with accessible automated external defibrillators (100 m) were calculated. The number of community automated external defibrillators per 10,000 population and public access defibrillation rate were also calculated and compared with those in other countries.

RESULTS

There were a total of 207 community automated external defibrillators in the territory. The number of automated external defibrillators per 10,000 population was 1.942. All facilities with automated external defibrillators in this territory had more than 0.2 out-of-hospital cardiac arrests per automated external defibrillator per year within 100 m. Among all out-of-hospital cardiac arrests, 25.2% could have an automated external defibrillator reachable within 100 m. The public access defibrillation rate was 0.168%.

CONCLUSIONS

The number and accessibility of community automated external defibrillators in this territory are comparable to those in other developed countries. The placement site of community automated external defibrillators is cost-effective. However, the public access defibrillation rate is low.

Comparison of different intubation techniques performed inside a moving ambulance: a manikin study

OBJECTIVE. Airway management and endotracheal intubation may be required urgently when a patient deteriorates in an ambulance or aircraft during interhospital transfer or in a prehospital setting. The objectives of this study were: (1) to compare the effectiveness of conventional intubation by Macintosh laryngoscope in a moving ambulance versus that in a static ambulance; and (2) to compare the effectiveness of inverse intubation and GlideScope laryngoscopy with conventional intubation inside a moving ambulance. DESIGN. Comparative experimental study. SETTING. The experiment was conducted in an ambulance provided by the Auxiliary Medical Service in Hong Kong. PARTICIPANTS. A group of 22 doctors performed endotracheal intubation on manikins with Macintosh laryngoscope in a static and moving ambulance. In addition, they performed conventional Macintosh intubation, inverse intubation with Macintosh laryngoscope, and GlideScope intubation in a moving ambulance in both normal and simulated difficult airways. MAIN OUTCOME MEASURES. The primary outcome was the rate of successful intubation. The secondary outcomes were time taken for intubation, subjective glottis visualisation grading, and eventful intubation (oesophageal intubation, intubation time >60 seconds, and incisor breakage) with different techniques or devices. RESULTS. In normal airways, conventional Macintosh intubation in a static ambulance (95.5%), conventional intubation in a moving ambulance (95.5%), as well as GlideScope intubation in a moving ambulance (95.5%) were associated with high success rates; the success rate of inverse intubation was comparatively low (54.5%; P=0.004). In difficult airways, conventional Macintosh intubation in a static ambulance (86.4%), conventional intubation in a moving ambulance (90.9%), and GlideScope intubation in a moving ambulance (100%) were associated with high success rates; the success rate of inverse intubation was comparatively lower (40.9%; P=0.034). CONCLUSIONS. En-route intubation in an ambulance by conventional Macintosh laryngoscopy is superior to inverse intubation unless the cephalad access is impossible. GlideScope laryngoscopy appears to be associated with lower rates of eventful intubation in difficult airways and has better laryngoscopic view versus inverse intubation.

A Case of Tolterodine Poisoning

We present a case of acute tolterodine overdose with anticholinergic toxidrome including drowsiness, confusion and pyrexia. Tolterodine was commonly used in recent years for the treatment of overactive bladder syndrome. Experience with acute tolterodine poisoning was limited. The pharmacology, clinical use and side effects of tolterodine were reviewed. The clinical manifestations, toxicology and management of tolterodine poisoning are discussed.