Descriptive analysis of poisoning cases involving attention deficit hyperactivity disorder medications in Hong Kong

INTRODUCTION

The number of poisoning cases involving attention deficit hyperactivity disorder (ADHD) medications has reportedly risen with their increased use. However, there is limited relevant evidence from Asia. We analysed the characteristics of poisoning events involving these medications in Hong Kong.

METHODS

We retrieved data regarding ADHD medication-related poisoning cases from the Hong Kong Poison Information Centre and conducted a descriptive analysis of the demographic information and poisoning information including sources of cases, exposure reason, exposure location, and outcome. The HKPIC data were linked with the Hospital Authority Clinical Data Analysis and Reporting System (CDARS) via de-identified Accident and Emergency numbers of public hospitals to investigate clinical characteristics. We also retrieved ADHD medication prescription records from the CDARS, then compared trends between poisoning cases and ADHD medication use.

RESULTS

We identified 72 poisoning cases involving ADHD medications between 2009 and 2019, of which approximately 70% occurred in the affected individual's residence; most were intentional poisoning events (65.3%). No statistically significant association was observed between ADHD medication prescription trends and poisoning events involving ADHD medications. Of the 66 cases (91.7%) successfully linked to CDARS, 40 (60.6%) occurred in individuals with ADHD (median age: 14 years); 26 (39.4%) occurred in individuals who lacked ADHD (median age: 33 years) but displayed higher rates of other mental disorders including depression and anxiety.

CONCLUSION

No significant correlation was evident between ADHD medication prescriptions and poisoning events involving ADHD medications. However, medication management and caregiver education must be emphasised to prevent potential poisoning events.

Vaccine effectiveness of BNT162b2 and CoronaVac against SARS-CoV-2 omicron infection and related hospital admission among people with substance use disorder in Hong Kong: a matched case-control study

BACKGROUND

People with substance use disorder have a high risk of SARS-CoV-2 infection and subsequent poor outcomes. Few studies have evaluated COVID-19 vaccine effectiveness among people with substance use disorder. We aimed to estimate the vaccine effectiveness of BNT162b2 (Fosun-BioNTech) and CoronaVac (Sinovac) against SARS-CoV-2 omicron (B.1.1.529) infection and related hospital admission in this population.

METHODS

We did a matched case-control study using electronic health databases in Hong Kong. Individuals diagnosed with substance use disorder between Jan 1, 2016, and Jan 1, 2022, were identified. People aged 18 years and older with SARS-CoV-2 infection from Jan 1 to May 31, 2022, and people with COVID-19-related hospital admission from Feb 16 to May 31, 2022, were included as cases and were matched by age, sex, and previous clinical history with controls from all individuals diagnosed with substance use disorder who attended the Hospital Authority health services: up to three controls for SARS-CoV-2 infection and up to ten controls for hospital admission. Conditional logistical regression was used to evaluate the association between vaccination status (ie, one, two, or three doses of BNT162b2 or CoronaVac) and the risk of SARS-CoV-2 infection and COVID-19-related hospital admission, adjusted for baseline comorbidities and medication use.

FINDINGS

Among 57 674 individuals with substance use disorder, 9523 people with SARS-CoV-2 infections (mean age 61·00 years, SD 14·90; 8075 [84·8%] males and 1448 [15·2%] females) were identified and matched to 28 217 controls (mean age 60·99 years, 14·67; 24 006 [85·1%] males and 4211 [14·9%] females), and 843 people with COVID-19-related hospital admissions (mean age 70·48 years, SD 14·68; 754 [89·4%] males and 89 [10·6%] females) were identified and matched to 7459 controls (mean age 70·24 years, 13·87; 6837 [91·7%] males and 622 [8·3%] females). Data on ethnicity were not available. We observed significant vaccine effectiveness against SARS-CoV-2 infection for two-dose BNT162b2 vaccination (20·7%, 95% CI 14·0-27·0, p<0·0001) and three-dose vaccination (all BNT162b2 41·5%, 34·4-47·8, p<0·0001; all CoronaVac 13·6%, 5·4-21·0, p=0·0015; BNT162b2 booster after two-dose CoronaVac 31·3%, 19·8-41·1, p<0·0001), but not for one dose of either vaccine or two doses of CoronaVac. Significant vaccine effectiveness against COVID-19-related hospital admission was detected after one dose of BNT162b2 vaccination (35·7%, 3·8-57·1, p=0·032), two-dose vaccination (both BNT162b2 73·3%, 64·3 to 80·0, p<0·0001; both CoronaVac 59·9%, 50·2-67·7, p<0·0001), and three-dose vaccination (all BNT162b2 86·3%, 75·6-92·3, p<0·0001; all CoronaVac 73·5% 61·0-81·9, p<0·0001; BNT162b2 booster after two-dose CoronaVac 83·7%, 64·6-92·5, p<0·0001), but not after one dose of CoronaVac.

INTERPRETATION

For both BNT162b2 and CoronaVac, two-dose or three-dose vaccination was protective against COVID-19-related hospital admission and the booster dose provided protection against SARS-CoV-2 infection among people with substance use disorder. Our findings confirm the importance of booster doses in this population during the period dominated by the omicron variant.

FUNDING

Health Bureau, the Government of the Hong Kong Special Administrative Region.

Derivation and internal validation of a clinical prediction score to predict major effect or death in acute metamfetamine toxicity

OBJECTIVE

Metamfetamine use can cause serious complications or death. We aimed to derive and internally validate a clinical prediction score to predict major effect or death in acute metamfetamine toxicity.

METHODS

We performed secondary analysis of 1,225 consecutive cases reported from all local public emergency departments to the Hong Kong Poison Information Centre between 1 January 2010 and 31 December 2019. We split the entire dataset chronologically into derivation (first 70% of cases) and validation (the remaining 30% of cases) cohorts. Univariate analysis was conducted, followed by multivariable logistic regression in the derivation cohort to identify independent predictors of major effect or death. We developed a clinical prediction score based on the regression coefficients of the independent predictors in the regression model and compared its discriminatory performance with five existing early warning scores in the validation cohort.

RESULTS

The MASCOT (Male, Age, Shock, Consciousness, Oxygen, Tachycardia) score was derived based on the six independent predictors: male gender (1 point), age (≥35 years, 1 point), shock (mean arterial pressure <65 mmHg, 3 points), consciousness (Glasgow Coma Scale <13, 2 points), need for supplemental oxygen (1 point), and tachycardia (pulse rate >120 beats/min, 1 point). The score ranges from 0-9, with a higher score indicating higher risk. The area under the receiver operating characteristic curve of the MASCOT score was 0.87 (95% CI 0.81-0.93) in the derivation cohort and 0.91 (95% CI 0.81-1.00) in the validation cohort, with a discriminatory performance comparable with existing scores.

CONCLUSIONS

The MASCOT score enables quick risk stratification in acute metamfetamine toxicity. Further external validation is warranted before wider adoption.

Hong Kong poison information centre: Annual report 2020

Background:

The Hong Kong Poison Information Centre has provided consultation service to healthcare professionals and collected epidemiological data on poisoning in Hong Kong since 2005.

Objective:

To analyse and report the poisoning data of Hong Kong Poison Information Centre in 2020 during the COVID-19 pandemic.

Methods:

A retrospective review of all poisoning cases recorded in the Poison Information and Clinical Management System of Hong Kong Poison Information Centre in 2020.

Results:

A total of 3633 poisoning cases were analysed. Compared to 2019 (pre-COVID era), there was a reduction of ~10% of total poisoning cases recorded (383 cases), with a majority (> 90%) of reduction from poisoning cases with no clinical effect (353 cases). A greater proportion of reduction was observed among the children (0–12 years), patients with general unintentional poisoning, poisoning due to therapeutic error and food poisoning. An increased number of cases was noted from abusive use, adverse herb/proprietary Chinese medicine reaction and poisoning related to household bleaches. Teenage (13–19 years) poisoning seemed to be unaffected by the COVID-19 pandemic and the previously observed increasing trend continued (up to 11.8% of total poisoning cases this year). Despite a total reduction in poisoning cases recorded, the number of deaths increased by 37% from 35 in 2019 to 48 in 2020 (mortality rate 1.5%). A total of seven interesting cases were discussed.

Conclusion:

This 15th annual report provides updated epidemiological information on poisoning patterns in Hong Kong during the COVID-19 pandemic. It also highlighted important changes and possible effects of the COVID-19 pandemic on poisoning in Hong Kong in comparison with our previous reports.

Hong Kong Poison Information Centre: Annual report 2019

Background:

The Hong Kong Poison Information Centre (HKPIC) provides consultation service to health care professionals and collect epidemiological data on poisoning in Hong Kong since 2005.

Objective:

To report and analyse the data of Hong Kong Poison Information Centre on poisoning in 2019.

Methods:

This was a retrospective review of all poisoning cases recorded in the Poison Information and Clinical Management System of Hong Kong Poison Information Centre in 2019.

Results:

A total of 4016 poisoned cases were analysed, which involved 1698 men (42.3%), 2312 women (57.6%) and 6 sex-unspecified patients (0.1%). Majority of cases (77.3%) were between 13 and 69 years of age, and 10.5% were teenagers 13–19 years of age. Self-harm/suicidal attempt (42.1%), unintentional exposure (18.1%) and abusive substance use (11.1%) were common reasons of poisoning. Excluding ethanol, which was the common co-ingestant, the five most common types of poison were benzodiazepines, paracetamol, household products, zopiclone and Chinese herbal medicine. While most patients were managed with supportive treatment, 16.5% and 16.8% of the consultation cases were treated with decontamination and antidotes, respectively. Majority of cases recovered uneventfully, but 1.0% died and 4.7% had a major outcome. A total of six interesting cases and two outbreaks were discussed in this report.

Conclusion:

This 14th annual report provided updated epidemiological information on the pattern of poisoning in Hong Kong and highlighted a number of important changes compared with our previous reports.

A 10-year retrospective review of stonefish sting injury in Hong Kong

Background:

Stonefish sting injury is one of the common marine stings in Hong Kong. It is commonly sustained during maritime activities, and it could be regarded as occupational hazard for chefs or domestic hazard for family. Its envenomation could lead to significant local symptoms (pain or swelling) and serious complications, including infection and compartment syndrome.

Objectives:

This study is to review its clinical presentation and various treatment modalities.

Methodology and study design:

Reported cases of stonefish stings to Hong Kong Poison Information Centre from October 2008 to October 2018 were included in the study. The cases were retrieved from the Hong Kong Poison Information Centre electronic database. Information on patient demographic data, clinical parameters (e.g. the site of injury, presenting symptoms), and various treatment modalities (e.g. analgesics, hot water immersion, and use of antivenom) was collected.

Results:

There were 32 eligible patients included in this case series. All of them sustained the injury over either their fingers or hands. All patients reported pain over the site of injury. Other reported symptoms included numbness (41%), swelling (81%), and redness (47%). Twenty-five patients (78%) had radiograph done, and one of them was noted to have foreign body retained at the site of envenomation. All patients received hot water immersion to the affected part at 40°C–45°C for at least 30 min. Altogether eight patients (25%) received stonefish antivenom for pain relief. One patient developed compartment syndrome and received emergency operation of fasciotomy of right hand and forearm.

Conclusion:

Stonefish envenomation can cause extreme pain, swelling, and erythema, which can be managed with hot water immersion, analgesics, and prophylactic antibiotics. Use of antivenom can be considered in selected case.

Hong Kong Poison Information Centre: Annual report 2018

Objective:

The aim of this study was to report and analyse the poisoning data of Hong Kong Poison Information Centre in 2018.

Methods:

In 2018, all poisoning cases received by Hong Kong Poison Information Centre were retrieved from its database, Poison Information and Clinical Management System, for analysis.

Results:

A total of 3960 poisoned cases were analysed. There were 1770 male patients (44.7%), 2188 female patients (55.3%) and 2 sex-unspecified patients (<0.1%). The majority of cases (68.3%) were between 20 and 69 years old, and 9.9% involved children of 0–5 years old. The common causes of poisoning were suspected self-harm/suicidal attempt (36.6%), unintentional exposure (18.4%) and abusive substance use (11.1%). Excluding the common co-ingestant ethanol, the five commonest types of poison were benzodiazepines, paracetamol, Chinese herbal medicine, household products and zopiclone. Most patients were managed with supportive measures, while 13.5% and 13.7% of consultation cases were treated by decontamination and antidotes, respectively. The majority of cases had uneventful recovery; 0.8% resulted in death and 4.9% had major outcomes. A total of eight interesting cases were discussed.

Conclusion:

This 13th annual report provided the updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparison with our previous reports.

Clinical manifestations and causes of gelsemium poisoning in Hong Kong from 2005 to 2017: Review of 33 cases

Background:

Gelsemium elegans is an extremely toxic plant, but gelsemium poisoning is seldom reported in the English literature.

Objectives:

To evaluate the clinical manifestations and causes of gelsemium poisoning in Hong Kong.

Methods:

A retrospective review of gelsemium poisoning recorded by the Hong Kong Poison Information Centre from 2005 to 2017.

Results:

In total, 33 cases (55% female, median age 44 (interquartile range: 30–56)) were identified in 14 incidences. Consumption of contaminated Ficus hirta (五指毛桃) soup is the commonest cause (52%). Other causes include misidentification of herbs (12%), consumption of parasitic plant Cassytha filiformis (無根藤) (15%) and suicidal ingestion of Gelsemium elegans (斷腸草) (3%). Most patients (94%) had mild to moderate toxicity, with one fatal case and one severe case presented with coma and respiratory depression. All patients complained of dizziness (100%), followed by visual blurring (34%) and nausea (28%). More than half (53%) had ocular manifestations (e.g. visual blurring, ptosis, nystagmus, diplopia) which are not commonly reported in other herbal poisoning. The time of symptom onset was early (median: 50 min (interquartile range: 30–60)) and all occurred within 2 h after oral intake. Most patients (94%) recovered uneventfully with conservative treatment.

Conclusion:

Most gelsemium poisoning in Hong Kong was due to contamination or misidentification. Early-onset dizziness (<2 h) with ocular symptoms after herbs consumption highly suggests Gelsemium poisoning. Good supportive care, particularly respiratory support, is the mainstay of management. Early recognition and the corresponding preventive measures would be useful.

Efficacy and safety of naltrexone for amfetamine and methamfetamine use disorder: a systematic review of randomized controlled trials

INTRODUCTION

Amfetamine and methamfetamine abuse remains a prevalent health problem, increasing the burden on healthcare. Naltrexone, a µ-opioid receptor antagonist, has been suggested as a promising treatment for amfetamine and methamfetamine use disorder.

OBJECTIVE

To review the current evidence for the efficacy and safety of naltrexone as a pharmacological treatment for amfetamine and methamfetamine use disorder. The primary outcome was defined as abstinence or reduction of use. Secondary outcomes were, attenuated "positive" subjective effects (e.g., "feel good," "craving," etc.) of amfetamine or methamfetamine after naltrexone treatment, adverse events and physiological changes (e.g., blood pressure, heart rate).

METHODS

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A systematic literature search was conducted on 2 April 2017, and updated on 31 March 2018. Records were retrieved from databases including PubMed, EMBASE Classic plus EMBASE 1980 via Ovid, and the databases were searched using keywords and/or headings: (naltrexone AND amfetamine AND dependence) OR (naltrexone AND amfetamine AND craving) OR (vivitrol AND amfetamine) OR (revia AND amfetamine) OR (naltrexone AND amfetamine) OR (naltrexone AND methamfetamine dependence) OR (naltrexone AND methamfetamine AND craving) OR (vivitrol AND methamfetamine) OR (revia AND methamfetamine) OR (naltrexone AND ice) OR (naltrexone AND crystal meth) OR (naltrexone AND methamfetamine). Studies investigating the effects of naltrexone on amfetamine or methamfetamine use were eligible for inclusion. All studies were rated as low risk of bias using the Cochrane tool for risk of bias.

RESULTS

Among 591 identified studies, there were four randomized controlled trials. Two studies investigated the effects of naltrexone on amfetamine use disorder and two on methamfetamine use. Compared to placebo, the abstinence rate was increased significantly (p < 0.05) by naltrexone in one of two amfetamine studies, whereas there was no statistical difference in the only study reporting methamfetamine use. In one out of two amfetamine studies, naltrexone significantly attenuated either craving levels or subjective effects (e.g., "want more," "like effect") relative to placebo (p < 0.05). Additionally, only in one of two methamfetamine studies did naltrexone produce a significant reduction (p < 0.05) in craving levels or attenuated subjective effects. Both amfetamine and methamfetamine studies showed good tolerability of naltrexone, with few adverse events seen.

CONCLUSIONS

There is presently insufficient evidence to support the use of naltrexone in amfetamine and metamfetamine use disorders. There is a compelling need for high-quality studies to further evaluate the potential use of naltrexone.

Hong Kong Poison Information Centre: Annual report 2017

Objectives:

To report and analyse the poisoning data of Hong Kong Poison Information Centre in 2017.

Methods:

In 2017, all poisoning cases received by Hong Kong Poison Information Centre were retrieved from its database (Poison Information and Clinical Management System) for analysis.

Results:

A total of 3956 poisoned cases were analysed. There were 1789 male patients (45.2%), 2159 female patients (54.6%) and 8 sex-unspecified patients (0.2%). The majority of cases (59.9%) were between 20 and 59 years old. The common causes of poisoning were suspected self-harm/suicidal attempt (36.2%), unintentional exposure (18.6%) and abusive substance use (13.7%). Excluding the common co-ingestant ethanol, the five commonest types of poison were benzodiazepines, paracetamol, zopiclone, Chinese herbal medicine and household products. Most patients were managed with supportive measures, while 17.4% and 13.2% of consultation cases were treated by decontamination and antidotes, respectively. The majority of the cases had uneventful recovery; 1.1% resulted in death and 4.3% had major outcomes. A total of 13 interesting cases and 1 poisoning outbreak were discussed.

Conclusion:

This 12th annual report provided the updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparison with our previous reports.

Injuries and envenomation by exotic pets in Hong Kong

INTRODUCTION

Exotic pets are increasingly popular in Hong Kong and include fish, amphibians, reptiles, and arthropods. Some of these exotic animals are venomous and may cause injuries to and envenomation of their owners. The clinical experience of emergency physicians in the management of injuries and envenomation by these exotic animals is limited. We reviewed the clinical features and outcomes of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre.

METHODS

We retrospectively retrieved and reviewed cases of injuries and envenomation by exotic pets recorded by the Hong Kong Poison Information Centre from 1 July 2008 to 31 March 2017.

RESULTS

There were 15 reported cases of injuries and envenomation by exotic pets during the study period, including snakebite (n=6), fish sting (n=4), scorpion sting (n=2), lizard bite (n=2), and turtle bite (n=1). There were two cases of major effects from the envenomation, seven cases with moderate effects, and six cases with mild effects. All major effects were related to venomous snakebites. There were no mortalities.

CONCLUSION

All human injuries from exotic pets arose from reptiles, scorpions, and fish. All cases of major envenomation were inflicted by snakes.

Accidental Ecstasy Poisoning in a Five-Year-Old Boy

We report a 5-year-old child with fever and confusion after ingestion of a tablet of methylenedioxymethamphetamine (MDMA). He was treated successfully with supportive measures and titrated doses of benzodiazepine. In children with unexplained fever, sympathetic hyperactivity, confusion or convulsion, MDMA poisoning should be considered.

Hong Kong Poison Information Centre: Annual Report 2015

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2015.

Methods

In 2015, all poisoning cases received by HKPIC were retrieved from its database [Poison Information and Clinical Management System (PICMS)] for analysis.

Results

A total of 3,960 poisoned cases were analysed. There were 1,770 male patients (44.7%), 2,176 female patients (55.0%) and 14 sex unspecified patients (0.4%). The majority of the cases (63.5%) were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (38.4%), unintentional exposure (17.4%) and abusive substances use (11.6%). Excluding the common co-ingestant ethanol, the five commonest types of poison were paracetamol, benzodiazepine, household products, zopiclone and Chinese herbal medicine. Most patients were managed with supportive measures, while 16.4% and 16.2% of them were treated by decontamination and antidotes respectively. Majority of the cases had uneventful recovery; 1% resulted in death and 4.3% had major outcomes. Seven interesting cases and one outbreak were discussed.

Conclusions

This 10th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparing with our previous reports.

Hong Kong Poison Information Centre: Annual Report 2008

Objective

To report the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2008.

Methods

From 1st January 2008 to 31st December 2008, all poisoning cases received by HKPIC were retrieved from its database (DATOX & PIC-MS) for analysis.

Results

4,029 poisoned cases were analyzed. There were 1,755 male patients (43.6%) and 2,262 female patients (56.1%). Nearly two-thirds of them were between 20 and 59 years old. Common causes of exposure were suspected self harm/suicidal attempt, unintentional exposure and abusive use. Sedatives, household products, paracetamol, and ketamine were common poisons exposed and non-benzodiazepine sedative-hypnotics were involved in about one-seventh of the poisoning cases. The majority of the patients were managed conservatively, with 6.0% and 5.9% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; about 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes.

Conclusions

This annual report provides updated epidemiological information on poisoning in Hong Kong in 2008 and highlights some changes in comparison with our previous reports. The increase in abusive substance poisoning, in particular ketamine, requires further attention.

Venomous Fish Sting Cases Reported to Hong Kong Poison Information Centre: A Three-Year Retrospective Study on Epidemiology and Management

Objective

To study the epidemiology of venomous fish sting injuries, management and clinical outcomes of injured patients reported to the Hong Kong Poison Information Centre (HKPIC).

Methods

All venomous fish sting cases reported to HKPIC from July 2005 to June 2008 were retrieved from its database (DATOX) and the Hong Kong Hospital Authority (HA) Electronic Patient Record (ePR) computer system for analysis.

Results

There were a total of 33 fish sting cases in this study. The average age of the patients was 43 years (range 20 to 84) and 24 patients were males. Most cases were injured by catfish (n=12), followed by stonefish (n=7) and lionfish (n=4). Ten cases sustained fish sting injury whilst at work. Five patients developed fish sting complications including cellulitis, subacute tenosynovitis, abscess formation and foreign body retention. No mortality was recorded. Within 7 cases of stonefish injury, 3 cases were classified as moderate effect outcome. Two patients received stonefish antivenom and none developed anaphylaxis.

Conclusion

The majority of marine envenomations did not result in significant morbidity and required only supportive management. However, stonefish injuries might be associated with an increased risk of severe local symptoms which therefore required aggressive treatment including antivenom.

Hong Kong Poison Information Centre: Annual Report 2007

Objective

To report the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2007.

Methods

From 1st January 2007 to 31st December 2007, all poisoning cases received by HKPIC were retrieved from its database (DATOX) for analysis.

Results

2842 poisoned cases were analyzed. There were 1199 male and 1610 female patients and more than two-thirds of the cases were between 20 and 59 years old. Common causes of exposure were suicidal attempt, accident and abusive use. Non-benzodiazepine sedative-hypnotic, household products and paracetamol were common poisons exposed. The majority of the patients were managed conservatively, with 8.4% and 6.4% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; less than 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes.

Conclusions

This 2007 annual report provided updated epidemiological information on the poisoning pattern in Hong Kong and highlighted some changes in comparison to the situation in 2006.

A Case of Convulsion: Brugada Syndrome

A healthy 28-year-old man presented with multiple brief episodes of convulsion. He was found to have ventricular fibrillation which required defibrillation in the emergency department. After exclusion of organic heart diseases, Brugada syndrome was diagnosed and required implantable cardioverter defibrillator (ICD) implantation. The case emphasized the recognition of malignant cardiac dysrrhythmias as a cause for seizures. The management in the emergency department was discussed.

Traditional Chinese Medicine Use among Emergency Patients in Hong Kong

Introduction

Traditional Chinese Medicine (TCM) use has been believed to be common in Hong Kong but no data existed on its prevalence among emergency patients. We conducted a prospective survey to study the prevalence of its use, the type of TCM use, frequency and nature of associated adverse reactions.

Methods

All accident & emergency department (AED) attendances at the United Christian Hospital were screened by the triage nurse and attending doctor for TCM use and its type in a consecutive 31 day period. The causal relationships between the TCM and their presenting illness were also assessed and decided by the doctor in-charge.

Results

291 out of 21,475 patients (1.4%) reported TCM use within one week. Among them, 117 (40.2%) consumed Chinese herbal medicine, 75 (25.8%) took proprietary Chinese medicine, 1 (0.3%) took both, 96 (33.0%) received topical treatment and 2 (0.7%) were unclassified, with 22 out of the 291 TCM users (7.6%) presented for TCM-related toxicity. Most complications were mild, the commonest ones being dermatitis after topical treatment (68.2%) and allergic reaction after oral intake (22.7%).

Conclusion

A small number of patients took TCM treatment shortly before AED consultation. Most TCM-related toxicities were mild and the commonest reactions were dermatitis and systemic allergy.

Hong Kong Poison Information Centre: Annual Report 2009

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2009.

Methods

In 2009, all poisoning cases received by HKPIC were retrieved from its database (PICMS) for analysis.

Results

Totally 4338 poisoned cases were analysed. There were 1955 male patients (45.1%), 2,367 female patients (54.6%) and 16 patients with no gender specified. More than two-third of cases (68.6%) were between 20 and 59 years old. Common causes of exposure were suspected self harm/suicidal attempt, abusive use and unintentional exposure. Paracetamol, ketamine, zopiclone, benzodiazepine and household products were the common poisons exposed. Majority of the patients were managed supportively, with 13.6% and 13.1% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; about 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes.

Conclusions

The 2009 annual report provides updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

Hong Kong Poison Information Centre: Annual Report 2010

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2010.

Methods

In 2010, all poisoning cases received by HKPIC were retrieved from its database (PICMS) for analysis.

Results

A total of 4,418 poisoned cases were analysed. There were 1,863 male patients (42.2%) and 2,540 female patients (57.5%). More than two-third of cases (68.3%) were between 20 and 59 years old. Common causes of exposure were suspected self harm/suicidal attempt, unintentional exposure and abusive use. Benzodiazepine, paracetamol, ketamine, zopiclone, and Chinese herbal medicine were the common agents involved. Majority of the patients were managed supportively, with 10.2% and 9.7% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 1.0% of the poison exposure resulted in death and 5.3% of the exposure had major outcomes.

Conclusions

This fifth annual report provides updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

Daytime versus Night Time Intentional Drug Overdose: The Outcome is Different

Introduction

In drug overdose, it is generally perceived that the dosage can predict the clinical outcome. Are the dosages of intentional drug overdosing the same between day and night? If so, are these overdoses followed by similar clinical outcomes? Answers to these two questions might affect resource allocation and clinical judgment. The present study was performed to establish whether daytime patients and night time patients report similar drug doses, and see which group of patients would have a higher incidence of severe outcomes.

Method

A retrospective observational study on intentional drug overdose was performed. The reported numbers of total tablets ingested and the incidences of major outcomes, in terms of death and intensive care unit admissions, were compared between daytime and night time.

Results

A total of 400 patients were included. The reported number of ingested tablets in daytime had no statistical difference with that at night time. The numbers of severe outcomes had no differences between the patients presenting to the emergency department at daytime or night time. Yet overdosing at night time was more likely associated with severe outcomes.

Conclusions

We advise a higher index of suspicion at the emergency department on the reliability of the dosages reported by patients who overdose during night time. The larger number of severe outcomes may also be related to more toxic drug exposures in the night time. More resources in the community could be allocated to self-harm prevention at night time.

A Prospective Epidemiological Study of Acute Poisoning in Hong Kong

Objective

To update our epidemiological knowledge of acute poisoning in Hong Kong.

Methods

A multi-centred prospective study was conducted for six months in six major accident and emergency departments in Hong Kong. A specially designed form was used to collect demographic data, type of poison involved, cause of poisoning, management, disposal as well as final outcome of the poisoned patients.

Results

A total of 1,467 patients (male: 588, female: 879) were included in the study. Most of them were young adults (32% were between 20 and 40 years old). Suicidal attempt (64%) was the most common cause of poisoning. Notably, 379 (26%) patients took more than one poison. Among the 2,007 counts of poison taken, sleeping pills (24%) and analgesics (18%) were the most commonly used drugs and paracetamol was the commonest single ingredient involved in poisoning. Most patients were treated with supportive measures, and about 40% and 15% of the patients were given gastrointestinal decontamination and specific antidotes respectively in their management, in which activated charcoal and N-acetylcysteine were the most common. Concerning disposal from the emergency department, 91% of the poisoned cases required in-patient management. Most patients had an uneventful recovery but 5 (0.3%) had significant disability and 21 (1.4%) died. Suicidal carbon monoxide poisoning was the leading cause of mortality in our study.

Conclusions

Most acute poisonings in Hong Kong were suicidal in nature and paracetamol was the commonest agent. Activated charcoal was the most commonly used decontamination method and most patients had an uneventful recovery.

Hong Kong Poison Information Centre: Annual Report 2013

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2013.

Methods

In 2013, all poisoning cases received by HKPIC were retrieved from its database [Poison Information and Clinical Management System (PICMS)] for analysis.

Results

A total of 3,783 poisoned cases were analysed. There were 1,595 male patients (42.2%), 2,185 female patients (57.8%) and 3 sex unspecified patients (0.1%). Middle aged group (30-39 years) composed about one-fifth (20.8%) of the poisoning cases while about two-third (66.8%) of them were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (43%), unintentional exposure (15.3%) and abusive substances use (14.5%). Five commonest types of poison exposed were paracetamol, benzodiazepine, zopiclone, household products and Chinese herbal medicine. Majority of the patients were managed with supportive measures, and 13.2% and 10.8% of them were treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 0.9% of the poisoning resulted in death and 4.3% had major outcomes.

Conclusions

This 8th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparing with our previous reports. (Hong Kong j. emerg.med. 2014;21:249-259)

Hot Water Immersion Therapy with a Thermal Isolator in Patient with Marine Envenomation

Objective

Hot water immersion (HWI) has been proven to be effective for the treatment of pain due to marine envenomation. Our preliminary study by simply measuring the temperature change over time on the hot water in our conventional metal tray method revealed a too rapid fall in water temperature that happened in minutes. The aim of this study was to review the current practice of HWI for patients with marine envenomation in the emergency departments in Hong Kong, and to look for the optimal equipment in performing HWI.

Method

We first conducted a phone survey to 16 registered nurses or nursing officers from 16 emergency departments of public hospitals in Hong Kong for the current practice of hot water immersion. The second part of our study was an in-vitro experiment done in observation room that a healthy subject immersed a hand into the water bath in metallic tray, sharp box and thermal isolator with and without covering of aluminum foil or plastic foil. The temperature change of the water bath in these containers was serially monitored.

Results

In our phone survey, 14 respondents used plastic tray or sharp box for hot water immersion. Nine of them claimed that they commonly encountered inadequate wound pain relief and early cooling of the hot water bath. The experiment showed that the water temperature dropped out of optimal range for 5 minutes and 15 minutes in metallic tray and sharp box respectively. The thermal isolator kept the optimal temperature throughout 30 minutes of the study time.

Conclusion

Our purposed thermal isolator is a safe, practical and effective device for HWI therapy.

Timolol Eye Drops Induced Bradycardia

We report a 25-year-old man with bradycardia after administration of ophthalmic timolol. The patient was asymptomatic, and his bradycardia resolved after stopping the eye drop. He was discharged after a four-hour observation. This case demonstrated that topical timolol eye drop may cause systemic adverse reaction. The use of timolol and its possible side-effects are discussed.

Hong Kong Poison Information Centre: Annual Report 2011

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2011.

Methods

In 2011, all poisoning cases received by HKPIC were retrieved from its database: Poison Information and Clinical Management System (PICMS) for analysis.

Results

A total of 4,331 poisoned cases were analysed. There were 1,915 male patients (44.2%), 2,411 female patients (55.7%) and 5 patients with sex unknown. More than two-third (68%) of them were between 20 and 59 years old. Common causes of exposure were suspected self-harm/suicidal attempt, unintentional exposure and abusive use. Paracetamol, benzodiazepine, household product, zopiclone, and Chinese herbal medicine were the top five commonest poisons encountered. Majority of the patients were managed supportively, with 12.1% and 8.5% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 1.0% of the poison exposure resulted in death and 4.8% of the exposure had major outcomes.

Conclusions

This 6th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

Two Cases of Anticholinergic Poisoning from Transdermal Scopolamine Patch

Scopolamine transdermal patch is a form of anticholinergic drug used to prevent motion sickness. We reported two cases of anticholinergic poisoning resulting from scopolamine transdermal patch. The first case experienced local toxicity and presented with right eye mydriasis for five days. The second case developed systemic anticholinergic toxidrome contributed by the scopolamine patch and presented with acute confusion. She was treated successfully by physostigmine, an anticholinergic antidote. The recommendation on physostigmine use was also discussed. We hope that these two case reports will raise the clinician awareness of the potential side effect of this kind of product.

Hong Kong Poison Information Centre: Annual Report 2006

Objective

To report the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2006.

Methods

From 1st January 2006 to 31st December 2006, all poisoning cases received by HKPIC were retrieved from its database (DATOX) for analysis.

Results

A total of 2555 poisoned cases were analysed. There were 1051 male and 1466 female patients and nearly 60% of the cases were between 20 and 49 years old. Common causes of exposure were suicidal attempts and accidents. Paracetamol, sedative-hypnotic and household products were common sources of poison exposure. The majority of the patients were managed conservatively, with 18.8% and 10.5% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; less than 1% of the poison exposure resulted in death and about 5% of the exposure had major outcomes. Nearly half of the cases were managed in the accident & emergency department without hospitalisation.

Conclusions

This annual report provides updated epidemiological information on poisoning in Hong Kong. Subsequent annual reports would provide important information on the trend of poisoning pattern and may guide further strategies in poison control and prevention in Hong Kong.

Hong Kong Poison Information Centre: Annual Report 2012

Objective

To report and analyze the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2012.

Methods

In 2012, all poisoning cases received by HKPIC were retrieved from its database: Poison Information and Clinical Management System (PICMS) for analysis.

Results

A total of 4,814 poisoned cases were analyzed. There were 1,771 male patients (42.3%), 2,399 female patients (57.3%) and 14 sex unspecified patients (0.3%). Middle aged group (30-39 years) contributed about one-fifth (20.1%) of the poisoning cases while more than two-third (67.7%) of them were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (45%), abusive substances use (13.9%) and unintentional exposure (13.0%). Five commonest types of poison exposed were paracetamol, benzodiazepine, zopiclone, bites and envenomation and household products. Majority of the patients were managed with supportive measures, and 15.7% and 11.9% of them were treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 0.6% of the poison exposure resulted in death and 4.7% of the exposure had major outcomes.

Conclusions

This seventh annual report provides updated epidemiological information on poisoning pattern in Hong Kong and highlights important changes in comparing with our previous reports. (Hong Kong j.emerg.med. 2013;20:371-381)

A Retrospective Survey on the Clinical Presentation of Ketamine Abusers in a Hong Kong Emergency Department

Objective

Ketamine is one of the commonest abusing agents in Hong Kong. Our study aims to identify their clinical pattern of presentations to emergency departments.

Method

This is a retrospective survey study. The studied group was ketamine abusers being referred to us from a source out of emergency department (ED). Control group was randomly selected from patients attending our ED. The electronic records of the ketamine abusers and the controls in the past 3 years (1st April 2004-31st March 2007) were reviewed and analysed.

Result

Total 91 subjects (48 in ketamine group, 43 in control group) were included. The mean age of ketamine abusers and control group are 21 and 22.2 year-old respectively. Most of them (97.9%) did not declare their background of ketamine abuse. The mean 3-year attendance rate for the ketamine group was 2.38 and for control group was 0.91, with a difference of 1.47 (95% CI 0.54-2.41, p=0.003). Most of their illnesses were diagnosed as epigastric pain (25%), followed by upper respiratory tract infection (18.8%), head injury (10.4%) and urinary tract infection (10.4%). Significantly higher number of ketamine abusers presented with epigastric pain compared with control group (odds ratio 143, p<0.001).

Conclusion

Most teenage ketamine abusers do not declare their background of drug abuse when they present to emergency departments. They tend to have a higher frequency of attendances. Most of their presenting problems are related to gastrointestinal system.

Hong Kong Poison Information Centre: Annual report 2016

Objective:

To report and analyse the poisoning data of Hong Kong Poison Information Centre in 2016.

Methods:

In 2016, all poisoning cases received by Hong Kong Poison Information Centre were retrieved from its database (Poison Information and Clinical Management System) for analysis.

Results:

A total of 4096 poisoned cases were analysed. There were 1871 male patients (45.7%), 2203 female patients (53.8%) and 22 sex unspecified patients (0.5%). The majority of the cases (63.1%) were between 20 and 59 years old. Common causes for poisoning were suspected self-harm/suicidal attempt (36.3%), unintentional exposure (18.4%) and abusive use (13.1%). Excluding the common co-ingestant ethanol, the five commonest types of poisons were benzodiazepines, paracetamol, household products, zopiclone and Chinese herbal medicine. Most patients were managed with supportive measures, while 14.3% and 12.9% of them were treated by decontamination and antidotes, respectively. Majority of the cases had uneventful recovery; 1% resulted in death and 3.9% had major outcomes. Six interesting cases and three poisoning outbreaks were discussed.

Conclusion:

This 11th annual report provided the updated epidemiological information on poisoning pattern in Hong Kong and highlighted important changes in comparing with our previous reports.

Safety profile of snake antivenom (use) in Hong Kong - a review of 191 cases from 2008 to 2015

INTRODUCTION

The mainstay of treatment for significant envenoming from snakebites is antivenom. However, there is insufficient data regarding the safety of antivenom used in Hong Kong. We describe the incidence of hypersensitivity reactions from antivenom use and review the frequency and reasons for intensive care unit (ICU) admission.

METHODS

The Hong Kong Poisons Information Centre database was reviewed. All patients given snake antivenom between 2008 and 2015 were included. Patient demographics, species of snake involved, details of antivenom used, treatment location, use of pre-treatment, reasons for ICU admission (where applicable) and details of early and late antivenom reactions were extracted.

RESULTS

There were 191 patients who received snake antivenom. Most (93%) were treated with either the green pit viper antivenom from Thailand or the Agkistrodon halys antivenom from China. The incidences of early hypersensitivity reactions to green pit viper antivenom and Agkistrodon Halys antivenom were 4.7% and 1.4%, respectively. Most patients (69%) were managed in the ED observation ward or general ward. There were 59 patients managed in ICU, most (90%) of whom were admitted for close monitoring during antivenom administration. There were no cases of significant morbidity from antivenom administration. Eight patients (5.6%) had features suggestive of mild serum sickness.

CONCLUSIONS

The incidence of immediate hypersensitivity reaction to antivenom commonly used in Hong Kong is low. Majority of patients were managed safely in the emergency department observation ward or general ward. Serum sickness appears to be uncommon and possible cases presented with mild features.

Two cases of valproic acid poisoning treated with l-carnitine

Two cases of acute valproic acid poisoning with central nervous system depression and raised ammonia level without hepatotoxicity were reported. They were treated successfully with the use of the antidotes: l-carnitine and other supportive measures. Clinical manifestation and progress was described, and discussion is focused on the use of l-carnitine in valproic acid–induced hyperammonemia, from its mechanism to the clinical experiences in the literature. Based on the favorable response of our two cases and the literature review, we recommend the administration of intravenous l-carnitine in patients of valproic acid overdose with hyperammonemia or valproic acid–induced hyperammonemic encephalopathy and hepatotoxicity at a dose of 50 mg/kg every 8 h for the first initial 24 h with further individual assessment.

Mushroom poisoning in Hong Kong: a ten-year review

INTRODUCTION

Mushroom poisoning is a cause of major mortality and morbidity all over the world. Although Hong Kong people consume a lot of mushrooms, there are only a few clinical studies and reviews of local mushroom poisoning. This study aimed to review the clinical characteristics, source, and outcome of mushroom poisoning incidences in Hong Kong.

METHODS

This descriptive case series review was conducted by the Hong Kong Poison Information Centre and involved all cases of mushroom poisoning reported to the Centre from 1 July 2005 to 30 June 2015.

RESULTS

Overall, 67 cases of mushroom poisoning were reported. Of these, 60 (90%) cases presented with gastrointestinal symptoms of vomiting, diarrhoea, and abdominal pain. Gastrointestinal symptoms were early onset (<6 hours post-ingestion) and not severe in 53 patients and all recovered after symptomatic treatment and a short duration of hospital care. Gastrointestinal symptoms, however, were of late onset (≥6 hours post-ingestion) in seven patients; these were life-threatening cases of amatoxin poisoning. In all cases, the poisonous mushroom had been picked from the wild. Three cases were imported from other countries, and four collected and consumed the amatoxin-containing mushrooms in Hong Kong. Of the seven cases of amatoxin poisoning, six were critically ill, of whom one died and two required liver transplantation. There was one confirmed case of hallucinogenic mushroom poisoning caused by Tylopilus nigerrimus after consumption of a commercial mushroom product. A number of poisoning incidences involved the consumption of wild-harvested dried porcini purchased in the market.

CONCLUSION

Most cases of mushroom poisoning in Hong Kong presented with gastrointestinal symptoms and followed a benign course. Life-threatening cases of amatoxin poisoning are occasionally seen. Doctors should consider this diagnosis in patients who present with gastrointestinal symptoms that begin 6 hours or more after mushroom consumption.

Paracetamol overdose in Hong Kong: is the 150-treatment line good enough to cover patients with paracetamol-induced liver injury?

OBJECTIVES

To evaluate the failure rate of the 150-treatment line for paracetamol overdose in Hong Kong, and the impact if the treatment threshold was lowered.

SETTING

Public hospitals, Hong Kong.

PATIENTS

All patients with acute paracetamol overdose reported to the Hong Kong Poison Information Centre from 1 January 2011 to 31 December 2013 were studied and analysed for the timed serum paracetamol concentration and their relationship to different treatment lines. Presence of significant liver injury following paracetamol overdose was documented. The potential financial burden of different treatment lines implemented locally was estimated.

RESULTS

Of 893 patients, 187 (20.9%) had serum paracetamol concentration above the 150-treatment line, 112 (12.5%) had serum paracetamol concentration between the 100- and 150-treatment lines, and 594 (66.5%) had serum paracetamol level below the 100-treatment line. Of the 25 (2.8%) patients who developed significant liver injury, two were between the 100- and 150-treatment lines, and the other two were below the 100-treatment line. The failure rate of the 150-treatment line was 0.45%. Lowering the treatment threshold to the 100-treatment line might lower the failure rate of the treatment nomogram to 0.22% but approximately 37 more patients per year would need to be treated. It would incur an additional annual cost of HK$189 131 (US$24 248), and an additional 1.83 anaphylactoid reactions per year. The number needed-to-treat to potentially reduce one significant liver injury is 112.

CONCLUSIONS

Lowering the treatment threshold of paracetamol overdose may reduce the treatment-line failure rate. Nonetheless such a decision must be balanced against the excess in treatment complications and health care resources.

Surveillance of emerging drugs of abuse in Hong Kong: validation of an analytical tool

OBJECTIVE

To validate a locally developed chromatography-based method to monitor emerging drugs of abuse whilst performing regular drug testing in abusers.

DESIGN

Cross-sectional study.

SETTING

Eleven regional hospitals, seven social service units, and a tertiary level clinical toxicology laboratory in Hong Kong.

PARTICIPANTS

A total of 972 drug abusers and high-risk individuals were recruited from acute, rehabilitation, and high-risk settings between 1 November 2011 and 31 July 2013. A subset of the participants was of South Asian ethnicity. In total, 2000 urine or hair specimens were collected.

MAIN OUTCOME MEASURES

Proof of concept that surveillance of emerging drugs of abuse can be performed whilst conducting routine drug of abuse testing in patients.

RESULTS

The method was successfully applied to 2000 samples with three emerging drugs of abuse detected in five samples: PMMA (paramethoxymethamphetamine), TFMPP [1-(3-trifluoromethylphenyl)piperazine], and methcathinone. The method also detected conventional drugs of abuse, with codeine, methadone, heroin, methamphetamine, and ketamine being the most frequently detected drugs. Other findings included the observation that South Asians had significantly higher rates of using opiates such as heroin, methadone, and codeine; and that ketamine and cocaine had significantly higher detection rates in acute subjects compared with the rehabilitation population.

CONCLUSIONS

This locally developed analytical method is a valid tool for simultaneous surveillance of emerging drugs of abuse and routine drug monitoring of patients at minimal additional cost and effort. Continued, proactive surveillance and early identification of emerging drugs will facilitate prompt clinical, social, and legislative management.

Chinese herbal medicine-induced anticholinergic poisoning in Hong Kong

OBJECTIVE

To study the epidemiology, causes, and clinical course of Chinese herbal medicine-induced anticholinergic poisoning in Hong Kong.

DESIGN

Case series.

SETTING

Hong Kong.

PATIENTS

All case histories of Chinese herbal medicine-induced anticholinergic poisoning (with laboratory confirmation) recorded by the Hong Kong Poison Information Centre over a 93-month period were accessed for analysis.

RESULTS

During the relevant period, 22 clusters of Chinese herbal medicine-induced anticholinergic poisoning involving 32 patients were retrieved. The commonest clinical features were mydriasis (n=32, 100%) and confusion (n=24, 75%). No gastro-intestinal decontamination was performed. None of these patients underwent intubation, defibrillation, cardioversion, pacing, fluid resuscitation, inotropic support or dialysis. Of the 32 patients, 17 (53%) were treated with physostigmine because of confusion, three of whom had previously received intravenous benzodiazepines. No patient could be effectively treated with benzodiazepines alone. There was no mortality, and all the patients were discharged within 3 days. None of them re-attended the emergency department within 1 week of discharge. The commonest cause was the substitution of flos campsis (Campsis grandiflora) by the flower of the Datura species (7 clusters [32%] in 10 patients).

CONCLUSION

Mydriasis and confusion were the commonest clinical features of Chinese herbal medicine-induced anticholinergic poisoning in Hong Kong. Physostigmine was frequently used in the treatment; benzodiazepines appeared ineffective. The commonest cause was the substitution of flos campsis (Campsis grandiflora) by the flower of the Datura species.

Aconite poisoning over 5 years: a case series in Hong Kong and lessons towards herbal safety

BACKGROUND

Aconite poisoning is a severe, life-threatening poisoning related to the use of traditional Chinese medicine (TCM). Despite current legislation, repeated poisoning cases are steadily encountered.

OBJECTIVE

The aim of the study was to summarize the clinical features and to elucidate the causative and contributory factors leading to aconite poisoning.

METHODS

This study was conducted within the Hospital Authority Toxicology Reference Laboratory, which is the sole tertiary referral clinical toxicology laboratory in Hong Kong. This retrospective study reviewed all confirmed aconite poisoning cases handled by a clinical toxicology laboratory between April 2004 and July 2009. The diagnosis in all cases was confirmed biochemically by detecting aconitum alkaloids in urine specimens. Additionally, herbal specimens were morphologically identified and herbal formulae were studied and transcribed. The cause of poisoning for each case was determined whenever possible.

RESULTS

Fifty-two cases were examined in this aconite poisoning case series. Neurological, cardiovascular and gastrointestinal toxicities were encountered in 49 (94.2%), 46 (88.5%) and 31 (59.6%) patients, respectively. The poisoning was severe in 6 (11.5%) patients, moderate in 17 (32.7%) patients and mild in 29 (55.8%) patients. Amongst 44 patients (84.6%) in whom the underlying reasons of poisoning could be determined, four major causes were found. These included overdose - prescription of a higher than recommended dosage of aconite herbs in 17 (32.7%) cases; 'hidden' poisoning (the aconite herb was not prescribed but dispensed inadvertently) in 17 (32.7%) cases; usage of inadequately processed herbs in 7 (13.5%) cases; and dispensary error in 2 (3.9%) cases. No case fatality was recorded.

CONCLUSION

In the majority of cases in this series, the causes of poisoning can be traced to poor-quality herbs, poor quality of prescription practice, or dispensary errors. The quality issues of TCM practice should be critically addressed to minimize this poisoning threat.

Accuracy of clinical diagnosis versus the World Health Organization case definition in the Amoy Garden SARS cohort

OBJECTIVES

To compare the diagnostic accuracy of emergency department (ED) physicians with the World Health Organization (WHO) case definition in a large community-based SARS (severe acute respiratory syndrome) cohort.

METHODS

This was a cohort study of all patients from Hong Kong's Amoy Garden complex who presented to an ED SARS screening clinic during a 2-month outbreak. Clinical findings and WHO case definition criteria were recorded, along with ED diagnoses. Final diagnoses were established independently based on relevant diagnostic tests performed after the ED visit. Emergency physician diagnostic accuracy was compared with that of the WHO SARS case definition. Sensitivity, specificity, predictive values and likelihood ratios were calculated using standard formulae.

RESULTS

During the study period, 818 patients presented with SARS-like symptoms, including 205 confirmed SARS, 35 undetermined SARS and 578 non-SARS. Sensitivity, specificity and accuracy were 91%, 96% and 94% for ED clinical diagnosis, versus 42%, 86% and 75% for the WHO case definition. Positive likelihood ratios (LR+) were 21.1 for physician judgement and 3.1 for the WHO criteria. Negative likelihood ratios (LR-) were 0.10 for physician judgement and 0.67 for the WHO criteria, indicating that clinician judgement was a much more powerful predictor than the WHO criteria.

CONCLUSIONS

Physician clinical judgement was more accurate than the WHO case definition. Reliance on the WHO case definition as a SARS screening tool may lead to an unacceptable rate of misdiagnosis. The SARS case definition must be revised if it is to be used as a screening tool in emergency departments and primary care settings.

Dettol poisoning and the need for airway intervention

OBJECTIVES. To (1) characterise the clinical features of Dettol poisoning on a territory-wide basis, (2) assess the need for airway intervention after such poisoning and its time frame after ingestion, and (3) identify predictors for such an intervention. DESIGN. Case series. SETTING. Sixteen accident and emergency departments in Hong Kong. PATIENTS. Patients with Dettol ingestion who presented within 48 hours of ingestion from July 2005 to June 2009, derived from the database of the Hong Kong Poison Information Centre. RESULTS. In all, 213 patient records were identified, of which 36 were excluded based on pre-defined criteria and 177 were analysed. Among the latter, the median age was 32 (range, 2-95) years and the male-to-female ratio was 1:2.7 (48:129). Intentional ingestion constituted the majority (95%) of cases. The most common symptoms were related to the local irritative/corrosive effects on the aero-digestive tract, such as gastro-intestinal upset and localised throat pain. Airway intervention was required in 14 (8%) patients. All interventions were performed within 12 hours of Dettol ingestion and three cases involved re-intubation after extubation. Univariate analysis showed that a Glasgow Coma Scale score of <8, older age, a larger amount ingested, lip swelling, lung crackles, and wheezing were all associated with airway intervention. In the multivariate analysis using forward stepwise logistic regression, only coma (Glasgow Coma Scale score of <8) remained statistically significant. CONCLUSIONS. Delayed airway obstruction (>12 hours after Dettol ingestion) is unlikely. For those who are intubated, careful assessment of airway adequacy before extubation is strongly recommended to avoid extubation failure and subsequent re-intubation. Patients in coma (Glasgow Coma Scale score of <8) should prompt airway intervention.

Green pit viper antivenom from Thailand and Agkistrodon halys antivenom from China compared in treating Cryptelytrops albolabris envenomation of mice

OBJECTIVE

To compare the relative efficacy of the green pit viper antivenom from Thailand and Agkistrodon halys antivenom from China. DESIGN. In-vivo experimental study.

SETTING

A wildlife conservation organisation, a university, a poison information centre, and a regional hospital in Hong Kong.

MAIN OUTCOME MEASURES

Pre- and post-antivenom lethal dose 50 (LD50) of the Cryptelytrops albolabris venom, median effective dose (ED50) of green pit viper antivenom and Agkistrodon halys antivenom against a lethal dose of the venom. SUBJECTS. Adult mice.

RESULTS

The intraperitoneal LD50 of the venom from locally caught Cryptelytrops albolabris was 0.14 microL. After post-exposure treatment with 10 microL of antivenom, it was elevated to 0.36 microL and 0.52 microL by the green pit viper antivenom and the Agkistrodon halys antivenom, respectively. The ED50 was 32.02 microL for green pit viper antivenom and 6.98 microL for Agkistrodon halys antivenom. Both green pit viper antivenom and Agkistrodon halys antivenom ameliorated the lethality of Cryptelytrops albolabris venom in mice.

CONCLUSION

The overall superior neutralisation capacity of Agkistrodon halys antivenom over green pit viper antivenom may be related to the geographic proximity of the venoms used for antivenom preparation. The results point towards the need for further comparison of the two antivenoms on protein or immunoglobulin weight basis, and with respect to non-lethal clinically significant toxicities.

Prediction of prognosis in acute paraquat poisoning using severity scoring system in emergency department

OBJECTIVE

The aim of this study was to validate and compare the performance of serum paraquat level, severity index of paraquat poisoning (SIPP), Acute Physiology And Chronic Health Evaluation II (APACHE II), modified Simplified Acute Physiology Score II (MSAPS II), and modified Expanded Simplified Acute Physiology Score II (MSAPS IIe) calculated immediately after arrival on emergency department (ED) for assessing the mortality of acute paraquat poisoning.

METHODS

A retrospective study design was employed with the main outcome measure being mortality from year 2001 to 2010. MSAPS II and MSAPS IIe were employed in that assessment of the 24-hour urine output were not included. The performance of APACHE II, MSAPS II, MSAPS IIe, serum paraquat level and SIPP for prediction of mortality in acute paraquat poisoning were compared.

RESULTS

A total of 102 patients were enrolled in the study. The area under the ROC curve for APACHE II (0.800) was statistically lower than those for MSAPS II, MSAPS IIe, SIPP and serum paraquat (0.879, 0.893, 0.924,and 0.951, respectively). The Hosmer-Lemeshow goodness-of-fit test C statistic revealed that APACHE II, MSAPS II, MSAPS IIe and serum paraquat level showed good calibrations (chi-square 8.477 and p = 0.388, chi-square 4.614 and p = 0.798, chi-squared 5.301 and p = 0.725, chi-squared 1.009 and p = 0.985 respectively), but poor calibration for SIPP (chi-square 21.293 and p = 0.006).

CONCLUSION

Serum paraquat level is still the most reliable prognosis factor in acute paraquat poisoning. But MSAPS II or MSAPS IIe calculated immediately after arrival on ED may be helpful to predict mortality in acute paraquat poisoning especially when hospital has no facility to measure serum paraquat level.

Causality assessment of herb-induced liver injury using multidisciplinary approach and Roussel Uclaf Causality Assessment Method (RUCAM)

OBJECTIVE

To evaluate an algorithmic approach involving a multidisciplinary team for causality assessment of suspected herb-induced liver injury (HILI) cases and to compare the causality score using this multidisciplinary approach and Roussel Uclaf Causality Assessment Method (RUCAM).

METHODS

A team consisting of hepatologist, clinical toxicologist, analytical toxicologist, and Chinese medicine (CM) pharmacist was formed to do causality assessment based on a protocol for suspected HILI cases. The likelihood of the diagnosis of individual case was first assessed systematically by a hepatologist and clinical toxicologist independently after collecting information about four aspects: (1) clinical course, (2) exclusion of alternative causes, (3) quality of the prescription and herbal product by examining the CM prescriptions and analysis of biological and herb samples, (4) scientific support on comprehensive literature review on English and Chinese medical database, and subsequently concluded in a consensus meeting held by the multidisciplinary team. The final causality score of each patient was compared with the likelihood of causality as assessed by RUCAM.

RESULTS

Between 2005 and 2007, 48 consecutive patients with suspected HILI were enrolled and 21 patients were excluded due to the establishment of an alternative cause of liver impairment or the lack of any information on the herbs taken. Twenty-seven patients were recruited, among them 15 consumed Chinese herbal medicines, 10 used proprietary Chinese medicinal products, and 2 used both. The concordance between the causality assessment of the hepatologist and clinical toxicologist was moderate (weighted κ = 0.48, 95%CI 0.30-0.66). The causality assessment process concluded that the likelihood of HILI was "highly probable" in 5 cases and "probable" in 12, whereas there were 5 "highly probable" and 16 "probable" cases as assessed by RUCAM. The causality assessment by the multidisciplinary approach and RUCAM also showed moderate agreement (weighted κ= 0.51, 95%CI 0.22-0.81).

CONCLUSION

A multidisciplinary approach using defined algorithms is a scientific approach in causality assessment for HILI. Further study is needed to assess its accuracy and applicability.

Early clinical predictors of severe acute respiratory syndrome in the emergency department

OBJECTIVES

To assess the association of diagnostic predictors available in the emergency department (ED) with the outcome diagnosis of severe acute respiratory syndrome (SARS).

METHODS

This retrospective cohort study describes all patients from the Amoy Garden complex who presented to an ED SARS screening clinic during a 2-month outbreak. Clinical and diagnostic predictors were recorded, along with ED diagnoses. Final diagnoses were established independently based on diagnostic tests performed after the ED visit. Associations of key predictors with the final diagnosis of SARS were described.

RESULTS

Of 821 patients, 205 had confirmed SARS, 35 undetermined SARS and 581 non-SARS. Multivariable logistic regression showed that the strongest predictors of SARS were abnormal chest x-ray (odds ratio [OR] = 17.4), subjective fever (OR = 9.7), temperature degrees >38 degrees C (OR = 6.4), myalgias (OR = 5.5), chills and rigors (OR = 4.0) and contact exposure (OR = 2.6). In a subset of 176 patients who had a complete blood cell count performed, the strongest predictors were temperature >or=38 degrees C (OR = 15.5), lymphocyte count <1000 (OR = 9.3) and abnormal chest x-ray (OR = 5.7). Diarrhea was a powerful negative predictor (OR = 0.03) of SARS.

CONCLUSIONS

Two components of the World Health Organization case definition - fever and contact exposure - are helpful for ED decision-making, but respiratory symptoms do not discriminate well between SARS and non-SARS. Emergency physicians should consider the presence of diarrhea, chest x-ray findings, the absolute lymphocyte count and the platelet count as significant modifiers of disease likelihood. Prospective validation of these findings in other clinical settings is desirable.

Emergency department presentation of ketamine abusers in Hong Kong: a review of 233 cases

OBJECTIVES

To study the acute clinical presentations of ketamine abusers in Hong Kong.

DESIGN

Retrospective chart review.

SETTING

Fifteen accident and emergency departments in Hong Kong.

PATIENTS

Consultations associated with recent ketamine use either confirmed by history or urine test were searched for from the database of the Hospital Authority Hong Kong Poison Information Centre from 1 July 2005 to 30 June 2008. Their medical records and investigation results were analysed.

RESULTS

A total of 233 records of ketamine use were included for review. Patient ages ranged from 13 to 60, with a median of 22 years, and the male-to-female ratio being 2.1:1. The most common symptoms of ketamine misuse were impaired consciousness (45%), abdominal pain (21%), lower urinary tract symptoms (12%), and dizziness (12%). The most common abnormal physical findings were high blood pressure (40%), followed by tachycardia (39%), abdominal tenderness (18%), and white powder in the nostrils (17%).

CONCLUSION

Most ketamine abusers presented acutely with transient central nervous system depression, abdominal pain, or lower urinary tract symptoms. Clinicians should be alert to the typical age-group, signs and symptoms of such abusers presenting in an acute medical setting.