Demographics of toxic exposures presenting to three public hospital emergency departments in Singapore 2001-2003

Student assistantship programme: an evaluation of impact on readiness to transit from medical student to junior doctor

BACKGROUND

Studies report that medical graduates are not prepared for practice as expected, and interventions have been developed to prepare them for practice. One such intervention is the assistantship, which provides hands-on opportunities to hone clinical skills and undertake responsibilities under supervision. The Lee Kong Chian School of Medicine (LKCMed) is Singapore's newest medical school, and students undergo a Student Assistantship Programme (SAP) to prepare for practice as junior doctors (PGY1). This study evaluated the SAP from the students' and clinical supervisors' perspectives.

METHODS

Students completed online questionnaires to assess readiness for practice before and after SAP, and a subsample were interviewed about their experiences of SAP and its impact on their preparedness for PGY1. In addition, after our graduates had begun work as PGY1 doctors, their clinical supervisors completed an online questionnaire and were interviewed about the perceived benefits of SAP and the attributes of our graduates as junior doctors.

RESULTS

Fifty (96%) students completed the pre-SAP questionnaire and 46 (92%) completed the post-SAP questionnaire. Levels of preparedness increased post-SAP (mean scores range pre-SAP: 2.38 to 4.32 vs post-SAP: 3.08 to 4.48); so did opportunities to undertake PGY1 duties (pre-SAP: 56% vs post-SAP: 96%), and hands-on experience in medical emergencies (pre-SAP: 76% vs post-SAP: 89%).Experience of acute care situations increased except "paracetamol overdose". Readiness to be first respondents in ten acute situations improved (statistically significant for asthma, chronic obstructive pulmonary disease exacerbation, gastrointestinal bleed, sepsis, and adverse drug reactions). Three themes emerged from twenty-five student interviews: learning about the work environment, opportunities to learn in a safe environment, and enhancing SAP for future students. Thirty-three supervisors completed the questionnaire, and 70% rated SAP positively in preparing students for PGY1. Eight supervisors interviewed shared positively about the content, timing, and duration of SAP; and suggested future SAPs help students to develop coping and reflective skills.

CONCLUSIONS

The SAP improved students' preparedness and experience across clinical areas, and students felt the SAP helped bridge undergraduate curriculum and work, provided opportunities to hone their skills and learn from junior doctors. Most clinical supervisors rated the SAP effective in preparing students for PGY1. This is the first formal evaluation of an assistantship in Singapore, and the findings are encouraging from the perspective of students and PGY1 supervisors.

Cost Savings and Efficacy in Management of Paracetamol Poisoning in a 23-hours Emergency Department Observation Unit: A Comparison to Inpatient Care

Introduction

Emergency department observation units (EDOU) have been shown to be effective in decreasing hospitalization rates and length of stay (LOS) for various conditions. However, cost savings and efficacy in the management of poisoning in EDOU have not been widely studied. The objective of our study is to compare the costs and effectiveness of managing paracetamol poisoned patients in the EDOU with those treated in the inpatient wards.

Methods

We conducted a historical controlled observational study comparing paracetamol-poisoned patients (who received at least 21 hours of IV N-acetylcysteine [NAC]) admitted to the EDOU during 2013-2014 with similar patients admitted to inpatient ward during 2011, 2013-2014. 

Results

We found 136 patients admitted to the inpatient ward and 95 to our EDOU due to paracetamol poisoning but only 78 and 39 patients respectively fulfilled the inclusion criteria. Between the EDOU and inpatient ward groups, we found similar demographics, poisoning presentation, treatment, and adverse event profiles. There were no fatalities and only two patients (one from each group) developed hepatotoxicity. The "medical" length of stay was 31.9 hours shorter in the EDOU group compared to the inpatient ward group (23.3 versus 55.2 hours). EDOU patients have statistically significant savings (comparing bill size) of S$784 per patient.

Conclusions

Admission to the EDOU resulted in significant cost savings and 58% decreased LOS when compared to inpatient wards. The EDOU is a cost-effective and safe alternative for the management of selected paracetamol poisonings requiring NAC. Further studies would be needed to verify these results. 

A 24/7 hospital toxicology service: Experience of a new start-up

Objectives:

A toxicology team providing round-the-clock consultations for poisoning was established in Changi General Hospital in November 2014. This study aims to describe the epidemiology of patients referred to this service in 2015.

Methods:

A retrospective electronic and paper records review of all patients referred to the toxicology service from January to December 2015 was performed for demographics, poisoning, clinical, and outcome data. The cases were graded for poisoning severity score (PSS), likelihood of poisoning exposure and relative contribution to fatality for death cases.

Results:

A total of 306 cases were referred to this service in 2015. The median age was 34 years with majority being females (54%). The most common cause of poisoning was deliberate self-harm (62%) and the most common route of poisoning was oral (85%). Analgesics (21%) and sedatives (19%) were the most common poisoning classes. Six per cent of patients received decontamination and 17% received antidotes. The likelihood of poisoning exposure was probable to definite certainty for 85% of the cases. Mild poisoning (PSS 0–1) constituted 76% of the cohort, while 22% had moderate to severe poisoning (PSS 2–3). Out of the five fatalities, three were exposure-related fatalities contributing to a fatality rate of 1%. Fifty-four per cent of patients were admitted to the emergency department observation unit, 17% to general inpatient wards and 9% to either intensive care unit or high dependency wards.

Conclusions:

Although most poisoning cases resulted in mild clinical effects, a small but significant number of severe acuity cases occurred in this cohort.

Performance of an emergency department observation unit protocol in reducing length of stay for acetaminophen overdose: a retrospective study

Introduction

Acetaminophen is one of the most common causes of poisoning among developed countries. The emergency department observation unit (EDOU) has been increasingly used in the management of various conditions to reduce hospitalisation but its efficacy in not well studied in management of poisoned patients. In this study, we aim to study the effectiveness of our EDOU in the management of acetaminophen overdosed patients.

Results

Medical records of patients admitted from the emergency department from 2012 to 2016 for acetaminophen overdose were reviewed. One hundred ninety-five patients presenting with acetaminophen overdose were admitted to the EDOU while 184 were admitted to the general ward. Of these, 27 patients admitted to EDOU did not meet the admission criteria for it while 71 patients who met EDOU criteria were admitted to the ward instead. For patients who fulfilled EDOU admission criteria, median length of stay for EDOU patients was 23 h (IQR 19–24) while that for those admitted to the ward was 66 h (IQR 62.5–88.3).

Conclusion

The EDOU is a safe alternative to hospitalisation for patients presenting with acetaminophen poisoning. It is also associated with a shorter length of stay for such patients. Further studies need to be done to assess the cost-effectiveness of EDOU for management of patients presenting with acetaminophen overdose.

Epidemiology of paediatric poisoning presenting to a children's emergency department in Singapore over a five-year period

INTRODUCTION

Paediatric poisoning accounts for 1% of daily emergency department presentations. The aim of this study was to review the characteristics and outcomes of paediatric patients who presented with drug overdose over a five-year period.

METHODS

We performed a retrospective review of paediatric poisoning cases at KK Women's and Children's Hospital (KKH), the largest children's public hospital in Singapore, from 1 January 2009 to 31 December 2013.

RESULTS

A total of 1,208 cases of poisoning were seen in KKH's Department of Children's Emergency during the study period. The gender distribution was about equal, with a slight male predominance. The majority of the poisoning cases were accidental. Slightly more than half of the intentional ingestions were of paracetamol and the majority were female patients belonging to the 12-16 year age group. The bulk of poisonings occurred in children aged 1-4 via the oral route, slightly more than half of the oral ingestions consisted of oral medications and a sizeable portion were of household liquids. Mothballs and silica gels accounted for almost a quarter of the solid household products ingested. Slightly less than half of the patients required admission and only a small portion of the admitted patients required intensive or high dependency care.

CONCLUSION

The prognosis of paediatric patients who presented with poisoning in our study was good, with a short median length of stay for those admitted and no fatalities being reported across the span of five years.

Poison Exposure in the Emergency Department: A Singaporean Experience

Introduction

Poison exposure is a significant problem in emergency departments (EDs) with high admission rates. Our study aims were to describe the demographics, exposure patterns and clinical outcomes of our ED patients as well as to explore predictors of Intensive Care Unit (ICU) / High Dependency (HD) admission.

Methods

In this retrospective study, we recruited patients aged over 16 years who presented with poison exposure to our ED over one year. We collected demographical and clinical data using our hospital databases. Primary outcomes were mortality rate and disposition status. Secondary outcomes were predictors for ICU/HD admission. Logistic regression was applied to identify these predictors.

Results

We recruited 615 patients from an ED attendance of 162,159. Four hundred and nineteen (68%) patients were females; the majority [410 (66.7%)] was Chinese. The median age was 33 years [interquartile range (IQR): 24-44]. Four hundred fifty-six (74.1%) and 159 (25.9%) exposures were intentional or accidental respectively. There were no mortalities. The majority [466 (75.8%)] was admitted to the general ward and only 24 (3.9%) cases were ICU/HD admissions. We identified four factors associated with ICU/HD admission. Odds ratios (95% confidence intervals) for hypotension (systolic blood pressure <90 mmHg), pupillary changes, previous psychiatric history and tricyclic antidepressant overdose were 19.7 (5.57-69.65), 31.9 (7.01-145.76), 3.1 (1.08-9.07) and 30.1 (9.40-96.52) respectively.

Conclusions

Poison exposure is an infrequent ED occurrence with high admission rates but low mortality. Our study identified risk factors for ICU/HD admission that could be used in future studies to triage at-risk patients for treatment escalation.

Cost Benefits of the Drug and Poison Information Centre in Preventing Unnecessary Hospitalisation: The Singapore Experience

Background

The Drug and Poison Information Centre (DPIC) in Singapore was piloted as a new service in April 2004. This study evaluated the cost benefits of its interventions in the first two years of its operation.

Method

A two-year retrospective review of DPIC call records was performed and the following outcome measures were noted: (A) proportion of patients who were managed onsite and hence did not need to attend the emergency department (ED); and (B) proportion of patients who were managed in the ED without the need for admission. Cost savings were calculated based on admission costs for patients with poisoning, including other out-of-hospital costs. This amounted to savings of S$1390 and S$1170 for patients who fulfilled outcome measures A and B respectively. Savings for the hospital was S$1477 per case. The cost of operating the DPIC over the same period was S$507,922.

Results

There were 831 calls on acute toxic exposures over the study period. Of these, 115 and 405 patients fulfilled outcome measure A and B respectively with consequent cost savings of S$159,850 (115 x S$1390 per patient), and S$473,850 (405 x S$1170 per patient). The hospitals saved S$768,040 (520 x S$1477) from prevented admissions. Excluding operating cost, this gave net savings of S$893,818 over the two years from DPIC interventions.

Conclusion

The cost savings from DPIC services is evident from this study. This translates to more effective use of limited healthcare resources.

Use of a 23-hour emergency department observation unit for the management of patients with toxic exposures

BACKGROUND

A significant proportion of patients with toxic exposures presenting to the ED require admission. However, most will improve within 24 hours, and so could potentially be managed in a short-stay observation unit. We describe the management and outcomes of these patients in a 23-hour ED observation unit (EDOU).

METHODS

A retrospective chart review of all patients with toxic exposures admitted to the EDOU in Singapore between 1 April 2013 and 31 March 2015 was performed. Patient demographics, exposure patterns, clinical presentation and interventions received were abstracted. The poisoning severity score (PSS) was retrospectively determined. Outcomes were length of stay and disposition.

RESULTS

A total of 286 patients were analysed, of which 78.0% had intentional self-poisoning, 12.2% had bites/stings and 9.8% had unintentional or occupational toxic exposures. Analgesics (29.4%), sedatives (12.3%) and antidepressants (6.8%) were the most common drugs encountered. The majority of patients had a mild (68.9%) or moderate (15.4%) PSS, but 4.2% were graded as severe. Most patients with deliberate self-poisoning were reviewed by psychiatry (88.8%) and social services (74.9%). Most patients (92.0%) were medically cleared during their stay in EDOU, including all 12 with a severe PSS. Of these, 200 (69.9%) were discharged and 63 (22.0%) were transferred directly to a psychiatric unit. The median length of stay in the EDOU was 18 hours (IQR 13-23).

CONCLUSION

Most patients admitted to the EDOU were successfully managed and medically cleared within 23 hours, including those with a severe PSS. The EDOU appears to be a suitable alternative to inpatient admission for selected patients.

Characterisation and outcomes of adult patients with paracetamol overdose presenting to a tertiary hospital in Singapore

INTRODUCTION

Paracetamol is the most common pharmaceutical agent implicated in toxic exposure in Singapore. This study aimed to describe the characteristics of paracetamol overdose in the adult population managed at a tertiary healthcare facility in Singapore.

METHODS

Medical records of adult patients hospitalised with a diagnosis of paracetamol overdose at National University Hospital, Singapore, over a three-year period from January 2011 to December 2013 were retrospectively reviewed.

RESULTS

A total of 177 patients had paracetamol overdose. The median age was 25 years, with a significant female predominance (71.2%). Intentional ingestion accounted for the majority (76.8%) of cases. The median dose of paracetamol ingested was 10 (interquartile range 8-15) g. Among patients who reported ingesting more than 10 g, 46.5% perceived the overdose as non-lethal. N-acetylcysteine was administered in 76.3% of patients, among whom 24.4% experienced an anaphylactoid reaction. Of the 10 (5.6%) patients who had severe hepatotoxicity, 2 (1.1%) developed acute liver failure. Most patients had resolving transaminases at discharge and none required liver transplantation. The median length of hospitalisation was three days. There were no fatalities.

CONCLUSION

Paracetamol overdose occurred predominantly in young adults with intentional ingestion, suggesting that preventive measures targeted at promoting public awareness may not suffice. However, the perceived lack of lethality by many patients who ingested potentially toxic amounts of paracetamol reflects a certain knowledge gap. Healthcare providers should proactively educate consumers on the proper use of paracetamol and the consequences of its overdose.

Childhood Injuries in Singapore: Can Local Physicians and the Healthcare System Do More to Confront This Public Health Concern?

Childhood injury is one of the leading causes of death globally. Singapore is no exception to this tragic fact, with childhood injuries accounting up to 37% of Emergency Department visits. Hence, it is important to understand the epidemiology and risk factors of childhood injuries locally. A search for relevant articles published from 1996–2016 was performed on PubMed, Cochrane Library and Google Scholar using keywords relating to childhood injury in Singapore. The epidemiology, mechanisms of injury, risk factors and recommended prevention strategies of unintentional childhood injuries were reviewed and described. Epidemiological studies have shown that childhood injury is a common, preventable and significant public health concern in Singapore. Home injuries and falls are responsible for majority of the injuries. Injuries related to childcare products, playground and road traffic accidents are also important causes. Healthcare professionals and legislators play an important role in raising awareness and reducing the incidence of childhood injuries in Singapore. For example, despite legislative requirements for many years, the low usage of child restraint seats in Singapore is worrisome. Thus, greater efforts in public health education in understanding childhood injuries, coupled with more research studies to evaluate the effectiveness and deficiencies of current prevention strategies will be necessary.

Cross-Reactivity against Naja sumatrana (Black Spitting Cobra) Envenoming from the Haffkine Antivenom in a Mouse Model

Naja sumatrana is the dominant cobra species in Malaysia, Singapore, Borneo, and Sumatra, and it does not have specific antivenom. The Haffkine antivenom has been advocated instead. This study aims to determine the efficacy of this antivenom against Naja sumatrana envenoming using a mouse model. Methods. Male Swiss albino mice were used. Intravenous LD50 was first determined separately for Naja naja and Naja sumatrana venom. ED50 was determined by preincubating antivenom with each venom at 2.5 LD50 before administering the mixture into the tail vein. Validation was carried out using a challenge test. Each mouse received 111 µg of Naja sumatrana venom intramuscularly followed by intraperitoneal administration of dilute Haffkine antivenom. Survival was recorded 24 hours after envenoming. Results. The LD50 of Naja naja venom was 78.13 µg, standard error (SE) 13.3 µg. The ED50 of the Haffkine antivenom against Naja naja venom was 45.9 mg, SE 7.5 mg. The LD50 and ED50 of Naja sumatrana venom were 55.5 µg, SE 12.0 µg; and 73.9 mg, SE 12.0 mg, respectively. The intra-peritoneal ED50 against 111 µg intramuscular Naja sumatrana venom was 136.95 mg, SE 36.74 mg. Conclusion. The Haffkine polyvalent antivenom exhibited cross-neutralisation against Naja sumatrana venom when used at a higher dose.

Scorpion stings presenting to an emergency department in Singapore with special reference to Isometrus maculatus

OBJECTIVE

We describe the epidemiology and clinical features of scorpion stings presenting to an emergency department in Singapore, including that of the venomous species Isometrus maculatus. A management approach to scorpion stings is proposed.

METHODS

A retrospective study was done for patients from 2004 to 2009. Cases were identified by searching through emergency department records with ICD code E905, inpatient records, and the hospital toxicology service records. Identification of species was assisted by the Venom and Toxin research program at the National University of Singapore.

RESULTS

A total of 13 cases of scorpion stings were identified. Eleven stings occurred locally, and the remaining 2 stings occurred in neighboring countries. The most common presenting symptoms were pain (92%), numbness (31%), and weakness (23%) confined to the region of the sting. The most common clinical signs recorded were redness (77%), tenderness (77%), and swelling (46%). Only 2 patients had significant alterations of vital signs: 1 had hypertension and the other had hypotension from anaphylaxis. Three patients experienced complications (abscess formation, anaphylaxis, cellulitis) requiring inpatient management. There were no fatalities, and all patients made a good recovery. Three cases were identified to be stings from I maculatus. These cases occurred locally, and mainly had clinical features of pain, redness, and mild regional numbness.

CONCLUSIONS

Scorpion stings are uncommon presentations to the emergency department. Most stings cause local reactions that can be managed with supportive treatment. Stings by I maculatus were observed to cause mild, self-limiting effects.

A dosing regimen for immediate N-acetylcysteine treatment for acute paracetamol overdose

CONTEXT

Current treatment of paracetamol (acetaminophen) poisoning involves initiating a 3-phase N-acetylcysteine (NAC) infusion after comparing a plasma concentration, taken ≥ 4 h post-overdose, to a nomogram. This may result in dosing errors, a delay in treatment, or possibly more adverse effects - due to the use of a high dose rate for the first infusion when treatment is initiated.

OBJECTIVE

Our aim was to investigate a novel dosing regimen for the immediate administration of NAC on admission at a lower infusion rate.

METHODS

We used a published population pharmacokinetic model of NAC to simulate a scenario where a patient presents to the hospital 2 h post-overdose. The conventional regimen is commenced 6 h post-overdose when the 4-h plasma paracetamol concentration is available. We investigated an NAC infusion using a lower dosing rate initiated immediately on presentation. We determined a dosing rate that gave an area under the curve (AUC) of the concentration-time curve that was the same or greater than that from the conventional regimen on 90% of occasions.

RESULTS

Lower dosing rates of NAC initiated immediately resulted in a similar exposure to NAC. An infusion of 110 mg/kg over the first 5 h (22 mg/kg/h) followed by the last two phases of the conventional regimen, or 200 mg/kg over 9 h (22.6 mg/kg/h) followed by the last phase of the conventional regimen could be used.

CONCLUSION

The novel dosing regimen allowed immediate treatment of a patient using a lower dosing rate. This greatly simplifies the current dosing regimen and may reduce NAC adverse effects while ensuring the same amount of NAC is delivered.

A simple modified bicarbonate regimen for urine alkalinization in moderate pediatric salicylate poisoning in the emergency department

A 4-year-old Indian girl was seen in our emergency department for unintentional ingestion of topical medication oil with subsequent salicylate poisoning. Serum levels were 52 mg/dL at 12 hours after ingestion.She was started on urine alkalization therapy to enhance salicylate elimination. This was achieved by a bicarbonate bolus of 1 mEq/kg for an hour and a continuous bicarbonate-potassium-dextrose combination infusion. The infusion regimen was modified from adult recommendations to tailor for pediatric physiological requirements in a young child. This consisted of a combination solution of dextrose 5%-sodium bicarbonate-potassium chloride with similar sodium content as half-strength (0.45%) saline and supplemental potassium, which is crucial for effective urine alkalinization. The combination fluid was administered at a rate 1.5 times her maintenance fluid requirement to achieve a urine output of 1.5 to 2 mL/kg per hour and a urine pH of 7.5 to 8.5. This regimen was well tolerated with good outcome.Many pediatricians and toxicologists achieve urine alkalinization by giving multiple bicarbonate boluses and have separate hydration fluids with dextrose and supplemental potassium. These regimens may involve complex calculations and multiple infusions that may lead to increased risk of calculation and medication errors especially in the busy emergency department setting. This case report highlights the use of a simple modified urine alkalinization regimen for moderate salicylate poisoning in a young child in the emergency department.