A Retrospective Review: Acute Poisonings Presenting to the Accident and Emergency Department in Botswana

Keywords

Poisoning; Accident and emergency department

Abstract

Background: Acute poisonings commonly present to the Accident and Emergency (A&E) department, but specific epidemiologic data regarding poisonings in Botswana is limited in the current medical literature. This study was performed to generate patterns on which future studies and preventative programs can be based.

Methods: This is a retrospective chart review conducted on poisoning cases which presented to the A&E in Princess Marina Hospital (PMH) in Gaborone, Botswana from January 2016 to June 2016.

Results: 289 patients were seen in the A&E at PMH for acute poisonings. Of these, 57% were female. Of all the toxic exposures, 58% were intentional. Patients who were age 16-35 were more commonly affected than younger and older patients. While most patients were admitted, only 3 required ICU and the case fatality rate among all patients was 0.7%.

Conclusion: The rate of toxic exposure cases in Botswana appears to be increasing. Paraffin, paracetamol, snake bites, traditional medicines and unknown ingestions are the most commonly encountered poisonings presenting to the A&E in the first half of the year. Many of these are mild and can be discharged home without hospital admission; however, some are deadly and require close monitoring and aggressive care. Paraffin ingestion is quite common among children, at times fatal and almost always accidental making it an ideal target for public health initiatives. Women are more likely than men to ingest toxic substances and more commonly do so intentionally. This investigation was limited by its retrospective design, but shows basic patterns on which larger and prospective studies can be based.

Introduction

According to the World Health Organization (WHO) there are 2 million suicide attempts and 1 million accidental poisonings worldwide each year [1]. Acute poisoning is one of the most common conditions evaluated in the Accident and Emergency department (A&E) in Princess Marina Hospital (PMH) in Gaborone, Botswana, accounting for 1.9% of all visits [2].

Deliberate self-harm is common in developing regions of the world and often takes the form of acute toxic ingestion. Additionally, the mortality rate from poisonings in these parts of the world is often high due to innate toxicity of compounds, availability of such toxins due to less stringent regulation and decreased access to medical care [3].

A 2001 WHO report asserts that 94% of the world’s fatal poisonings occurred in low and middle income countries [1]. A recent investigation in Botswana listed acute poisoning as the third leading cause of non-HIV related admission to PMH [4]. Due to limited documentation, scarcity of resources and diagnostic challenges, these cases are likely underreported and possibly much more common than described.

Princess Marina Hospital, a public teaching hospital is one of two tertiary referral centers in Botswana which receives patient transfers from other clinics and hospitals throughout the country. PMH has 525 beds and is located in Gaborone, the capital and largest city in Botswana. The A&E has an 18-bed capacity with 2 resuscitation bays and treats both adult and pediatric patients. Toxic ingestions and exposures are commonly encountered presentations to PMH and contribute significantly to patient morbidity and mortality [5].

Unfortunately, there is no centralized reporting system for poisonings in Botswana and the overall risk and incidence of such exposures is not yet known. In 2008, Malangu et al. published a study which found that acute poisonings in Botswana had a case fatality rate of 2.6% which is significantly higher than most parts of the world [4]. However, from the time of their retrospective review in 2005, no follow-up data has been published on poisonings in Botswana. Studies from diverse regions of the world demonstrate distinctive temporal patterns of poisonings as well as wide variations among the most commonly exposed toxins [6].

The goal of this study was to gather information regarding specific toxins, risk factors, frequency, temporal relationships and intentionality as an important initial step to gaining a general understanding of poisonings encountered in Botswana. Identifying high risk patients and toxic agents may facilitate further, more specified investigations, design of targeted preventive initiatives and development of focused education on individualized treatments which will serve to ultimately advance the overall care of acutely poisoned patients.

Methods

Permission for this study was granted by the Research and Ethics Committee of the Office of Research and Development at the University of Botswana as well as the Ministry of Health and the Research and Ethics Committee at Princess Marina Hospital. A retrospective review was conducted on the charts of poisoning cases seen in the A&E in PMH from January 1, 2016 to June 30, 2016. Patients were included if they were found to have an acute toxic ingestion, dermal or inhaled chemical exposure or animal envenomation. Patients were excluded if there was unverifiable data or if the chart was incomplete. Two pre-approved personnel collected data on demographic information including age, sex and month of presentation. In addition, information about intentionality, specific toxin exposure and disposition was also gathered. Data was entered into a spreadsheet and was analyzed by Microsoft Excel software in order to maintain accurate computations. We use descriptive statistics to present data. Means are used to present continuous variables and percentages are used to present the categorical data. All information was kept on a password protected hard drive and all identifying patient information was removed to ensure privacy protection.

Results

In the first half of 2016, 289 patients were seen in the A&E at PMH for acute poisonings (Table 1). Of these, 57% were female. Of all the toxic exposures, 58% were intentional. Patients who were age 16-35 were more commonly affected than younger and older patients. While most patients were admitted, only 3 required ICU admission.

Table 1: Sex, Age and Disposition by Intentionality.

The case fatality rate among all patients was 0.7%. One of the two deaths resulted from accidental ingestion of a traditional medicine and the other from a scorpion sting. The five most common toxic exposures presenting to the A&E department from January to June of 2016 were snake bites, paraffin ingestion, paracetamol ingestion, scorpion stings and ingestion cases in which the substance was unknown. The most common exposures seen each month are depicted in figure 1. Snake bites occurred more commonly from January to April while there were no cases in May and June. All five of the most common poisonings appeared to present less commonly from the winter months of May through June compared to the warmer months of January through April.

Figure 1: Top 5 Poisonings by Month. This table shows the five most common poisonings seen in the A&E department each month. Snake bites were more common from January to April. None occurred in May or June.

In comparison by sex, women were more likely than men to present to the A&E with a toxin exposure, 57.4% and 40.8% respectively (Figure 2). Of patients presenting with toxic ingestions, women were much more likely than men to have consumed the toxin intentionally (Figure 3). While only 43% (51/118) of male cases presenting with toxic ingestions were intentional, 69% (116/166) of female cases of ingestion were intentional. Male ingestions were more.

Figure 2: Poisonings by Sex. Women were more likely than men to present to the A&E with a toxic ingestion, 57.4% and 40.8% respectively.

Figure 3: Intentionality by Sex. Women were more likely to intentionally ingest toxic substances than men.

commonly accidental events. Most intentional poisonings occurred in patients from 16 to 50 years of age. Not surprisingly, childhood toxic ingestions before age 11, while common, were all accidental. Interestingly, ingestions after the age of 50 were relatively uncommon (Figure 4) and none were intentional up to 80 years of age. However, elderly patients presenting with toxic ingestions after the age of 80 were all intentional (Figure 5). Women were more likely than men to intentionally ingest toxins in all age groups except age group 11-15 (n=5) in which the reverse was true (Figure 6).

Figure 4: Age and Intentionality. Childhood toxic ingestions before age 11 were all unintentional. Ingestions over the age of 80 were all intentional.

Figure 5: Intentionality by age. Many unintentional poisonings occurred in children. Adults over the age of 50, but under the age of 80 were unlikely to present with toxic ingestions and all were unintentional. Toxic ingestions involving patients over age 80 were intentional (n=2).

Figure 6: Intentionality by Age and Gender. Women were more likely than men to intentionally ingest toxins in all age groups except age group 11-15 (n=5).

Paraffin

Paraffin poisoning was more common in the early years of life. This particular toxin, while common, was accidental in 88% of cases (15/17) (Figures 7 and 8) and common in both sexes. The majority of patients who ingested paraffin were sent home (Figure 9). Those who were admitted were able to be managed in the ward; none required ICU or surgical intervention.

Figure 7: Paraffin Ingestion by Sex and Age. Paraffin was common in male and female patients age 0-5, but uncommon after age 5.

Figure 8: Paraffin Intentionality. Ingestions with paraffin were accidental 88% of the time.

Figure 9: Paraffin Disposition. Patients with paraffin ingestions were either admitted to the ward or discharged home; none required ICU or surgical intervention.

Paracetamol poisoning

The majority of patients presenting after paracetamol ingestion were ages 16-25 (Figure 10). Patients in this age group were more than twice as likely to be female than male. Ninety percent of paracetamol ingestions were intentional (Figure 11). One patient required ICU, but the majority of paracetamol ingestions were managed in the ward (Figure 12).

Figure 10: Paracetamol Poisoning by Sex and Age. In ages 16-25, women were more likely to present with paracetamol ingestion.

Figure 11: Paracetamol Intentionality. Ninety percent of paracetamol ingestions were intentional.

Figure 12: Paracetamol Disposition. Most patients with paracetamol poisonings were managed in the ward, but 1 patient required ICU admission.

Discussion

This study, while limited by its retrospective design, serves as a resource on which to build further investigations. During the analysis from January to June of 2016, toxic exposures accounted for 2.7% of all A&E visits; this is an increase from 1.9% reported in 2010 [2]. This trend is consistent with findings from the National Poison Data system in the United States showing that the rate of death from poisoning has more than doubled from 1999 to 2010 [7].

While this present investigation was similar to the review conducted by Malangu et al. regarding poisonings in Botswana in 2005, there are several notable differences between these two studies [6]. Firstly, Malangu et al. found that only 50% of poisoning cases involved female patients and two-thirds of the occurrences were determined to be accidental. Also, their sub-group of males aged 30 and older had more intentional poisonings than women. These results differed from our investigation, which found a predominance of female cases (57%). Moreover, women were more likely than their male counterparts to have intentional ingestions across all age groups except the youngest group (11-14 years).

Although Malangu et al. found most cases to be accidental, 60% of the cases in our analysis were found to be non-accidental. However, cases of alcohol intoxication were not included in this present investigation. This variance from the Malangu study may explain both the higher prevalence of male poisonings as well as the higher proportion of males with intentional ingestions over the age of 30 in that study. Additionally, Malangu et al. also used data from both Gaborone and Francistown as opposed to this study, which only analyzed data from PMH in Gaborone.

While both Francistown and Gaborone hospitals are large referral centers which often receive patients from the same areas, it is possible that some differences may exist regarding poisoning patterns in these respective areas. Malangu and colleagues found a case-fatality rate of 2.6% whereas the case-fatality rate in this study was approximately 0.7%. This large difference may be because this current study analyzed all patients seen in A&E, while the Malangu study only examined cases admitted to the ward. Patients who required admission were likely sicker and therefore the case fatality from that group is expected to be higher than our cohort, of which 42.5% were discharged home from the A&E. The case-fatality rate among admitted patients in our study was 1.2% which is much higher, but still lower than the Malangu study.

These differences may be attributable to improvements in patient care over the last 11 years. However, it may be an insignificant difference that is only apparent due to the small sample sizes of each study (Number of deaths: Malangu study n=3, present study n=2). In summary, the case-fatality from poisonings of patients requiring admission is approximately 1-2.6%, which highlights the necessity for preventative and therapeutic public health interventions. Similar to the Malangu study, paraffin was one of the leading causes of unintentional overdose in this review.

One patient in the Malangu study died from paraffin ingestion. Although no patients in the present study died from paraffin poisoning, these ingestions did account for a large portion of presenting cases and hospital admissions. One study in Nigeria found a case fatality rate of 5.5% among pediatric patients admitted with paraffin ingestions [1]. Because most cases were accidental ingestions by children, interventions such as childproofing containers or education regarding safe storage of paraffin out of the reach of children may drastically reduce these occurrences and even prevent fatalities.

One investigation in South Africa found that amongst children who had ingested paraffin, almost 80% lived in a household where it was stored on the ground. Additionally, 72% of these patients were given home remedies to induce vomiting before going to the hospital. Counting both our analysis and the Malangu study, 3 out of the 5 deaths resulted from ingestion of traditional medicines. Malangu et al. did not comment on the intentionality of these deaths, but the one fatality in our analysis appeared to be accidental.

Accordingly, pursuits of a public health education program highlighting the dangers of traditional medicine may help decrease associated morbidity and mortality from these toxins. Also, a better understanding of what these medications contain may instruct health care professionals on which effective treatment regimens to utilize for affected patients. A Tlaleletso paper published in 2012 provides guidance on how to manage acute poisonings in Botswana [8].

While this is an admirable resource, the results of this present study suggest it would be beneficial to include treatment strategies for the most common and deadly encountered poisons in Botswana in the next edition. Namely, paraffin ingestion, snake bites and exposure to traditional medicines were common poisonings seen in this study and would be beneficial additions to the present instructions, which focus on traditional, commonly encountered poisons in more developed settings. For this review, a retrospective chart was utilized for ease and expediency.

However, due to the retrospective design, there are many inherent limitations to this study. For example, confounders are difficult to account for, allowing for formulation of associations only, rather than concluding causal relationships. Additionally, some data may be missing due to lack of documentation. Furthermore, because the sample size is quite small and only includes the first half of the year there is a risk for sampling bias.

Future studies covering years of data in a prospective manner will be superior for tracking temporal relationships and will allow for more dependable conclusions. This investigation was intended to gather initial data from which to generate hypotheses which can be studied further in the future.

Conclusion

Despite the many limitations, we now know that paraffin, paracetamol, snake bites, traditional medicines and unknown ingestions are the most commonly encountered toxic exposures presenting to the A&E in the first half of the year. Many of these are mild and can be discharged home without hospital admission; however, some are deadly and require close monitoring and aggressive care. For example, paraffin appears to be very common, at times fatal and almost always accidental; thus, it is a perfect target for public health initiatives. Lastly, women are more likely than men to ingest toxins and more commonly do so intentionally; thus, obtaining a careful history in these patients may reveal the value of employing psychiatric and social services for many patients.

References

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Citation

Rodriguez A, Shibata J, Pon P, Ciroe E and Cox M. A Retrospective Review: Acute Poisonings Presenting to the Accident and Emergency Department in Botswana. SM Emerg Med Crit Care. 2017; 1(3): 1011.