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Abstract

MJA 1997; 167: 142-146  

Introduction

With a few exceptions, deliberate self-poisoning is managed on an ad-hoc basis in Australian hospitals. Commonly, the patient is managed in the emergency department and, if required, admission occurs under the general physician of the day or under the specialty which best corresponds to the patient's toxicological problem. Other models include medical management for most patients occurring entirely within the emergency department/intensive care axis. In one centre, 30% of patients with deliberate self-poisoning were not formally admitted.⁵ In many centres, expertise in toxicology comes from outside the service providing the patient care (e.g., from Poisons Information Centres).

In these models of management, not every patient with deliberate self-poisoning receives formal psychiatric assessment. Despite evidence that psychiatric intervention after parasuicide is worthwhile,⁶ psychiatric resources are commonly concentrated on those patients who require admission and those who have the most medically severe poisoning.⁷ However, significant suicidal risk is present for many patients with toxicologically "trivial" poisonings.  

Service structure

All deliberate self-poisoning patients are formally admitted under the HATS clinical toxicologist, who retains primary responsibility for care during the whole admission. A toxicology data collection form was developed which is also the formal admission record. The psychiatry team assess all patients with deliberate self-poisoning and, on request, other poisonings. Referral to the drug and alcohol service occurs as necessary. The patient is determined as medically fit for discharge by the toxicologist and the decision on appropriate discharge destination is made by the psychiatrist. Medical follow-up, when required, is the responsibility of the toxicologist.

A relational database for collecting data on poisoned patients⁴ was written (by I M W) in late 1986. The complexity of this database has progressively increased and an extensive psychiatric component (written by G L C) became operational in January 1996.

HATS was transferred to the Newcastle Mater Misericordiae Hospital in 1991 and took on an Area role (population, 385 000). All poisoning cases are transferred, either directly or after assessment at a closer hospital, to the Newcastle Mater Misericordiae Hospital unless they are too ill. If they are admitted to another hospital, they are admitted under the care of HATS. In practice, this relates to critically ill patients who are admitted to the intensive care unit at the presenting hospital under the care of the toxicologist from HATS, and discharged directly from that unit or transferred to the Newcastle Mater Misericordiae Hospital if they need more inpatient care after their intensive care stay.

HATS provides a 24-hour telephone consulting service for the Upper and Lower Hunter Areas (population, 100 000) and a tertiary referral service when required. The clinical pathway for this managed care is shown in Figure 1.

HATS medical management is provided by a full time equivalent clinical toxicologist (currently two clinical pharmacologists) and a registrar in clinical toxicology. The after hours service is provided by the two clinical pharmacologists with the addition of another clinical pharmacologist and a drug and alcohol specialist with an interest in toxicology. Every toxicology admission is seen by the medical team (at least once a day), seven days a week.

HATS psychiatric care is provided by a psychiatrist, a psychiatry registrar and a clinical nurse consultant in psychiatry. An after hours service is provided by part of an area roster of psychiatry registrars and four to six "second on call" psychiatrists. Every deliberate self-poisoning admission is seen by the psychiatry team (at least once a day), seven days a week. Even when the patient is consciously or cognitively impaired, our practice is to begin the psychiatric assessment by obtaining a collateral history from family/friends and health care workers before proceeding with individual psychiatric assessment. If the patient presents with a toxicologically trivial poisoning after 5 pm or on weekends (which would allow discharge before the routine morning psychiatric review) then the psychiatric registrar on call will come in to do the assessment and decide on appropriate discharge destination.  

Philosophy and strategies

Nursing perspective

Psychiatric perspective

Medical perspective

Outcomes and resource use

In 1995 there were 736 admissions to HATS (see Box 1). The median (range) hospital stay is calculated because the data are not normally distributed. The lower quartile is at 10.5 hours and the upper quartile at 27.5 hours. The distribution of hospital stay for deliberate self-poisoning patients is shown in Figure 2. In 1994-1995, for all hospitals with an emergency department in the Greater Newcastle area, deliberate self-poisoning comprised 1.2% of medical admissions; most presented to Newcastle Mater Misericordiae Hospital, where they comprised 7.3% of medical admissions. Of the 520 deliberate self-poisoning admissions who received formal psychiatric assessment, 492 (94.6%) had had one or more formal diagnoses¹¹ made of psychiatric disorder, personality disorder or other condition ("V" codes¹¹).

Average length of stay data for HATS compared with national data and all NSW public hospitals are shown in Boxes 2 and 3, respectively. Box 2 compares data derived from the HATS database for 1991-1994 with national data for 1992 (the most recent year available). Box 3 presents data from the NSW Health Department Inpatient Statistics Collection (1994-1995), and compares deliberate self-poisoning admissions to Newcastle Mater Misericordiae Hospital with the mean for all public hospitals in NSW. The data from Newcastle Mater Misericordiae Hospital in Box 3 are not derived from the HATS database, but rather from independent coding by the Medical Records Department of the Newcastle Mater Misericordiae Hospital according to ICD-9-CM.¹⁰ Both comparisons show a substantial reduction in bed stay for HATS. Since those patients not formally admitted at other hospitals are likely to be short stay presentations and thus not reported in the Inpatient Statistics Collection, we further analysed HATS data for 1993-1995. For all admissions average length of stay was 1.5 days; for all admissions with a hospital stay greater than 12 hours (72.6% of admissions) average length of stay was 1.69 days; for all admissions that required intensive care admission (16.8%), average length of stay was 2.59 days.

There has been no evidence that reduced bed stay has compromised patient care, as mortality from deliberate self-poisoning during this period (1987-1995) has been 0.6% (24 deaths in 3856 deliberate self-poisoning admissions; 95% CI, 0.4-0.9). Most of these patients had an out-of-hospital cardiac arrest and death was inevitable on presentation.⁴ NSW Health Department data for 1992 (the most recent year for which death data are available) show 13 inpatient deaths in 2876 admissions in NSW (0.5%; 95% CI, 0.2-0.8). HATS data for 1992 show one inpatient death in 512 deliberate self-poisoning admissions (0.2%; 95% CI, 0.0-1.1). These proportions are not significantly different (chi-squared = 2.04; P = 0.36). Standardised mortality ratios for suicide in NSW show the Hunter Area has no greater all-cause suicide mortality.¹³

HATS' prospective data collection on all presentations in a defined population is a very powerful tool for observational research. We have been able to identify public health issues related to patterns of drug use,^14,15 relative toxicity of drugs within classes^16-18 and the impact of safety packaging of medications.¹⁹

The NSW Health Department, as part of its health outcomes strategy, has provided funds to HATS to develop the management model (and the database) so that it can be trialled at other centres in NSW.  

Discussion

It could be argued that shorter length of stay in the Hunter is due to our policy of admitting all patients with deliberate self-poisoning regardless of severity. However, the greatest difference in average length of stay occurs in those patients with complications or comorbidities (Boxes 2 and 3), who require admission under any policy. Figure 2 shows that 90% of all our patients stay in hospital for less than 50 hours, which is less than the average length of stay for uncomplicated poisoning in NSW public hospitals (Box 3). In addition, HATS bed stay for all admissions (complicated and uncomplicated) after excluding those admitted for less than 12 hours (27.3% of presentations) is still shorter than the average length of stay for uncomplicated admissions to all NSW hospitals. The average length of stay for HATS admissions requiring intensive care is more than two days shorter than the average length of stay for all complicated admissions to NSW hospitals.

The model of management of self-poisoning described in this article is, we believe, unique in Australia. The differences we have identified in this model are:

• all toxicology presentations in one Area Health Service are diverted (by ambulance services and emergency departments) to one hospital

• all deliberate self-poisoning presentations are admitted

• all admissions are to one team

• the team is multidisciplinary, with medical, psychiatric, drug and alcohol, and nursing participation

• all deliberate self-poisoning admissions receive psychiatric assessment

• a 24-hour service for management and advice is provided.

We argue that all patients who present with deliberate self-poisoning should be admitted for several reasons:

• deliberate self-poisoning is a presenting symptom for another problem that requires assessment and intervention

• most deliberate self-poisoning admissions (94.6%) have a diagnosable psychiatric disorder, personality disorder or other psychiatric condition

• formal admission facilitates more efficient and effective assessment and management of both medical and psychiatric issues

• as more than half the presentations occur after hours, overnight admission is required to ensure adequate psychiatric assessment.

This model has resulted in a substantial and significant reduction in bed stay, which increases beds available for other purposes in the Area. There are two ways of calculating the monetary cost if funding were on a diagnosis-related group (DRG) basis. The first is to multiply the bed-days saved by the DRG cost of a bed-day, as in Box 2 and Box 3. The second is to assume the saved beds will be occupied by patients attracting further DRG funding. Assigning a monetary value to this is not possible. It is clear, however, that based on DRG funding these saved bed-days are worth more to the Area than the cost of running the service.

The reduction in bed stay has not been accompanied by a worsening in outcome, as defined by in-hospital mortality from deliberate self-poisoning or standardised mortality ratios for all-cause suicide. While the number of admissions to HATS in 1992 appears disproportionate, it is consistent with the proportion of admissions to other major hospitals^1,2 and reflects our policy of admitting all patients who present with deliberate self-poisoning. It appears likely the Department of Health figures for admissions significantly underestimate the number of presentations for deliberate self-poisoning to NSW hospitals. If so, while the magnitude of the saving per admission may be uncertain, on a State-wide basis the potential savings from implementing our model are even greater.

Without further data, determining the reasons for the shorter average length of stay is not possible, but anecdotal comparisons with other hospitals suggest the following possibilities:

• centralised, evidence-based management of specific poisonings resulting in

• earlier recognition of non-toxic or minimally toxic exposure

• more efficient gastrointestinal decontamination

• better management of significant toxic exposure

• more efficient use of psychiatric assessment, aftercare and discharge planning

• increased involvement of nursing staff in a multidisciplinary approach.

Our current model of management has evolved using the skills and experience of those interested in poisoning in Newcastle. The only new position created was the registrar position in clinical pharmacology. We do not believe, however, that replicating the model or its outcomes is dependent on replicating our subspecialty mix. Nevertheless, the identification of a team to manage poisoning is crucial. In many health areas the emergency physicians may be the logical choice for such a team. This would require an extension of admitting rights into the general hospital or a collaborative venture with an identifiable medical team. A specific group of psychiatrists is also required.

We believe that Area Health Services should consolidate acute toxicology services. A potential disadvantage of consolidation is loss of skills in the management of toxicological problems in other hospitals in the Area. This could be offset by making the service part of registrar and nursing training rotations. The advantages of consolidation include:

• individualising patient care

• continuity of care

• a better learning curve via greater experience

• training, education and research.

The efficiencies of this model are a product of the reorganisation of largely existing resources to provide a multidisciplinary team approach to the management of poisoned patients. The provision of care is based on a philosophy that these patients are entitled to a legitimate sick role. The major stumbling block to establishing a similar dedicated service is in making the decision to reorganise existing services. As House et al. state, after reviewing services in the United Kingdom, "there is much to recommend in clinical diversity, but nothing to recommend [in] unplanned and incoordinated service provision".⁶  

Acknowledgements

References

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