Guidelines for poison control
II. Technical guidance - 3. Clinical services
Cases of poisoning may be treated in many places, e.g. at the scene of the accident, during transport, in a hospital. The type of care that can be given will depend on whoever makes the initial contact with the patient and in what circumstances. Certain members of the community, such as firemen, policemen, and teachers, may frequently be the first to be faced with poisoning cases. In rural areas, nurses and primary health care workers, and even agronomists and veterinarians, may have to deal with poisoned persons. They all need at least some basic training in first aid as well as in decontamination and measures for their own protection. An IPCS handbook on this first level of response to poisoning is in preparation.1
1 Management of poisoning. A handbook for health care workers. Geneva, World Health Organization (in preparation).
General practitioners or family doctors are often the first medically qualified persons consulted. They must be able to give appropriate initial treatment and may need to contact their local poison information centre. Most patients with serious poisoning, if they survive, will sooner or later reach a hospital, ideally one with a wide range of medical facilities, including intensive care. In some places, specialized treatment services have been established offering the best possible conditions for the management of poisoning. These services also have the advantage of ready access to a wide range of related medical facilities.
Most cases of poisoning, however, will be treated through a country's normal health service facilities, usually at a general hospital, far from a poison information centre and without access to a specialized clinical toxicology unit. According to patients' needs, treatment may be given by different services within the hospital, including the following:
* Emergency services. In practice, emergency services receive a relatively high number of poisoning cases, as they function on a round-the-clock basis and are provided with trained personnel and basic equipment for decontamination and life-support measures.
* Intensive care units. Intensive care units are usually well provided with highly specialized personnel and equipment for resuscitation, life-support measures, and care of critical poisoning cases.
* General medical units. Basic medical care of non-critical poisoning cases can be provided within general medical units in which staff have received some training in, or information on, clinical toxicology and which are in close contact with poison information centres.
* Specialized services. Specialized services offer the advantage of well trained medical staff and appropriate equipment for the management of poisoning cases in which specific organs or physiological functions are affected; they include nephrology, gastroenterology, neurology, cardiology, and haematology services.
* Paediatric departments. Poisoned children are frequently treated in paediatric departments.
To be able to treat poisoned patients, general hospitals need equipment for:
*gastrointestinal, cutaneous, and ocular decontamination (e.g. equipment for gastric lavage)
*immediate, and often longer-term, life-support measures (e.g. endotracheal intubation, assisted and controlled ventilation, parenteral fluid therapy, pharmacological treatment, cardiac pacing, defibrillation)
*continuous cardiac and circulatory monitoring (through ECGs, blood pressure measurements, etc.) and monitoring of other vital functions
*initial and repeated general biomedical laboratory analyses (e.g. acid-base balance, blood gases, electrolytes, blood glucose, liver and kidney function, and coagulation)
*initial and repeated specific toxicological analyses of body fluids such as blood, urine, and stomach contents (the choice of analyses will vary according to local patterns of poisoning)
*haemodialysis, peritoneal dialysis, haemoperfusion
*administration of appropriate antidotes (some of which may be specific to local needs and all of which should be stored in accordance with WHO recommendations1.
In an emergency, it is essential that the relevant medical personnel at general hospitals and other health service facilities where poisoning cases are treated have rapid access to toxicological information and experience. Here, the poison information centre plays a key role through its telephone advice service. Ideally, centres should circulate information to general hospitals and other health service facilities on a regular basis. This information should be adapted to suit local needs and should include general advice on the diagnosis and management of poisoning cases commonly expected to be treated at the particular hospital or facility, as well as information on new developments in patient management and on new types of poisoning.
The information flow should be a two-way process. General hospitals and health science facilities should be encouraged to maintain close contact with national and regional poison information centres and to furnish these centres with regular reports on cases of poisoning, particularly the more unusual ones. Such reporting helps to maintain an up-to-date national database on poisoning and is important for toxicovigilance.
1 The International Pharmacopoeia, Third edition. Vol. 2, Quality specifications. Geneva, World Health Organization, 1981.
The training of medical personnel in relevant aspects of toxicology for their work in managing poisoned patients is another important task for the poison information centre. For this purpose, it is essential that the centre itself is closely involved in the management of poisoning cases.
Some countries have found it valuable to have one or more specialized clinical toxicology units where the most important cases of poisoning in a region are treated. In some cases an intensive care unit is associated with, or forms part of, a clinical toxicology unit. The latter would normally be associated with a national or regional poison information centre.
Clinical toxicology units
Roles and functions
While general clinical wards and various specialized services that treat both poison victims and other types of patient are potential participants in poison control programmes, clinical toxicology units deal exclusively with the management of poisoning. These independent specialized units may have three principal functions besides patient management, namely toxicovigilance, education, and research. Locating a poison information service and analytical facilities in the same department or building as a clinical toxicology unit is an advantage and may be of benefit to patients. However, where there is no common location, highly reliable communications between the unit, the information service, and the laboratory are essential in order to establish a partnership between them in the diagnosis and management of poisoning.
Ideally, a specialized clinical toxicology unit should be part of national or regional medical facilities for the management and treatment of poisoning. It provides for:
*optimal treatment of poisoned patients
*identification of the effects of chemicals and natural toxins on health
*evaluation of the cause-effect relationship in a case of poisoning
*assessment of new developments in clinical and analytical methods of diagnosis and in treatment
*development of specific therapeutic management
*appropriate follow-up and surveillance of cases for identification and assessment of sequelae, and
*study of the circumstances of the poisoning and predisposing factors (data can then be used for planning preventive action).
Clinical toxicology units should record data on poisoning cases and toxicological consultations in a standardized format, preferably compatible with that used by poison information centres. Full case data, including follow-up, should be recorded.
Location and facilities
The minimum requirements for setting up a clinical unit for the treatment of acute poisoning are:1
*availability of methods, equipment, and areas for the resuscitation, decontamination, and initial management of poisoning cases
*good communication links with a poison information centre
*well established protocols for the treatment of common cases of acute poisoning
*availability of antidotes for immediate use, in quantities appropriate to the frequency of the main forms of poisoning (see Section 7)
*laboratory facilities for standard biological analyses and for toxicological screening (see Section 4)
*availability of emergency transport for patients
*an emergency plan for dealing with disasters and major chemical accidents.
1See also Table 1.
There should be sufficient space for all levels of patient care, and for the activities of the staff on duty, including administration, small conferences, education activities, and storage of clinical records.
Consideration should also be given to such practical matters as a comfortable rest area, personal hygiene facilities, parking space, and the provision of food and beverages round the clock for duty staff.
Initially, the staff may consist of emergency-room physicians to provide resuscitation and first aid, plus paediatricians, anaesthetists, and intensive-care staff to look after severely poisoned patients. However, in developing countries or in newly established clinical units, there may be a shortage of sufficiently well qualified medical personnel, in which case medical officers or adequately trained paramedical personnel have an important part to play in the initial evaluation, transfer, and referral of poisoning cases. They should be capable, for example, of recognizing a case of, poisoning, of identifying the main toxic syndromes (e.g. anticholinergic, cholinergic, opioid), and especially of recognizing situations that require the immediate application of life-saving measures.
Ideally, therefore, the staff should consist of:
*The medical director of the clinical toxicology service, who should be qualified to:
-organize the care of poisoned patients, both directly and through case consultation
-implement, review, and update protocols for the evaluation and treatment of poisoning cases
-supervise staff performance
-promote toxicological research
-identify those programmes or agencies that might provide funding for research or the further development of the service.
*Trained specialist(s) in clinical toxicology with practical experience and, ideally, with a professional qualification.
*Physician(s) with competence in the care of critically ill patients.
*Advisers from other medical disciplines, e.g. pharmacology, and from non-medical areas of interest.
*Supporting paramedical staff (e.g. nurses, medical officers).
*Administrative staff and record-keepers.
While the need for clinical toxicology services is becoming increasingly obvious, the growing demand for adequate, trained personnel is not being met. Physicians from countries with no appropriate facilities should be sent for training in toxicology to established centres where poisoned patients are treated. The objective in each case should be for the trainee to obtain experience of every aspect of the work of a centre, so as to be able to initiate or develop poison control activities in his or her own country. It is important for trainees to know the problems and special "risk profiles" associated with poisoning in their own countries before starting their courses.
Physicians from developing countries where facilities for training in some aspects of clinical toxicology are available could be trained in their own countries if appropriate programmes were organized, with visiting experts invited to teach those subjects for which training facilities are lacking. Alternatively, trainees could be sent to centres abroad to supplement or enlarge experience gained at home.
A training programme for clinical toxicologists should include education in the theoretical aspects of human toxicology, preparation for a dissertation, and teaching activities. Trainees should also gain experience of work in:
*a poison information centre (including training in preparing documents, collecting information, replying to enquiries, recording case data, and follow-up of cases);
*a clinical toxicology unit, emergency department, or intensive care unit where poisoned patients are treated; and
*a toxicological laboratory, where a practical understanding of sampling and analytical methods and of the medical interpretation of the results of analyses is provided.
There should also be opportunities to attend or participate in seminars, courses, lectures, conferences, and meetings within and outside the centre.
This training programme would be expected to take two years and should be undertaken preferably by physicians with some experience in related disciplines and some knowledge of chemistry, biochemistry, statistics, epidemiology, pharmacology, and information technology. It should cover all the main areas of toxicology in general, while stressing those in which local cases or risks of poisoning are frequent or severe. The basic contents of such a training programme are indicated in Table 2.
Although the basic professional training of clinical staff is supplemented by experience obtained in the course of their work, the rapid development of toxicology makes continuing education and updating of knowledge a professional and ethical responsibility. Means of achieving this include the reading of scientific literature, participation in local, regional, and national seminars, meetings, and workshops, or attendance at training courses of several days' or weeks' duration. The continued updating of expertise can be stimulated by, for example, making participation in scientific meetings a condition of certification. In the USA, where professional certification is controlled by the American Board of Medical Toxicology, the American Board of Veterinary Toxicology, and the American Board of Toxicology, evidence of active interest in new developments is necessary in order to maintain expert status in toxicology. This system not only encourages continuing education but also contributes to career advancement by boosting professional status.
Nurses and paramedical personnel working in clinical units where cases of poisoning are treated should also be given special training in toxicology. This is especially important in countries where qualified physicians are scarce or are overwhelmed by crowded emergency rooms and outpatient consultations.
Nurses, paramedical personnel, and clinical officers will need a concise and more practical training course than that given to physicians, perhaps based on the training programme on clinical toxicology outlined in Table 2. For example, the principles of quick clinical diagnosis, first-aid measures, decontamination techniques, and recognition of life-threatening symptoms are of primary importance. Other more theoretical aspects of toxicology may be omitted altogether or considered only briefly.
Clinical toxicology is still not acknowledged as a separate medical discipline in most countries. Its full acceptance as such by medical schools and the public health service is therefore desirable, and the importance of active collaboration among scientists and professionals in this area has now been internationally recognized. Every effort must be made to ensure that the relevant human resources are developed as quickly and effectively as possible. Measures to harmonize approaches to clinical toxicology throughout the world and to coordinate the work of international organizations and other international bodies in this area should be reinforced.
At the national level, the following measures should be taken to support and promote clinical toxicology:
*Clinical toxicology services should be established wherever the need for them is identified.
*The discipline of clinical toxicology should be given official recognition, as should the trained professionals who may be already working in this field.
*Academic institutions should be encouraged to develop clinical toxicology as a discipline in its own right, e.g. by establishing a department within a teaching hospital with an intensive care unit, outpatient clinic, laboratory for toxicological analysis, etc. This would be a step towards the institution of an academic career structure for clinical toxicologists.
Additional, internationally coordinated measures that would be useful in promoting clinical toxicology include the establishment of:
*mechanisms for ensuring unimpeded communication and exchange information and experience
*collaborative research projects on clinical toxicology
*international collaboration in establishing protocols for the treatment of poisoned patients and for the evaluation of antidotes
*international mechanisms for ensuring the adequate availability of antidotes and early warning of toxic hazards
*appropriate international educational programmes and exchanges.