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BMJ. Apr 20, 2002; 324(7343): 958–962.
PMCID: PMC1122904
Recent developments

Emergency medicine

Daniel M Fatovich, specialist in emergency medicine

Most people believe that the emergency department is always available to help provide non-elective acute hospital care. Daniel Fatovich explains why this is not necessarily so

Emergency medicine is a field of practice based on the knowledge and skills required for the prevention, diagnosis, and management of the acute and urgent aspects of illness and injury affecting patients of all age groups with a full spectrum of undifferentiated physical and behavioural disorders.1 It is a specialty in which time is critical. Anyone who has been to an emergency department will appreciate that it is a complex and often turbulent environment. The emergency department is like the fire brigade—you hope you won't need it, but if you do, you expect a timely response.

Emergency medicine is a fairly new specialty. Resuscitation, toxicology, and clinical criteria for imaging represent some of the core topics of the practice of emergency medicine. This review focuses on these key areas and underlines the major problem that the specialty faces—namely, overcrowding.

Summary points

  • Overcrowding is the most serious issue confronting emergency departments in the developed world, with quality and timeliness of emergency care being compromised
  • Amiodarone is the antiarrhythmic drug of choice for cardiac arrest due to shock refractory ventricular fibrillation and ventricular tachycardia
  • For calcium channel blocker toxicity, the induction of hyperinsulinaemia and euglycaemia has striking bemefits
  • Octreotide prevents the rebound hypoglycaemia of sulphonylurea overdose
  • Validated clinical criteria for requesting imaging have been developed for cervical spine injury and are being developed for minor head injury

Methods

Many advances have been made in emergency medicine recently. I surveyed colleagues both locally and internationally to nominate suitable topics. The topics I have chosen were considered to be clinically useful and educational. They reflect subjects of change or advancement. Once the topics were chosen, I performed a directed review of leading relevant journals, mostly from publications in 2000-1. Because of space restrictions, this article cannot be a comprehensive review of all recent advances.

Overcrowding in the emergency department

Overcrowding in the emergency department is the biggest impediment to the delivery of timely and adequate emergency care. It is an international problem, and it is getting worse.2 It is often manifest as diversion of ambulances—an emergency department instructs the ambulance service to divert ambulances elsewhere because it is unsafe for more patients to attend.

Overcrowding in the emergency department is caused by a complex web of inter-related issues; these have been reported previously and are summarised in boxes boxesB1B1 and andB2B2.2 Figure Figure11 outlines basic processes of patient flow in the emergency department. In simple terms, if inflow is greater than outflow the result is overcrowding. This has been called “exit block” in the past, but it is now referred to as “access block,” as the patient is denied access to ongoing inpatient care.

Figure 1
Flow of patients in an emergency department
Causes of overcrowding in the emergency department (adapted from Derlet and Richards2)
Effects of overcrowding in the emergency department (adapted from Derlet and Richards2)

The main cause of access block is a lack of beds for acute inpatients. Some emergency departments are, however, experiencing “entry block” or entry overload—overwhelming numbers of patients presenting to the emergency department in a short time (fig (fig2).2). This results in impaired access to emergency care.3

Figure 2
A typical scene of overcrowding in an emergency department. Situations such as these lead to loss of clinical productivity and effectiveness and place the safety of patients at risk

Health systems in the United States, United Kingdom, Australia and New Zealand, and Canada are having similar difficulties, which implies that a profound change has occurred in the delivery of Western medicine. Health care in Western societies has been through a period of severe economic rationalisation, resulting in the closure of thousands of beds in the acute hospital system. In the United States, the number of medical and surgical beds declined by 18% in 1994-9. From 1990 to 1999, attendances at emergency departments increased by 15%.4 Many beds for elderly people have been closed or changed to community based facilities.

After a decade of hospitals downsizing and reducing operating costs, local healthcare systems have been left with little slack to accommodate unforeseen trends in the number of patients.4 Stopgap measures (box (boxB3)B3) provide only some temporary relief.

Some measures to address overcrowding in emergency departments

Longer term measures are required to deal with all the causes of overcrowding in emergency departments. Governments at all levels need to recognise and acknowledge the problem, which requires a system-wide approach. The government of the Australian state of Victoria has published a paper on how to manage emergency demand, which reports that the equivalent of another major suburban hospital is required.5 Opening additional beds in 1999-2000 led to a reduction of 24% in the number of patients waiting in emergency departments for admission for longer than 12 hours, and the episodes of ambulance diversion fell by 30%. In July, August, and September 2000, however, access block and ambulance diversions increased again, showing that the hospital system was operating at capacity and was unable to absorb further pressure.5

Emergency departments are the main point of entry into inpatient settings for people requiring non-elective acute hospital care. If all else fails in the health system, the emergency department is always available to help. That basic tenet is now being challenged, and the general public may no longer be able to rely on emergency departments for emergency care that is timely and of high quality.2

Resuscitation in cardiac arrest

As a result of an international conference in 2000, revised guidelines and algorithms on cardiopulmonary resuscitation and emergency cardiovascular care have been published (fig (fig3).3). Drugs such as adrenaline, antiarrhythmics, and buffer agents have been relegated to a secondary role. Systematic reviews show that no evidence exists to confirm a benefit resulting from these agents.6

Figure 3
International algorithm for advanced cardiac life support (adapted from Resuscitation Council UK website, www.resus.org.uk/pages/alsalgo.pdf). (BLS=basic life support, VF/VT=ventricular fibrillation/ventricular tachycardia, CPR=cardiopulmonary ...

Two new drugs have been recommended, vasopressin and amiodarone. Vasopressin is included as an option in the algorithm for ventricular fibrillation and ventricular tachycardia (level of evidence: acceptable, not harmful, supported by fair evidence).6 Vasopressin, a natural antidiuretic hormone, becomes a powerful vasoconstrictor when used at much higher doses than are normally present in the body. The drug has positive effects that duplicate the positive effects of adrenaline, but it does not replicate the adverse effects of adrenaline.6

Vasopressin is recommended as a single dose of 40 units. Its half life is 10-20 minutes, compared with the 3-5 minute half life of adrenaline. It can be given as an alternative to adrenaline, but a recent trial indicates the outcome is the same as with adrenaline.7 Adrenaline at high dosage (0.1 mg/kg) is not recommended for routine use but can be considered if doses of 1 mg fail.6

Amiodarone has a similar level of evidence as vasopressin and is supported by a better evidence base than any other antiarrhythmic drug.6 It should be the first choice antiarrhythmic drug for ventricular fibrillation and ventricular tachycardia that do not respond to defibrillation. The recommended dose for patients with cardiac arrest is 300 mg given intravenously as a bolus. If ventricular fibrillation or pulseless ventricular tachycardia recurs, a second dose of 150 mg should be considered. Lignocaine has an indeterminate level of recommendation.6

Biphasic defibrillators are now commonplace. They deliver current that flows in a positive direction for a specified duration. The current then reverses and flows in a negative direction for the remaining milliseconds of the electrical discharge. Biphasic waveforms have proved superior to monophasic waveforms for defibrillation by implantable defibrillators.6 Further research indicates that repetitive biphasic waveform shocks at lower energy (repeated shocks at <200 J) have equivalent or higher success for eventual termination of ventricular fibrillation than defibrillators that increase the current with successive escalating shocks (200 J, 300 J, 360 J). The energy level of the biphasic first shock yielding the highest termination rate of fibrillation is unknown.6

A more recent development in resuscitation of patients with cardiac arrest is the role of thrombolysis. Initial results show that thrombolysis in cardiac arrest may represent an important advance.8,9

Toxicology update

Up to 5% of patients presenting to an emergency department have taken an overdose. The drugs taken most often include benzodiazepines, paracetamol, alcohol, antidepressants, antipsychotics, anticonvulsants, and non-therapeutic substances. Many ingestions involve multiple drugs.

As new drugs are developed and released, inevitably patients take overdoses of them. This section briefly reviews some of these drugs that are now seen in overdose, or some of the newer treatment options. One such drug is bupropion, which has been licensed to help people stop smoking. Large quantities of bupropion have been prescribed over a short time. Buproprion is a unique monocyclic antidepressant that has structural similarities to amphetamines. Seizures have been a major concern with therapeutic use of bupropion, at a rate of around 0.4%. One study found a seizure rate of 21% in patients who had taken an overdose. Most convulsions either stopped spontaneously or were controlled with benzodiazepine. The time to onset of the first seizure ranged from 1 hour to 8 hours (mean 3.7 hours). Other toxicity affecting the central nervous system included lethargy, tremors, confusion, lightheadedness, hallucinations, and paresthesias. Sinus tachycardia is the most common cardiovascular effect.10,11 Treatment is supportive.

Another recent development is the use of atypical antipsychotic agents (respiridone, clozapine, quetiapine, olanzapine, ziprasidone, sertindole), which have largely replaced traditional agents as first line drugs for the treatment of schizophrenia. Most patients who take an overdose of atypical antipsychotic drugs will remain asymptomatic or develop only mild to moderate toxicity. Death is rare. Toxic effects begin within 1-2 hours after ingestion and peak by 4-6 hours. Toxicity is variably characterised by depression of the central nervous and respiratory systems, meiosis or mydriasis, hypertension or orthostatic hypotension, sinus tachycardia, agitation, delirium, anticholinergic stigmata, and, uncommonly, seizures and arrhythmias. Treatment is primarily supportive.12

A new treatment has been reported for poisoning with calcium channel blockers.13 Conventional treatment includes intravenous fluids, calcium, dopamine, dobutamine, noradrenaline, and glucagon. Inducing hyperinsulinaemia and euglycaemia as adjunctive treatment has resulted in striking benefits (dosage 0.5 units insulin/kg body weight/h, 10% dextrose 100 ml/h). The exact mechanism is poorly defined.

Overdose of sulphonyl urea is potentially life threatening. Traditional treatment includes intravenous dextrose and frequent monitoring of blood glucose concentrations. A dose of dextrose is a potent stimulus for additional release of insulin and often results in rebound hypoglycaemia that can be recurrent and prolonged. Octreotide acetate, a synthetic octapeptide analogue of the endogenous human hormone somatostatin, directly inhibits the secretion of insulin from the pancreas and prevents rebound hypoglycaemia. In one review, the dosing of octreotide ranged from a single subcutaneous dose of 40 μg to an intravenous infusion of 125 μg/hour.14

For people who take overdoses to harm themselves deliberately emergency departments need to address the psychiatric aspects of attempted suicide. Recent guidelines for the management of deliberate self harm in young people represent a consensus overview on the reasonable management of deliberate self harm in young people.15

Finally, with the new risks of bioterrorism, emergency physicians need to lead in the early diagnosis of illnesses such as anthrax, smallpox, plague, tularaemia, and botulism. Clinical vigilance for unusual or unexplained clusters of illness is the key to early detection and reporting.16

Improved clinical criteria for imaging

Injury to the cervical spine

Unrecognised injury to the cervical spine can produce catastrophic neurological disability. Fear of failing to diagnose such injuries has led to the liberal use of radiography of the cervical spine. This practice exposes many patients to radiography, at considerable expense, but detects injury only in a few.17

The National Emergency X-Radiography Utilisation Study (NEXUS) was a prospective, multicentre, observational study of patients with blunt trauma for which cervical spine imaging was ordered.18 NEXUS was organised to evaluate previously derived clinical criteria (box (boxB4)B4) and determine whether they can reliably identify patients who have no risk of cervical spine injury.

NEXUS cervical spine criteria18

The decision instrument was tested in 34 069 patients and the sensitivity of the criteria approached 100% for clinically important injuries. Only 2.4% of patients had a radiographically documented injury to the cervical spine. The overall rate of missed injury was less than one in 4000 patients, which was estimated to represent once in every 125 years of clinical practice.17

Computed tomography for minor head injury

Computed tomography is widely used to screen patients with minor head injury, which is defined as witnessed loss of consciousness, definite amnesia, or witnessed disorientation in a patient with a Glasgow coma score of 13-15. The controversy about the use of computed tomography is considerable, and guidelines are conflicting. Until recently, the evidence base of who should receive a scan for minor head injury has been limited.

In 2000, Haydel et al derived and validated a set of clinical criteria that could be used to identify patients with minor head injury in whom computed tomography could be forgone.19 They found that one or more of seven findings (headache; vomiting; age >60; drug or alcohol intoxication; defects in short term memory; physical evidence of trauma above the clavicle; seizure) had a sensitivity of 100% for identifying patients with positive results on scans, and the absence of all seven findings had a negative predictive value of 100%.

In 2001, Stiell et al's study on the use of computed tomography in minor head injury showed five high risk factors that were 100% sensitive for predicting the need for neurosurgical intervention and would require only 32% of patients to undergo computed tomography (box (boxB5B5).20 The group intends to validate the rule prospectively and explicitly in multiple sites in a further study.

Canadian computed tomography head rule (adapted from Stiell et al20)

Drug or alcohol intoxication is not a feature of these criteria: clinical examination in patients with suspected intoxication was neither reliable nor discriminating, and serum concentrations of alcohol were not correlated with important brain injury. Patients with intoxication who present with a Glasgow coma score of 13 or 14 therefore do not automatically require immediate computed tomography, but should be scanned if they do not improve to a Glasgow coma score of 15 within two hours of the injury.20

Additional educational resources

EMedHome (www.emedhome.com)

Contains useful reviews, clinical cases, kernels of information that may not be widely known but are extremely useful in clinical practice, a database of protocols, and links to helpful sites

Rehoboth McKinley Christian Hospital Emergency Department (www.rmch.org/erlinks.htm)

Contains a huge number of links and educational material, including emergency medicine and trauma related sites, radiology sites, medical and surgical specialties, paediatrics and family medicine, and advanced cardiac life support guidemaps.

National Center for Emergency Medicine Informatics (www.ncemi.org)

Contains many useful algorithms and educational material, including weekly electrocardiograms, x ray films, and photographs, as well as clinical decision rules, diagrams, and scoring systems.

Best Evidence Topics (www.bestbets.org)

Provides rapid evidence-based answers to real life clinical questions (accessed 28 Mar 2002)

Footnotes

 Competing interests: None declared.

References

1. Australasian College for Emergency Medicine. Policy document. Standard terminology. Carlton: Australasian College for Emergency Medicine, 15 November 2001. www.acem.org.au/open/documents/standard.htm (accessed 28 Mar 2002).
2. Derlet RW, Richards JR. Overcrowding in the nation's emergency departments: complex causes and disturbing effects. Ann Emerg Med. 2000;35:63–68. [PubMed]
3. Fatovich DM, Hirsch RL. Entry overload: a new cause of emergency department overcrowding and ambulance bypass [abstract] Emerg Med. 2002;14:A9.
4. Brewster LR, Rudell LS, Lesser CS. Emergency room diversions: a symptom of hospitals under stress. Issue Brief Cent Stud Health Syst Change. 2001;38:1–4. [PubMed]
5. Acute Health Division. Emergency demand management. Melbourne, Victoria: Victorian Government Department of Human Services; 2001.
6. Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Part 6: advanced cardiovascular life support: section 1: introduction to ACLS 2000: overview of recommended changes in ACLS from the guidelines 2000 conference. The American Heart Association in collaboration with the International Liaison Committee on Resuscitation. Circulation. 2000;102:1–384. [PubMed]
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13. Boyer EW, Shannon M. Treatment of calcium-channel-blocker intoxication with insulin infusion [letter] N Engl J Med. 2001;344:1721–1722. [PubMed]
14. McLaughlin SA, Crandall CS, McKinney PE. Octreotide: an antidote for sulfonylurea-induced hypoglycemia. Ann Emerg Med. 2000;36:133–138. [PubMed]
15. Australasian College for Emergency Medicine; Royal Australian and New Zealand College of Psychiatrists. Carlton/Melbourne: Australasian College for Emergency Medicine, Royal Australian and New Zealand College of Psychiatrists; 2000. Guidelines for the management of deliberate self harm in young people.www.acem.org.au/open/documents/youthsuicide.pdf (accessed 28 Mar).
16. Eitzen EM. Education is the key to defense against bioterrorism [editorial] Ann Emerg Med. 1999;34:221–223. [PubMed]
17. Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. N Engl J Med. 2000;343:94–99. [PubMed]
18. Vinson DR. NEXUS cervical spine criteria [letter] Ann Emerg Med. 2001;37:237–238. [PubMed]
19. Haydel MC, Preston CA, Mills TJ, Luber S, Blaudau E, DeBlieux PMC. Indications for computed tomography in patients with minor head injury. N Engl J Med. 2000;343:100–105. [PubMed]
20. Stiell IG, Wells GA, Vandemheen K, Clement C, Lesiuk H, Laupacis A, et al. The Canadian CT head rule for patients with minor head injury. Lancet. 2001;357:1391–1396. [PubMed]

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