# Emergency Medicine

Emergency medicine (EM) involves the diagnosis and management of urgent medical conditions, especially life-threatening medical situations like motor vehicle accidents, heart attacks or the ingestion of poisons. EM physicians and pre-hospital personnel, such as ambulance workers provide initial patient care with the aim of providing patient comfort and improving long-term patient outcome.

## Organization of emergency medicine

Main article: Organization of emergency medicine

## The specialty of emergency medicine

In some jurisdictions, Emergency Medicine is almost regarded as a sub-discipline to Family Medicine. Most authors would now hold that Emergency Medicine has become sufficiently specialised, in techniques and knowledge scope, to be a discipline in its own right. While there can be a General Practice component to many cases seen in the typical emergency room, most emergency rooms now have to deal with an acuity and complexity of case that general practitioners are no longer sufficiently skilled to handle such cases. For General Practitioners who expect to practise in smaller towns or in rural areas, it is particularly important to incorporate good Emergency Medicine experience into their training.
Usually practicing in a hospital setting, EM physicians have training to deal with most medical emergencies, and usually maintain certifications in CPR, at least the first two of the following:
* Advanced Cardiac Life Support (ACLS)
* Advanced Trauma Life Support (ATLS)
For those who also operate in the extramural (pre-hospital) setting:
* PreHospital Trauma Life Support (PHTLS)
* PreHospital Pediatric Emergency Care (PPEC)
For those who specialize in pediatric trauma care:
* Advanced Pediatric Trauma Life Support (APTLS)
In addition, in cases of disasters requiring special resources, many hospitals have protocols to rapidly deploy on-site and off-site staff.
The management of both emergency department (ED) and inpatient medical emergencies are guided by the basic ACLS and ATLS principles and protocols. Irrespective of the nature of the clinical emergency, maintenance of adequate blood pressure, adequate blood flow to vital organs and adequate oxygenation and ventilation are important guiding principles. (Although sometimes these principles must be deliberately broken, as in the deliberate clamping of an arterial bleeder to prevent exsanguination).
The first step in emergency medicine is triage: determining who (if there are multiple casualties) requires medical assistance first. Triage is done at multiple stages in the care process, especially in case of incidents involving many casualties.
* On-site personnel decides which victims are treated on the scene and which are to be taken to a hospital, and in which order.
* At the entrance to the ED, an ED worker (usually a nurse) determines to which treatment room each victim should be taken.
* The ED physician checks which patient he needs to attend to first.

## Introduction to emergency medicine

The art of emergency medicine can best be described using the following ideas examined upon initial evaluation:
* Airway
* Breathing
* Circulation
* Disability (neurologic)
These point are known as the ABC(D)'s of Emergency Medicine.
Then the general steps of practicing Emergency Medicine:
* Assessment
* Diagnosis
* Treatment
* Disposition
The ABC's of emergency medicine are basic to life support. Every time one enters into an emergency one should determine whether the patient has an open airway, if they are breathing in an unobstructed manner, if they have an adequate pulse (circulation), if they have any obvious sources of bleeding, and if they have any (neurologic) disability (e.g. a broken neck that has led to neurological injury.)
Assessment using the ABC's is the cornerstone of emergency care and it should be a continous and ongoing process. Just because initally someone's airway is patent doesn't mean it necessarily will stay that way. So the key point is to stay flexible in assement and treament. The mark of an ED physician is someone who can manage the airway (intubate), someone who can manage the breathing of a patient (set a ventilator) and somone who can provide cardiac or respiratory support (ACLS treatment of cardiac problems like shock, myocardial infarction or arrhythmias.)

## Disposition

The EM physician must decide where a patient should go after stabilization: home, to the operating room for surgery, to a regular nursing floor, to a step-down unit, to the Intensive Care Unit (ICU) etc. Thus a role central to the EM physician is triage, and his or her best tool is often the telephone, in asking for advice and help. If, for instance, the EM physician encounters a patient suffering from a myocardial infarction, he or she might start MONA (Morphine, Oxygen, Nitroglycerine and Aspirin) and promptly contact a cardiologist to take over care since "time is myocardium".
In the United States, ED physicians have completed a residency in Emergency Medicine and most U.S. hospitals require that the ED physician is board-certified in Emergency Medicine (EM). Previously, ED physicians may have trained in Internal Medicine, Orthopaedics or Surgery; however, EM is now recognized as a specialty that requires unique training. Other countries may still use generalists in the ED.

## Clinical crisis protocol

The "clinical crisis protocol" is an approach to dealing with urgent problems when a patient's life is in danger and there is limited time to act. Thus, diagnosis of the problem must be accompanied by initial empirical treatment, i.e. diagnosis and treatment must be carried out concurrently, even when it's far from clear what is going on. For example, severe bradycardia (heart rate < 40) may or may not be associated with symptoms such as syncope and can be due to many different causes, (e.g. third degree heart block, beta blocker overdose, use of an anti-cholinesterase without sufficient anticholinergic (e.g. neostigmine without glycopyrrolate or atropine), increased intracranial pressure, etc.)
An approach to rapidly assess the patient the trouble is sometimes needed:
LOOK: Color (cyanosis, erythema, pallor), respirations (rate, pattern), diaphoresis, bleeding/dressings/drains, neck (jugular venous distenstion, tracheal deviation), restlessness, discomfort
LISTEN: breath sounds (?equal), wheezes, crackles, stridor, heart sounds, patient’s complaints, observations of bystanders
FEEL: pulse (rate, intensity, pattern), grip strength (esp. after muscle relaxants given), forehead (temperature, diaphoresis)
GET: help, vital signs, old chart, crash cart, labs, chest x-ray... Again, we emphasize that initial empirical treatment is essential while we are finding out what is going on. For example, in the case of symptomatic severe bradycardia, intravenous atropine (0.6 - 1 mg) should be given (among other things).

## Circulatory emergencies
### Cardiology: circulatory emergencies

* Ventricular tachycardia / ventricular fibrillation
* Loss of pulse in an extremity (esp. following vascular surgery)
* Severe bradycardia or other rhythm disturbance
* Severe hypotension or hypertension
* Myocardial ischemia (with or without angina or electrocardiographic changes)
* Angina, acute coronary insufficiency, myocardial infarction
* Aortic dissection or aneurysm
* Cardiac arrhythmias
* Cardiopulmonary resuscitation

### Shock

Shock is the lack of perfusion of vital organs, that is, blood flow and pressure are inadequate to facilitate gas transport. Types of shock include:
Distributive shock
* Neurogenic shock
* Anaphylactic shock
* Septic shock
Cardiogenic shock
* Valve disease
* Cardiomyopathy
Hypovolemic shock
* Dehydration
* Hemorrhagic shock (blood loss)

## Respiratory emergencies
### Pulmonology: respiratory emergencies

* Cyanosis / hypoxemia
* Stridor (noisy inspiration from partial upper airway obstruction)
* Respiratory failure
* Smoke inhalation
* Cardiopulmonary resuscitation

## Neurological and psychiatrical emergencies
### Neurology: neurological emergencies

* Grand-mal seizures / unresponsive patient / coma
* Cerebrovascular accident (stroke)
* Headaches (especially migraines, cluster headaches, and those due to intracerebral bleeds)
* Epileptic seizure

### Psychiatry: psychiatrical emergencies

* Post-traumatic stress syndrome

## Abdominal emergencies
### Abdominal (surgical) emergencies

* Abdominal pain
* Appendicitis (with or without peritonitis)
* Hernia (inguinal, incisional, femoral, or hiatal)

### Urology: urological emergencies

* Urinary retention

## Injuries
### Penetrating injuries

* Bleeding
* Gunshot wounds
* Stab wounds

### Non-penetrating injuries

* Burns (first degree, second degree, third degree)
* Drowning and near-drowning
* Electric shock / electrocution / electric burns

## Metabolical emergencies
### Endocrinology: endocrinological emergencies

* Diabetic coma

### Poisoning

* Drug overdose

## Critical care medicine

* ICU monitoring
* Cardiac monitoring (CVP, PAOP, CO etc.)
* Neurologic monitoring (ICP etc.)

## Pediatry: pediatrical emergencies

* Neonatal resuscitation