Advanced life support
Advanced Life Support (ALS) implies that an emergency medical technician (EMT) is capable of performing advanced life support skills as either an EMT-A (Advanced), EMT-I (Intermediate) or an EMT-P (Paramedic), commonly referred to simply as a paramedic or medic. Canadian paramedics may be certified in either ALS or in only basic life support (see paramedics in Canada).
ALS (in most cases) refers to the skills and knowledge that a practitioner possess. The ALS provider may perform advanced procedures and skills on a patient involving invasive and non-invasive procedures including;
- Cardiac monitoring
- Cardiac defibrillation
- Transcutaneous pacing
- Intravenous cannulation (IV)
- Intraosseous (IO) access and intraosseous infusion
- Surgical cricothyrotomy
- Needle cricothyrotomy
- needle decompression of tension pneumothorax
- Advanced medication administration through parental and enteral routes (IV, IO, PO, PR, ET, SL, topical, and transdermal)
- Following algorhythms as set forth by AHA Advanced Cardiac Life Support (ACLS)
- Following algorhythms as set forth by AHA Pediatric Advanced Life Support (PALS) or Pediatric Emergencies for Pre-Hospital Providers (PEPP)
- Following algorhythms as set forth by Pre-Hospital Trauma Life Support (PHTLS), Basic Trauma Life Support (BTLS) or International Trauma Life Support (ITLS)
In the United States, Advanced, Intermediate and Paramedic level services are referred to as Advanced Life Support. Services staffed by basic EMTs are referred to as Basic Life Support. This terminology extends beyond emergency cardiac care to describe all capabilities of the providers.
ALS is a treatment consensus for cardiopulmonary resuscitation in cardiac arrest and related medical problems, as agreed in Europe by the European Resuscitation Council, most recently in 2005. It is practiced by in-hospital cardiac arrest teams, which generally consist of junior doctors from various specialties (anesthetics, general or internal medicine). Emergency medical technicians (EMTs) are often skilled in ALS, although they may employ slightly modified version of the algorithm.
The main algorithm of ALS, which is invoked when actual cardiac arrest has been established, relies on the monitoring of the electrical activity of the heart on a cardiac monitor. Depending on the type of cardiac arrhythmia, defibrillation is applied, and medication is administered. Oxygen is administered and endotracheal intubation may be attempted to secure the airway. At regular intervals, the effect of the treatment on the heart rhythm, as well as the presence of cardiac output, is assessed.
Medication that may be administered may include adrenaline (epinephrine), amiodarone, atropine, bicarbonate, calcium, potassium and magnesium. Saline or colloids may be administered to increase the circulating volume.
While CPR is given (either manually, or through automated equipment such as AutoPulse), members of the team consider eight forms of potentially reversible causes for cardiac arrest, commonly abbreviated as "6Hs & 5Ts" according to the new 2005 AHA ACLS <ref>Part 7.2: Management of Cardiac Arrest - 112 (24 Supplement): IV-58 - Circulation</ref><ref name=ACLS_2003_H_T>ACLS: Principles and Practice. p. 71–87. Dallas: American Heart Association, 2003. ISBN 0-87493-341-2.</ref><ref name=ACLS_2003_EP_HT>ACLS for Experienced Providers. p. 3-5. Dallas: American Heart Association, 2003. ISBN 0-87493-424-9.</ref><ref name="ECC_2005_7.2">"2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 7.2: Management of Cardiac Arrest." Circulation 2005; 112: IV-58 – IV-66.</ref>. Note these reversible causes are usually taught and remembered as 4Hs and 4Ts<ref>Resuscitation Council UK adult ALS algorithm 2005</ref>—including hypoglycaemia and acidosis with hyper/hypokalaemia and 'metabolic causes' and omitting trauma from the T's as this is redundant with hypovolaemia—this simplification aids recall during resuscitation.
Hs and Ts
- Hypoxia: low oxygen levels in the blood
- Hypovolemia: low amount of circulating blood, either absolutely due to blood loss or relatively due to vasodilation
- Hyperkalemia or hypokalemia: disturbances in the level of potassium in the blood, and related disturbances of calcium or magnesium levels.
- Hypothermia: body temperature not maintained
- Hydrogen ions (Acidosis)
- Hypoglycemia: Low blood glucose levels
- Tension pneumothorax: tear in the lung leading to collapsed lung and twisting of the large blood vessels
- Tamponade: fluid or blood in the pericardium, compressing the heart
- Toxic and/or therapeutic: chemicals, whether medication or poisoning
- Thromboembolism and related mechanical obstruction (blockage of the blood vessels to the lungs or the heart by a blood clot or other material)
- Trauma (Hypovolemia): Reduced blood volume.
As of December 2005, Advanced Life Support guidelines have changed significantly. A major new worldwide consensus has been sought based upon the best available scientific evidence. The ratio of compressions to ventilations is now recommended as 30:2 for adults, to produce higher coronary and cerebral perfusion pressures. Defibrillation is now administered as a single shock, each followed immediately by two minutes of CPR before rhythm is re-assessed (five cycles of CPR). See Advanced Cardiac Life Support
ALS also covers various conditions related to cardiac arrest, such as cardiac arrhythmias (atrial fibrillation, ventricular tachycardia), poisoning and effectively all conditions that may lead to cardiac arrest if untreated, apart from the truly surgical emergencies (which are covered by Advanced Trauma Life Support).