Intensive care medicine - AbsoluteAstronomy.com

Intensive-care medicine or critical-care medicine is a branch of medicine concerned with the diagnosis and management of life threatening conditions requiring sophisticated organ support and invasive monitoring.

Overview

Patients requiring intensive care may require support for hemodynamic instability (hypertension

Hypertension

Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...

/hypotension

Hypotension

In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...

), airway or respiratory compromise (such as ventilator

Medical ventilator

A medical ventilator can be defined as any machine designed to mechanically move breatheable air into and out of the lungs, to provide the mechanism of breathing for a patient who is physically unable to breathe, or breathing insufficiently....

support), acute renal failure

Acute renal failure

Acute kidney injury , previously called acute renal failure , is a rapid loss of kidney function. Its causes are numerous and include low blood volume from any cause, exposure to substances harmful to the kidney, and obstruction of the urinary tract...

, potentially lethal cardiac arrhythmias, or the cumulative effects of multiple organ failure, more commonly referred to now as multiple organ dysfunction syndrome

Multiple organ dysfunction syndrome

Multiple organ dysfunction syndrome ', previously known as multiple organ failure or multisystem organ failure , is altered organ function in an acutely ill patient requiring medical intervention to achieve homeostasis...

. They may also be admitted for intensive/invasive monitoring, such as the crucial hours after major surgery when deemed too unstable to transfer to a less intensively monitored unit.

Intensive care is usually only offered to those whose condition is potentially reversible and who have a good chance of surviving with intensive care support. Since the critically ill are so close to dying, the outcome of this intervention is difficult to predict. A prime requisite for admission to an Intensive Care Unit is that the underlying condition can be overcome.

Medical studies suggest a relation between intensive care unit (ICU) volume and quality of care for mechanically ventilated patients. After adjustment for severity of illness, demographic variables, and characteristics of the ICUs (including staffing by intensivists), higher ICU volume was significantly associated with lower ICU and hospital mortality rates. For example, adjusted ICU mortality (for a patient at average predicted risk for ICU death) was 21.2% in hospitals with 87 to 150 mechanically ventilated patients annually, and 14.5% in hospitals with 401 to 617 mechanically ventilated patients annually. Hospitals with intermediate numbers of patients had outcomes between these extremes.

In general, it is the most expensive, technologically advanced and resource-intensive area of medical care. In the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, estimates of the 2000 expenditure for critical care medicine ranged from US$15–55 billion. During that year, critical care medicine accounted for 0.56% of GDP

Gross domestic product

Gross domestic product refers to the market value of all final goods and services produced within a country in a given period. GDP per capita is often considered an indicator of a country's standard of living....

, 4.2% of national health expenditure and about 13% of hospital costs.

Organ systems

Intensive care usually takes a system by system approach to treatment, rather than the SOAP (subjective, objective, analysis, plan) approach of high dependency care. The nine key systems (see below) are each considered on an observation-intervention-impression basis to produce a daily plan. As well as the key systems, intensive-care treatment raises other issues including psychological health, pressure points, mobilisation and physiotherapy, and secondary infections.

The nine key IC systems are (alphabetically): cardiovascular system, central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

, endocrine system

Endocrine system

In physiology, the endocrine system is a system of glands, each of which secretes a type of hormone directly into the bloodstream to regulate the body. The endocrine system is in contrast to the exocrine system, which secretes its chemicals using ducts. It derives from the Greek words "endo"...

, gastro-intestinal tract (and nutritional condition), hematology

Hematology

Hematology, also spelled haematology , is the branch of biology physiology, internal medicine, pathology, clinical laboratory work, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases...

, microbiology

Microbiology

Microbiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell , cell clusters or no cell at all . This includes eukaryotes, such as fungi and protists, and prokaryotes...

(including sepsis status), peripheries (and skin), renal (and metabolic), respiratory system

Respiratory system

The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...

.

The provision of intensive care is, in general, administered in a specialized unit of a hospital

Hospital

A hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....

called the intensive-care unit (ICU) or critical-care unit (CCU). Many hospitals also have designated intensive-care areas for certain specialities of medicine, such as the coronary intensive-care unit (CCU or sometimes CICU, depending on hospital) for heart disease, medical intensive-care unit (MICU), surgical intensive-care unit (SICU), pediatric intensive-care unit (PICU), neuroscience critical-care unit (NCCU), overnight intensive-recovery (OIR), shock/trauma intensive-care unit (STICU), neonatal intensive-care unit (NICU), and other units as dictated by the needs and available resources of each hospital. The naming is not rigidly standardized. For a time in the early 1960s, it was not clear that specialized intensive care units were needed, so intensive-care resources (see below) were brought to the room of the patient that needed the additional monitoring, care, and resources. It became rapidly evident, however, that a fixed location where intensive-care resources and personnel were available provided better care than ad hoc provision of intensive care services spread throughout a hospital.

Equipment and systems

Common equipment in an intensive-care unit (ICU) includes mechanical ventilation

Mechanical ventilation

In medicine, mechanical ventilation is a method to mechanically assist or replace spontaneous breathing. This may involve a machine called a ventilator or the breathing may be assisted by a physician, respiratory therapist or other suitable person compressing a bag or set of bellows...

to assist breathing through an endotracheal tube

Tracheal intubation

Tracheal intubation, usually simply referred to as intubation, is the placement of a flexible plastic or rubber tube into the trachea to maintain an open airway or to serve as a conduit through which to administer certain drugs...

or a tracheotomy

Tracheotomy

Among the oldest described surgical procedures, tracheotomy consists of making an incision on the anterior aspect of the neck and opening a direct airway through an incision in the trachea...

; hemofiltration

Hemofiltration

In medicine, hemofiltration, also haemofiltration, is a renal replacement therapy similar to hemodialysis which is used almost exclusively in the intensive care setting...

equipment for acute renal failure

Acute renal failure

; monitoring equipment; intravenous lines for drug infusions fluids or total parenteral nutrition

Total parenteral nutrition

Parenteral nutrition is feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulae that contain nutrients such as glucose, amino acids, lipids and added vitamins and dietary minerals...

, nasogastric tubes, suction pumps, drains and catheters; and a wide array of drugs

Pharmacology

Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...

including inotrope

Inotrope

An inotrope is an agent that alters the force or energy of muscular contractions. Negatively inotropic agents weaken the force of muscular contractions...

s, sedatives, broad spectrum antibiotics and analgesics.

Medical specialties

Critical-care medicine is a relatively new but increasingly important medical specialty. Physicians with training in critical-care medicine are referred to as intensivists. The specialty requires additional fellowship training for physicians having completed their primary residency training in internal medicine, pediatrics, anesthesiology, or surgery. Board certification in critical care medicine is available through all four specialty boards. Respiratory Therapists though already specialists in cardiopulmonary critical care have additional credentialing in Adult Critical Care (ACCS) and Neonatal and Pediatric (NPS) specialties. Nurse intensivists receive their training after basic education through ASTNA. Paramedics are certified to levels of CCEMTP or FP-C

FP-C

FP-C is an abbreviation indicating that an individual is Flight Paramedic-Certified. This certification is for paramedics who have demonstrated their knowledge of critical care medicine by successfully passing a two-and-a-half-hour exam consisting of 125 multiple-choice questions...

. Intensivists-physicians with a primary training in internal medicine sometimes pursue combined fellowship training in another subspecialty such as pulmonary medicine, cardiology, infectious disease, or nephrology. The Society of Critical Care Medicine

Society of Critical Care Medicine

Society of Critical Care Medicine , established in 1970, is an independently incorporated, international, educational and scientific society, serving its 15,000 members world-wide who are dedicated to providing the highest quality care to all critically ill and injured patients...

is a well-established multiprofessional society for practitioners working in the ICU, including intensivists. Most medical research has demonstrated that ICU care provided by intensivists produces better outcomes and more cost-effective care. This has led the Leapfrog Group to make a primary recommendation that all ICU patients be managed or co-managed by a dedicated intensivist who is exclusively responsible for patients in one ICU. However, there is a critical shortage of intensivists in the United States, and most hospitals lack this critical physician team member.

Patient management in intensive-care differs significantly between countries. In Australia, where Intensive Care Medicine is a well-established speciality, ICUs are described as 'closed'. In a closed unit the intensive-care specialist takes on the senior role where the patient's primary doctor now acts as a consultant. The advantage of this system is a more coordinated management of the patient based on a team who work exclusively in ICU.
Other countries have open Intensive Care Units, where the primary doctor chooses to admit and, in general, makes the management decisions. There is increasingly strong evidence that 'closed' Intensive-Care Units staffed by Intensivists provide better outcomes for patients.

Florence Nightingale era

The ICU's roots can be traced back to the Monitoring Unit of critical patients through nurse Florence Nightingale

Florence Nightingale

Florence Nightingale OM, RRC was a celebrated English nurse, writer and statistician. She came to prominence for her pioneering work in nursing during the Crimean War, where she tended to wounded soldiers. She was dubbed "The Lady with the Lamp" after her habit of making rounds at night...

. The Crimean War

Crimean War

The Crimean War was a conflict fought between the Russian Empire and an alliance of the French Empire, the British Empire, the Ottoman Empire, and the Kingdom of Sardinia. The war was part of a long-running contest between the major European powers for influence over territories of the declining...

began in 1853 when Britain, France, and Turkey declared war on Russia. Because of the lack of critical care and the high rate of infection, there was a high mortality rate of hospitalised soldiers, reaching as high as 40% of the deaths recorded during the war. Nightingale and 38 other volunteers had to leave for the Fields of Scurati, and took their "critical care protocol" with them. Upon arriving, and practicing, the mortality rate

Mortality rate

Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...

fell to 2%. Nightingale contracted typhoid, and returned in 1856 from the war. A school of nursing dedicated to her was formed in 1859 in England. The school was recognised for its professional value and technical calibre, receiving prizes throughout the British government. The school of nursing was established in Saint Thomas Hospital, as a one-year course, and was given to doctors. It used theoretical and practical lessons, as opposed to purely academic lessons. Nightingale's work, and the school, paved the way for intensive care medicine.

Dandy era

Walter Edward Dandy was born in Sedalia, Missouri

Sedalia, Missouri

Sedalia is a city located about south of the Missouri River in Pettis County, Missouri. U.S. Highway 50 and U.S. Highway 65 intersect in the city. As of 2006, the city had a total population of 20,669. It is the county seat of Pettis County. The Sedalia Micropolitan Statistical Area consists of...

. He received his BA in 1907 through the University of Missouri

University of Missouri

The University of Missouri System is a state university system providing centralized administration for four universities, a health care system, an extension program, five research and technology parks, and a publishing press. More than 64,000 students are currently enrolled at its four campuses...

and his M.D. in 1910 through the Johns Hopkins University School of Medicine. Dandy worked one year with Dr. Harvey Cushing

Harvey Cushing

Harvey Williams Cushing, M.D. , was an American neurosurgeon and a pioneer of brain surgery, and the first to describe Cushing's syndrome...

in the Hunterian Laboratory of Johns Hopkins before entering its boarding school and residence in the Johns Hopkins Hospital. He worked in the Johns Hopkins College in 1914 and remained there until his death in 1946. One of the most important contributions he made for neurosurgery was the air method in ventriculography, in which the cerebrospinal fluid is substituted with air to help an image form on an X-Ray of the ventricular space in the brain. This technique was extremely successful for identifying brain injuries. Dr. Dandy was also a pioneer in the advances in operations for illnesses of the brain affecting the glossopharyngeal as well as Ménière's syndrome, and he published studies that show that high activity can cause sciatic pain.
Dandy created the first ICU in the world, 03 beds in Boston in 1926.

Ibsen era

Bjørn Aage Ibsen

Bjørn Aage Ibsen was a Danish anesthetist and founder of intensive-care medicine. He graduated in 1940 from medical school at the University of Copenhagen and trained in anesthesiology from 1949 to 1950 at the Massachusetts General Hospital, Boston...

(1915–2007) graduated in 1940 from medical school at the University of Copenhagen and trained in anesthesiology from 1949 to 1950 at the Massachusetts General Hospital, Boston. He became involved in the 1952 poliomyelitis outbreak in Denmark, where 2722 patients developed the illness in a 6 month period, with 316 suffering respiratory or airway paralysis. Treatment had involved the use of the few negative pressure respirators available, but these devices, while helpful, were limited and did not protect against aspiration of secretions. Ibsen changed management directly, instituting protracted positive pressure ventilation by means of intubation into the trachea, and enlisting 200 medical students to manually pump oxygen and air into the patients lungs. At this time Carl-Gunnar Engström had developed one of the first positive pressure volume controlled ventilators, which eventually replaced the medical students. In this fashion, mortality declined from 90% to around 25%. Patients were managed in 3 special 35 bed areas, which aided charting and other management. In 1953, Ibsen set up what became the world's first Medical/Surgical ICU in a converted student nurse classroom in Kommunehospitalet (The Municipal Hospital) in Copenhagen, and provided one of the first accounts of the management of tetanus with muscle relaxants and controlled ventilation. In 1954 Ibsen was elected Head of the Department of Anaesthesiology at that institution. He jointly authored the first known account of ICU management principles in Nordisk Medicin, September 18, 1958: ‘Arbejdet på en Anæsthesiologisk Observationsafdeling’ (‘The Work in an Anaesthesiologic Observation Unit’) with Tone Dahl Kvittingen from Norway. He died in 2007.

Safar era

Peter Safar

Peter Safar was an Austrian physician of Czech descent. He is credited with pioneering cardiopulmonary resuscitation.- Early life :...

, the first Intensivist doctor in the USA, was born in Austria as the son of two doctors. He first migrated to the United States in 1949. Safar first got certification as an anesthesiologist

Anesthesiologist

An anesthesiologist or anaesthetist is a physician trained in anesthesia and peri-operative medicine....

, and, in the 1950s, he started and praised the "Urgency & Emergency" room setup (now known as an ICU). It was at this time the ABC (Airway, Breathing, and Circulation) protocols were formed, and artificial ventilation as well as cardiopulmonary resuscitation

Cardiopulmonary resuscitation

Cardiopulmonary resuscitation is an emergency procedure which is performed in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person in cardiac arrest. It is indicated in those who are unresponsive...

became popular. These experiments counted on volunteers of its team, and used only minimal sedation. It was through these experiments that the techniques for maintaining life in the critical patient were established.

The first surgical ICU was established in Baltimore, and, in 1962, in the University of Pittsburgh, the first Critical Care Residency was established in the United States. It was around this time that the induction of hypothermia in critical patients was also tested.

In 1970, the Society of Critical Care Medicine