Intensive care medicine

Intensive care medicine, or critical care medicine, is a branch of medicine concerned with the diagnosis and management of life-threatening conditions that may require sophisticated life support and intensive monitoring.

VIP Bird2
Mechanical ventilation may be required if a patient's unassisted breathing is insufficient to oxygenate the blood.
Intensive care medicine
Respiratory therapist
Example patient managed under intensive care
Significant diseasesRespiratory failure, Organ failure, Multiorgan failure
SpecialistIntensivist

Overview

Patients requiring intensive care may require support for cardiovascular instability (hypertension/hypotension), potentially lethal cardiac arrhythmias, airway or respiratory compromise (such as ventilator support), acute renal failure, or the cumulative effects of multiple organ failure, more commonly referred to now as multiple organ dysfunction syndrome. 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.

Medical studies suggest a relation between ICU volume and quality of care for mechanically ventilated patients.[1] 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. ICU delirium, formerly and inaccurately referred to as ICU psychosis, is a syndrome common in intensive care and cardiac units where patients who are in unfamiliar, monotonous surroundings develop symptoms of delirium (Maxmen & Ward, 1995). This may include interpreting machine noises as human voices, seeing walls quiver, or hallucinating that someone is tapping them on the shoulder.[2] There exists systematic reviews in which interventions of sleep promotion related outcomes in the ICU have proven impactful in the overall health of patients in the ICU.[3]

In general, it is the most expensive, technologically advanced and resource-intensive area of medical care. In the United States, 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, 4.2% of national health expenditure and about 13% of hospital costs.[4] In 2011, hospital stays with ICU services accounted for just over one-quarter of all discharges (29.9%) but nearly one-half of aggregate total hospital charges (47.5%) in the United States. The mean hospital charge was 2.5 times higher for discharges with ICU services than for those without.[5]

Organ systems

Intensive care usually takes a system-by-system approach to treatment. As such, the nine key systems are each considered on an observation-intervention-impression basis to produce a daily plan. In addition to the key systems, intensive care treatment raises other issues including psychological health, pressure points, mobilisation and physiotherapy, and secondary infections.

In alphabetical order, the nine key systems considered in the intensive care setting are: cardiovascular system, central nervous system, endocrine system, gastro-intestinal tract (and nutritional condition), hematology, integumentary system, microbiology (including sepsis status), renal (and metabolic), and respiratory system.

Intensive care is usually provided in a specialized unit of a hospital 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) 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 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 dedicated personnel were available provided better care than ad hoc provision of intensive care services spread throughout a hospital.

Equipment and systems

Sondeintubation
An endotracheal tube

Common equipment in an intensive care unit includes mechanical ventilation to assist breathing through an endotracheal tube or a tracheotomy; hemofiltration equipment for acute renal failure; monitoring equipment; intravenous lines for drug infusions fluids or total parenteral nutrition, nasogastric tubes, suction pumps, drains and catheters; and a wide array of drugs including inotropes, sedatives, broad spectrum antibiotics and analgesics.

Medical specialties

Critical care medicine is an increasingly important medical specialty. Physicians with training in critical care medicine are referred to as intensivists.[6] In the United States, the specialty requires additional fellowship training for physicians having completed their primary residency training in internal medicine, pediatrics, anesthesiology, surgery or emergency medicine. US board certification in critical care medicine is available through all five specialty boards. Intensivists 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 American Society of Critical Care Medicine is a well-established multiprofessional society for practitioners working in the ICU including nurses, respiratory therapists, and physicians. Most medical research has demonstrated that ICU care provided by intensivists produces better outcomes and more cost-effective care.[7] 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, in the US, there is a critical shortage of intensivists and most hospitals lack this critical physician team member.

Other members of the critical care team may also pursue additional training in critical care medicine. Respiratory therapists may pursue additional education and training leading to credentialing in adult critical care (ACCS) and neonatal and pediatric (NPS) specialties. Nurses may pursue additional education and training in critical care medicine leading to certification as a CCRN by the American Association of Critical Care Nurses. Pharmacists help manage all aspects of drug therapy and may pursue additional credentialing in critical care medicine as BCCCP by the Board of Pharmaceutical Specialties. Paramedics are certified to levels of CCEMT-P, PNCCT-P, CCP-C and/or FP-C depending upon their speciality (e.g. air, ground, adult, pediatric and/or neonatal medicine). Nutrition in the intensive care unit presents unique challenges and critical care nutrition is rapidly becoming a subspecialty for dieticians who can pursue additional training and achieve certification in enteral and parenteral nutrition through the American Society for Parenteral and Enteral Nutrition (ASPEN). Pharmacists may pursue additional training in a postgraduate residency and become certified as critical care pharmacists.

Patient management in intensive care differs significantly between countries. In countries such as Australia, New Zealand and Spain, where intensive care medicine is a well-established speciality, many larger ICUs are described as "closed". In a closed unit the intensive care specialist takes on the senior role where the patient's primary physician 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 ICUs, where the primary physician 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.[8][9]

In veterinary medicine, critical care medicine is recognized as a specialty and is closely allied with emergency medicine. Board-certified veterinary critical care specialists are known as criticalists, and are generally employed in referral institutions or universities.

History

Florence Nightingale era

Florence Nightingale 1920 reproduction
Florence Nightingale

The ICU's roots can be traced back to the Monitoring Unit of critical patients through nurse Florence Nightingale. The Crimean War began in 1853 when Britain, France, and the Ottoman Empire (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. Upon Nightingale's arrival and practicing, the mortality rate 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. He received his BA in 1907 through the University of Missouri and his M.D. in 1910 through the Johns Hopkins School of Medicine. Dandy worked one year with Dr. Harvey Cushing (the father of modern neurosurgery) in the Hunterian Laboratory of Johns Hopkins before entering its boarding school and residence in the Johns Hopkins Hospital. He worked at Johns Hopkins University 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 nerve 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 (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,[10] 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.[11] 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 three 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,[10] 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, 18 September 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

The first surgical ICU was established in Baltimore. In 1962, in the University of Pittsburgh, the first Critical Care Residency was established in the United States.

In 1970, the Society of Critical Care Medicine was formed.[12]

See also

Notes

  1. ^ Kahn, JM; Goss, CH; Heagerty, PJ; Kramer, AA; O'Brien, CR; Rubenfeld, GD (2006). "Hospital volume and the outcomes of mechanical ventilation". The New England Journal of Medicine. 355 (1): 41–50. doi:10.1056/NEJMsa053993. PMID 16822995.
  2. ^ Nolen-Hoeksema, Susan. "Neurodevelopmental and Neurocognitive Disorders." (Ab)normal Psychology. Sixth ed. New York City: McGraw-Hill Education, 2014. 314. Print.
  3. ^ Flannery, Alexander H.; Oyler, Douglas R.; Weinhouse, Gerald L. (December 2016). "The Impact of Interventions to Improve Sleep on Delirium in the ICU". Critical Care Medicine. 44 (12): 2231–2240. doi:10.1097/ccm.0000000000001952. ISSN 0090-3493. PMID 27509391.
  4. ^ Halpern, Neil A.; Pastores, Stephen M.; Greenstein, Robert J. (June 2004). "Critical care medicine in the United States 1985–2000: An analysis of bed numbers, use, and costs". Critical Care Medicine. 32 (6): 1254–1259. doi:10.1097/01.CCM.0000128577.31689.4C. PMID 15187502.
  5. ^ Barrett ML; Smith MW; Elizhauser A; Honigman LS; Pines JM (December 2014). "Utilization of Intensive Care Services, 2011". HCUP Statistical Brief #185. Rockville, MD: Agency for Healthcare Research and Quality.
  6. ^ "What – or Who -- Is an Intensivist?". Healthcare Financial Management Association. Archived from the original on 27 September 2009.
  7. ^ "Association between Critical Care Physician Management and Patient Mortality in the Intensive Care Unit". Annals of Internal Medicine. 3 June 2008. Volume 148, Issue 11. pp. 801–809.
  8. ^ Manthous, CA; Amoateng-Adjepong, Y; Al-Kharrat, T; Jacob, B; Alnuaimat, HM; Chatila, W; Hall, JB (1997). "Effects of a medical intensivist on patient care in a community teaching hospital". Mayo Clinic Proceedings (Abstract). 72 (5): 391–9. doi:10.4065/72.5.391. PMID 9146680.
  9. ^ Hanson CW; Deutschman, CS; Anderson, HL; Reilly, PM; Behringer, EC; Schwab, CW; Price, J (1999). "Effects of an organized critical care service on outcomes and resource utilization: a cohort study". Critical Care Medicine (Abstract). 27 (2): 270–4. doi:10.1097/00003246-199902000-00030. PMID 10075049.
  10. ^ a b "The Danish anaesthesiologist Björn Ibsen a pioneer of long-term ventilation on the upper airways, Louise Reisner-Sénélar, 2009" (pdf).
  11. ^ Reisner-Sénélar, Louise (2011). "The Birth of Intensive Care Medicine: Björn Ibsen’s Records" (PDF format).Intensive Care Medicine. Retrieved 2 October 2012.
  12. ^ history reference: Brazilian Society of Critical Care SOBRATI Video:ICU History Historical photos

References

Further reading

External links

Anesthesiology

Anesthesiology, anaesthesiology, anaesthesia or anaesthetics (see Terminology) is the medical speciality concerned with the total perioperative care of patients before, during and after surgery. It encompasses anesthesia, intensive care medicine, critical emergency medicine, and pain medicine. A physician specialised in this field of medicine is called an anesthesiologist, anaesthesiologist or anaesthetist, depending on the country (see Terminology).The core element of the specialty is the study and use of anesthesia and anesthetics to safely support a patient's vital functions through the perioperative period. Since the 19th century, anesthesiology has developed from an experimental area with non-specialist practitioners using novel, untested drugs and techniques into what is now a highly refined, safe and effective field of medicine. In some countries anesthesiologists comprise the largest single cohort of doctors in hospitals, and their role can extend far beyond the traditional role of anesthesia care in the operating room, including fields such as providing pre-hospital emergency medicine, running intensive care units, transporting critically ill patients between facilities, and prehabilitation programs to optimize patients for surgery.

Antihypotensive agent

An antihypotensive agent, also known as a vasopressor agent or pressor, is any medication that tends to raise low blood pressure. Some antihypotensive drugs act as vasoconstrictors to increase total peripheral resistance, others sensitize adrenoreceptors to catecholamines - glucocorticoids, and the third class increase cardiac output - dopamine, dobutamine.

If low blood pressure is due to blood loss, then preparations increasing volume of blood circulation—plasma-substituting solutions such as colloid and crystalloid solutions (salt solutions)—will raise the blood pressure without any direct vasopressor activity. Packed red blood cells, plasma or whole blood should not be used solely for volume expansion or to increase oncotic pressure of circulating blood. Blood products should only be used if reduced oxygen carrying capacity or coagulopathy is present. Other causes of either absolute (dehydration, loss of plasma via wound/burns) or relative (third space losses) vascular volume depletion also respond, although blood products are only indicated if significantly anemic.

Arterial line

An arterial line (also art-line or a-line) is a thin catheter inserted into an artery. It is most commonly used in intensive care medicine and anesthesia to monitor blood pressure directly and in real-time (rather than by intermittent and indirect measurement) and to obtain samples for arterial blood gas analysis. Arterial lines are generally not used to administer medication, since many injectable drugs may lead to serious tissue damage and even require amputation of the limb if administered into an artery rather than a vein.

An arterial line is usually inserted into the radial artery in the wrist, but can also be inserted into the brachial artery at the elbow, into the femoral artery in the groin, into the dorsalis pedis artery in the foot, or into the ulnar artery in the wrist. A golden rule is that there has to be collateral circulation to the area affected by the chosen artery, so that peripheral circulation is maintained by another artery even if circulation is disturbed in the cannulated artery.Insertion is often painful; an anesthetic such as lidocaine can be used to make the insertion more tolerable and to help prevent vasospasm, thereby making insertion of the arterial line somewhat easier. Arterial lines are typically inserted by Physicians, Acute Care Nurse Practitioners (ACNP), ICU Physician Assistants (PAs), Anesthesiologist Assistants (CAAs), Nurse Anesthetists (CRNAs), and Respiratory Therapists.

Critical Care Medicine (journal)

Critical Care Medicine is a peer-reviewed monthly medical journal in the field of intensive-care medicine. The journal was established in 1973. It is the official publication of the Society of Critical Care Medicine and is published by Lippincott Williams & Wilkins. The journal's editor-in-chief is Timothy G. Buchman.

Faculty of Intensive Care Medicine

The Faculty of Intensive Care Medicine is the organisation involved with the training, assessment, practice and continuing professional development of Intensive care medicine consultants in the United Kingdom. The current Dean is Dr Anna Batchelor. The Faculty is based at Churchill House, London.

The Faculty has seven parent Colleges, reflecting the multiprofessional nature of ICM.

Royal College of Anaesthetists, which acts as lead governance College of the Faculty.

Royal College of Emergency Medicine

Royal College of Physicians of Edinburgh

Royal College of Physicians of London

Royal College of Physicians and Surgeons of Glasgow

Royal College of Surgeons of Edinburgh

Royal College of Surgeons of EnglandOn 22 November 2010, Professor Julian Bion was admitted as the first Dean of the new faculty.As of January 2015 the faculty has 1901 Fellows and Members and 129 trainees.

Induced coma

An induced coma, also known as a medically induced coma, a barbiturate-induced coma, or a barb coma, is a temporary coma (a deep state of unconsciousness) brought on by a controlled dose of a barbiturate drug, usually pentobarbital or thiopental. Barbiturate comas are used to protect the brain during major neurosurgery, as a last line of treatment in certain cases of status epilepticus that have not responded to other treatments, and in refractory intracranial hypertension following traumatic brain injury.

Induced coma was a feature of the Milwaukee protocol, a now-discredited method that was promoted as a means of treating rabies infection in people.Induced coma usually results in significant systemic adverse effects. The patient is likely to completely lose respiratory drive and require mechanical ventilation. Gut motility is reduced. Hypotension can complicate efforts to maintain cerebral perfusion pressure and often requires the use of vasopressor drugs. Hypokalemia often results. And the completely immobile patient is at increased risk of bed sores as well as infection from indwelling lines.

Injury Severity Score

The Injury Severity Score (ISS) is an established medical score to assess trauma severity. It correlates with mortality, morbidity and hospitalization time after trauma. It is used to define the term major trauma. A major trauma (or polytrauma) is defined as the Injury Severity Score being greater than 15. The AIS Committee of the Association for the Advancement of Automotive Medicine (AAAM) designed and improves upon the scale.

Intensive Care Medicine (journal)

Intensive Care Medicine is a monthly peer reviewed medical journal covering intensive care or critical care and emergency medicine. It was established in 1975 as the European Journal of Intensive Care Medicine and obtained its current name in 1977. It is the official journal of the European Society of Intensive Care Medicine and the European Society of Paediatric and Neonatal Intensive Care. The editor-in-chief is Giuseppe Citerio (University of Milano Bicocca). It is published by Springer Science+Business Media.

Medical Scoring Systems

There are several scoring systems in intensive care units (ICUs) today.

Nutrient enema

A nutrient enema, also known as feeding per rectum, rectal alimentation, or rectal feeding, is an enema administered with the intent of providing nutrition when normal eating is not possible. Although this treatment is ancient, dating back at least to Galen and a common technique in 19th century medicine, nutrient enemas have been superseded in modern medical care by tube feeding and intravenous feeding.

A variety of different mixes have been used for nutrient enemas throughout history. A paper published in Nature in 1926 stated that because the rectum and lower digestive tract lack digestive enzymes, it is likely that only the end-products of normal digestion such as sugars, amino acids, salt and alcohol, will be absorbed.This treatment was given to U.S. President James A. Garfield after his shooting in 1881, and is asserted to have prolonged his life.When the United States Senate Intelligence Committee published an unclassified summary of its 6,000 page classified report on the CIA's use of torture, its previously unknown use of "rectal rehydration" for punishment and torture became apparent.

PIM2

PIM2 is a scoring system for rating the severity of medical illness for children, one of several ICU scoring systems. Its name stands for "Paediatric Index of Mortality". It has been designed to provide a predicted mortality for a patient by following a well defined procedure. Predicted mortalities are good when dealing with several patients, because the average predicted mortality for a group of patients is an indicator for the morbidity of these patients.

Just like APACHE II and SAPS II, it doesn't provide a real-life predicted mortality. The standard is too old, variations in mortality are huge between countries and departments, and the definition of mortality is varying, too. However, PIM2 provides a good way to benchmark different sets of patients.

Positive end-expiratory pressure

Positive end-expiratory pressure (PEEP) is the pressure in the lungs (alveolar pressure) above atmospheric pressure (the pressure outside of the body) that exists at the end of expiration. The two types of PEEP are extrinsic PEEP (PEEP applied by a ventilator) and intrinsic PEEP (PEEP caused by an incomplete exhalation). Pressure that is applied or increased during an inspiration is termed pressure support.

Respiratory failure

Respiratory failure results from inadequate gas exchange by the respiratory system, meaning that the arterial oxygen, carbon dioxide or both cannot be kept at normal levels. A drop in the oxygen carried in blood is known as hypoxemia; a rise in arterial carbon dioxide levels is called hypercapnia. Respiratory failure is classified as either Type I or Type II, based on whether there is a high carbon dioxide level. The definition of respiratory failure in clinical trials usually includes increased respiratory rate, abnormal blood gases (hypoxemia, hypercapnia, or both), and evidence of increased work of breathing.The normal partial pressure reference values are: oxygen PaO2 more than 80 mmHg (11 kPa), and carbon dioxide PaCO2 lesser than 45 mmHg (6.0 kPa).

Resuscitation

Resuscitation is the process of correcting physiological disorders (such as lack of breathing or heartbeat) in an acutely ill patient. It is an important part of intensive care medicine, trauma surgery and emergency medicine. Well known examples are cardiopulmonary resuscitation and mouth-to-mouth resuscitation.

SAPS II

SAPS II is a severity of disease classification system. Its name stands for "Simplified Acute Physiology Score", and is one of several ICU scoring systems.

SOFA score

The sequential organ failure assessment score (SOFA score), previously known as the sepsis-related organ failure assessment score, is used to track a person's status during the stay in an intensive care unit (ICU) to determine the extent of a person's organ function or rate of failure. The score is based on six different scores, one each for the respiratory, cardiovascular, hepatic, coagulation, renal and neurological systems.

The score tables below only describe points-giving conditions. In cases where the physiological parameters do not match any row, zero points are given. In cases where the physiological parameters match more than one row, the row with most points is picked.

The quick SOFA score (qSOFA) assists health care providers in estimating the risk of morbidity and mortality due to sepsis.

Stress ulcer

A stress ulcer is a single or multiple mucosal defect which can become complicated by upper gastrointestinal bleeding physiologic stress. Ordinary peptic ulcers are found commonly in the gastric antrum and the duodenum whereas stress ulcers are found commonly in fundic mucosa and can be located anywhere within the stomach and proximal duodenum.

Systemic inflammatory response syndrome

Systemic inflammatory response syndrome (SIRS) is an inflammatory state affecting the whole body. It is the body's response to an infectious or noninfectious insult. Although the definition of SIRS refers to it as an "inflammatory" response, it actually has pro- and anti-inflammatory components.

Ventilator-associated lung injury

Ventilator-associated lung injury (VALI) is an acute lung injury that develops during mechanical ventilation and is termed ventilator-induced lung injury (VILI) if it can be proven that the mechanical ventilation caused the acute lung injury. In contrast, ventilator-associated lung injury (VALI) exists if the cause cannot be proven. VALI is the appropriate term in most situations because it is virtually impossible to prove what actually caused the lung injury in the hospital.

Intensive care medicine
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Conditions
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ICU scoring systems
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