[1] Patients are admitted to the intensive care unit if their medical needs are greater than what the general hospital ward can provide.

Indications for the ICU include blood pressure support for cardiovascular instability (hypertension/hypotension), sepsis, post-cardiac arrest syndrome or certain cardiac arrhythmias.

These include: Medical studies suggest a positive correlation between ICU volume and quality of care for mechanically ventilated patients.

[13] The English nurse Florence Nightingale pioneered efforts to use a separate hospital area for critically injured patients.

During the Crimean War in the 1850s, she introduced the practice of moving the sickest patients to the beds directly opposite the nursing station on each ward so that they could be monitored more closely.

Ibsen changed the management directly by instituting long-term positive pressure ventilation using tracheal intubation, and he enlisted 200 medical students to manually pump oxygen and air into the patients' lungs around the clock.

[17] At this time, Carl-Gunnar Engström had developed one of the first artificial positive-pressure volume-controlled ventilators, which eventually replaced the medical students.

In 1953, Ibsen set up what became the world's first intensive care unit in a converted student nurse classroom in Copenhagen Municipal Hospital.

He jointly authored the first known account of intensive care management principles in the journal Nordisk Medicin, with Tone Dahl Kvittingen from Norway.

These can include tests to evaluate blood flow and gas exchange in the body, or to assess the function of organs such as the heart and lungs.

[1] Invasive monitoring generally provides more accurate measurements, but these tests may require blood draws, puncturing the skin, and can be painful or uncomfortable.

A wide array of drugs including but not limited to: inotropes such as Norepinephrine, sedatives such as Propofol, analgesics such as Fentanyl, neuromuscular blocking agents such as Rocuronium and Cisatracurium as well as broad spectrum antibiotics.

Training usually takes place over 2 years during which time candidates rotate through different ICU's (Medical, Surgical, Paediatric etc.)

Training in ICM is offered through various recognized programs that equip healthcare professionals with the necessary skills to manage critically ill patients.

[29] These certifications became more specialized to the patient population in 1997 by the American Association of Critical care Nurses, to include pediatrics, neonatal and adult.

[4] These providers have fewer years of in-school training, typically receive further clinical on the job education, and work as part of the team under the supervision of physicians.

[6] 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.

[31] Respiratory therapists may pursue additional education and training leading to credentialing in adult critical care (ACCS) and neonatal and pediatric (NPS) specialties.

[31] They may be involved in emergency care like inserting and managing an airway, humidification of oxygen, administering diagnostic lung mechanics tests, invasive or non-invasive mechanical ventilation management, weaning the ventilator, aerosol therapy (pulmonary vasodilatory medications included), inhaled Nitric oxide therapy, arterial blood gas analysis, and providing physiotherapy.

Additionally, Respiratory Therapists are commonly involved in ECMO management and many pursue certification in such therapies due to the intimate relationship of the heart and lungs.