Acute injuries of various etiologies (such as trauma, infection and shock) can cause immediate local and systemic physiologic and biochemical responses involving all major organ systems.
The timing and intensity of the physiologic response to injury is affected by the severity of the injury as well as host factors. Both pro- and anti-inflammatory pathways are activated in critically ill patients. Clinically, the initial response is likely to be proinflammatory, followed by late immunosuppression.
The principal defects in critically ill patients include endothelial leakage, epithelial barrier dysfunction, and disrupted cellular metabolism.
Organ dysfunction in critical illness is characterized by a striking discord between profound loss of function and relatively mild structural changes. The cellular response to critical illness may be considered analogous to a “hibernation” phenotype, minimizing function, and metabolic needs to survive the period of acute stress.
Our increased understanding of the pathophysiology of critical illness has not yet translated into successful biologic therapies. Harnessing the tools of “big data” in medicine and using systems biology approaches may provide a complementary approach to traditional reductionist methods in critical illness research.
Critical illness may be defined as a life-threatening condition requiring support of vital organs to prevent imminent death,1 and can be precipitated by a variety of insults, such as severe trauma, complicated surgery, or major medical illness. Critical care medicine grew out of a realization that seriously ill or injured patients would benefit from closer attention than was needed for less acutely ill patients.2 The birth of modern critical care medicine can be traced to the 1952 epidemic of polio in Denmark, where patients with bulbar poliomyelitis were ventilated with positive pressure ventilation through a tracheostomy, greatly improving outcomes.3 This marked the first large-scale adoption of techniques that anesthesiologists used in the operating room to treat medical patients. Björn Ibsen, an anesthesiologist who was responsible for the successful use of positive pressure ventilation in polio, went on to establish what was perhaps the world’s first multidisciplinary intensive care unit in Copenhagen, in 1953.4
From its relatively modest beginnings, the field of critical care has grown rapidly. Through a combination of technologic advancement and improved understanding of the pathophysiology of acute illness, intensivists have been able to make rapid advances in the supportive care and management of acutely ill patients. The ability of surgeons to perform increasingly skilled and complex surgeries has depended on the capacity of anesthesiologists to provide expert care to patients in the operating room and in the intensive care unit (ICU). With the growth of the multidisciplinary critical care team, the management of many conditions—from drug overdoses to severe trauma has resulted in significant improvements in patient outcomes.
Anesthesiologists care for critically ill patients in the operating room, in the intensive care unit (ICU), and during procedures in areas outside of the operating room, such as radiologic, endoscopic, ...