Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV) is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. Mechanical ventilation is used for many reasons, including to protect the airway due to mechanical or neurologic cause, to ensure adequate oxygenation, or to remove excess carbon dioxide from the lungs. Various healthcare providers are involved with the use of mechanical ventilation and people who require ventilators are typically monitored in an intensive care unit.
Intensive care medicine, also called critical care medicine, is a medical specialty that deals with seriously or critically ill patients who have, are at risk of, or are recovering from conditions that may be life-threatening. It includes providing life support, invasive monitoring techniques, resuscitation, and end-of-life care. Doctors in this specialty are often called intensive care physicians, critical care physicians or intensivists.
Cerebral edema is excess accumulation of fluid (edema) in the intracellular or extracellular spaces of the brain. This typically causes impaired nerve function, increased pressure within the skull, and can eventually lead to direct compression of brain tissue and blood vessels. Symptoms vary based on the location and extent of edema and generally include headaches, nausea, vomiting, seizures, drowsiness, visual disturbances, dizziness, and in severe cases, coma and death.
Battlefield medicine, also called field surgery and later combat casualty care, is the treatment of wounded combatants and non-combatants in or near an area of combat. Civilian medicine has been greatly advanced by procedures that were first developed to treat the wounds inflicted during combat. With the advent of advanced procedures and medical technology, even polytrauma can be survivable in modern wars. Battlefield medicine is a category of military medicine.
Intracranial pressure (ICP) is the pressure exerted by fluids such as cerebrospinal fluid (CSF) inside the skull and on the brain tissue. ICP is measured in millimeters of mercury (mmHg) and at rest, is normally 7–15 mmHg for a supine adult. The body has various mechanisms by which it keeps the ICP stable, with CSF pressures varying by about 1 mmHg in normal adults through shifts in production and absorption of CSF.
Respiratory arrest is a medical condition caused by apnea or respiratory dysfunction severe enough that it will not sustain the body. Prolonged apnea refers to a patient who has stopped breathing for a long period of time. If the heart muscle contraction is intact, the condition is known as respiratory arrest. An abrupt stop of pulmonary gas exchange lasting for more than five minutes may permanently damage vital organs, especially the brain. Lack of oxygen to the brain causes loss of consciousness. Brain injury is likely if respiratory arrest goes untreated for more than three minutes, and death is almost certain if more than five minutes.
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity ranging from mild traumatic brain injury (mTBI/concussion) to severe traumatic brain injury. TBI can also be characterized based on mechanism or other features. Head injury is a broader category that may involve damage to other structures such as the scalp and skull. TBI can result in physical, cognitive, social, emotional and behavioral symptoms, and outcomes can range from complete recovery to permanent disability or death.
An induced coma – also known as a medically induced coma (MIC), barbiturate-induced coma, or drug-induced coma – is a temporary coma brought on by a controlled dose of an anesthetic drug, often a barbiturate such as pentobarbital or thiopental. Other intravenous anesthetic drugs such as midazolam or propofol may be used.
Status epilepticus (SE), or status seizure, is a medical condition consisting of a single seizure lasting more than 5 minutes, or 2 or more seizures within a 5-minute period without the person returning to normal between them. Previous definitions used a 30-minute time limit. The seizures can be of the tonic–clonic type, with a regular pattern of contraction and extension of the arms and legs, or of types that do not involve contractions, such as absence seizures or complex partial seizures. Status epilepticus is a life-threatening medical emergency, particularly if treatment is delayed.
Intracerebral hemorrhage (ICH), also known as cerebral bleed, intraparenchymal bleed, and haemorrhagic stroke, is a sudden bleeding into the tissues of the brain, into its ventricles, or into both. An ICH is one kind of bleeding within the skull and one kind of stroke. Symptoms can include headache, one-sided weakness, vomiting, seizures, decreased level of consciousness, and neck stiffness. Often, symptoms get worse over time. Fever is also common.
Osmotherapy is the use of osmotically active substances to reduce the volume of intracranial contents. Osmotherapy serves as the primary medical treatment for cerebral edema. The primary purpose of osmotherapy is to improve elasticity and decrease intracranial volume by removing free water, accumulated as a result of cerebral edema, from brain's extracellular and intracellular space into vascular compartment by creating an osmotic gradient between the blood and brain. Normal serum osmolality ranges from 280 to 290 mOsm/kg and serum osmolality to cause water removal from brain without much side effects ranges from 300 to 320 mOsm/kg. Usually, 90 mL of space is created in the intracranial vault by 1.6% reduction in brain water content. Osmotherapy has cerebral dehydrating effects. The main goal of osmotherapy is to decrease intracranial pressure (ICP) by shifting excess fluid from brain. This is accomplished by intravenous administration of osmotic agents which increase serum osmolality in order to shift excess fluid from intracellular or extracellular space of the brain to intravascular compartment. The resulting brain shrinkage effectively reduces intracranial volume and decreases ICP.
Intraventricular hemorrhage (IVH), also known as intraventricular bleeding, is a bleeding into the brain's ventricular system, where the cerebrospinal fluid is produced and circulates through towards the subarachnoid space. It can result from physical trauma or from hemorrhagic stroke.
Targeted temperature management (TTM) previously known as therapeutic hypothermia or protective hypothermia is an active treatment that tries to achieve and maintain a specific body temperature in a person for a specific duration of time in an effort to improve health outcomes during recovery after a period of stopped blood flow to the brain. This is done in an attempt to reduce the risk of tissue injury following lack of blood flow. Periods of poor blood flow may be due to cardiac arrest or the blockage of an artery by a clot as in the case of a stroke.
The Brain Trauma Foundation (BTF) was founded in 1986 to develop research on traumatic brain injury (TBI). Since its formation the foundation's mission has expanded to improving the outcome of TBI patients nationwide through working to implement evidence-based guidelines for prehospital and in-hospital care, quality-improvement programs, and coordinating educational programs for medical professionals.
An external ventricular drain (EVD), also known as a ventriculostomy or extraventricular drain, is a device used in neurosurgery to treat hydrocephalus and relieve elevated intracranial pressure when the normal flow of cerebrospinal fluid (CSF) inside the brain is obstructed. An EVD is a flexible plastic catheter placed by a neurosurgeon or neurointensivist and managed by intensive care unit (ICU) physicians and nurses. The purpose of external ventricular drainage is to divert fluid from the ventricles of the brain and allow for monitoring of intracranial pressure. An EVD must be placed in a center with full neurosurgical capabilities, because immediate neurosurgical intervention can be needed if a complication of EVD placement, such as bleeding, is encountered.
The following outline is provided as an overview of and topical guide to emergency medicine:
The Neurocritical Care Society (NCS) is an international, multidisciplinary medical society first established in 2002. The Society is dedicated to improving the care and outcomes of patients with life-threatening neurologic illnesses in the intensive care unit. Common illnesses requiring neurocritical care include ischemic stroke, subarachnoid hemorrhage, intracranial hemorrhage, traumatic brain and spinal cord injury, coma, and status epilepticus. Its members are health professionals providing care to critically ill and injured patients. The Society supports research and education, and advocates on issues related to neurointensive care, neurocritical care, and general critical care.
Clinicians routinely check the pupils of critically injured and ill patients to monitor neurological status. However, manual pupil measurements have been shown to be subjective, inaccurate, and not repeatable or consistent. Automated assessment of the pupillary light reflex has emerged as an objective means of measuring pupillary reactivity across a range of neurological diseases, including stroke, traumatic brain injury and edema, tumoral herniation syndromes, and sports or war injuries. Automated pupillometers are used to assess an array of objective pupillary variables including size, constriction velocity, latency, and dilation velocity, which are normalized and standardized to compute an indexed score such as the Neurological Pupil index (NPi).
Sherry Hsiang-Yi Chou is a Canadian neurologist and an Associate Professor of Neurology and Chief of Neurocritical Care at the Northwestern University Feinberg School of Medicine and Northwestern Medicine. She is a Fellow of the Neurocritical Care Society and the Society of Critical Care Medicine. During the COVID-19 pandemic Chou assembled a worldwide team of physicians and scientists to better understand the neurological impacts of COVID-19, forming the Global Consortium Study of Neurologic Dysfunction in COVID-19 (GCS-NeuroCOVID). The first report of this large, multicenter, multicontinent consortium found that neurological manifestations are present in 8 out of 10 adult patients hospitalized with COVID-19 and are associated with increased mortality.
Stephan A. Mayer is an American neurologist and critical care physician who currently serves as Director of Neurocritical Care and Emergency Neurology Services for the Westchester Medical Center Health System. Mayer is most noted for his research in subarachnoid and intracerebral hemorrhage, acute ischemic stroke, cardiac arrest, coma, status epilepticus, brain multimodality monitoring, therapeutic temperature modulation, and outcomes after severe brain injury. He has gained media attention for popularizing the concept that physicians have historically underestimated the brain’s resilience and capacity for recovery. He has authored over 400 original research publications, 200 chapters and review articles, and 370 abstracts.
