Brain Death

The fundamental neurologic principle that all brainstem function must have irreversibly ceased—in the overwhelming proportion, but not exclusively from massive damage to both cerebral hemisphere—must be understood before brain death testing proceeds. Brain death is a non- functioning destroyed (“dead”) brain with absent breathing and no circulation if support is not provided.

Inotropes, Vasopressors, and Antihypertensive Agents

Pharmacologic manipulation of the cardiovascular system is considered one of the cornerstones of day-to-day management of critically ill patients. For formulation of an adequate hemodynamic plan, it is crucial 1) to have a thorough understanding of cardiovascular physiology and its intricate relationship with the autonomic nervous system and 2) to identify a clear hemodynamic goal, such as maintenance of oxygen delivery and perfusion in shock, permissive hypertension in acute stroke, or blood pressure control in hypertensive emergencies.

Intracranial Pressure Monitoring and External Ventricular Drainage

Several studies have shown that increased ICP has been associated with poor neurologic outcomes. Management of elevated ICP can improve neurologic outcomes and influence medical and surgical therapy, and accurate recording of ICP is helpful in assessing a patient’s clinical status. Currently, the 2 most common forms of monitoring ICP involve 1) placement of a fiberoptic or strain gauge intraparenchymal monitor or 2) placement of a ventricular drain.

Interventional Radiology Procedures

Most patients in an intensive care unit are critically ill, hemodynamically unstable, and have multiple comorbidities. Interventional radiology procedures can offer therapeutic options for these patients and avoid the risks associated with invasive surgery and general anesthesia.

Tracheostomy

Tracheostomy is a procedure where a conduit is created between the skin and the trachea. Tracheostomy is one of the most frequent procedures undertaken in critically ill patients. Each year, approximately 10% of critical care patients in the United States require a tracheostomy, most often for prolonged mechanical ventilation.

Basics of Airway and Oxygen Delivery Devices

One of the greatest responsibilities in managing an airway is to maintain a continuously patent airway. Any loss of patency of the patient’s airway is critical, and if the ability to provide ventilatation is lost, brain damage can rapidly develop potentially lead to brain death. The definition of difficult airway is not standardized in the anesthesiology literature, but it has been described as the situation when “a conventionally trained anesthesiologist experiences difficulty with facemask ventilation of the upper airway, difficulty with tracheal intubation, or both”

Intensive Care After Neuroendovascular Procedures

Endovascular therapy for cerebrovascular disease is widespread. Patients with brain aneurysms, acute stroke, brain vascular malformations, and tumors are treated with endovascular techniques primarily or in conjunction with other traditional surgical and medical approaches. Postprocedural concerns unique to endovascular treatment include complications related to access or arterial puncture, contrast nephrotoxicity, and radiation dose complications (eg, alopecia and skin burns). Other complications, such as stroke and hemorrhage, that are not unique are discussed below.

Radiation Therapy

Radiation oncology is the specialty of medicine in which ionizing radiation is used to treat both malignant and benign conditions. The term radiation therapy (RT) is used, in part, as a differentiator from diagnostic radiation. In radiation oncology, treatment is provided with a team-based approach by physicians, nurses, physicists, dosimetrists, and radiation therapists. Dosimetrists perform the initial planning and mapping of the radiation fields. Radiation therapists deliver the treatment with external beam radiation therapy machines.

Rapidly Progressive Dementia and Coma

In most patients with dementia, the clinical signs and symptoms progress gradually over many years. However, neurointensivists may encounter patients who have rapidly progressive dementia (RPD). Often these patients need to be admitted to the intensive care unit for management of status epilepticus, agitation, or ventilation in coma. Although the prototype of RPD is Creutzfeldt-Jakob disease, this chapter reviews other common causes of RPD. An established definition of RPD does not exist, but in this chapter RPD refers to the loss of more than 1 cognitive domain and functional ability, usually occurring over a few months.

Myopathy and Neuropathy Acquired in the Intensive Care Unit

Acquired weakness in critically ill patients is common, affecting between one-third to one-half of patients in the intensive care unit (ICU). Exposure to simultaneous stressors such as metabolic derangements, fluid and electrolyte shifts, infection, catabolic stress, and medications put patients in the ICU at risk for damage to both nerve and skeletal muscle with substantial and often lasting morbidity. Critical illness polyneuropathy is a length-dependent, axonal peripheral neuropathy occurring in patients in the ICU and unrelated to the primary illness. Critical illness myopathy is an ICU-associated muscle disorder occurring independently of denervation and uniquely identified by electrophysiologic and histologic characteristics.