The Role of the ICU in the Care of Neurosurgery Patients

Originally, the primary systems model for neuro-ICU care was a “low-intensity” model that involved direct management of neurosurgical patients almost exclusively by neurosurgeons, with limited consultation by other medical and surgical services.⁴ These ICUs first developed with the need for artificial ventilator support and high-intensity nursing for neurosurgical postoperative patients. The escalation in care from that on surgical floors or intermediate-care floors generally involved a higher level of monitoring, including the use of arterial lines, mechanical ventilation, central venous access, invasive cardiac monitoring (Swan-Ganz hemodynamic monitoring), and potentially ICP monitors and ventricular drainage. These higher levels of monitoring and more frequent nursing evaluations were otherwise solely managed by the neurosurgeon with either no intensivist available or elective intensivist consultation. With the development of critical care medicine, neurosurgeons were assisted with consultation when requested by physicians specializing in critical care medicine or surgery.

Practice-of-care models were then developed in “closed” or “semiclosed” multisystem medical or surgical ICUs where patients were directly managed by a dedicated full-time intensive care team that led the management of ICU patients for the length of their ICU stay.⁵ The most responsible physician would be a general medical or surgical intensivist. These specialists would directly manage all organ systems with consultation from the neurosurgical team, which would transition to primary responsibility once patients no longer had active critical care issues. Provonost and colleagues⁶ showed that staffing an ICU with critical care practitioners positively affected the outcome of ICU patients. Critical care intensivists help organize patient care, decrease resource utilization, prevent complications, and decrease length of ICU stay. Studies have suggested that ICUs with mandatory intensivist consultation have been associated with decreased hospital mortality as well as decreased hospital length of stay.^7,8 In these particular studies, critical care clinicians were experts in multiorgan system failure and critical care cardiopulmonary needs but generally were less experienced in specific neurological complications. This model, which exists in many hospitals today, mandates close involvement with a neurosurgeon to evaluate patients with complicated neurological examinations and conditions while managing specific neurological complications with which neurosurgeons have experience, such as external ventricular drains and ICP monitors, or following patients who may need a decompressive craniectomy.

Trends in medical and surgical critical care units have carried over further to the neuro-ICU with a need for specialized intensivists with knowledge of and expertise in neurological disorders as well as the systemic manifestations of disease. Starting in the 1980s, specialized neuro-ICUs were developed not only for neurosurgical postoperative patients, but also to manage TBI, intracerebral hemorrhage and SAH, status epilepticus, and ischemic stroke.⁴ Neurological complications specifically monitored in the neuro-ICU setting include intracranial hypertension, cerebral edema, intracerebral hematoma expansion, cerebral vasospasm, and nonconvulsive seizures. Prompt management and avoidance of these potential complications necessitated intensivists focused on subtle changes in the neurological examination as well as expertise in managing ICP, cerebral blood flow, neuropharmacology, and electroencephalography.⁴ Neurointensivists, as neurosurgeons or neurologists specializing in critical care, would be primarily responsible for the patient care. These neurointensivists require expertise not only in general ICU technologies such as mechanical ventilation but also in those technologies specific to neurological disorders, such as parenchymal brain tissue oxygen sensors and microdialysis. These new neurological monitoring devices allow for closer management of physiologic parameters. Neurosurgical intensive care has developed as a subspecialty of neurology and neurosurgery in managing multidisciplinary dedicated neuro-ICUs.