The medical care of the critically ill neurological patient has changed dramatically over the past two decades. The emergence of neurocritical care as a subspecialty along with improved medical and microsurgical treatments has made it possible for a new breed of intensivists, called neurointensivists, to provide better care for the intensive care unit (ICU) patient after neurological injury.

However, such advancements have also brought added costs to an already expensive discipline. Thus, it is not surprising that more research articles are being devoted to the study of cost containment and outcomes research to maximize resource use.

The determination of clinical parameters that have an impact upon patient care has been the focus of much work in modern medicine. Since the publication of the Apgar score in 1953 to evaluate the newborn child, many other disease-specific scores were developed to select patients that might benefit from new therapies.1 Since the 1980s, severity of disease scoring systems have become common practice in critical care. The scoring system most widely used is the Acute Physiology and Chronic Health Evaluation score (APACHE II and III).2 The APACHE score has been used mainly for clinical research (i.e., stratification of patients with similar severity of disease), performance assessment (i.e., compare multiple ICUs with similar case-mix), and for resource allocation (i.e., determination of patients that may not need ICU care).

The first neurological scale that was introduced was the Glasgow Coma Scale (GCS) in 1974 to determine the severity of coma.3 The usefulness and validity of the GCS have been confirmed in multiple data sets of patients with various neurological disorders. Several other scales to determine risk assessment in the neurocritically ill patient have been introduced, including some very crude ones such as the Glasgow Outcome Scale (GOS)4 (Table 1). Despite the fact that such disease-specific neurological scales have predicted patients’ outcomes, there is a growing trend to include general severity of disease scoring systems such as APACHE in neurological outcome predictive models.

The advantage of such an approach is the inclusion of underlying medical co-morbidities and other transfer and disposition characteristics of patients that may influence their final outcomes. The main outcomes that have been studied in the neurocritically ill include mortality, length of stay and long-term functional status. Mortality can be easily and reliably determined. However, it does not provide information on the functional status of survivors. Scales that measure functional status include the Barthel Index5 and Rankin Scale.6 The latest outcome research has moved beyond the measurement of functional capacity to include measures of health status and quality of life. These instruments include the Short-Form 36 Health Survey, the Quality of Life Scale, and the Stroke Impact Scale.7,8 Based on all these developments in neurological outcomes research, investigators have been able to gauge some predictive factors of outcome to improve the healthcare delivery system to affect them.

Neurointensivist-led ICU

The authors of at least two articles have commented on the fact that neurocritically ill patients, specifically those with intracerebral hemorrhage, may benefit from admissions to specialized neuro ICUs, compared to general ICUs,9,10 because such units are associated with reduced mortality. Recently it has been reported that the introduction of a specialized neurocritical care team may be associated with significant reductions in in-hospital mortality (23% relative risk reduction) and length of stay in a group of neurocritically ill patients without affecting the readmission rate or long-term mortality.11 The beneficial effect was observed independent of baseline APACHE score, age, and several other underlying characteristics.

Stroke

Stroke of any type is associated with high morbidity and mortality in critically ill patients.12-14 In-hospital mortality of acute stroke patients who require ICU admission can be as high as 50%. Of those who survive, many are left dependent (up to 50%). Both APACHE score and disease-specific scale scores are good predictors of mortality and dependency. Despite the high mortality rates, modifiable risk factors associated with bad outcome such as hyperthermia and hyperglycemia have been identified.15 Such factors can be best controlled in the ICU, providing an opportunity for performance improvement in the future.

Traumatic Brain Injury

Severe traumatic brain injury (TBI), as determined by the GCS score, is associated with significant mortality rates (up to 30%). The GCS has been the main scale to estimate the severity of illness and probability of death in TBI patients. However, other scoring systems such as APACHE and Mortality Probability Models (MPM) can also predict mortality.16 Long-term outcome has been mainly determined by the GOS. It is clear that other measures focusing on quality of life are needed.

Status Epilepticus

Status epilepticus is a common and serious condition that carries mortality up to 22%. It has become clear that important pre-existing clinical factors influence the short- and long-term outcome of these patients.17-19 In status epilepticus, prognosis and outcome are largely determined by the nature of the underlying neurological or systemic disorders that precipitated it. Thus, it would be very important for future studies to include severity of disease scoring systems along with post-discharge functional outcome.

Predicting the outcome of neurocritically ill patients has undergone significant changes in the past few years. Disease-specific scales have been used to predict mortality and outcome in these patients. However, variation in death rates and outcomes reflect the nature of the underlying systemic condition. The use of severity of disease scoring systems in conjunction with the other neurological disease specific scales is needed to better predict and assess mortality and outcomes in future studies.