SPECIALIZED UNITS: DO THEY SAVE

LIVES? NEUROCRITICAL CARE

David Zygun MD MSc FRCPC

Zone Clinical Department Head

Critical Care Medicine, Edmonton Zone

Professor and Director

Division of Critical Care Medicine

University of Alberta

Care of the Neurologically Injured

• “Closed” ICU• Care is primarily provided general intensivists, who rely heavily on

consultative support from neurosurgeons and neurologists

• Common in Canada, Australia, New Zealand, and some European countries

• Admissions and discharges are largely the responsibility of the attending intensivist

• Daily multidisciplinary rounds with a single team of clinicians

• “Open” ICU• Care is primarily delivered by neurosurgeons or neurologists,

depending greatly on consultative input from various subspecialists.

• At any given time, there may be multiple attending physicians with patients admitted under their care, each of which, in turn, has numerous consultants involved

• This approach has, historically, been the most common in the United States.

Care of the Neurologically Injured

• “General” ICU

• ICU bedside nurses and ancillary health professionals (e.g.,

respiratory therapists, pharmacists, social workers are usually well-

trained in the provision of physiologic support, especially to patients

with multi-organ failure

• However, specific nuances that are important to subspecialties

such as neurocritical care patients may sometimes be under-

recognized.

• “Specialty” ICU

• Nurses and ancillary health profesionals are specifically trained to

detect and treat neurologic deterioration in a timely fashion

• However, there may be less experience in the management of

systemic complications.

• 41 general ICUs and 1 neuro ICU from Project Impact

dataset

• Merged with data from one nonparticipating neuro ICU

that prospectively collects similar data by using the QuIC

data system

• nontraumatic ICH

• Severity adjusted in two ways: APACHE II and GCS

(radiographic features unavailable)

• 1038 patients

• 266 neuro ICU

• 772 general ICU

• Retrospective cohort study using the Acute Physiology and Chronic Health Evaluation (APACHE) IV database (Cerner Corporation, Kansas City, MO)

• 3 categories of exposure: general ICU, ideal specialty ICU, and non-ideal specialty ICU

Acknowledgement

Andreas Kramer MD FRCPC

Objectives

• To summarize evidence with respect to the effects of specialty neurocritical care models on outcomes in critically ill adults with life threatening neurologic injury

• Methods• OVID interface to search MEDLINE, EMBASE and Cochrane

Databases from their inception until the third week of February, 2011. The keyword search terms we used included “neurocritical care”; “neurointensive care” or “neuro-intensive care”; “neurointensivist” or “neuro-intensivist”; “neuro$ ICU or “neuro$ intensive care unit”

• Study Selection• We included retrospective or prospective cohort studies comparing two

or more models of care, one of which involved specialized care, for critically ill patients with neurologic disorders.

• We excluded studies which involved subsets of previously published data

• Outcomes • neurologic outcome, mortality

Results

Results

• 12 studies involving 24,520 patients

Results - Mortality

Results – Neurological Outcome

Heterogeneity

• Mortality

• I2 = 80%, Q = 53.7, P < 0.0001

• Neurological Outcome

• I2 = 74%, Q = 35.0, P < 0.0001

• When analyis restricted to studies with an

neurointensivist:

• Mortality: OR 0.85, 95% CI 0.74–0.98, P = 0.03

• Favorable outcome: OR 1.38, 95% CI 1.15–1.66, P = 0.0005

• Heterogeneity in results was less (I2 9 and 51%, respectively)

Neurointensivists

• Additional Benefits

• reductions in length of stay (not consistent)

• cost savings

• less need for ventriculoperitoneal shunts in SAH patients

• improved documentation

• increased organ and tissue donation rates

Limitations

• Conflict of Interest

• Publication Bias

• Historically controlled studies, especially within a single ICU, are susceptible to a „„Hawthorne effect‟‟

• Other positive changes may have been introduced at individual centers over time, apart from implementation of a neurocritical care service (ex. clip to coil)

• It is likely that the technical skills and judgment of other clinicians, such as neurosurgeons or neuro-interventionalists, have matured over time.

• Some of the benefits may largely reflect the introduction of an intensivist-led, systematic, organized approach to critically ill patients, rather than only to specific content expertise in neurocritical care

• Published studies do not clarify which specific interventions or modifications in practice were responsible for the observed positive effects

Explanations

• Provider Volume-Outcome association

• “… it is virtually impossible to find a surgical procedure or medical

condition that has been evaluated in more than one study that does

not have a volume-outcome association.”

• “Practice makes perfect”

• “Selective referral” – David R. Urbach HCQ 2004

Explanations

• Coherence

• “What is one plus one?... Four... principle of coherence, the

magnifying effect of one factor upon another... Each piece of the

system reinforces the other parts of the system to form a integrated

whole that is much more powerful than the sum of the parts. It is

only through consistency over time, through multiple generations,

that you get maximum results. ”

– Jim Collins, Good to Great, Harper Collins, 2001

Explanations

Explanations

Explanations

Conclusions

• Existing studies have notable limitations, and there is a

considerable degree of heterogeneity in the published

results.

• However, the cumulative experience, involving almost

25,000 patients, suggests that specialized neurocritical

care units are associated with decreased mortality and

improved neurological outcome.

• Unfortunately, published studies do not clarify which

specific interventions or modifications in practice were

responsible for the observed positive effects.

• Future research should aim to determine which factors

are of particular benefit.