FOUR Score Coma Scale - ICU

FOUR Score Coma Scale
Full Outline of Unresponsiveness

Geschiedenis
•1974 Teasdale and Jenett
Attempt to bring uniformity to the clinical
examination and clinical communication
about the level of consciousness
GCS
Not designed to capture distinct details of
the neurologic examination

FOUR

FOUR

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Voordelen
•Measurement of brainstemreflexes
•Determination of eye opening, blinking and
tracking
•A broad spectrum of motor responses
•Presence of abnormal breath rhythms and
a respiratory drive
•NO assessment of verbal responses
(intubation)

Eye response
•Differentiation between
◦Vegetative state
(eyes open but do not track)
◦Locked in syndrome
(eyes open, blink and track vertically on command)

Motor assessment
•Combination:
◦Withdrawal reflex
◦Decorticate rigidity
Complex command (alert)
•Severe cerebral dysfunction
(Myoclonic status epilepticus)

Brainstem components
•Pons
•Mesencephalon
•Medulla oblongata
Various combinations

Breathing components
•Cheyne-Stokes respiration
•Irregular breathing
Bihemispheric or lower brainstem
dysfunction
Intubation: presence or absence of a
respiratory drive

Studie
•Different types of examiners
◦ Watched a 20min instruction on the FOUR
score (videos with patient examples)
•Exclusie sedation/neuromuscular function
blockers

Studie
•4 categories:
◦Alert
◦Drowsy
◦Stuporous
◦Comatose
Each patient was rated on both scales by
two different raters (1 hours)

Outcome assessment
•A robust predictor of:
◦In-hospital mortality (withdrawal of life support)
◦Functional outcome at hospital discharge
•Clinical diagnosis of brain death
•Morbidity at 3 months
Modified Rankin Scale

Rankin score
0 : No symptoms
1 : No evident disability despite symptoms
2 : Slight disability, with an inability to carry
out all previous activities
3 : Moderate disability, with the need for
some help but the ability to walk without
assistance

Rankin score
4 : Moderately severe disability, with the
inability to walk without assistance or to
attend to bodily needs without assistance
5 : Severe disability, with the patient being
bedridden and incontinent and requiring
constant nursing care
6 : Death

Ideal coma scale
•Reliable (measures what it is supposed to
measure)
•Valid (yields the same results with
repeated testing)
•Linear (gives all component equal weight)
•Easy to use (provides simple instructions
without the need for tools or cards)

Shortcomings GCS
•Verbal component
◦Orientation
•Quickly abnormal (agitation/confusion)
•Conversely no respose → alert
◦Intubation
•Poorly assessing patients with less severe
degrees of coma

Shortcomings GCS
• No assessment of brainstem reflexes
(eye movements, complex motor responses)
Reliability
• Numerically toward motor responses
Linearity
• May not detect subtle changes
→ Attempts to improve GCS (lengthy)

FOUR: Voordelen
• High degree of:
◦Internal consistency
◦Interrater reliability (interobserver agreement)*
• Intubated patients
• Brainstem reflexes
• Respiratory patterns
• Further characterizes the severity of the
comatose state in patients with lowest GCS
(Mortality)
* High proportion alert patient (ER)

FOUR: Voordelen
• Detects early changes in consciousness
(Acute metabolic derangements, sepsis, shock,
other nonstructural brain injuries)
• Frequent use of mild sedation affects:
◦Eye opening
◦Motor response
• NOT:
◦Brainstem reflexes
◦Respiration.

Limitations
•4 maal: familiarity
•Number of patients
•Nurse/nurse
•Target enrollment cohort
•Alert patients
•Single center study

Conclusion
•Easily taught, simple to administer and
provides essentiel neurologic information
limited experience neuroscience
•‘Accurately’ predicts pour outcome
•Interobserver agreement (GCS)
•Detect occurence of brain death
•Diagnose a locked-in syndrome

Referenties
• Vivek et all. Validity of the FOUR score coma
scale in the medical intensive care unit. Mayo
Clinic Proc. 2009;84(8):694-701
• Latha et all. Validation of a new coma scale, the
FOUR score, in the emergency department.
Neurocrit Care. 2009; 10:50-54
• Chris et all. Further validation of the FOUR score
coma scale by intensive care nurses. Mayo Clin
Proc. 2007; 82(4):435-438
• Eelco et all. Validation of a new coma scale: the
FOUR score. Ann Neurol. 2005;58:585-593