How to perform a neurological assessment on an intubated patient with a Glasgow Coma Scale (GCS) score of 10?

Neurological Assessment in Intubated Patients with GCS 10

In an intubated patient with GCS 10, perform a modified Glasgow Coma Scale assessment using only the eye (E) and motor (M) components, integrate pupillary examination, and consider using the FOUR score for a more comprehensive brainstem assessment. 1

Modified GCS Assessment in Intubated Patients

Core Components to Assess

The verbal component cannot be assessed in intubated patients, so document the GCS as "E + M + VT" (V-intubated) rather than attempting to estimate a total score. 1 While mathematical models exist to derive verbal scores from eye and motor components, these add no clinically meaningful advantage for outcome prediction in intubated patients. 2

• Eye Opening (E1-4): Assess spontaneous eye opening, opening to voice, opening to pain, or no response 1
• Motor Response (M1-6): Evaluate best motor response - obeys commands, localizes to pain, withdraws from pain, abnormal flexion, abnormal extension, or no response 1
• Document sedation status: All consciousness scales are confounded by sedation, opioids, and neuromuscular blockade, so explicitly note these medications and their timing 1

Critical Pitfall to Avoid

Do not attempt to calculate a "total GCS" by estimating the verbal component in intubated patients for clinical decision-making. 1, 2 The motor component alone provides the most prognostic information and contributes more to outcome variability than estimated total scores. 2

Integrate Pupillary Assessment

Pupillary responses must be assessed alongside GCS, as they are strong predictors of outcome and compensate for the limitation of intubation on the verbal component. 1

• Assess bilaterally: Size (in mm), reactivity to light (brisk/sluggish/absent), and symmetry 1
• Document objectively: Use pupillometry devices if available for objective measurement of diameter and speed of response 1
• Integrate with GCS: The combination of GCS motor score and pupillary responses provides greater prognostic specificity than GCS alone 1

Consider the FOUR Score as Alternative

The Full Outline of Unresponsiveness (FOUR) score may provide superior assessment in intubated patients, particularly those who are deeply unresponsive, as it eliminates the verbal component entirely and adds brainstem reflexes. 1, 3

FOUR Score Components (Each 0-4)

• Eye response: Tracks commands with eyes, blinks to command, eye opening to voice/pain, or absent 1, 3
• Motor response: Similar to GCS motor but includes tracking commands 1, 3
• Brainstem reflexes: Pupillary and corneal reflexes, cough to suction 1, 3
• Respiration pattern: Assesses breathing pattern and ventilator triggering 1, 3

The FOUR score has demonstrated superior discrimination for early mortality prediction in intubated patients (AUC 0.90) compared to GCS (AUC 0.80). 3 However, clinical experience with FOUR remains more limited than with GCS. 1

Serial Assessments and Trending

Perform neurological assessments at regular intervals (typically hourly in acute phase) and document trends, as deterioration is more clinically significant than absolute values. 1

• Significant deterioration: A fall in GCS of ≥2 points or motor score of ≥1 point warrants immediate evaluation for new neurological insult 1, 4, 5
• Chart both components: Document eye and motor scores separately rather than summing them 1

Additional Monitoring in Brain-Injured Patients

Physiological Parameters

Maintain strict physiological targets during assessment to avoid confounding neurological examination with secondary brain injury. 1

• Blood pressure: Maintain MAP >80-90 mmHg (specific targets vary by injury type) 1
• Oxygenation: Target PaO₂ ≥13 kPa or SpO₂ ≥95%, avoiding hyperoxia 1
• Ventilation: Maintain normocapnia (PaCO₂ 4.5-5.0 kPa), avoiding hyperventilation except for impending herniation 1

Pain and Sedation Assessment

Brain-injured patients experience significant pain that confounds neurological assessment, requiring systematic evaluation even in those with altered consciousness. 1

• If responsive: Use Numeric Rating Scale (NRS 0-10) for self-report 1
• If unresponsive: Use Behavioral Pain Scale (BPS) or Critical Care Pain Observation Tool (CCPOT) 1
• Sedation level: Monitor with Richmond Agitation Sedation Scale (RASS) or Sedation-Agitation Scale (SAS) 1

Common Pitfalls in Intubated Patients

• Assuming neuromuscular blockade has worn off: Verify absence of paralysis before attributing lack of motor response to neurological injury 1
• Ignoring sedation timing: Recent sedative boluses render neurological assessment unreliable for 30-60 minutes 1
• Overlooking new neurological events: In neurocritical care patients, apparent "delirium" or agitation may represent progression of underlying disease requiring urgent imaging 1
• Delaying assessment for "wake-up tests": In patients with intracranial hypertension, sedation interruption poses significant risk of physiological decompensation and should generally be avoided unless benefit clearly outweighs risk 1