Clinical Assessments & Deterioration

Neurological Observations: GCS, Pupils & Consciousness

Not just a score — spotting change before it’s too late. What to check, how to score, and when to speak up.

Neurological observations are some of the most powerful — and most intimidating — checks you’ll perform. They tell you how the brain is functioning right now. And because the brain cannot store oxygen or glucose, even small changes can be early warning signs: rising pressure, reduced blood flow, infection, or the quiet slide into deterioration.

This guide breaks it all down simply. No unnecessary jargon. Just what you actually need on the ward: what each check means, how to do it properly, what counts as normal, and exactly what to report. Every principle here is grounded in national clinical guidance — referenced clearly so you can cite them in assignments and trust them in practice.

Why These Checks Matter — The Evidence Base

The brain needs a constant, uninterrupted supply of oxygen and glucose. When that supply shifts, brain function shifts — often long before a patient loses consciousness. NICE states neurological assessment is a core clinical skill, and early recognition of deterioration directly improves outcomes.

RCN evidence shows delays in detecting neurological change are a recurring factor in avoidable harm — particularly in stroke, head injury, and sepsis. In many cases observations were recorded, but the significance of the change was missed. That’s why this guide focuses not just on how to score, but on what the score actually means.

Glasgow Coma Scale — Explained Simply

The universal standard — three separate responses, scored and added together. 15 = fully alert. 3 = deeply unconscious. Students often memorise the numbers but don’t know how to apply them. Let’s fix that.

Eye Response (E) — 1 to 4

• 4 — Spontaneous: Eyes open on their own. Normal.
• 3 — To speech: Open when spoken to — call their name, don’t just make noise.
• 2 — To pain: Open only with firm stimulus — nail bed or trapezius squeeze. Rubbing shoulders doesn’t count.
• 1 — No response: Escalate immediately.

Document ‘C’ if eyes are swollen shut — never guess.

Verbal Response (V) — 1 to 5

• 5 — Oriented: Knows who, where, when. Converses normally.
• 4 — Confused: Clear speech but mixed up about time, place, situation.
• 3 — Inappropriate words: Phrases that don’t make sense. No sustained conversation.
• 2 — Incomprehensible sounds: Moans, grunts — no recognisable words.
• 1 — No sound: Escalate.

Document ‘T’ if intubated — never score 1, they cannot speak.

Motor Response (M) — 1 to 6

• 6 — Obeys commands: “Squeeze my hand” — does it on request.
• 5 — Localises to pain: Reaches towards or pushes away the stimulus.
• 4 — Withdraws: Pulls limb away — not targeted, just away.
• 3 — Abnormal flexion: Arms bend in, legs extend — significant brain dysfunction.
• 2 — Extension: Limbs stiff and straight — brainstem involvement, serious sign.
• 1 — No movement: Escalate immediately.

Total = E + V + M. 13–15 = mild; 9–12 = moderate; ≤8 = severe — airway protection at risk. A drop of 2+ points from their personal baseline is a red flag — even if still above 8. Trends matter more than the number alone.

AVPU — The Quick Check

Fast, reliable screening — correlates well with GCS:

• A — Alert: Fully awake ≈ GCS 15
• V — Responds to Voice: Wakes when spoken to ≈ GCS 12–14
• P — Responds to Pain: Only with stimulus ≈ GCS 8–11
• U — Unresponsive: No response ≈ GCS ≤7 — urgent help needed

Any drop from ‘A’ triggers a full GCS and review.

Pupil Assessment — What You’re Looking For

Pupils reflect brainstem function — changes here are serious. Check these three things every time:

1. Size: Normal 2–4mm. Record in mm — not “small/big”. Unequal = red flag.
2. Shape: Perfectly round. Oval/irregular may indicate raised pressure or surgery.
3. Reaction: Should constrict briskly to light. Sluggish = concern. Fixed = does not react = urgent concern.

Check both separately. Document fully: “R 3mm brisk; L 3mm brisk” — not just “pupils normal”. Lighting affects size — note conditions. Compare to their baseline, not a textbook.

Confusion, Delirium & Drowsiness — Telling Them Apart

• Delirium — acute, fluctuating: Hours/days onset. Worse at night. Agitated then drowsy. Causes: infection, dehydration, meds, constipation, pain. Reversible if treated. NICE CG103 applies.
• Dementia — chronic, progressive: Steady long-term decline. Sudden change is NOT just dementia. Always investigate.
• Drowsiness: Slowing response, drifting off mid-conversation. Check blood glucose first — it takes seconds and saves lives. Common culprits: opioids, infection, stroke, rising pressure.

Red Flags — Beyond the Score

• Asymmetry: One-sided weakness, droop, speech change → FAST → stroke team immediately. Time = brain.
• New speech change: Slurred, absent, nonsensical — document exactly what was said.
• Headache + vomiting: Worse when lying down → possible raised intracranial pressure.
• Seizures: Even with recovery → medical review. Note onset, duration, behaviour, post-ictal state.
• Slow recovery post-seizure: Confusion beyond 30–60 mins is not normal — investigate.

When & What to Report

Frequency follows NICE CG176 and clinical need — more often when unstable.

Escalate immediately if:

• GCS drops by 2+ points from last observation
• GCS ≤ 8 — airway risk
• Pupil dilated, unequal, unreactive
• New weakness, speech loss, facial droop
Worsening drowsiness that doesn’t improve with stimulation

Use SBAR to speak up confidently. → Shift Handover Guide has the full framework.

The Honest Reality

I’ve stood there, torch shaking slightly, wondering if that pupil was reacting properly. I’ve second-guessed confusion. It takes practice — and that’s okay.

If in doubt — ask someone else to check. “I’m concerned about this change — could you come assess?” That is not failing. That is safe, professional practice. The NMC Code says exactly that: know your limits and call for support.

You are the constant observer. That slow, small change you’ve noticed over hours might be the one that gets them help in time. Trust that. Report it.