On call, you will often arrive to a patient who is clearly unwell.

At that moment, your job is not to:

❌ order scans
❌ read old notes
❌ build long differentials

Your job is:

👉 Fix anything immediately life-threatening

Because small early actions save far more lives than perfect diagnoses.

Good on-call doctors don’t ask:

“What is the diagnosis?”

They ask:

“What can I improve in the next 2 minutes?”

First mindset shift

Before investigations, always think:

Air. Oxygen. Fluids. Glucose. Antibiotics. Help.

These six things solve most emergencies.

Seriously.

Most ward deteriorations improve with just these.

The Golden Rule

If something is abnormal on A–E:

👉 Treat it immediately

Do not wait for:

blood results
scans
senior review
confirmation

Treat first.

Investigate after.

🅐 Airway – fix first, always

Airway problems kill fastest.

If you see:

reduced GCS
choking/gurgling
unable to talk
secretions

Do immediately:

sit patient upright
suction if needed
high-flow oxygen
call for help early
prepare airway support

Don’t:

❌ start taking history

Airway first. Always.

🅑 Breathing – oxygen early

Hypoxia is extremely common and very fixable.

If:

sats low
breathless
increased work of breathing

Do immediately:

give oxygen
sit upright
neb if wheezy
ABG if unwell
CXR later

Don’t:

❌ wait for CXR before oxygen

Oxygen is treatment, not investigation.

🅒 Circulation – access + fluids fast

Most overnight crashes are circulatory (sepsis, bleeding, dehydration).

If:

hypotension
tachycardia
poor perfusion
low urine output

Do immediately:

2 IV cannulas
bloods + lactate
fluid bolus
stop bleeding if present

Key principle:

IV access early saves huge time later

Never delay cannulation.

🅓 Disability – glucose early

Low glucose is:

common
dangerous
instantly reversible

Yet often forgotten.

Always check:

capillary glucose

If low:

give glucose immediately

Don’t wait for labs.

One of the easiest “wins” on call.

🅔 Exposure – look properly

You miss diagnoses if you don’t look.

Quickly check:

rashes
bleeding
distension
infection sources
pressure areas
temperature

So many answers are visible, not lab-based.

High-yield immediate treatments you should start without delay

These are safe, common, and often life-saving.

You don’t need permission to start them.

Oxygen

For hypoxia or distress
Low risk, high benefit

IV fluids

For hypotension/dehydration/sepsis
Most patients improve quickly

Antibiotics

If sepsis suspected
Earlier = better outcomes

Don’t wait for perfect diagnosis

Nebulisers

For wheeze/COPD/asthma
Quick improvement

Glucose

For hypoglycaemia
Immediate fix

Analgesia

For severe pain
Improves obs + cooperation

Pain itself causes tachycardia and stress

The “2-minute rule”

Ask yourself:

👉 “Is there anything I can fix in 2 minutes that makes this patient safer?”

Usually yes:

oxygen
fluids
cannula
glucose
antibiotics

Do those first.

Then think.

Real NHS examples

Example 1

Hypoxic patient
Bad: wait for CXR
Good: oxygen immediately

Example 2

Septic patient
Bad: wait for cultures first
Good: cultures + antibiotics straight away

Example 3

Confused patient
Bad: long history
Good: check glucose first

Simple actions prevent big problems.

Common junior mistakes

❌ overthinking
❌ waiting for results
❌ delaying oxygen/fluids
❌ doing admin first
❌ trying to “diagnose perfectly”
❌ not cannulating early

Perfection delays treatment.

Treatment saves lives.

Senior doctor mindset

Watch experienced registrars.

They don’t look rushed.

They just quietly:

give oxygen
get access
start fluids
give antibiotics
call for help

All within minutes.

Simple. Systematic. Safe.

Not fancy.

Simple bedside checklist

When patient looks unwell:

✅ Oxygen
✅ IV access
✅ Bloods
✅ Fluids
✅ Glucose
✅ Antibiotics (if sepsis)
✅ Escalate if needed

If you do just these, you’ve already done 80% of what matters.

Take-home concept

On-call medicine is not about cleverness.

It’s about early basic interventions.

Small actions done quickly save far more lives than complex plans done late.

Fix the basics first.

Always.

Stabilise → then investigate → then diagnose.

Never the other way around.