Clinical Skills · Children's Nursing

IM & SC Injections

How to do IM and SC injections in children, with the practical details people usually wish they had in one place.

The Nurse Lab · Children's Hub

Save for later

Injections are one of the first clinical skills you'll actually do on placement (not just watch). Getting the site, angle and needle length right matters — especially in kids where there's less muscle mass to work with. This guide covers both IM and SC with paed-specific stuff your lectures probably rushed through.

IM vs SC at a glance

Intramuscular (IM)

Into muscle tissue
90° angle to skin
Faster absorption than SC
Larger volumes OK (up to 1ml infants, 2ml children)
Common drugs: vaccines, antibiotics, adrenaline

Subcutaneous (SC)

Into fatty tissue below the skin
45° angle (or 90° with short needle)
Slower, sustained absorption
Smaller volumes (up to 1ml usually)
Common drugs: insulin, heparin, some vaccines

Quick way to remember

IM = into Muscle = 90°. SC = Shallow = 45°. The angle matches the depth you're aiming for. If you can remember that, you're halfway there.

IM site selection

In paediatrics, site choice depends on the child's age and muscle development. You can't just default to the deltoid like you would with adults — babies don't have enough muscle there yet.

Site	When to use	Key points
Vastus lateralis	First choice for infants & under 2s	Middle third of outer thigh. Large muscle, easy to access, well-developed even in small babies.
Deltoid	Children over 2 (if muscle bulk is adequate)	Two finger-widths below the acromion process. Good for older kids and vaccines. Smaller muscle = smaller volumes.
Ventrogluteal	Over 7 months (when walking develops muscle)	Between greater trochanter and iliac crest. Becoming more recommended — fewer nerves and vessels than dorsogluteal.

Avoid the dorsogluteal site

The traditional "upper outer quadrant of the buttock" is falling out of favour because of the risk of sciatic nerve injury. Most trusts and the RCN now recommend ventrogluteal instead. If your mentor asks you to use dorsogluteal, it's worth knowing this — but follow your local policy.

Needle selection

This is where people get confused. The needle needs to be long enough to reach the muscle (for IM) but not so long it goes through it. In kids, that window is smaller than adults.

Patient	IM needle	SC needle
Preterm / very small neonate	16mm (25G)	16mm (25G) at 45°
Term neonate – 2 months	16mm (25G)	16mm (25G) at 45°
2 months – 1 year	25mm (23G or 25G)	16mm (25G) at 45°
1 – 5 years	25mm (23G)	16mm (25G) at 45°
6 – 12 years	25mm (23G)	16mm (25G) at 45°
Over 12 / adolescent	25–38mm (21G or 23G)	16mm (25G) at 45°

Drawing up vs injecting

You draw up with a larger gauge needle (e.g. 18G or 19G — the "pink" or "cream" needle) and then swap to a smaller gauge for injection. Drawing up with the injection needle blunts it and makes it more painful. Always change the needle before injecting.

IM technique step-by-step

Check the prescription — right patient, drug, dose, route, time. Get a second checker if needed.
Gather equipment — correct syringe, drawing-up needle, injection needle, alcohol swab (check local policy), sharps bin.
Draw up the medication using the larger gauge needle. Tap out air bubbles, swap to the injection needle.
Position the child and identify your site. For vastus lateralis: middle third of the outer thigh.
Clean the site if required by local policy (some vaccine guidelines say you don't need to — check your trust).
Spread the skin taut (Z-track is preferred for many IM injections — pull the skin to one side, inject, release).
Insert the needle at 90° in one smooth motion. Don't jab — but don't go slowly either.
Aspirate is no longer routinely recommended for most IM injections (WHO & RCN guidance). Exception: when giving into the dorsogluteal site, aspiration may still be advised locally.
Inject slowly and steadily — about 1ml per 10 seconds.
Withdraw the needle, apply gentle pressure with gauze. Don't rub the site.
Dispose of the needle straight into the sharps bin — do not resheath.
Document: drug, dose, route, site, time, batch number (for vaccines), any reactions.

SC technique

SC injections go into the fatty layer just beneath the skin. They're simpler in some ways, but you still need to get the angle right or you'll end up going intradermally (too shallow) or into muscle (too deep).

Common SC sites

Outer upper arm (over the triceps area)
Anterior thigh
Abdomen (avoiding 5cm around the umbilicus) — mainly for insulin in older children

Technique

Prepare as for IM — check prescription, draw up, change needle.
Pinch a fold of skin between your thumb and index finger. You want to lift the subcutaneous tissue away from the muscle.
Insert the needle at 45° into the skin fold (or 90° if using a short 8mm insulin needle).
Do not aspirate — not needed for SC injections.
Inject slowly, withdraw, release the skin fold, apply gentle pressure.
Document as above.

Pinch vs spread

SC = pinch the skin (lifts fatty tissue). IM = spread the skin taut (flattens tissue so needle reaches muscle). Getting these mixed up is a classic OSCE mistake.

Site rotation

For children who have regular injections (insulin, growth hormone, enoxaparin), rotating sites is really important. Repeated injections in the same spot cause lipohypertrophy — hard lumpy areas of fatty tissue that mess up absorption.

Rotate between different body areas (e.g. left arm → right arm → left thigh → right thigh)
Within each area, move at least 2.5cm from the last injection site
Keep a rotation chart — especially for kids on insulin. Parents should be involved in tracking this
If you feel a lump at the site, avoid that area until it resolves

Red flags & complications

Stop and escalate if you see

Anaphylaxis signs (wheeze, swelling, rash, hypotension) — call for help, give IM adrenaline. Severe pain or numbness radiating down the limb (possible nerve injury). Significant bleeding or haematoma. Signs of infection at the site within 24–48 hours (redness, warmth, swelling, pus). Any signs of extravasation or tissue necrosis.

Complication	Why it happens	How to avoid it
Sciatic nerve injury	Dorsogluteal injection in small children	Use vastus lateralis or ventrogluteal instead
Lipohypertrophy	Repeated SC injections in same spot	Rotate sites systematically
Abscess / infection	Poor aseptic technique	Clean technique, check local ANTT policy
Needle too short (IM)	Drug deposits in SC tissue instead of muscle	Choose needle length based on age & site
Pain & bruising	Injecting too fast, wrong angle, or blunt needle	Inject slowly, change needle after drawing up, correct angle

Pain minimisation in children

This is the bit that matters most on placement — kids remember pain, and how you manage it affects whether they cooperate next time. Plus examiners love asking about this.

Topical anaesthetic cream (e.g. EMLA or Ametop) — apply 30–60 mins before if planned. Doesn't work for all injection types but always worth considering
Distraction — bubbles, counting, phone/tablet, conversation. Tailor to the child's age and interests
Comfort positioning — let them sit on a parent's lap if possible, not pinned to the bed
Breastfeeding during injection (for infants) — evidence-based pain reduction
Sucrose solution (24%) — for neonates, 2 mins before the procedure
Cold spray (ethyl chloride) — numbs for a few seconds, good for quick injections
Don't say "it won't hurt" — be honest. "You might feel a sharp scratch" is better than lying
Inject the most painful drug last if giving multiple injections

From placement

Honestly, the distraction thing makes such a difference. I've seen kids who were screaming before the needle even came out completely forget about it because a play specialist had them blowing bubbles. If there's a play team available, get them involved. It's not a "nice to have" — it's part of the skill.

OSCE tips

Injection stations come up a lot. Here's what examiners are actually looking for beyond just "can you stick the needle in the right place."

Consent & explanation

Explain the procedure in age-appropriate language. For young children, talk to the parent. For older kids, address them directly. Get verbal consent.

Site selection reasoning

Don't just say "I'll use the thigh." Say why — "vastus lateralis is the recommended site for infants because the muscle is well-developed and there's lower risk of nerve injury."

Sharps safety

Dispose immediately into the sharps bin. Never resheath. Never walk across the room holding a used needle. Examiners watch for this closely.

Pain management

Mention at least one pain minimisation technique unprompted. Distraction, topical anaesthetic, comfort positioning — show you've thought about the child's experience, not just the procedure.

Z-track technique

If they ask you to demonstrate, pull the skin to one side before inserting at 90°, hold while injecting, then release. This seals the track and prevents drug leaking back into subcutaneous tissue.

Documentation

Finish by stating what you'd document: drug, dose, route, site used, time, batch number, any adverse reactions, who administered and who checked.

Top tip: practise on the injection simulation arms/legs in the skills lab as much as you can before your OSCE. The technique feels very different on a real person vs reading about it. If you can, ask to observe or assist with vaccinations on placement — it's the best way to build confidence.

← Back to Hub

← Hub