Emergency Medicine: ED procedures

• Analgesia and sedation: Analgesia in the ED | Analgesia in Children | Procedural Sedation | Ketamine and Propofol
• Local and regional anaesthesia: Local Anaesthetics and Toxicity | Fascia Iliaca and Femoral Nerve Blocks | Digital, Haematoma and Bier's Blocks
• Reductions and immobilisation: Shoulder Dislocation Reduction | Other Dislocations and Fracture Reductions | Splints, Plaster Casts and Slings
• Other procedures: Vascular and Intraosseous Access | Pleural Procedures and Chest Drains | Lumbar Puncture | Joint Aspiration
• Revision: ED Procedures at a Glance | Spot the Diagnosis | Exam-style Scenarios | Key Points | Guidelines and Further Reading

💉 ED procedures — analgesia, procedural sedation, nerve blocks, reductions and practical skills. Relieving pain quickly and doing common procedures safely is at the heart of emergency medicine. Every procedure needs consent, the right environment, the right monitoring, a plan for complications and clear documentation. (Rapid sequence induction is covered in the Anaesthetics and Critical Care chapter.)
Your four questions for every ED procedure: Is it indicated — and what are the alternatives? Have I got consent, the right kit, the right people and the right monitoring? What are the complications — and how will I manage them? How will I document it, check the result and arrange follow-up?

Analgesia in the ED

• Assess pain early — at triage (pain score 0–10, or faces scales or behavioural tools for children and people with cognitive impairment); RCEM standards — analgesia for severe pain within 20–30 minutes of arrival; reassess within 60 minutes.
• Non-drug measures — reassurance, splinting and immobilisation, elevation, ice, dressing burns (cling film), reducing dislocations.
• Step-wise approach (by pain severity — RCEM):

  Pain	Options
  Mild (1–3)	Oral paracetamol and/or ibuprofen
  Moderate (4–6)	Paracetamol plus ibuprofen; oral codeine or oral morphine; Entonox for short periods
  Severe (7–10)	IV morphine (titrated — e.g. 0.1 mg/kg in 1–2 mg increments in adults); IV paracetamol; intranasal fentanyl or diamorphine (children); nerve blocks; methoxyflurane (Penthrox) inhaler

• NSAIDs — avoid in renal impairment, active peptic ulcer, late pregnancy, anticoagulation and severe asthma with NSAID sensitivity; good for renal colic (IM or PR diclofenac or IV paracetamol), musculoskeletal pain.
• Opioids — titrate IV to effect; give an antiemetic if needed; monitor sedation and breathing; naloxone available; reduce doses in older people and renal impairment.
• Entonox (50% nitrous oxide / 50% oxygen) — rapid onset and offset, self-administered; avoid in pneumothorax, bowel obstruction, diving, head injury with reduced consciousness, recent eye surgery with gas, first trimester (relative).
• Methoxyflurane (Penthrox) — inhaled analgesic for moderate to severe trauma pain in conscious adults — maximum 6 mL a day; avoid in renal impairment and malignant hyperthermia susceptibility.
• Ketamine at sub-dissociative doses (e.g. 0.1–0.3 mg/kg IV) — for severe pain, opioid-tolerant patients.
• Lidocaine patches, regional blocks — for rib fractures (serratus anterior or erector spinae plane blocks), hip fractures.

Analgesia in Children

• Pain tools — FLACC (Face, Legs, Activity, Cry, Consolability) for preverbal children, Wong–Baker faces, numeric scale for older children.
• Distraction and comfort — parent present, play specialists, bubbles, tablets and videos, sucrose for neonates, splinting.
• Paracetamol and ibuprofen — weight-based; give early, at triage.
• Intranasal opioids — fast, needle-free analgesia for severe pain (fractures, burns):
  • Intranasal diamorphine — 0.1 mg/kg (given in a small volume — 0.2 mL — via a mucosal atomiser).
  • Intranasal fentanyl — 1.5 micrograms/kg (max about 100 micrograms) — onset 5–10 minutes.
• Oral morphine — for moderate to severe pain when IV access isn't needed.
• Codeine — contraindicated under 12 years (and after tonsillectomy under 18) — unpredictable metabolism by CYP2D6 (ultra-rapid metabolisers — respiratory depression).
• Topical anaesthetic before cannulation — EMLA (lidocaine–prilocaine — 60 minutes) or Ametop (tetracaine — 30–45 minutes); vapocoolant spray for rapid effect.
• LAT gel (lidocaine–adrenaline–tetracaine) — topical anaesthesia for lacerations in children (apply for 20–30 minutes).
• Entonox — from about age 5 years (needs to self-administer).

Procedural Sedation

• Levels of sedation:

  Level	Response	Airway and breathing
  Minimal (anxiolysis)	Normal response to voice	Unaffected
  Moderate ("conscious sedation")	Purposeful response to voice or light touch	No intervention needed
  Dissociative (ketamine)	Trance-like state — profound analgesia and amnesia	Airway reflexes and breathing usually maintained
  Deep	Purposeful response only to repeated or painful stimulus	May need airway support
  General anaesthesia	Unrousable	Often needs airway intervention

• Indications in the ED — dislocations (shoulder, hip prosthesis, elbow), fracture manipulation, cardioversion, complex wound care, abscess drainage (some), children's procedures.
• Pre-sedation assessment — airway (difficult airway predictors), ASA grade (ASA 3 and above — involve senior or anaesthetist), comorbidities, allergies, previous anaesthesia, fasting status, consent.
• Fasting — strict fasting isn't required for ED sedation; the risk of aspiration is very low — decisions are individualised (RCEM/RCoA guidance — consider timing of the last meal, the urgency, the depth of sedation and aspiration risk factors).
• The team and kit (RCoA / RCEM — Safe Sedation of Adults in the Emergency Department):
  • Three people — a sedationist (with advanced airway skills for deep or dissociative sedation), a procedure operator and a nurse to monitor.
  • Resuscitation area with oxygen, suction, airway equipment, bag-valve-mask, defibrillator and reversal agents (naloxone, flumazenil — rarely used).
  • Monitoring — SpO₂, ECG, BP (every 5 minutes) and capnography (waveform end-tidal CO₂ — earliest sign of apnoea) during deep or dissociative sedation.
  • Use a checklist (e.g. RCEM sedation checklist).
• Discharge criteria — back to baseline consciousness, stable observations, able to drink and walk (age appropriate), responsible adult, written advice (no driving or machinery for 24 hours).
• Midazolam plus opioid — moderate sedation (e.g. for dislocation) — titrate slowly; synergistic respiratory depression — more risk in older people.

⚠️ Safety Pearl: Sedation is a continuum — a patient intended for moderate sedation can slide into deep sedation and apnoea. The sedationist must be able to rescue the airway, and capnography shows apnoea before the saturations fall.

Ketamine and Propofol

• Ketamine — NMDA receptor antagonist — dissociative sedation with strong analgesia and amnesia:
  • Dose — IV 1–1.5 mg/kg (sedation), further 0.5 mg/kg doses as needed; IM 4 mg/kg (children).
  • Advantages — airway reflexes, breathing and BP are usually maintained — good in children and haemodynamically unstable patients.
  • Side effects — emergence phenomena (agitation, hallucinations — more in adults; midazolam can help), laryngospasm (rare — jaw thrust, positive pressure ventilation, propofol or suxamethonium), vomiting (ondansetron), hypersalivation, raised BP and heart rate, nystagmus, transient apnoea with rapid injection.
  • Cautions — under 12 months (higher airway risk), uncontrolled hypertension or ischaemic heart disease, active psychosis, airway procedures (pharyngeal stimulation — laryngospasm), raised intraocular pressure (relative).
• Propofol — GABA-A agonist — short-acting deep sedation:
  • Dose — IV 0.5–1 mg/kg then 0.25–0.5 mg/kg boluses, titrated.
  • Advantages — rapid onset (30–60 seconds) and recovery (5–10 minutes), antiemetic — good for shoulder reductions and cardioversion.
  • Side effects — respiratory depression and apnoea, hypotension, pain on injection; no analgesia (give an opioid or block).
  • Needs advanced airway skills; avoid in shocked patients (or reduce the dose).
• Ketofol (ketamine plus propofol) — balances the hypotension of propofol with the BP support of ketamine; some EDs use it.
• Midazolam — benzodiazepine — anxiolysis and amnesia, no analgesia; reversal with flumazenil (seizure risk — avoid in benzodiazepine dependence).
• Fentanyl — short-acting opioid — analgesia during sedation; chest wall rigidity with rapid high doses.

Local Anaesthetics and Toxicity

• How they work — block voltage-gated sodium channels in nerve membranes; small, unmyelinated fibres (pain, temperature) are blocked first.
• Maximum doses (approximate — adult):

  Drug	Plain	With adrenaline	Notes
  Lidocaine	3 mg/kg (max 200 mg)	7 mg/kg (max 500 mg)	Fast onset, 1–2 hours
  Levobupivacaine / bupivacaine	2 mg/kg (max 150 mg)	2 mg/kg	Slow onset, long-acting; cardiotoxic
  Prilocaine	6 mg/kg (max 400 mg)	8 mg/kg	Used for Bier's block; methaemoglobinaemia

• Working out doses — 1% = 10 mg/mL; so 1% lidocaine — a 70 kg adult can have 21 mL plain (210 mg — round to max 200 mg = 20 mL).
• Adrenaline — vasoconstriction prolongs action, reduces bleeding and toxicity; traditionally avoided in end arteries (fingers, toes, penis) — evidence now suggests adrenaline in digital blocks is safe, but follow local policy.
• Reducing infiltration pain — warm the solution, buffer with bicarbonate, use a fine needle, inject slowly, inject through wound edges.
• Local anaesthetic systemic toxicity (LAST):
  • Early — circumoral tingling, metallic taste, tinnitus, light-headedness, slurred speech, agitation.
  • Severe — seizures, reduced consciousness, arrhythmias (bradycardia, VT, VF), cardiovascular collapse.
  • Management (AAGBI/ Association of Anaesthetists) — stop injecting, call for help, ABCDE, oxygen, treat seizures (benzodiazepine), ALS (prolonged CPR), and IV lipid emulsion (Intralipid 20%) — 1.5 mL/kg bolus over 1 minute then 15 mL/kg/hour infusion (repeat boluses as needed).
• Allergy to amide local anaesthetics is very rare (ester local anaesthetics — more allergic; preservatives).

Fascia Iliaca and Femoral Nerve Blocks

• Indications — hip fracture (NICE CG124 recommends nerve blocks), femoral shaft fracture (femoral nerve block — children and adults).
• Fascia iliaca compartment block (FICB):
  • Local anaesthetic is injected below the fascia iliaca, spreading to block the femoral nerve, lateral cutaneous nerve of the thigh and sometimes the obturator nerve.
  • Landmark technique — a point one-third of the way along the line from the ASIS to the pubic tubercle, 1 cm below the inguinal ligament — two "pops" (fascia lata and fascia iliaca); or ultrasound-guided (preferred; suprainguinal approach covers more of the hip).
  • Large volume of dilute long-acting local anaesthetic (e.g. 30–40 mL levobupivacaine 0.25% — within maximum dose).
• Femoral nerve block — needle lateral to the femoral artery at the inguinal crease (NAVY — nerve, artery, vein, Y-fronts — lateral to medial); ultrasound guidance.
• Safety — check weight and dose, aspirate before injecting, monitor for LAST (observations for 30–60 minutes), document; check for compartment syndrome risk (tibial fractures — discuss before blocking).
• Other ED blocks — serratus anterior plane or erector spinae plane blocks for rib fractures; supraclavicular or interscalene blocks for upper limb (specialist); ankle block; dental blocks; regional blocks for facial lacerations (supraorbital, infraorbital, mental nerves).

Digital, Haematoma and Bier's Blocks

• Digital nerve block — for finger and toe injuries (nail bed repair, nail removal, laceration repair, dislocations):
  • Each finger has 4 digital nerves (2 palmar, 2 dorsal) running beside the bone.
  • Ring block at the base of the digit (dorsal injections either side), or a single palmar (transthecal or subcutaneous) injection at the palmar crease.
  • Plain lidocaine 1% (2–3 mL a side) or levobupivacaine; check sensation before blocking and document.
• Haematoma block — for distal radius (Colles') fractures in adults:
  • Aseptic technique; aspirate blood from the fracture haematoma (confirms position), then inject about 10–15 mL of 1% plain lidocaine; wait 5–10 minutes before manipulation.
  • Less effective than Bier's block; converts a closed fracture to an "open" one in theory (low infection risk).
• Bier's block (intravenous regional anaesthesia — IVRA) — for forearm fracture manipulation (distal radius):
  • Two cannulas (one in the injured hand, one in the other arm); double-cuff tourniquet checked; exsanguinate the arm (elevation); inflate the cuff to about 100 mmHg above systolic (e.g. 250–300 mmHg).
  • Inject prilocaine 0.5% (about 3 mg/kg — e.g. 40 mL) into the injured arm — never bupivacaine (cardiotoxic).
  • Keep the cuff inflated for at least 20 minutes (and under 1–2 hours) — early release causes LAST.
  • Contraindications — sickle cell disease, severe hypertension, peripheral vascular disease, Raynaud's, crush injury, cellulitis, allergy, uncooperative patient.
  • Monitoring, resuscitation equipment and lipid emulsion available.

Shoulder Dislocation Reduction

• Anterior dislocation (about 95%) — fall on an outstretched hand or abducted, externally rotated arm — loss of shoulder contour ("squared-off"), arm held in slight abduction and external rotation, humeral head palpable anteriorly.
• Before reduction — check and document axillary nerve (regimental badge area sensation and deltoid), distal pulses and the rest of the neurovascular status; X-ray (AP and lateral/scapular Y or axial views) to confirm and exclude fracture (some experienced clinicians skip pre-reduction X-ray in recurrent atraumatic dislocations).
• Fracture-dislocations (especially humeral neck fracture) — orthopaedic reduction, usually in theatre.
• Reduction techniques (analgesia or sedation as needed):
  • Cunningham technique — massage of biceps, trapezius and deltoid with the patient sitting — no sedation needed.
  • External rotation (Kocher-type modified — Hennepin) — slow external rotation with the elbow at the side.
  • FARES (Fast, Reliable, Safe) — gentle traction with oscillation and gradual abduction.
  • Scapular manipulation, Milch technique, Stimson (prone with weight hanging), traction–countertraction.
  • Avoid Hippocratic method (foot in axilla) and classic Kocher's (forceful leverage — fracture risk).
• After reduction — repeat neurovascular check, post-reduction X-ray (look for Hill–Sachs lesion, Bankart fracture, greater tuberosity fracture), broad arm sling, analgesia, fracture clinic and physiotherapy; young patients have a high recurrence risk (surgery may be offered).
• Posterior dislocation — epileptic seizure or electric shock; arm held internally rotated; "light bulb" sign on AP X-ray — often missed — orthopaedic reduction.
• Inferior dislocation (luxatio erecta) — arm fixed above the head — rare.

Other Dislocations and Fracture Reductions

• General principles — analgesia; check and document neurovascular status before and after; X-ray before (unless time-critical) and after; immobilise; fracture clinic follow-up (virtual fracture clinics are common).

Splints, Plaster Casts and Slings

• Backslab (partial cast) — used for acute fractures to allow for swelling in the first days; completed or replaced later.
• Full cast — once swelling settles; plaster of Paris or fibreglass (lighter, stronger, can't be moulded as easily).
• Applying plaster — stockinette, padding (wool), plaster slab, crepe bandage; mould while setting; position joints correctly (e.g. ankle at 90° for most fractures); check that it isn't too tight.
• Patient advice — elevate, move fingers or toes, keep dry; return immediately with increasing pain, numbness, tingling, colour change, cold digits, or a tight cast (compartment syndrome — split the cast to the skin).
• VTE risk — lower limb immobilisation in a cast — assess VTE risk and consider LMWH prophylaxis (NICE NG89).
• Common immobilisation:
  • Broad arm sling — shoulder dislocation, clavicle, proximal humerus, forearm injuries.
  • Collar and cuff — humeral shaft fractures (gravity aligns), supracondylar fractures (children — after assessment).
  • High arm sling — hand injuries and infections (elevation).
  • Buddy strapping — stable finger and toe injuries.
  • Mallet splint — mallet finger (6–8 weeks continuously).
  • Thumb spica — suspected scaphoid fracture.
  • Futura (wrist) splint — buckle fractures in children (no follow-up needed in many cases), wrist sprains.
  • Walking boot — stable ankle fractures (Weber A and some Weber B), 5th metatarsal fractures.
  • Knee splint (cricket pad) — patella dislocation, quadriceps or patellar tendon injuries.

Vascular and Intraosseous Access

• Peripheral IV cannulation — flow depends on the radius (to the 4th power — Poiseuille's law) and length — short, wide cannulas (14G or 16G) for resuscitation; ultrasound guidance for difficult access.
• Intraosseous (IO) access:
  • Indications — cardiac arrest or shock when IV access fails or would be delayed (children and adults).
  • Sites — proximal tibia (2–3 cm below and medial to the tibial tuberosity — flat anteromedial surface), proximal humerus (adults — faster flow), distal femur, distal tibia (above the medial malleolus).
  • Device — powered drill (e.g. EZ-IO) or manual needle; confirm by aspiration of marrow, a stable needle and free flushing without swelling.
  • Any drug or fluid can be given (flush, use a pressure bag); marrow can be sent for glucose, cross-match and some tests (tell the lab).
  • Contraindications — fracture of that bone, previous IO attempt in the same bone, infection at the site, osteogenesis imperfecta.
  • Complications — extravasation and compartment syndrome, osteomyelitis (rare), growth plate injury (rare); remove within 24 hours.
  • Conscious adults — infuse lidocaine through the IO before fluids (pain).
• Central venous access — ultrasound-guided internal jugular (preferred), subclavian or femoral — vasopressors, poor peripheral access, CVP; complications — arterial puncture, pneumothorax, infection, thrombosis, air embolism.
• Arterial line — radial artery (check collateral flow) — continuous BP monitoring, frequent gases.
• Venous cutdown — rarely used now (IO preferred).

Pleural Procedures and Chest Drains

• Needle decompression for tension pneumothorax — 4th or 5th intercostal space, mid-axillary line (ATLS 10th edition for adults) or 2nd intercostal space mid-clavicular line (children; older guidance) — followed by a chest drain; in trauma arrest — finger thoracostomy.
• Chest drain insertion (BTS pleural guideline 2023):
  • Indications — pneumothorax (tension after decompression, large or symptomatic secondary pneumothorax, ventilated patients), haemothorax, empyema and complicated parapneumonic effusion, malignant effusion.
  • Safe triangle — anterior border of latissimus dorsi, lateral border of pectoralis major, a line through the 5th intercostal space (nipple level), and the apex below the axilla.
  • Ultrasound to mark the site for fluid; check clotting if elective.
  • Seldinger (small-bore — 12–14 F — most pneumothoraces and effusions) or blunt dissection (large-bore — trauma, haemothorax — 28–32 F).
  • Insert just above the upper border of the rib (the neurovascular bundle runs below each rib).
  • Connect to an underwater seal — check for swinging (and bubbling with air leak); chest X-ray after insertion.
  • Never clamp a bubbling drain; drain large effusions slowly (re-expansion pulmonary oedema — max about 1.5 L at a time).
• Complications — malposition, injury to lung, liver, spleen, heart or intercostal vessels, surgical emphysema, infection, drain blockage or dislodgement, re-expansion pulmonary oedema.
• Primary spontaneous pneumothorax (BTS 2023) — conservative management or ambulatory device or needle aspiration in symptomatic patients depending on patient priorities.
• Pleural aspiration (diagnostic) — ultrasound-guided — send fluid for protein, LDH, glucose, pH, cytology, microbiology (Light's criteria).

Lumbar Puncture

• Indications — suspected meningitis or encephalitis, subarachnoid haemorrhage with normal CT more than 6 hours after onset (xanthochromia — LP at 12 hours or later), idiopathic intracranial hypertension (opening pressure), Guillain–Barré syndrome.
• Contraindications — signs of raised ICP (reduced or fluctuating GCS, focal neurology, papilloedema, seizures, abnormal posturing — CT first), coagulopathy (platelets under 40–50, INR over 1.4 or anticoagulants), local infection, haemodynamic instability, meningococcal septicaemia with purpura.
• Technique:
  • Consent; left lateral position, knees to chest (or sitting); identify L3/4 or L4/5 (line between the iliac crests — Tuffier's line — crosses L4).
  • Aseptic technique, local anaesthetic; atraumatic (pencil-point) needle reduces post-dural puncture headache.
  • Measure opening pressure in the lateral position (normal about 10–20 cmH₂O; legs extended).
  • Collect samples — microscopy, culture and Gram stain; protein; glucose (with a paired plasma glucose); virology PCR; xanthochromia (protect from light); cytology; oligoclonal bands (with serum).
• CSF interpretation:

  	Bacterial	Viral	Tuberculous
  Appearance	Turbid	Clear	Clear or fibrin web
  Cells	High — neutrophils	Raised — lymphocytes	Raised — lymphocytes
  Protein	High	Normal or mildly raised	Very high
  Glucose (CSF:plasma)	Low (under 0.4)	Normal (over 0.6)	Low

• Complications — post-dural puncture headache (worse when upright, better lying flat — fluids, analgesia, caffeine, epidural blood patch), back pain, infection, bleeding (spinal haematoma), coning (if raised ICP).
• Don't delay antibiotics for LP in suspected bacterial meningitis.

Joint Aspiration

• Indications — suspected septic arthritis (the main ED indication — aspirate before antibiotics if it won't cause delay in a septic patient), crystal arthritis (gout, pseudogout), haemarthrosis, symptom relief of a large effusion.
• Contraindications — overlying cellulitis or skin infection (relative — go through clean skin), prosthetic joint (orthopaedics should aspirate — in theatre or under strict asepsis), severe coagulopathy (relative).
• Knee aspiration — supine with the knee slightly flexed (or extended); lateral or medial approach under the patella (superolateral approach into the suprapatellar pouch); aseptic technique; local anaesthetic; 18–21G needle; ultrasound guidance for small effusions and other joints (hip — always ultrasound-guided, usually by orthopaedics or radiology).
• Send synovial fluid for — Gram stain and culture, cell count, polarised light microscopy for crystals; send blood cultures too.
• Interpretation:
  • Septic — turbid or purulent, WCC usually over 50,000/mm³ with over 90% neutrophils — orthopaedic washout and IV antibiotics.
  • Gout — needle-shaped, negatively birefringent monosodium urate crystals.
  • Pseudogout — rhomboid, weakly positively birefringent calcium pyrophosphate crystals.
  • Haemarthrosis — fat globules suggest an intra-articular fracture (lipohaemarthrosis).
  • Crystals and infection can coexist — always culture.
• Septic arthritis — Staph. aureus commonest; gonococcus in young sexually active adults; flucloxacillin (clindamycin if penicillin allergy) — BSR/BOA guidance; MRSA cover (vancomycin) if risk.

ED Procedures at a Glance

Spot the Diagnosis