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Emergency Medicine Procedures: Deep Clinical Reference

Overview

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1. PERIPHERAL IV CANNULATION

Overview

Gauge Selection by Clinical Context

Site Selection

• First choice: Antecubital fossa (median cubital, cephalic, basilic) - large, easily visible
• Second choice: Forearm (cephalic, basilic)
• Third choice: Dorsum of hand
• Avoid: Lower limb veins (high DVT/phlebitis risk), femoral vein for peripheral (infection risk), limb with AV fistula, mastectomy side, or limb with lymphoedema

Technique (Step by Step)

1. Prepare patient: Explain procedure, obtain consent, position arm at heart level or below.
2. Apply tourniquet: 10-15cm proximal to insertion site. Ask patient to open and close fist.
3. Vein identification: Visually identify and palpate - a patent vein feels soft and bouncy. Use warm compresses or transillumination for difficult veins.
4. Asepsis: Don gloves. Clean site with chlorhexidine or 70% alcohol swab for 30 seconds; allow to dry completely.
5. Skin stretch: Use non-dominant hand to apply traction distal to insertion site, anchoring the vein.
6. Insertion: With bevel up, insert at 15-30 degree angle in the direction of venous flow (toward heart). Advance until a flashback of blood is seen in the chamber.
7. Advance cannula: Lower angle to almost skin level, advance the catheter 1-2mm further into the vessel to ensure the plastic cannula tip is intraluminal, then slide cannula off the needle while keeping needle still.
8. Release tourniquet: Before removing the needle/stylet.
9. Secure and flush: Apply digital pressure proximal to tip, remove needle, connect to cap/giving set, flush with 10mL normal saline and observe for resistance or swelling (extravasation).
10. Secure dressing: Apply transparent sterile dressing. Document date, time, gauge, and site.

Complications and Management

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2. CENTRAL VENOUS CATHETERISATION (CVC)

Indications

• Peripheral venous access impossible (obesity, collapsed veins)
• Cardiac arrest / CPR - emergency access
• Central venous pressure (CVP) monitoring
• Administration of vasopressors (noradrenaline, adrenaline)
• Total parenteral nutrition (TPN) or hyperosmolar solutions
• Chemotherapy agents causing peripheral phlebitis
• Haemodialysis / plasmapheresis
• Pulmonary artery catheter placement (Swan-Ganz)
• Transvenous cardiac pacing

Absolute Contraindications

• Patient refusal
• Distorted local anatomy (trauma, prior surgery, radiation, tumour)
• Superior vena cava syndrome (for subclavian/IJ routes)
• Bleeding diathesis with noncompressible vessel
• Active infection at insertion site

Routes Compared

The Seldinger Technique (Universal Method for CVC)

1. Set up: Full aseptic technique - sterile gown, gloves, mask, cap, large sterile drape. Open commercial CVC kit.
2. Position: Trendelenburg (head down 15-20°) for IJ/subclavian to distend veins and reduce air embolism risk. NOT required for femoral.
3. Anaesthesia: Infiltrate 2mL of 1% lidocaine (with 25G needle) into skin and deeper tissues.
4. Seeker needle: Attach 22G "seeker" to 5mL syringe. Advance with continuous gentle aspiration until free blood return confirms venous placement.
5. Introducer needle: Once vein located, use 18G introducer needle (with syringe) to puncture at the same trajectory, aspirating continuously. Dark, non-pulsatile blood = vein; bright red/pulsatile = artery (withdraw immediately, compress).
6. Guidewire: Remove syringe. Thread J-wire (0.089cm diameter, 45cm long) through the needle into the vein. The wire must pass without resistance. Never lose control of the proximal end of the wire.
7. Remove needle: Holding the wire steady, remove the introducer needle over the wire.
8. Skin nick: Make a small stab incision with a #11 scalpel blade at the wire entry site.
9. Dilator: Thread dilator over wire to dilate subcutaneous track. Remove dilator, maintaining wire position.
10. Catheter placement: Thread CVC over the wire. The wire must be visible at the proximal end of the catheter before advancing. Advance catheter to appropriate depth (right IJ: ~15cm; right subclavian: ~15cm; left-sided: ~17-20cm; femoral: ~30cm for IVC reach).
11. Remove wire: Hold catheter firmly, remove wire completely.
12. Confirm and aspirate: Aspirate each lumen for blood return, then flush all lumens with saline.
13. Secure: Suture catheter hub to skin with 3-0 silk. Apply chlorhexidine-impregnated dressing.
14. Post-insertion CXR: Mandatory - confirm tip position (should be at SVC-RA junction, NOT in right atrium or ventricle) and exclude pneumothorax/haemothorax.

Subclavian Vein - Infraclavicular Approach

• Patient in Trendelenburg with ipsilateral arm by side
• Identify landmarks: thumb on distal clavicle, middle finger on sternoclavicular joint - insertion point is where the index finger crosses the inferior border of the clavicle
• Aim needle toward the sternal notch, advancing under the clavicle "hugging" the inferior cortex
• Direct the needle medially, staying parallel to the floor

Internal Jugular Approach

• Position: Head rotated 30-45° contralaterally (not excessively)
• Identify the triangle formed by the two heads of sternocleidomastoid (SCM)
• Insert at the apex of the triangle at 30-45° angle toward ipsilateral nipple
• Ultrasound guidance is strongly recommended and evidence-based - reduces complications significantly in both adult and paediatric patients

Ultrasound Guidance

CVC Complications

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3. ENDOTRACHEAL INTUBATION (ETI)

Indications

• Refractory hypoxaemic respiratory failure (SpO2 <90% despite high-flow O2)
• Hypercapnic respiratory failure (rising pCO2, tiring patient)
• Airway protection: intoxication, head trauma, severe haematemesis, coma (GCS ≤8)
• Upper airway obstruction: angioedema, tumour, epiglottitis
• Severe metabolic acidosis/haemodynamic shock ("type 4 respiratory failure")
• Need for controlled hyperventilation (raised ICP management)

Pre-intubation Checklist (SOAPME)

• S - Suction (working, at bedside)
• O - Oxygen (15L/min via BVM; pre-oxygenate to SpO2 >95% for 3-5 minutes)
• A - Airway adjuncts (oral airway, nasopharyngeal airway, LMA as rescue)
• P - Position ("sniffing" position: neck flexed, head extended; ramp for obese patients)
• M - Monitoring (SpO2, ECG, NIBP, capnography)
• E - Equipment (laryngoscope + blade tested, ETT with stylet and tested cuff, 10mL syringe, end-tidal CO2 colorimeter, video laryngoscope as backup, bougie/tracheal tube introducer)

Drugs for Rapid Sequence Intubation (RSI)

Direct Laryngoscopy - Step by Step Technique

1. End-tidal CO2 colorimeter (yellow = CO2 = correct placement)
2. Auscultation: bilateral breath sounds over chest AND absence of gurgling over epigastrium
3. Chest X-ray: tip should be 3-5cm above the carina

Post-Intubation Management

• Cuff pressure: Monitor regularly; maintain <25 mmHg (below capillary filling pressure) to prevent ischaemic mucosal injury
• Secure ETT with tape or commercial holder
• Continuous sedation and analgesia (see post-intubation sedation table below)

Post-Intubation Sedation

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4. VIDEO LARYNGOSCOPY

• Cervical spine immobilisation (cannot optimally position)
• Facial/oral trauma with distorted anatomy
• Obese patients with short neck
• Predicted difficult airway (LEMON score positive)

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5. DIFFICULT AIRWAY AND RESCUE TECHNIQUES

LEMON Score (Predict Difficult Airway)

• L - Look externally (micrognathia, macroglossia, short neck)
• E - Evaluate 3-3-2 rule (3 finger mouth opening; 3 finger hyoid-chin distance; 2 finger thyroid-floor of mouth)
• M - Mallampati score (Class III-IV = difficult)
• O - Obstruction (foreign body, angioedema, tumour)
• N - Neck mobility

Needle Cricothyrotomy (Cannot Intubate/Cannot Oxygenate)

1. Extend neck; identify the cricothyroid membrane (inferior to thyroid cartilage, superior to thyroid gland - felt as a soft indent in the midline)
2. Stabilise thyroid cartilage with non-dominant hand
3. Insert 14G cannula on syringe at 45° angle through membrane, aspirating continuously
4. Free air aspiration confirms tracheal placement
5. Advance cannula to hub; remove needle
6. Attach syringe barrel (plunger removed) then 7mm ETT adaptor for BVM ventilation
7. Limitation: Allows oxygenation only (~30-40 min before CO2 build-up); bridges to definitive airway

Surgical Cricothyrotomy

1. Extend neck; palpate and identify cricothyroid membrane
2. Stabilise thyroid cartilage with non-dominant hand
3. Make 1cm horizontal skin incision just above the superior border of the cricoid cartilage
4. Use Kelly forceps to dissect until cricothyroid membrane is visible
5. Make a vertical incision through the midline of the membrane (depth: 1-1.5cm, do not pass too deeply)
6. Widen incision with Kelly forceps; insert 6mm ETT or cric tube through incision
7. Inflate cuff; confirm with capnography and auscultation
8. Secure tube

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6. URINARY CATHETERISATION

Indications

• Urinary retention (acute)
• Accurate urine output monitoring in critically ill patients
• Pre-operative/peri-operative bladder decompression
• Collection of uncontaminated urine specimen
• Bladder irrigation (haematuria, clot retention)
• Administration of intravesical medication

Catheter Types

• Foley catheter: Most common; balloon retention; sizes 12-18 French (smaller = thinner)
• Coude catheter: Curved tip; preferred in male patients with benign prostatic hyperplasia (BPH) or urethral stricture
• Three-way catheter: Extra port for continuous bladder irrigation (haematuria)
• Intermittent/in-out catheter: No balloon; single drainage then removed

Male Technique (Step by Step)

1. Equipment: Catheterisation pack (drape, cleansing solution, forceps, urinary catheter, 10mL sterile water for balloon, drainage bag, lubricating gel with lignocaine)
2. Position: Supine; expose genitalia
3. Sterile field: Open pack aseptically; don sterile gloves
4. Clean: Hold penis with non-dominant hand (becomes non-sterile); retract foreskin (document if phimosis). Cleanse glans and urethral meatus with chlorhexidine or antiseptic from meatus outward, 3 times.
5. Lubricate: Instil 10-15mL lignocaine gel into the urethra; wait 3-5 minutes for effect
6. Insert catheter: Hold catheter with sterile dominant hand; insert into urethral meatus advancing smoothly. For male, advance the full length (~20cm) before inflating balloon - the urethra is long (~20-25cm) and the balloon must NOT be inflated in the urethra
7. Confirm placement: Urine drains freely into catheter. If no drainage, connect drainage bag and apply gentle suprapubic pressure, OR ask patient to cough
8. Inflate balloon: Once urine drains, inflate balloon with 10mL sterile water (as per catheter label). Gently pull back to feel balloon seat at bladder neck
9. Replace foreskin: Critical - prevents paraphimosis
10. Connect drainage bag: Hang below bladder level for gravity drainage
11. Secure catheter: Tape to inner thigh to prevent traction

Female Technique

1. Position in dorsal lithotomy; identify urethral meatus (between clitoris above and vaginal orifice below)
2. Cleanse labia minora and meatus with downward strokes, inner-to-outer
3. Insert lubricated catheter 5-7cm into urethra (female urethra ~4cm)
4. Confirm urine drainage; inflate balloon with 10mL sterile water
5. Attach drainage bag

Difficulty Encountered

• Male - resistance at external sphincter: Ask patient to take deep breath and bear down; avoid excessive force
• Male - resistance at prostatic urethra: Use Coude catheter (curved tip facilitates passage through BPH)
• Cannot pass at all: Do NOT force; consider urological suprapubic catheterisation
• No urine despite correct placement: Bladder may be empty; flush with 20mL saline to confirm intravesical position

Complications of Urinary Catheterisation

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7. CLINICAL PEARLS ACROSS PROCEDURES

1. RSI drug selection by haemodynamic state: Use etomidate or ketamine in haemodynamic instability. Reserve propofol for haemodynamically stable patients.
2. Never lever a laryngoscope - lift vertically in the direction of the handle. Levering risks dental injury and poor glottic view.
3. The 3-attempt rule: No more than 3 intubation attempts before declaring a failed airway and activating the difficult airway algorithm (LMA → cricothyrotomy).
4. Peripheral > central in haemorrhage: A 14G peripheral cannula in the antecubital fossa delivers more volume per minute than a 16G triple-lumen CVC.
5. Flush before blood products: Never run blood through a glucose-containing line - causes haemolysis. Flush with normal saline first.
6. Seldinger principle: The wire must ALWAYS be visible at the proximal end of any catheter before advancing. If you lose the wire, STOP - it can embolise.
7. Post-intubation cuff pressure: Monitor at regular intervals and keep <25 mmHg to prevent tracheal ischaemia and subsequent stricture.
8. Urinary catheters: Advance fully in males before balloon inflation - the male urethra is 20cm long; premature balloon inflation is the most common cause of urethral rupture.

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• The Washington Manual of Medical Therapeutics (Airway Management and Endotracheal Intubation section, p.280-283)
• Pfenninger and Fowler's Procedures for Primary Care, 3rd Edition (Central Venous Catheter Insertion chapter)
• Roberts and Hedges' Clinical Procedures in Emergency Medicine (Central Venous Access chapter)