The epidural space is a potential space between the ligamentum flavum and the dura mater. It contains fat, blood vessels, and nerve roots.
Typically 4–6 cm in adults (varies with BMI and vertebral level). Identified by loss-of-resistance technique (saline or air).
Epidural catheters use yellow NRFit connectors (ISO 80369-6). Clearly labelled "EPIDURAL" — incompatible with IV Luer-lock by design to prevent misconnection.
Drugs deposited in the epidural space diffuse across the dura and act on spinal nerve roots as they exit the cord, producing segmental blockade.
Blocks Na⁺ channels → inhibits sensory (A-delta, C fibres) and, at higher doses, motor (A-alpha) fibres. Differential block: sensory > motor at low concentrations.
Acts on mu-receptors in dorsal horn (Rexed layers I, II). Synergistic with LA → allows lower doses of each, reducing side effects.
Pump delivers a fixed rate (e.g., 6–12 ml/hr). Consistent blood levels. Less patient involvement. Common post-operative.
Patient activates bolus (e.g., 5 ml) with a lockout (15–30 min). May have background infusion. Preferred in labour — reduces total drug use.
Nurse- or anaesthetist-administered boluses. Used for top-up, conversion to CS, or when pump unavailable.
GCC Context: Gulf hospitals have among the highest caesarean section rates globally (UAE ~35%, KSA ~40% in some centres). Epidural/spinal analgesia for labour and conversion capability for emergency CS is a core competency for GCC nurses. Post-CS epidural or intrathecal morphine is standard for post-operative analgesia.
Monitoring Principle: Epidural monitoring is a nursing responsibility. Sedation precedes respiratory depression — always check sedation score before pain score intervention. Never increase an epidural rate without completing a full assessment.
Assess with ice or cold spray (ethyl chloride). Apply to dermatomal levels bilaterally, working cephalad from the lowest level. Patient reports altered cold sensation.
| Indication | Target Level |
|---|---|
| Labour analgesia | T10 bilaterally |
| Lower abdominal surgery | T6–T8 |
| Upper abdominal / thoracic | T4–T6 |
| Pre-CS test before incision | T4 bilateral |
| Hip / knee surgery | T12–L1 |
T4 = nipple line. T10 = umbilicus. L1 = inguinal ligament. Use anatomical landmarks to estimate.
Assess lower-limb motor block. Excessive motor block is a patient safety risk (falls, pressure injury). Score both legs.
Bromage ≥2: Pause infusion, ensure patient is safe and in bed, document, call senior/anaesthetist. Reassess in 30 min. Do not restart without review.
Epidural sympathetic block → peripheral vasodilation → hypotension risk. Higher block level = greater haemodynamic effect.
Common with fentanyl/diamorphine component. Assess using NRS nausea (0–10).
Spinal/epidural opioid-specific effect. Not histamine-mediated — antihistamines less effective.
Sacral nerve block → detrusor relaxation. All epidural patients should have urinary catheter.
Safety Priority: High block, total spinal, and epidural haematoma are time-critical emergencies. Every nurse caring for an epidural patient must know the early warning signs and escalation pathway.
Recognition: Postdural puncture headache (PDPH) — bilateral, frontal/occipital, severe, postural (worse sitting/standing, better lying flat). May have associated neck stiffness, photophobia, tinnitus. Onset 24–48h after procedure.
EMERGENCY — Act immediately
Recognition: Block rising above T4 → bilateral arm weakness, dyspnoea, hypotension. Above C3–C4 → respiratory arrest, loss of consciousness.
Recognition: Rapid onset (within minutes of injection) — complete bilateral block, loss of consciousness, apnoea, severe hypotension/cardiac arrest. Occurs if epidural catheter migrates intrathecally and large dose administered.
Full cardiopulmonary resuscitation as per ALS protocol. Intubation and mechanical ventilation. Vasopressors. Effects are temporary — support until block recedes (1–2 hours).
Risk Factors: Anticoagulation (LMWH, warfarin, NOACs), coagulopathy, difficult insertion, multiple attempts, thrombocytopenia.
Onset: Usually 3–5 days after epidural siting. Risk factors: immunosuppression, diabetes, prolonged catheter duration (>3–4 days), breach of aseptic technique.
Management: Remove catheter, blood cultures + wound swab, emergency MRI, IV antibiotics (Staph aureus most common), neurosurgical drainage if cord compression.
Recognition: Usually detected by test dose. Signs of IV bupivacaine toxicity: tinnitus, metallic taste, perioral numbness, agitation, seizures, cardiovascular collapse (VT/VF).
Widens interspinous spaces. Preferred in obese patients. Patient hunches forward, "C-shape" back, supported by midwife.
Knees to chest, chin on chest. May be needed if patient cannot sit due to contractions or fatigue.
L2–L4 interspace insertion → T10 sensory block. First stage: T10 (uterine). Second stage: S2–S4 (perineum) — may need lower catheter or position change.
3 ml of 1.5% lignocaine + adrenaline 1:200,000 (15 mcg epinephrine):
12–15 ml bupivacaine 0.1% + fentanyl 2 mcg/ml in divided doses (3 ml every 5 min × 4–5 doses). Assess block level and BP after each aliquot.
Rapid top-up via existing epidural catheter to achieve T4 bilateral block for surgery:
Total 15–20 ml administered in 5 ml aliquots with BP monitoring. Time to T4: approximately 10–15 min with well-functioning epidural.
Confirm T4 bilateral cold block AND loss of sharp sensation (pinprick). Do not proceed to incision without confirmed block. Communicate clearly with surgeon.
Failed/Inadequate Block: Inform anaesthetist and surgeon immediately of anticipated delay.
| Drug | Minimum Gap |
|---|---|
| LMWH prophylactic | ≥12 hours before/after |
| LMWH therapeutic | ≥24 hours before/after |
| Warfarin | INR <1.5 before removal |
| NOAC (rivaroxaban etc) | ≥24 hours (dose-dependent) |
Patient-Controlled Analgesia (PCA) allows the patient to self-administer preset IV opioid boluses on demand. The pump delivers a bolus when the button is pressed, subject to a lockout interval.
| Drug | Bolus Dose | Lockout |
|---|---|---|
| Morphine | 1–2 mg | 5–10 min |
| Fentanyl | 10–20 mcg | 5–10 min |
| Hydromorphone | 0.2–0.4 mg | 5–10 min |
| Oxycodone | 1–2 mg | 5–10 min |
Controversial: Background infusions increase respiratory depression risk without consistent analgesic benefit in opioid-naive adults. Avoid unless on specialist pain team instruction or for opioid-tolerant patients.
Two-nurse independent check is mandatory for PCA programming and drug loading. Both nurses must independently verify each item before activation.
Sedation precedes respiratory depression. Act on sedation score ≥2 — do not wait for respiratory rate to fall.
Gulf hospital patient populations are highly diverse. PCA education must be delivered and confirmed in the patient's primary language.
DHA (Dubai), DOH (Abu Dhabi), MOH (Saudi/UAE national), QCHP (Qatar), NHRA (Bahrain) — all require signed PCA prescription, two-nurse check documentation, and hourly monitoring records as per controlled drug protocols.
| Score | Description | Action |
|---|---|---|
| 0 | Full movement | Continue |
| 1 | Cannot raise extended leg | Monitor |
| 2 | Cannot flex knee | PAUSE — review |
| 3 | No ankle/foot movement | STOP — anaesthetist |
| Complication | Key Recognition Feature | Immediate Action | Time-Sensitivity |
|---|---|---|---|
| Dural puncture headache | Postural, bilateral, frontal headache | Bed rest, hydration, blood patch | Hours–days |
| Hypotension | SBP <90 mmHg | Fluids, vasopressor, lateral tilt | Minutes |
| High block | Rising block, arm weakness, dyspnoea | STOP infusion, O₂, call anaesthetist | Immediate |
| Total spinal | Rapid LOC + apnoea after injection | CPR, intubation, vasopressors | Immediate |
| LAST | Tinnitus → seizures → VF | Stop injection, Intralipid 20% | Immediate |
| Epidural haematoma | Back pain + progressive neuro deficit | Emergency MRI, neurosurgery | Within 8 hours |
| Epidural abscess | Fever + back pain + neuro deficit (days) | MRI, antibiotics, neurosurgery | Hours |
| Respiratory depression (PCA) | Sedation score ≥2, RR <8 | Stop PCA, O₂, naloxone 0.1 mg IV | Immediate |
A: Pause the epidural infusion and call for senior review. Bromage ≥2 indicates excessive motor block. Ensure patient is in bed and safe. Do NOT continue or increase infusion.
A: (1) Left lateral tilt / left uterine displacement in obstetric patients. (2) IV fluid bolus (Hartmann's 250–500 ml). (3) Ephedrine or phenylephrine IV. (4) Reduce infusion rate if persistent.
A: Normal epidural motor block is expected and often bilateral but resolves when infusion stopped. Epidural haematoma presents with new or progressive back pain PLUS neurological deficit (often after epidural removed or rate reduced). Symptoms persist/worsen despite stopping infusion — emergency MRI required.
A: Yellow NRFit connectors (ISO 80369-6) are epidural-specific. They are physically incompatible with IV Luer-lock connectors, preventing accidental intravascular injection of epidural drugs — a critical patient safety design feature.
A: Only the patient. Family members pressing the PCA button bypasses the sedation safety mechanism — a sedated patient would not self-administer, preventing overdose. This is called "PCA by proxy" and is a medication error risk.
A: Two scenarios being excluded: (1) Intravascular placement — adrenaline causes HR rise >20 bpm. (2) Intrathecal placement — lignocaine causes rapid dense block within 3–5 min. Negative test on both = safe to proceed.
A: T4 bilateral — confirmed with ice/cold spray AND loss of sharp sensation. T4 = nipple line. Below T4, peritoneal manipulation causes pain. Above T4 can indicate developing high block.
A: 12 hours after prophylactic dose LMWH; 24 hours after therapeutic dose. Same intervals apply for catheter insertion. Next LMWH dose should not be given until ≥4 hours after catheter removal. Check local protocol and individual coagulation status.