Failed spinal and high spinal

Surgical approach (context-dependent)

• Not a single operation: these are complications of spinal anaesthesia during surgery (commonly obstetrics, orthopaedics, urology, general surgery).
• Typical procedures where spinal is used
  • Caesarean section (elective/emergency).
  • Hip/knee arthroplasty; hip fracture fixation.
  • TURP/TURBT; lower limb vascular procedures; hernia repair.
• If neuraxial inadequate or high spinal occurs, surgeon may need to
  • Pause surgery, pack/hold, optimise maternal/foetal status (obstetrics), expedite delivery if foetal compromise and anaesthetist requests.
  • Convert to alternative technique (e.g., GA) once safe; consider local infiltration by surgeon as bridging measure in selected cases.

Anaesthetic management (overview)

• Type of anaesthesia
  • Planned: spinal anaesthesia (often with intrathecal opioid). Backup: repeat spinal / CSE / epidural top-up / GA.
• Airway device if conversion to GA
  • RSI with cuffed ETT is typical for obstetrics/urgent conversion; SGA may be acceptable in selected non-obstetric, fasted, low aspiration risk cases with experienced operator and stable conditions.
• Duration
  • Procedure-dependent: C-section commonly ~45–90 min; arthroplasty ~1.5–3 h; TURP ~0.5–1.5 h.
• How painful (if neuraxial inadequate)
  • C-section: peritoneal traction/uterine exteriorisation can be very painful if block inadequate.
  • Orthopaedics: tourniquet pain may occur despite adequate sensory block; deep pain may break through.
• Key principle
  • Treat failed spinal and high spinal as time-critical events: early recognition, clear communication, and decisive escalation.

Failed spinal: definition and patterns

• Definition: inadequate neuraxial anaesthesia after intended intrathecal injection such that surgery cannot proceed comfortably and safely.
• Patterns
  • Complete failure: no sensory/motor block.
  • Patchy/unilateral block.
  • Insufficient height (e.g., T10 when T4 needed for C-section).
  • Inadequate density: touch/pain persists; visceral pain on traction.
  • Delayed onset/slow onset (may be mislabelled failure).

Failed spinal: causes (exam-friendly categories)

• Wrong place / not intrathecal
  • False-positive CSF: saline/LA in needle hub; dural puncture not maintained (needle moves out).
  • Subdural injection (rare): delayed, patchy, high sensory with minimal motor; can progress.
  • Epidural or intraligamentous injection due to misidentification of space.
• Drug / dose / baricity / volume issues
  • Wrong drug or concentration; drug error (e.g., intrathecal opioid alone).
  • Inadequate dose for indication (e.g., low bupivacaine dose for C-section).
  • Expired/ineffective local anaesthetic (rare).
  • Baricity/position mismatch: hyperbaric solution with unexpected spread due to tilt; hypobaric/isobaric variability.
• Technical factors
  • Needle obstruction (tissue plug), failure to inject full dose, leakage, disconnection.
  • Intrathecal catheter not actually intrathecal; catheter migration.
• Patient/anatomical factors
  • Obesity, scoliosis, previous spinal surgery.
  • Low CSF volume (pregnancy, obesity) affects spread (usually higher, but variability).
  • Very anxious patient: misinterpretation of pressure/touch as pain; inadequate counselling/testing.

Failed spinal: assessment and confirmation

• Before declaring failure
  • Allow adequate time for onset (typically 5–10 min for bupivacaine; longer if low dose/isobaric).
  • Check sensory level with cold/light touch and pain (pinprick) appropriately; document dermatome and symmetry.
  • Assess motor block (Bromage), haemodynamic response (hypotension suggests sympathetic block).
• For C-section: minimum acceptable block
  • Aim: bilateral sensory block to at least T4 to cold, with dense block to surgical stimulation; anticipate visceral pain despite T4 if density inadequate.

Failed spinal: management options (stepwise)

• Immediate actions
  • Stop/avoid incision; communicate with surgeon; reassure patient; call for help early if obstetric/urgent.
  • Optimise positioning (supine with left uterine displacement in pregnancy), oxygen, IV access, monitoring.
• If partial/low block and time allows
  • Reposition (e.g., lateral tilt adjustments), consider waiting a few minutes if still ascending.
  • Analgesic adjuncts: small IV opioid doses, ketamine, nitrous oxide; be cautious—may mask inadequacy and risk awareness/distress.
• Repeat spinal
  • Appropriate if clear failure (no block) and no concern about high block from partial intrathecal dose.
  • Use a new ampoule, correct dose; consider reducing dose if any evidence of partial block to reduce risk of high spinal.
  • Prefer experienced operator; consider different interspace/approach; ensure free-flowing CSF before injecting.
• Convert to epidural/CSE (if catheter in situ or feasible)
  • If labour epidural in situ: assess function; consider incremental top-up with appropriate agent (e.g., lidocaine 2% + adrenaline ± bicarbonate; or chloroprocaine where available).
  • If epidural is patchy/unreliable and urgent: early decision for GA may be safer than repeated top-ups.
• Convert to GA
  • Indications: urgent surgery, distress/pain, inadequate block despite troubleshooting, or concern about local anaesthetic toxicity with further dosing.
  • Obstetric conversion: treat as full-stomach; RSI with cricoid (as per local policy), cuffed ETT, left uterine displacement, vasopressors ready.
  • Maintain communication: explain to patient (if awake) that conversion is for safety/comfort; document events and consent where possible.

High spinal / total spinal: definition and pathophysiology

• Definition: excessive cephalad spread of neuraxial block causing significant sympathetic blockade, high sensory/motor block, and potentially brainstem effects (apnoea/unconsciousness).
• Mechanisms
  • High intrathecal dose or unrecognised intrathecal injection during epidural top-up (e.g., intrathecal catheter or unrecognised dural puncture).
  • Reduced CSF volume (pregnancy, obesity) increases spread for a given dose.
  • Positioning effects (head-down tilt) with hyperbaric solutions.

High spinal: recognition (clinical features)

• Early features
  • Rapid hypotension, nausea/vomiting, dizziness, feeling faint (sympathetic blockade).
  • Upper limb tingling/weakness (block to C8–T1 and above).
  • Dyspnoea: may be from high block (intercostal paralysis) or from inability to feel chest wall; assess ability to speak and objective ventilation.
• Progression (severe/high/total spinal)
  • Bradycardia (T1–T4 cardioaccelerator fibres) and severe hypotension → cardiovascular collapse.
  • Respiratory insufficiency/apnoea; difficulty speaking; reduced consciousness.
  • Loss of protective airway reflexes; aspiration risk.

High spinal: immediate management (ALS-style priorities)

• Call for help and declare emergency
  • Summon senior anaesthetist, ODP, obstetric/neonatal team if relevant; stop surgery if possible.
• Airway and breathing
  • High-flow oxygen; support ventilation with bag-mask early if hypoventilation or reduced consciousness.
  • Early tracheal intubation if apnoea, inability to protect airway, or rapidly deteriorating ventilation; treat as full stomach in obstetrics.
• Circulation
  • Left uterine displacement in pregnancy; elevate legs, consider manual uterine displacement if needed.
  • Rapid IV fluid bolus (crystalloid) while prioritising vasopressors; consider additional large-bore access if not already.
  • Vasopressors: phenylephrine for hypotension with maintained HR; ephedrine if bradycardic; adrenaline for severe hypotension/bradycardia/collapse.
  • Treat bradycardia: atropine; if severe with hypotension consider adrenaline boluses and follow peri-arrest algorithm.
• If cardiac arrest
  • Start CPR immediately; follow ALS; in pregnancy follow maternal cardiac arrest modifications and consider perimortem caesarean (resuscitative hysterotomy) if indicated and gestation viable.
• Ongoing care
  • Sedation/anaesthesia while ventilated (e.g., propofol infusion or volatile if intubated); analgesia as required.
  • Continuous haemodynamic monitoring; consider arterial line if unstable; treat hypothermia and acidosis.
  • Expect recovery as block regresses; extubate when awake, ventilating adequately, and haemodynamically stable.

Prevention strategies (failed spinal and high spinal)

• Technique and checking
  • Ensure clear CSF flow before injection; aspirate gently if needed; inject slowly with stable needle position.
  • Use correct dose for indication; be cautious with repeat spinal dosing.
  • Standardised block testing and documentation before incision; do not rely on 'can move legs' alone.
• Epidural top-up safety (obstetric high spinal risk)
  • Assess epidural function before top-up (bilateral sensory change with test dose/previous boluses, catheter depth, absence of red flags).
  • Incremental dosing with frequent aspiration and monitoring; avoid large rapid boluses.
  • Be vigilant after accidental dural puncture or suspected intrathecal catheter—label clearly and use dedicated protocols.

Communication, documentation, and follow-up

• Intraoperative communication
  • Tell surgeon early if block inadequate or high spinal developing; request pause if needed.
  • Keep patient informed; acknowledge pain; avoid minimising symptoms.
• Post-event
  • Explain what happened, apologise appropriately, and provide reassurance; offer follow-up and documentation for obstetric anaesthetic record.
  • Datix/incident reporting for high spinal or significant failed spinal; review drug/technique factors; team debrief.