Slow IV bolus · 1–1.5 mg/kg over 2–4 min (max 20 min) · Oxford Handbook of Anaesthesia
Dose
Duration
Maintenance Infusion
0.5–2 mg/kg/hr · Usual starting rate 1 mg/kg/hr
Rate
mg/kg/hr
Conc
Preparation
Syringe driver (50 ml) or pre-mixed 0.1% bag — based on infusion settings above
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LAST risk — consider total lidocaine load
If IV lidocaine is being used alongside a peripheral nerve block containing lidocaine, the doses accumulate within the same 6-hour window. Use the Blocks tab to calculate the combined fractional dose and ensure total exposure remains within safe limits (plain: 3 mg/kg / 200 mg; with adrenaline: 7 mg/kg / 500 mg).
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Dilutions
Mixing / Dilution Calculator
Mix two strengths, or dilute with saline — set Conc 1 to 0 for saline
Conc 1 (%)%
Conc 2 (%)%
Target (%)%
Total volumeml
Result
Quick Presets
Adrenaline Calculator
Add adrenaline to plain LA, or calculate the resulting concentration when mixing solutions with different adrenaline strengths.
Add to Plain LA
LA volumeml
Target
Mix Two Solutions
e.g. 10 ml 1% + 1:200k & 10 ml 2% plain → 1.5% + 1:400k
Solution Aml
Solution Bml
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Obstetrics
kg⌄
Spinal for Caesarean Section
Bupivacaine
Volume
ml
Adjuvant
solo only
can combine
Diamorphine
mcg
Morphine PF
mcg
Fentanyl
mcg
Epidural Top-up for CS
Existing block
Prepared mix
Levo 0.5%
ml
Lido 2%
ml
Volume administered
ml
⏱ Onset to T4: 15–20 min. Give in 3–5 ml increments with 5 min between doses.
Levo 0.5%
ml
⏱ Onset to T4: 20–25 min. Slower onset than levo/lido mix — allow adequate time before reassessing block height.
Local recipe — 20 ml total
Lidocaine 2%17 ml → 340 mg
Adrenaline 1:10,0001 ml → 100 mcg
NaHCO₃ 8.4%2 ml
Total20 ml
Volume administered
ml
⏱ Onset to T4: 10–12 min (alkalinisation + adrenaline accelerate onset). Do not substitute bupivacaine or levobupivacaine — NaHCO₃ causes precipitation. Give in 3–5 ml increments.
Concentration
Volume
ml
⏱ Onset to T4: 15–20 min at 0.75%; 20–25 min at 0.5%. Verify ropivacaine is approved for epidural CS top-up at your centre.
Labour Epidural — Running Dose
Estimate total LA received from PCEA/infusion within the 6-hour window.
Mix
+ Fentanyl 2 mcg/ml (informational only — not counted toward LAST limit)
Rateml/hr ×hrs
Total volml
Cumulative Dose Tracker
Include sources from above. Uses 6-hour LAST window — same fractional logic as the Blocks tab.
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Non-Obs Spinal
kg⌄
Drug & Preparation
Bupivacaine 0.5% heavy — standard for most spinal anaesthesia; predictable block height with positioning
Volume
ml
Intrathecal Adjuncts
Improves quality & reduces LA dose required
Diamorphine
Morphine PF
Diamorphine 300–1000 mcg: post-op analgesia 12–18 h; monitor ≥ 12 h. Morphine PF 100–300 mcg: analgesia up to 24 h; monitor ≥ 24 h. Fentanyl 25 mcg: rapid onset, no delayed respiratory risk.
Note: Spinal bupivacaine doses are not strictly weight-based — baricity, position, and patient factors (height, age, pregnancy) influence spread. These are guidance ranges only. Verify with local protocol.
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LAST Rescue
kg⌄
⚠ EMERGENCY PROTOCOL
Call for help · Stop LA · O₂ · Seizures → benzodiazepine · Arrest → CPR + consider ECMO