Train-of-Four (TOF) Neuromuscular Monitoring
Interprets Train-of-Four ratio to assess depth of neuromuscular blockade and guide reversal of non-depolarising muscle relaxants.
Score interpretation
No twitch to train-of-four: deep block (intense block if the post-tetanic count is also 0).
→ Continue blockade if required; do NOT attempt reversal; consider sugammadex if urgent reversal needed
One to three twitches to train-of-four.
→ Allow spontaneous recovery, or reverse with sugammadex — adults: 2 mg/kg once the second twitch has returned (TOF count ≥ 2), 4 mg/kg if only one twitch; neostigmine not appropriate. Children: use a children's formulary.
Four twitches with marked fade (TOF ratio < 0.4).
→ Adults: sugammadex 2mg/kg or neostigmine + atropine; recheck TOF before extubation. Children: use a children's formulary.
Residual neuromuscular block — not adequate for extubation.
→ Adults: sugammadex 2mg/kg or neostigmine + atropine; recheck TOF before extubation. Children: use a children's formulary.
TOF ratio ≥ 0.9 measured quantitatively.
→ Safe to extubate; full neuromuscular recovery confirmed
Interpretation bands for the TOF / Neuromuscular Block. Apply clinical judgement and local guidance.
References
- Naguib M, et al. Consensus statement on perioperative use of neuromuscular monitoring. Anesth Analg. 2018;127(1):71–80.
- Fuchs-Buder T, et al. Peri-operative management of neuromuscular blockade: a guideline from the European Society of Anaesthesiology and Intensive Care. Eur J Anaesthesiol. 2023;40(2):82–94.
Related
Curated clinical cross-links plus same-class fallbacks.
- Sugammadex · Selective Neuromuscular Blockade Reversal Agent
- Sugammadex · Neuromuscular Blockade Reversal
- Neostigmine · Acetylcholinesterase Inhibitor / Neuromuscular Blockade Reversal
- Neostigmine (with Glycopyrronium) · Anticholinesterase — Neuromuscular Blockade Reversal
- Neostigmine · Anticholinesterase (Reversal Agent)
- Cisatracurium · Neuromuscular Blocking Agent (Non-Depolarising)
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.