Shivering in TTM-Treatment

Tier (progression)	Intervention(s) & Typical Dosing	Key Points / When to Move On
0 – Preventive non-sedating	• Skin counter-warming: forced-air blanket ≈ 43 °C • Acetaminophen 650–1000 mg IV/PO q4-6 h • Buspirone 30 mg PO/NG q8 h • Magnesium SO4 2 g IV load, then 0.5–1 g h-1 (goal Mg 3–4 mg/dL)	Start before cooling. Escalate if BSAS ≥ 2 despite these.
1 – Mild sedation single agent	Choose one: • Dexmedetomidine 0.2–1.5 µg kg-1 h-1 IV or • Opioid (e.g., Fentanyl 25–100 µg h-1 or Meperidine 25–50 mg IV q4-6 h / 12.5–35 mg h-1 infusion)	Re-score BSAS after titration; add second class if BSAS ≥ 2.
2 – Moderate sedation dual therapy	Dexmedetomidine plus opioid (Tier 1 doses) & continue Tier 0 measures.	Synergistic effect. Move to Tier 3 if shivering persists or deep sedation already needed.
3 – Deep sedation	• Propofol 50–75 µg kg-1 min-1 (up to 200 µg kg-1 min-1 if tolerated) • Continue earlier-tier agents as needed	Aim BSAS 0-1; watch for hypotension, hyper-triglyceridemia, PRIS.
4 – Neuromuscular blockade	Preferred Cisatracurium: 0.15 mg kg-1 bolus, then 1–3 µg kg-1 min-1 Alternate Vecuronium: 0.1 mg kg-1 bolus, then 0.8–1.2 µg kg-1 min-1	Use after adequate analgesia/sedation; reassess daily, monitor TOF 1–2/4.

Practical Tips & Adjuncts

• Sedation foundation: Most postarrest patients are intubated; pair this algorithm with baseline analgesia (e.g., fentanyl) and light sedation even at Tier 0.
• Adjunct/rescue agents (if limited by side-effects): low-dose ketamine 0.1–0.5 mg kg^-1 h^-1, clonidine 0.1–0.2 mg PO/NG, ondansetron 4 mg IV, or dantrolene 2.5 mg kg^-1 IV.
• Monitoring: Check BSAS hourly, core temperature continuously, and serum magnesium & triglycerides daily.
• Weaning sequence: During re-warming, stop NMB first, then propofol, then dexmedetomidine/opioids; keep Tier 0 measures until normothermia has been shiver-free for ≥ 4 h.

What Is the BSAS?

The Bedside Shivering Assessment Scale (BSAS) is a quick 4-point scale used at the bedside to grade the intensity of shivering during targeted-temperature management. The goal during TTM is a BSAS of 0–1.

Score	Shivering Description	Clinical Notes
0 (None)	No shivering detected on visual inspection or palpation of masseter, neck, or chest wall.	Target value during cooling; no metabolic penalty.
1 (Mild)	Shivering localized to the neck and/or thorax; may appear only as ECG artifact.	Begin Tier 0–1 measures if persistent.
2 (Moderate)	Intermittent shivering involving upper extremities ± thorax.	Escalate to dual therapy (Tier 2) if not already in use.
3 (Severe)	Generalized or sustained shivering involving the entire body.	Requires deep sedation or neuromuscular blockade (Tier 3–4).

Suggested assessment frequency: every 15–30 min during induction, hourly during maintenance, and every 30 min during re-warming.