Hydroxocobalamin

• •Cyanide toxicity (smoke inhalation from house fires, sodium nitroprusside infusion >2 mcg/kg/min, industrial exposure)
• •Vasoplegic syndrome post-cardiopulmonary bypass (off-label, growing evidence)
• •Distributive shock refractory to vasopressors (off-label)

Onset minutes; cyanocobalamin formed within minutes; half-life ~26-31 hr; renal excretion.

Modest ↑ MAP via NO scavenging — clinically meaningful in vasoplegic states. Less hypotensive than sodium thiosulfate.

• !Red/orange discoloration of skin, urine, plasma (lasts 5-35 days)
• !Lab interference (chromogenic assays affected — creatinine, AST, ALT, magnesium falsely altered)
• !Pulse oximetry artifact (falsely low SpO2)
• !Allergic reaction / anaphylaxis (rare)
• !Acute renal injury (oxalate crystals)
• !Hypertension (transient, mild)

• ×Hypersensitivity

• ★FIRE VICTIMS with smoke inhalation + altered mental status + lactate >10 mmol/L → empirically give Cyanokit even before lab confirmation. Cyanide tox often coexists with CO toxicity (treat both: 100% O2 ± hyperbaric for CO; hydroxocobalamin for cyanide).
• ★ICE: Cyanokit 5g vial reconstitutes in 200 mL NS → infuse over 15 min via dedicated line.
• ★VASOPLEGIA: when methylene blue contraindicated (G6PD, serotonergic drugs) or has failed, hydroxocobalamin is the next move. Compounded with epinephrine + NE + vasopressin in refractory cases.
• ★Lab artifact for 24-48 hours — communicate with lab + ICU team.

• Dantrolene

  Blocks RYR1 (ryanodine receptor) → ↓ Ca²⁺ release from sarcoplasmic reticulum → muscle relaxation. The only drug for malignant hyperthermia.

• Lipid Emulsion 20%

  Theory: 'Lipid sink' sequesters lipophilic drugs (especially LAs), shifts to better Ca²⁺ handling, fatty acid metabolic support.

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