Methylene blue is used in vasoplegic shock when high-dose norepinephrine, vasopressin, and steroids fail to maintain MAP ≥ 65 mmHg. It works by inhibiting nitric oxide (NO)-mediated vasodilation, helping restore vascular tone. Indications for Methylene Blue in Septic Shock * Refractory Septic Shock (MAP < 65 mmHg despite high-dose vasopressors). * Vasoplegia (Distributive Shock) with High Cardiac Output, Low SVR. * Septic Shock with Profound Acidosis (Lactate > 4 mmol/L, pH < 7.2). * Post-cardiopulmonary bypass vasoplegia (if refractory to catecholamines). For the Infusion Protocol 1. Loading Dose (Slow IV Bolus Over 15-30 Minutes): • 1–2 mg/kg IV over 15–30 minutes • Dilution: Mix 50 mg (5 mL) of 1% methylene blue in 100 mL Normal Saline (NS) or D5W. • Infusion rate: Administer at 200–300 mL/hour to avoid hypotension. 2. Continuous Infusion (If Needed): • 0.25–0.5 mg/kg/hour IV infusion for 6–12 hours. • Dilution: Prepare 50 mg in 500 mL NS or D5W and run at 2–5 mL/hour (titrate based on response). For Monitoring & Precautions * Monitor BP every 5 minutes during bolus → Rapid infusion may cause paradoxical hypotension. * Check methemoglobin levels if prolonged infusion (>6 hrs). * Watch for rebound hypotension after stopping infusion. * Monitor renal & hepatic function (risk of toxicity in dysfunction).🏳️