A 58-year-old man with hypertension and type 2 diabetes mellitus is scheduled for elective laparoscopic cholecystectomy. After induction with propofol (2 mg/kg IV) and intubation with succinylcholine, his blood pressure drops from 140/90 mmHg to 85/50 mmHg within 2 minutes. Heart rate is 68 bpm, SpO₂ is 98% on 100% O₂, and end-tidal CO₂ is 35 mmHg. The surgeon has not yet made an incision. What is the most appropriate immediate management?

Explanation

## Clinical Context The patient has acute hypotension immediately post-induction in the absence of hypoxia, hypercarbia, or anaphylaxis. This is **propofol-induced hypotension**, the most common cause of intraoperative hypotension in the early perioperative period. ## Pathophysiology of Propofol-Induced Hypotension 1. Direct myocardial depression (↓ contractility) 2. Peripheral vasodilation (↓ systemic vascular resistance) 3. Blunted baroreceptor reflex 4. Particularly pronounced in elderly, hypovolemic, or critically ill patients ## Immediate Management Algorithm ```mermaid flowchart TD A[Post-induction hypotension<br/>BP 85/50, HR 68, SpO₂ 98%]:::outcome --> B{Hypoxia or<br/>hypercarbia?}:::decision B -->|Yes| C[Increase FiO₂,<br/>check ventilation]:::action B -->|No| D{Anaphylaxis<br/>signs?}:::decision D -->|Yes| E[Epinephrine 0.5 mg IV]:::urgent D -->|No| F[Propofol-induced<br/>hypotension]:::outcome F --> G[IV fluid bolus<br/>+ reduce propofol dose]:::action G --> H{Response?}:::decision H -->|Adequate| I[Continue with<br/>reduced induction dose]:::action H -->|Inadequate| J[Consider vasopressor<br/>phenylephrine/noradrenaline]:::action ``` ## Management Steps **Key Point:** Propofol hypotension is dose-dependent and reversible with fluid resuscitation and dose reduction. 1. **Increase FiO₂** to 100% (already done; maintain) 2. **Rapid IV fluid bolus** (500–1000 mL crystalloid) to restore intravascular volume 3. **Reduce propofol maintenance dose** by 25–50% or switch to lower-dose infusion 4. **Position:** Maintain supine or slight head-down tilt 5. **Reassess** BP and perfusion within 1–2 minutes 6. **Vasopressor only if fluid + dose reduction fails** (phenylephrine 50–100 mcg IV or noradrenaline infusion) ## Why This Patient Fits the Pattern - **Age 58** with hypertension → increased sensitivity to propofol - **Immediate onset** (within 2 min) → drug effect, not surgical - **Normal oxygenation and ventilation** → not hypoxia or hypercarbia - **No anaphylaxis signs** (no rash, bronchospasm, or tachycardia) - **Surgeon has not incised** → not blood loss or peritoneal insufflation **Clinical Pearl:** In elderly or hypertensive patients, use **reduced-dose propofol induction** (1–1.5 mg/kg) rather than standard 2 mg/kg to minimize hypotension risk. **High-Yield:** The combination of **IV fluid + dose reduction** is first-line; vasopressors are second-line and should not be given before fluid resuscitation in propofol hypotension.