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 and intubation with succinylcholine, his blood pressure drops from 140/90 mmHg to 85/50 mmHg within 2 minutes. SpO₂ remains 98% on 100% O₂. Heart rate is 62 bpm. There is no anaphylaxis, no bronchospasm, and no malignant hyperthermia signs. What is the most appropriate immediate management?

Explanation

## Diagnosis: Propofol-Induced Hypotension **Key Point:** Propofol causes direct myocardial depression and peripheral vasodilation, leading to hypotension in 20–30% of inductions, especially in elderly and hypertensive patients. This is the most common cause of induction hypotension in routine anesthesia. **Clinical Pearl:** The hypotension occurs within 1–3 minutes of propofol administration and is dose-dependent. In this case, the patient received a standard induction dose (2 mg/kg) but has risk factors: age >55 years, hypertension, and diabetes (impaired autonomic compensation). **High-Yield:** Differential diagnosis of induction hypotension: | Cause | Mechanism | SpO₂ | HR | Management | |-------|-----------|------|----|-----------| | Propofol | Myocardial depression + vasodilation | Normal | ↓ or normal | Fluid bolus, vasopressor (phenylephrine or epinephrine) | | Anaphylaxis | IgE-mediated | ↓ | ↑ | Epinephrine 0.3–0.5 mg IM/IV, antihistamine, steroid | | Sepsis/infection | Endotoxin-mediated vasodilation | ↓ | ↑ | Fluids, broad-spectrum antibiotics, vasopressor | | Hypovolemia | Reduced preload | Normal/↓ | ↑ | Rapid fluid resuscitation | | Malignant hyperthermia | Rhabdomyolysis + hyperkalemia | ↓ | ↑ | Stop triggering agents, dantrolene 2.5 mg/kg IV | **Mnemonic: CHAMP** — Cardiac (propofol, volatile), Hypovolemia, Anaphylaxis, Malignant hyperthermia, Positioning/Pneumoperitoneum. ### Why Epinephrine 0.3 mg IV is Correct In the absence of anaphylaxis (no urticaria, bronchospasm, or angioedema), this is simple propofol-induced hypotension with preserved oxygenation and mild bradycardia. Immediate management is: 1. **Stop propofol infusion** (if running). 2. **Rapid IV fluid bolus** (500 mL crystalloid). 3. **Vasopressor:** Epinephrine 0.3 mg IV bolus (or 3–5 mcg/min infusion) restores both inotropy and vasoconstriction, raising BP within 30–60 seconds. Alternatively, phenylephrine 100–200 mcg IV can be used, but epinephrine is preferred in this context because it also increases contractility (β₁ effect), which is impaired by propofol. **Tip:** Do NOT delay vasopressor administration in symptomatic hypotension (SBP <80 mmHg, altered mental status, or oliguria). Fluid alone may take 2–3 minutes; vasopressor works in seconds. [cite:Gupta & Singh Essentials of Anesthesia Ch 8]