A 32-year-old woman with a BMI of 38 kg/m² presents to the emergency department with acute appendicitis requiring emergency surgery. She has a history of gastroesophageal reflux disease (GERD) and ate a full meal 2 hours ago. On examination, she is anxious, blood pressure 140/90 mmHg, heart rate 110/min, respiratory rate 22/min. The anesthesiologist decides to perform rapid sequence induction (RSI). Which of the following is the MOST appropriate sequence of drug administration during RSI in this patient?

Explanation

## Rapid Sequence Induction: Drug Selection and Sequence ### RSI Principles in This Patient This patient has multiple risk factors for aspiration: emergency surgery, recent food intake, obesity (BMI 38), and GERD history. RSI with cricoid pressure (Sellick maneuver) and appropriate drug selection is mandatory. ### Induction Agent Selection | Agent | Dose | Advantages | Disadvantages | Use in RSI | |-------|------|-----------|---------------|----------| | **Etomidate** | 0.2–0.3 mg/kg | Minimal CV depression, airway reflexes preserved, rapid onset | Single-dose adrenal suppression (controversial in sepsis) | **PREFERRED** in hemodynamically unstable/aspiration risk | | **Propofol** | 1.5–2.5 mg/kg | Smooth induction, antiemetic | Profound CV depression, hypotension risk | Avoid in hypotensive/obese patients | | **Thiopental** | 3–5 mg/kg | Rapid onset | Severe CV depression, contraindicated in hypovolemia | Rarely used now | | **Midazolam** | 0.1–0.2 mg/kg | Anxiolytic | Slow onset (2–3 min), unsuitable for RSI | Not for RSI | **Key Point:** Etomidate is the induction agent of choice for RSI in patients with aspiration risk, hemodynamic instability, or obesity due to preserved airway reflexes and minimal cardiovascular depression. ### Neuromuscular Blocking Agent **High-Yield:** In RSI, the blocking agent is administered IMMEDIATELY after loss of consciousness (not after waiting for drug effect): - **Succinylcholine 1.5 mg/kg IV** — onset 30–60 sec, duration 5–10 min. Causes fasciculations → risk of hyperkalemia in burn/crush injury patients. - **Rocuronium 1.2 mg/kg IV** — onset 60–90 sec, longer duration (30–40 min). Preferred in hyperkalemia risk; requires reversal with sugammadex. **Clinical Pearl:** Succinylcholine is still acceptable for RSI in non-hyperkalemia-risk patients because of its rapid onset and short duration, allowing faster airway assessment if intubation fails. ### Why Etomidate + Succinylcholine? 1. Etomidate provides rapid, smooth induction with hemodynamic stability and preserved airway reflexes. 2. Succinylcholine provides rapid-onset paralysis (30–60 sec) suitable for RSI timeline. 3. Both are administered in quick succession: induction agent → immediate loss of consciousness → THEN succinylcholine (not after waiting for drug effect). ### Adjuncts in This Patient - **Cricoid pressure (Sellick maneuver):** Apply 10 N before loss of consciousness, increase to 30 N after loss of consciousness. - **Head-up position:** 15–30° reverse Trendelenburg to reduce aspiration risk in obese patient. - **Preoxygenation:** 3–5 min with 100% O₂ or 8 vital capacity breaths. **Warning:** Do NOT use midazolam as induction agent in RSI — it has slow onset and is unsuitable for emergency airway management.