During rapid sequence induction in a 38-year-old man with acute appendicitis, which is the most common complication encountered immediately after loss of consciousness and before intubation?

Explanation

## Most Common Complication of Rapid Sequence Induction **Key Point:** Aspiration of gastric contents is the PRIMARY complication that RSI is specifically designed to prevent, and it remains the most common serious airway emergency during the induction-intubation window. ### Why Aspiration Occurs in RSI Rapid sequence induction (RSI) is performed precisely because: 1. Emergency patients (trauma, acute abdomen, full stomach) have a high risk of aspiration 2. Loss of consciousness → loss of airway protective reflexes 3. Cricoid pressure (Sellick maneuver) may be incomplete or improperly applied 4. Positive pressure ventilation before intubation distends the stomach further ### Pathophysiology of Aspiration ```mermaid flowchart TD A[Loss of consciousness]:::outcome --> B[Loss of airway reflexes]:::outcome B --> C{Cricoid pressure adequate?}:::decision C -->|No| D[Gastric contents enter pharynx]:::urgent C -->|Yes| E[Airway protected]:::action D --> F[Aspiration into lungs]:::urgent F --> G[Aspiration pneumonitis/pneumonia]:::outcome ``` ### Comparison: RSI Complications by Frequency | Complication | Timing | Frequency | Preventable by RSI? | |---|---|---|---| | **Aspiration** | Induction-intubation window | Most common | Yes (cricoid pressure, NPO status) | | Esophageal intubation | Post-intubation | Common but detected early | No (technique-dependent) | | Laryngospasm | Induction phase | Less common in adults | Partially (avoid light anesthesia) | | Dental trauma | Intubation attempt | Rare | No (mechanical complication) | **High-Yield:** The entire purpose of RSI protocol—cricoid pressure, avoidance of bag-mask ventilation, rapid intubation—is to minimize the window during which aspiration can occur. **Clinical Pearl:** Even with perfect RSI technique, aspiration can still occur if the patient vomits forcefully or if cricoid pressure is inadequate. This is why post-operative vigilance for aspiration pneumonitis is mandatory in emergency patients. [cite:Miller's Anesthesia 8e Ch 37]