How does fasting status impact procedural sedation in emergency departments?

From the Guidelines

Fasting status should not delay emergency procedural sedation when clinically indicated. The risk of delaying necessary procedures often outweighs the theoretical aspiration risk, and recent evidence suggests that the actual incidence of clinically significant aspiration during emergency procedural sedation is extremely low, even in non-fasted patients 1. Traditional NPO (nothing by mouth) guidelines (6-8 hours for solids, 2-4 hours for clear liquids) are not strictly applicable in emergency settings.

Emergency physicians should assess each case individually, considering the urgency of the procedure, the patient's last oral intake, and their overall risk factors. For higher-risk patients (those with recent large meals, obesity, pregnancy, or conditions affecting gastric emptying), physicians may consider modified sedation approaches such as using ketamine (1-2 mg/kg IV or 4-5 mg/kg IM), which preserves protective airway reflexes, or lighter sedation with agents like propofol (0.5-1 mg/kg initial dose) or etomidate (0.1-0.2 mg/kg) 1.

Some key points to consider when evaluating the need for procedural sedation in emergency departments include:

• The timing and nature of recent oral intake
• The urgency of the procedure
• The patient's overall risk factors for aspiration
• The use of dissociative sedation, such as ketamine, which can be safely administered intramuscularly without need for intravenous access
• The use of inhaled nitrous oxide and intranasal medications, which can be safely administered without intravenous access 1.

Positioning patients in a slight head-up position and having suction readily available can further mitigate aspiration risk. The theoretical concern about aspiration must be balanced against the real risks of delaying necessary care, including prolonged pain, increased procedural difficulty, and extended ED stays. A multidisciplinary consensus statement on fasting before procedural sedation in adults and children supports the idea that fasting strategies in procedural sedation can reasonably be less restrictive 1.

From the FDA Drug Label

Sedation guidelines recommend a careful presedation history to determine how a patient’s underlying medical conditions or concomitant medications might affect their response to sedation/analgesia as well as a physical examination including a focused examination of the airway for abnormalities. Further recommendations include appropriate presedation fasting

The fasting status may impact procedural sedation in emergency departments, as presedation fasting is recommended in sedation guidelines. However, the specific effects of fasting status on procedural sedation are not explicitly stated in the drug label. 2

From the Research

Fasting Status and Procedural Sedation

• The need for pre-procedure fasting to minimize aspiration among adults undergoing procedural sedation and analgesia for emergency procedures has been studied 3.
• A study found that recent food intake is not a contraindication for administering procedural sedation and analgesia, and the risk of aspiration is expected to be lower in procedural sedation and analgesia than in general anesthesia 3.
• Another study compared patients who last ate or drank more than 6 and 2 hours from induction, respectively, with those who last ate or drank within 6 and 2 hours, and found no cases of aspiration in both groups 3.

Procedural Sedation and Analgesia in Emergency Departments

• Procedural sedation and analgesia is frequently administered outside of the operating room in emergency departments (EDs) and ICUs, and evidence suggests that it is safe when administered by trained personnel 4.
• The use of propofol, ketamine, midazolam, and fentanyl for procedural sedation and analgesia in the ED has been studied, and these medications are considered appropriate with proper monitoring and personnel 5, 6, 7, 4.
• A study found that low-dose fentanyl, propofol, midazolam, ketamine, and lidocaine combination was more successful in induction of deep sedation compared to regular dose of propofol and fentanyl combination 5.

Risk Factors for Sedation-Related Events

• Risk factors for sedation-related events during procedural sedation in the emergency department include increasing age, level of sedation, pre-medication with fentanyl, and sedation with propofol, midazolam, or fentanyl 7.
• Ketamine was found to be a protective factor, and hypotension and vomiting were rare but possible complications 7.
• Vomiting was not associated with fasting status, and other events were rare 7.