Why Paralytics Should Be Used with Sedation in Pre-Hospital Advanced Airway Management
Rapid-acting neuromuscular blocking agents (paralytics) must be administered together with sedation during pre-hospital emergency anaesthesia because the majority of severely ill and injured patients have intact airway reflexes that require drugs to facilitate tracheal intubation, and sedation alone results in significantly higher complication rates including aspiration, airway trauma, and death. 1, 2
The Fundamental Physiological Requirement
The core issue is straightforward: most critically injured patients requiring pre-hospital intubation have intact airway reflexes that physically prevent safe intubation without neuromuscular blockade. 1 The Association of Anaesthetists of Great Britain and Ireland explicitly states that "the majority of severely ill and injured patients have intact airway reflexes, and require drugs to facilitate tracheal intubation." 1
Evidence of Harm from Sedation-Only Approaches
The data demonstrating superiority of combined sedation-paralytic technique over sedation alone is compelling:
A prospective study of 233 emergency intubations found that sedation without paralysis resulted in aspiration in 15% of patients, airway trauma in 28%, and death in 3%, while rapid sequence intubation with paralytics had ZERO occurrences of these complications (P < .0001). 2
The study concluded that "rapid-sequence intubation when compared with intubation minus paralysis significantly reduces complications of emergency airway management." 2
Guideline-Based Standards of Care
Pre-hospital rapid sequence induction should be practiced to the same standard as emergency department RSI, and this standard mandates the use of neuromuscular blocking agents. 3 The AAGBI 2017 guidelines emphasize that "despite variable pre-hospital conditions, the standard of care delivered should be the same as that for in-hospital emergency anaesthesia." 1
The Society of Critical Care Medicine provides strong guidance: "Administering an NMBA when a sedative-hypnotic induction agent is used is strongly recommended (strong recommendation, low quality evidence)." 4 Furthermore, "a sedative-hypnotic induction agent must be administered when an NMBA is used for intubation." 4
Improved Success Rates and Reduced Need for Surgical Airways
The use of paralytics dramatically improves intubation success and reduces the need for emergency surgical airways:
Systems using paralytic agents achieve oral intubation success rates of 97.8-98.4%, with only 0.6-1.1% requiring surgical airway access. 5
In contrast, systems without routine paralytic use report surgical airway rates of 3.8-14.9%. 5
The Society of Critical Care Medicine indicates that RSI is used for optimization of intubating conditions to reduce the occurrence of difficult or failed airways, esophageal tube placement, and complications. 4
Recommended Paralytic Agents
Either succinylcholine (1-1.5 mg/kg) or rocuronium (0.9-1.2 mg/kg) is suggested when no contraindications to succinylcholine exist. 4
Critical caveat: Sugammadex must be immediately available when rocuronium is used for potential "cannot intubate/cannot oxygenate" scenarios. 4
The Complete RSI Protocol
The proper technique involves rapid succession administration:
- Preoxygenation (consider semi-Fowler position to reduce aspiration risk) 4
- Sedative-hypnotic induction agent (etomidate 0.3 mg/kg or ketamine 1-2 mg/kg for hemodynamically unstable patients) 4
- Neuromuscular blocking agent administered immediately after induction 4
- Immediate endotracheal tube placement before assisted ventilation begins 4
Common Pitfalls to Avoid
- Never use a paralytic without a sedative-hypnotic agent - this causes awareness and is unethical 4
- Inadequate preoxygenation increases desaturation risk - ensure proper technique 4
- Failure to have backup airway equipment immediately available can lead to catastrophic outcomes 4
- Attempting intubation with sedation alone in patients with intact airway reflexes leads to preventable complications 2
When Drugs Are NOT Required
The exception is cardiac arrest patients, where tracheal intubation has not been shown to improve outcome and drugs are not usually required to facilitate intubation in this patient group. 1 These patients lack airway reflexes, making paralysis unnecessary.
System Requirements
Pre-hospital RSI should only be performed by providers with the same level of training and competence that would enable them to perform unsupervised emergency anaesthesia and tracheal intubation in the emergency department. 1 Studies have demonstrated that "poorly performed advanced airway management is harmful and that less-experienced providers have higher intubation failure rates and complication rates." 3