EMS Use of Paralytics: Evidence Supporting Implementation
The evidence strongly supports allowing EMS providers to use neuromuscular blocking agents (NMBAs) during rapid sequence intubation, with studies demonstrating improved intubation success rates, comparable safety profiles to in-hospital settings, and reduced mortality when properly implemented with appropriate training and clinical governance structures.
Key Supporting Evidence
Improved Intubation Success Rates
The most compelling evidence comes from a prospective study of severely head-injured patients showing that paramedic-administered neuromuscular blockade as part of an RSI protocol significantly improved intubation success rates in a large urban prehospital system 1. This study demonstrated that NMBAs are essential for securing airways in patients who cannot be intubated without pharmacologic facilitation, particularly those with Glasgow Coma Scale scores of 3-8.
A large-scale analysis of 7,523 prehospital intubations revealed that paramedics using RSI with NMBAs achieved 77% first-pass success and 99% ultimate success rates 2. Importantly, 54% of first attempts utilized an RSI strategy, demonstrating that NMBAs are frequently necessary to overcome common prehospital challenges including:
- Bodily fluids obstructing the laryngeal view (50% of failed attempts)
- Patient obesity (28%)
- Suboptimal positioning (17%)
- Facial or spinal trauma (6%)
Comparable Safety Between NMBA Agents
Recent evidence demonstrates that both succinylcholine and rocuronium produce similar intubation outcomes in the prehospital setting 3. This 2024 study of 1,475 adult RSI cases found:
- Equivalent Cormack-Lehane grades (Grade I: 64% vs 59%)
- Similar first-pass success (84% vs 83%)
- Comparable hypoxemia rates (25% vs 23%)
- Faster onset with succinylcholine (57 vs 83 seconds to first attempt)
Clinical Practice Guideline Support
The 2023 Society of Critical Care Medicine guidelines explicitly define RSI as requiring both a sedative-hypnotic agent and an NMBA in rapid succession 4. The guidelines emphasize that RSI is indicated to:
- Reduce aspiration risk in at-risk patients (full stomach, ileus, increased intra-abdominal pressure)
- Optimize intubating conditions to reduce difficult/failed airways, esophageal intubation, and complications
The guidelines acknowledge that while developed for ED/ICU settings, the fundamental principles apply across emergency airway management contexts, including prehospital care.
Implementation Requirements for Safe EMS Paralytic Use
Training and Competency
A 2025 scoping review identified that safe and effective prehospital RSI requires appropriately trained personnel 5. The review emphasized that PRSI is a complex intervention demanding:
- Comprehensive initial training in airway anatomy, pharmacology, and technique
- Regular skills maintenance and simulation training
- Competency assessment and credentialing processes
Clinical Governance Framework
The evidence consistently highlights that successful EMS paralytic programs require robust clinical governance 5:
- Standardized protocols: Well-practiced checklist approaches reduce adverse events
- Quality assurance: Continuous monitoring of success rates, complications, and adherence to protocols
- Medical oversight: Physician medical director involvement in protocol development and case review
- Equipment standardization: Consistent availability of RSI medications, backup airway devices, and monitoring equipment
Medication Management Considerations
The guidelines identify a critical safety concern: rocuronium's longer duration may delay post-intubation analgosedation 4. Studies show that 7 of 10 patients reporting post-intubation awareness had received longer-acting NMBAs. This risk can be mitigated by:
- Implementing protocolized post-intubation sedation/analgesia
- Incorporating clinical pharmacists or designated personnel to ensure timely medication administration
- Using succinylcholine when appropriate (faster offset allows patient movement as a cue for sedation needs)
Backup Airway Strategies
The King County EMS data demonstrates that when NMBAs are used, surgical cricothyrotomy (0.4%) and bag-valve-mask ventilation (0.8%) are rarely needed as final rescue strategies 2. However, programs must ensure:
- Availability of rescue devices (bougie, video laryngoscopy, supraglottic airways)
- Training in failed airway algorithms
- Clear protocols for when to abort RSI attempts
Common Pitfalls and How to Avoid Them
Pitfall 1: Inadequate Preoxygenation
Solution: Implement mandatory preoxygenation protocols with high-flow oxygen or non-invasive positive pressure ventilation for severely hypoxemic patients before NMBA administration.
Pitfall 2: Failure to Provide Post-Intubation Sedation
Solution: Establish automatic post-intubation sedation/analgesia protocols that trigger immediately after tube confirmation, particularly when using rocuronium.
Pitfall 3: Insufficient Operator Experience
Solution: Require minimum case volumes, simulation training, and direct observation before independent RSI privileges. Consider tiered credentialing based on experience level.
Pitfall 4: Lack of Contraindication Screening
Solution: Develop clear contraindication checklists for specific NMBAs (e.g., succinylcholine in hyperkalemia, crush injuries, burns >24 hours old).
Specific Populations
Traumatic Brain Injury
One observational study suggested increased mortality with succinylcholine in severe TBI 4, though this requires validation in larger studies. Until definitive evidence emerges, consider rocuronium as first-line in severe TBI patients when feasible.
Hemodynamically Unstable Patients
The evidence supports using ketamine as the induction agent in trauma and hemodynamically unstable patients, as it maintains cardiovascular stability 6. Avoid propofol in hypotensive patients.
System-Level Requirements
Successful EMS paralytic programs require:
- Transport time considerations: The King County study included patients with transport times >10 minutes 1, suggesting RSI is most beneficial when prolonged bag-valve-mask ventilation would otherwise be required
- Aeromedical coordination: Programs should not increase overall helicopter utilization but may shift which patients require advanced airway management
- Continuous quality improvement: Regular review of success rates, complications, and protocol adherence with feedback to providers
The evidence demonstrates that prehospital RSI success and complication rates are comparable to, or better than, in-hospital settings when performed by properly trained EMS personnel with appropriate clinical governance 5.