Abstract
To the Editor:
Regarding our recent study on regional anesthesia in austere environments,1 we appreciate our colleagues’ interest and insightful comments.2 We would like to address the issues raised to offer more information and understanding.
Safety and Dosage of Local Anesthetic
Our original paper primarily focused on the experience and feasibility of various regional anesthesia techniques in austere environments rather than on the specifics of local anesthetic dosing. However, we fully acknowledge that precise dosing is crucial to prevent complications such as local anesthetic systemic toxicity (LAST). In the studies referenced, different local anesthetics were used: some papers utilized lidocaine with or without epinephrine, and others used ropivacaine, bupivacaine, or even a combination of different local anesthetics. The recommended dosages in out-of-hospital settings are typically conservative to mitigate risks. For example, lidocaine is often used in doses of 3 mg/kg without epinephrine and up to 7 mg/kg with epinephrine, while bupivacaine is usually administered in doses of 2.5 mg/kg. Given the variability in the anesthetics used, it is crucial to establish well-defined protocols to avoid complications like LAST. Providers in austere environments must be thoroughly trained not only in the administration but also in the recognition and management of complications, including the availability of intravenous lipid emulsion for treatment.
High-Risk Blocks and Ultrasound Guidance
We appreciate the opportunity to clarify the administration of high-risk blocks mentioned in our paper. While it is true that emergency medicine (EM) physicians have been able to safely and effectively perform certain regional blocks, our study highlighted that specific high-risk blocks, such as interscalene and infraclavicular brachial plexus blocks, were indeed carried out exclusively by anesthesiologists, utilizing nerve stimulation technology as described in the original studies.3 These blocks were also performed under ultrasound guidance by these anesthesiologists, who have extensive experience in this domain. While regional anesthesia can be delivered by a range of providers, including EM physicians and paramedics, we emphasize that the complexity and risks associated with certain blocks necessitate a higher level of expertise and should be reserved for those with specialized training. Our study aimed to explore the range of practices across different contexts, and we support the cautious expansion of such techniques to non-anesthesiologists under appropriate conditions and training.
Ultrasound Guidance
While ultrasound guidance can lower the rate of complications, we wholeheartedly advocate its use for all regional blocks. Nonetheless, it is important to recognize the practical limitations of ultrasonography in harsh conditions. The use of ultrasound in the field may be limited by factors like battery life, maintenance requirements, and access to suitable training.4 Despite these obstacles, we support the use of ultrasonography technology wherever it may be applied and suggest approaches to overcome these constraints, like specialized training initiatives and portable power solutions.
Landmark-Guided Techniques
We acknowledge that, in comparison to ultrasound-guided methods, complications are more common with landmark-guided techniques, which constituted most of the procedures in our study. However, landmark-guided procedures are frequently the only realistic choice in environments with low resources due to their practicality. We recommend that training initiatives concentrate on enhancing these methods’ safety and accuracy while simultaneously working to incorporate more sophisticated approaches when funding permits.
Erector Spinae Plane Block
We are grateful that the erector spinae plane block (ESPB) was brought up as a possible substitute for treating pain resulting from chest trauma. The ESPB is indeed a promising technology that needs more research and thought in harsh conditions. We hope that future studies will address the possibility of this block in an austere environment.
Training and Provider Competency
It is imperative that emergency medical care nurses and paramedics have proper training. Although our study found that providers could safely perform fascia iliaca blocks after just 1 day of training, we believe that this is a minimal standard. Furthermore, it should be made clear that the only procedures these EMS nurses did were landmark-guided fascia iliaca blocks and, in one case report, ring blocks.5,6 To guarantee safe and efficient practice, simulation training, ongoing education, and competency assessments ought to be essential components of every training program. We are in favor of creating comprehensive training programs that go beyond basic education.
Follow-up and Complication Reporting
While identifying and reporting nerve injury and other problems in austere environments might be difficult, it is essential for understanding the true incidence of complications. We advise establishing post-procedural care guidelines, improving the quality of reports, and using telemedicine when it is suitable and accessible.
We value the thorough input and detailed feedback and are committed to addressing these important issues in future research and practice. Our goal remains to improve the safety and efficacy of regional anesthesia in challenging environments, ensuring that all patients receive the best possible care.