To RSI or Not to RSI: A Prehospital Debate
September 2023
Author: Shriman Balasubramanian DO PGY3
Peer Reviewers: Reena Sheth MD PGY4, Michael DeFilippo DO MICP PGY4
Faculty Editor: Adam Blumenberg MD, Assistant Professor of Emergency Medicine at Columbia University Medical Center
Background
Many Emergency Medical Services (EMS) systems throughout the United States of America allow for paramedics to perform endotracheal intubation (ETI). Paramedics education includes close to 2000 hours of classroom didactics, field ride-along hours, emergency department (ED) hours, operating room hours, and labor & delivery hours as seen in Table 1. However, additional training is required to be able to perform rapid sequence intubation (RSI) with induction agents and paralytics, a procedure that is not performed too often in the prehospital environment. This post will walk through a case of determining the need for prehospital RSI, and discuss the evidence behind this practice and its utility. The utility of this discussion stems from the vastly different practice patterns. While large urban environments tend to have shorter transport times with multiple hospitals, more suburban and rural environments tend to have prolonged extrication or transport times requiring multiple levels of prehospital care. Throughout the country, emergency physicians will be asked to provide online medical control orders for paramedics to perform prehospital RSI.
Case
You are an emergency physician working at a community medical center, when you receive a phone request for medical control from EMS.
A 62 year-old male with a history of hypertension, COPD, multiple admissions for community acquired pneumonia being brought in by EMS for altered mental status, hypoxia, and hypotension.
Initial Vitals on scene:
HR 122 bpm
RR 36, shallow
SpO2 76% on room air
BP 92/48
Blood Glucose 92
Initial exam report by EMS:
Minimally responsive to deep physical stimuli
Pupils 3mm round, reactive to light
Dry mucous membranes
Tachycardia, regular
Tachypneic, shallow respirations with diffuse crackles/rhonchi
Abdomen soft, nondistended, nontender
Thready peripheral pulses
Paramedics placed the patient on a non-rebreather, obtained 2 large-bore IV’s, extricated the patient to the ground EMS unit and began emergent transport. En route, a total of 250ml’s of normal saline have been administered with an increase in SpO2 to 88% on a non-rebreather but the patient has had progressive worsening in his mental status. A 12-Lead ECG shows sinus tachycardia without any acute ischemic changes. The EMS unit is 40 minutes away from your facility with no closer hospitals, and asks for orders to RSI.
Discussion
Most clinicians reading this would agree that this patient will likely require an airway intervention. However, what remains unanswered is which airway intervention, when, and who will perform this intervention in the prehospital setting.
Paramedics are trained in drug assisted intubation (DAI) in the pediatric and adult setting, and have the option to add further training in the use of rapid sequence intubation (RSI) with paralytics. However, not all paramedics practice in settings with the regular training and use of RSI. Prehospital RSI has multiple theoretical benefits, including protection of a decompensating airway in the field, improved oxygenation and ventilation, and aspiration risk. However there are multiple risks including inability to intubate or ventilate after paralysis, prolonged scene time, prolonged time to definitive care, as well as the cost and resources involved with training and continuing education.
There have been multiple studies done in both ground and aeromedical EMS literature. Aeromedical literature has produced success rates with paramedic/nurse combination flight crews of 95-96%. The main airways missed were successfully managed by cricothyrotomy, and immediate adverse effects include aspiration without increased risk of developing pneumonia, multiple intubation attempts, and arrhythmia. Most evidence points towards aeromedical EMS RSI as safe, and necessary due to patient acuity, however more long-term outcome data is needed. On the ground EMS side, there have been multiple studies that have sought to answer whether prehospital RSI is safe and effective. First studies were published in 1988, boasting success rates of 96% similar to aeromedical EMS providers. However, paramedics were required to perform three intubations per quarter, and had mandatory monthly operating room clinical hours. The San Diego RSI Trial was the first prehospital prospective trial, involving 813 paramedics attempting RSI in traumatic head injuries with a GCS less than, could not be intubated without medications, and farther than ten minutes from a hospital. The success rate was 84%. However, this included 26 esophageal intubations that were all recognized and removed in the field, and scene times were 13.3 minutes higher when RSI was done on scene. Overall, aeromedical EMS has very high success rates of RSI, and while ground EMS has the potential to have equally high success rates as aeromedical, there are many challenges with experience, cost, and continuing education.
Physician considerations when providing online medical control can be challenging as well. ED physicians should take into consideration the level of training paramedics are receiving for RSI, as well as the unique circumstances surrounding the case. These include transport times, transport options, intubation equipment, adequate resuscitation prior to intubation, etc. For example, a patient who is ten minutes away from a hospital, adequately ventilating and oxygenating with noninvasive ventilation (NIV) may be more suitable for RSI on the ED as opposed to someone who has failed a trial of NIV and is forty minutes away from the ED.
Case Resolution
You are familiar with the agency, their continuing education standards, and their equipment which includes a video laryngoscopy and a ventilator. You order for further fluid resuscitation with a 30mL/kg bolus rapidly infused through a large bore IV, followed by RSI with Ketamine and Rocuronium while en route to your facility. The patient is intubated successfully, and arrives at your ED 45 minutes later.
Take Home Points
Try and get as much useful information from EMS crews
Understand the experience and equipment available to the EMS crews
Ask about resources available including ground, air, and times to closest hospitals
Be specific with giving orders
Always ensure EMS crews have a back up plan
Trust your EMS crews, but always verify
References
Broderick ED, Sauerberg N, Reed JJ. EMS Pros And Cons Of Drug-Assisted Intubation. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK518969/
Lossius HM, Røislien J, Lockey DJ. Patient safety in pre-hospital emergency tracheal intubation: a comprehensive meta-analysis of the intubation success rates of EMS providers. Crit Care. 2012;16(1):R24. Published 2012 Feb 11. doi:10.1186/cc11189
Rose WD, Anderson LD, Edmond SA. Analysis of intubations before and after establishment of a rapid-sequence intubation protocol for air medical use. Air Med J 13:475 - 478.
Sloane C, Vilke GM, Chan TC, et al. Rapid-sequence intubation in the field versus hospital in trauma patients. J Emerg Med 19:259 - 264, 2000.
Wang HE, Yealy DM. Out-of-hospital rapid-sequence intubation: Is this really the "success" we envisioned? Ann Emerg Med 40:168 - 171, 2002.
Prekker ME, Kwok H, Shin J, Carlbom D, Grabinsky A, Rea TD. The process of prehospital airway management: challenges and solutions during paramedic endotracheal intubation. Crit Care Med. 2014;42(6):1372-1378. doi:10.1097/CCM.0000000000000213
