P027: A CASE OF MODIFIED RSI - OPTIMAL DEPTH OF SEDATION IS THE KEY
Kevin Marfiak, DO, MPH; Nicolas Lara, MD; Xiao Rui Yang, MD; R. Victor Zhang, MD, PhD
University of Florida
Introduction: Pulmonary aspiration has been known as a leading cause of perioperative morbidity and mortality since the 1950s.1,2 By the 1970s techniques for safer and faster airway control emerged for patients with aspiration precautions, including Sellick maneuver and rapid sequence induction (RSI).3,4 However, the 2020 international survey published in the European Journal of Anaesthesiology5 found significant heterogeneity in the practice of RSI, emphasizing the need for international RSI guidelines. With increasing prevalence in the use of GLP-1 agonists that delay gastric emptying, there is an increasing need for optimization of the RSI technique.
Methods: As anesthetic care was judged as substandard in most of the pulmonary aspiration claims,2 adequate anesthetic depth at the time of intubation is of vital importance. Our modified RSI focuses on achieving an optimal depth of anesthesia, combined with patient in a 15-20 degree head up position and use of video laryngoscopy for intubation. Induction of anesthesia is not rushed, and adequate time is allowed to achieve proper depth of anesthesia at the time of intubation. Blood pressure (BP) was used as a surrogate for anesthesia depth and neuromuscular blockade is used to achieve a favorable condition for intubation. However, waiting for a full paralysis before intubation is distracting and unnecessary.
Case Description: A 52-year-old 109-kg male for kidney transplant was on semaglutide for treatment of DM type 2. With his last dose of semaglutide 8 days earlier and NPO time of only 8 hours, he was at a high risk for pulmonary aspiration. Induction of anesthesia was performed in a controlled timely manner. Intravenous fentanyl (100 mcg) was first given and a minute was allowed for the patient to feel “calm”. Propofol was then given in divided doses (total 200 mg) based on BP measured repeatedly during induction and intubation. Rocuronium (60 mg) was also given as soon as he lost consciousness (LOC). The time from LOC to intubation was about 90 seconds, comparable to that for a regular RSI. Intubation was performed with a video laryngoscopy as the patient was properly relaxed with vocal cords at open positions. Post intubation BP was similar to preinduction values and rescue vasoactive agent was not required. No aspiration event was noted.
Conclusion: The core of original RSI is rapid induction with full paralysis to secure the airway as quickly as possible. However, it neglected the depth of anesthesia at the time of intubation. This original RSI for intubation can cause strong sympathetic response and positive pressure in the stomach, leading to increased risk for vomiting and aspiration. Our modified RSI focuses on achieving an optimal depth of anesthesia at the time of intubation, which significantly reduces the sympathetic response, avoids the positive pressure in the stomach, and therefore minimizes the risk for aspiration. This approach could also avoid severe hemodynamic instability from high dose agent given during RSI.
Reference:
1. Anaesthesia 1956;11(3):194-220
2. Anesthesiology 2021;135(2):284-91
3. Anesth Analg 1970;49(4):633-6
4. Lancet 1961;2(7199):404-6
5. Eur J Anaesthesiol 2020;37(6):435-442