[Rapid sequence induction and intubation in patients with risk of aspiration : Recommendations for action for practical management of anesthesia]

Abstract

Background: Induction of general anesthesia in patients with risk for aspiration needs special considerations to avoid the incidence and severity of complications. Since no evidence-based guidelines support the challenge for anesthesiologists various practical recommendations exist in clinical practice for rapid sequence induction and intubation (RSI). The aim of this systematic review is, to summarize the evidence and recommend a decision making process.

Material and methods: Multilevel RAND-delphi-method (RAND: Research and Development) combined with systematic literature research, individual assessment and evaluation, consensus conferences and final common sequence.

Results and discussion: The consideration of all practical, clinical procedures in patients at risk for aspiration represents an effective prevention of pulmonary aspiration during the induction of anesthesia. These include the optimal drug pre-treatment with antacids (e. g. sodium citrate) for highly aspiration-endangered and proton pump inhibitors or H2 blockers in other patients the evening before. Each patient should be examined and explained prior to RSI according to the recommendations of the National German Society of Anesthesiology for preoperative evaluation. A RSI should be performed in patients with no 2h liquid and no 6h food fasting or acute vomiting, sub-ileus or ileus, or no protective reflexes or a gastrointestinal passenger disorder. In addition, RSI should be performed in pregnant women after the 3rd trimester and during birth. The expertise and competence of the physician before and during rapid sequence induction and intubation about the respective task distribution minimizes the risk of aspiration, as does the adequate equipment, as well as an optimized upper body elevation of the patient. Consistent pre-oxygenation with an F_IO₂ of 1.0 (Fe_tO₂-concentration > 0.9) and an oxygen flow > 10 l/min using a completely sealing respiratory mask with capnography should take 3-5 minutes. Fast enough deep anesthesia and muscle relaxation to avoid coughing and choking can be achieved by a combination of opioid, hypnotic and muscle relaxation. In addition, an opioid of choice, propofol, thiopental, etomidate and ketamine can be used as hypnotic and rocuronium with the availability of sugammadex should be used as muscle relaxant. If there are no contraindications, succinylcholine can also be used as a muscle relaxant. In case of an unexpected difficult airway, a 2nd generation extraglottic airway device should be used. During regurgitation or aspiration, intensive medical monitoring and fiber-optic bronchoscopy should be performed, depending on the degree of severity and an X‑ray thorax image or a CT scan should be performed if symptoms arise. Three factors reduce the risk of aspiration: expertise, support from an experienced anesthesiologist and close monitoring of an inexperienced anesthesiologist.

Keywords: General anesthesia; Rapid sequence induction; Respiratory aspiration.