Agentes de indução para intubação de sequência rápida em adultos para medicina de emergência e cuidados intensivos

Abstract

Introduction: The first task of any clinician managing an acutely unstable patient is to protect the airway. In most circumstances, emergency physicians use rapid sequence intubation (RSI) to accomplish this task. The RSI incorporates a fast-acting sedative (i.e., induction) agent in addition to a neuromuscular blocking (i.e., paralytic) agent to create ideal intubation conditions. Selection of the sedative agent and dose most appropriate for the clinical scenario is an important component of RSI. Objective: to discuss rapid sequence induction agents for intubation in emergencies. Methodology: Literature review from Scielo, PubMed and VHL databases, from March to May 2024, with descriptors: "Induction agents", "Intubation" AND "Adults". Articles from 2019-2024 (total 112) were included, excluding other criteria and choosing 5 full articles. Results And Discussion: RSI is the virtually simultaneous administration of a sedative and a neuromuscular blocking agent to render a patient rapidly unconscious and flaccid in order to facilitate emergency endotracheal intubation and minimize the risk of aspiration. Induction agents (sedatives) are essential for the performance of rapid sequence intubation (RSI). They provide amnesia, blunt sympathetic responses and can improve intubation conditions. Sedatives improve laryngoscopy in part, complementing the still incomplete relaxation provided by the paralytic. In the patient with head injury or potentially elevated intracranial pressure (ICP), adequate cerebral perfusion pressure must be maintained to avoid secondary brain injury. We suggest etomidate or ketamine for induction of these patients during RSI. For hypotensive patients, etomidate or ketamine can be used. Ketamine should be avoided in patients with hypertension (MABP >120 mmHg) or if there are signs of brain herniation. Benzodiazepines cause sedation and amnesia through their effects on the gamma amino butyric acid (GABA) receptor complex. Midazolam is the fastest-acting drug commonly used. Ketamine is a dissociative anesthetic agent, structurally similar to phencyclidine (PCP). It is unique among sedative agents because it provides analgesia along with its amnesic and sedative effects. For induction of patients with cardiovascular compromise who require ISI, we suggest etomidate due to the hemodynamic stability it provides. For induction of the patient into shock requiring RSI, we suggest low-dose intravenous (IV) etomidate (0.15 mg/kg) or, alternatively, IV ketamine (1 mg/kg). If etomidate is used in a patient with sepsis and hypotension refractory to treatment with fluid resuscitation and a vasopressor, we suggest that a single dose of glucocorticoid (e.g., hydrocortisone 100 mg IV) be administered. Conclusion: RSI is the virtually simultaneous administration of a sedative and a neuromuscular blocking agent to render a patient rapidly unconscious and flaccid in order to facilitate emergency endotracheal intubation and minimize the risk of aspiration. Several studies confirm the high success rate of RSI using the combination of a sedative and a neuromuscular blocker.