Читать книгу Emergency Medical Services - Группа авторов - Страница 68

As with ETI, EMS medical directors and clinicians considering rapid sequence intubation (RSI) must place an emphasis on clinical decision making, not just procedural technique [35]. Drug‐facilitated intubation is an advanced technique that should be practiced by only the most qualified clinicians. The National Association of EMS Physicians has published national consensus standards for drug‐facilitated intubation [35].

RSI results in rapid and complete loss of airway reflexes. The consequence of failed RSI may be a patient who cannot be intubated or ventilated, with ensuing cardiac arrest. EMS personnel, including EMS physicians, performing prehospital RSI must possess exceptional ETI skills. EMS agencies that enable RSI must use monitors capable of continuous physiological monitoring, including cardiac rhythm, heart rate, blood pressure, pulse oximetry, and waveform capnography. These measures are important to warn of physiological decompensation such as hypercapnia, oxygen desaturation, and bradycardia. Finally, there must be a plan and appropriate preparation for those times when RSI fails, including a rescue airway.

Intensive continuing training is essential for maintaining a prehospital RSI program. Some EMS medical directors require that paramedics perform at least 12 ETIs annually, either on prehospital or in‐hospital (emergency department or operating room) patients [36]. Others have integrated human simulator‐based training to provide experience with managing difficult airway scenarios [37]. Video review of airways is one method of supplementing high‐fidelity simulation to demonstrate the range of anatomic differences and technical complications that may occur during RSI. The requirement for live ETI training remains controversial, with some proponents citing the value of live airway experience and opponents citing the absence of supporting data [35].

Rapid sequence airway (RSA) is a modification of RSI that replaces ETI with placement of an SGA [38]. RSI is difficult because of the need to rapidly accomplish tracheal intubation after the administration of paralytics. The appeal of RSA is that SGA insertion is simpler and contains fewer pitfalls than ETI. RSA case reports have demonstrated the feasibility of this approach. In a simulation study, when compared to RSI, RSA reduced time to airway placement and reduced hypoxia episodes [39]. When examined in an air medical system, however, no difference was detected between the two techniques [40]. However, for EMS agencies using traditional RSI, RSA may provide an important alternate option in the face of an anticipated or unanticipated difficult airway.

Sedation‐assisted intubation with a sedative agent only, without a concurrent neuromuscular blocking agent, is discouraged [35, 41–45]. Adverse events associated with RSI (e.g., iatrogenic oxygen desaturation and bradycardia) may be at least as likely with sedation‐assisted ETI [23, 46]. Sedation‐assisted intubation with etomidate has been demonstrated to have lower success rates when compared to RSI [47]. While etomidate results in more profound sedation than benzodiazepines, a formal comparison of etomidate with midazolam for prehospital sedation‐assisted intubation identified similar ETI success rates [43]. Ketamine has been described for prehospital sedation‐assisted intubation, but high‐level evidence is lacking.

Combinations of benzodiazepines and opiates to facilitate endotracheal intubation (e.g., combinations of diazepam, morphine, or other agents) are particularly unsafe since the single or combination use of these agents has rather slow onset and unpredictable sedative effects. These agents also have the strong potential for causing hypotension. The system‐level measures necessary to ensure airway management quality with sedation‐assisted intubation are essentially equal to those required for RSI programs.