Sluga and colleagues conducted a similar study to compare succinylcholine and rocuronium. They specifically addressed RSI in emergency nonscheduled intubations. The authors found that succinylcholine is superior in producing excellent intubation conditions and in reducing the amount of time necessary to perform the procedure.20 This randomized study involving 190 participants lacked blinding; the authors attempted to minimize the effects of this by including anesthesiologists who claimed to have no preference between the two agents. The authors also noted that low scores on intubation conditions were concentrated in the category of response to intubation,20 which was assessed after the tube had been passed. Ultimately, the researchers concluded that compared with rocuronium, succinylcholine allows more rapid endotracheal intubation and results in intubation conditions that are superior to those achieved with rocuronium.20 This was a well thought-out study with useful results.
Finally, a team of researchers led by Naguib examined the effective dose of the paralytic succinylcholine in a blinded randomized controlled trial. The authors studied six groups receiving succinylcholine doses that ranged from 0.0 mg/kg (control) to 2.0 mg/kg in a simulated RSI. The 180 subjects, who were scheduled for induction, were randomized and underwent RSI as if the situation was emergent. The main measurement was the percentage of subjects rated as having excellent intubation conditions within 60 seconds. The percentage of intubations rated as excellent was dose-dependent, beginning at zero in the control group and ranging from 43.3% in the 0.3-mg/kg group to 86.7% in the 2.0-mg/kg group.21 The difference between the 1.5-mg/kg and the 2.0-mg/kg group was only 6.7%. Because the sample was small, the authors concluded that this difference was not significant, leading them to recommend the 1.5-mg/kg dose.21 The procedure was carried out in a controlled anesthesia environment. The current recommendation is to use a succinylcholine dose of 0.3 to 1.1 mg/kg; therefore, these new data are quite useful and warrant replication.
PROTECTION AND POSITIONING
During visualization of the vocal cords and subsequent passage of the endotracheal tube, cricoid pressure, or Sellick's maneuver, has typically been applied both to aid in visualization and protect against aspiration. The pressure on the cricoid ring compresses the esophagus, theoretically decreasing the risk of aspiration. Two recent studies were identified regarding this practice.
In one study, Ellis and colleagues reviewed the available literature on cricoid pressure and its usefulness in preventing aspiration. This study was carried out to address concerns that cricoid pressure may not always be helpful during intubation.22 The data were varied (no systematic analysis was performed). The conclusion reached was that if any difficulty is encountered during the intubation, immediate consideration should be given to removing the cricoid pressure.22 This is an important review because clinicians are trained to apply cricoid pressure during intubation; however, this article suggests that pressure might not always be useful.
Another study, conducted by Levitan and colleagues, compared three methods of applying cricoid pressure versus no application of cricoid pressure at all. This nonblinded prospective study was carried out on cadavers by emergency physicians for emergency-airway providers. Standard anteroposterior cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy were compared. Using a scoring system that rated percentage of the vocal cords seen during the various techniques, the authors concluded that the bimanual technique is superior.23 In this approach, the clinician uses the hand opposite the laryngoscope to apply cricoid pressure, thereby manipulating the larynx with more visual accuracy. A second person takes over when the larynx is in view, freeing the first provider to handle the tube. The bimanual technique resulted in an improved laryngeal view in 89% of attempts versus 54% with the next most successful technique.23 These important data can be implemented immediately and should be considered by anyone who performs intubation.
POSTINTUBATION MANAGEMENT
Whenever the decision is made to perform RSI, the provider takes on the higher level of critical care that comes with an intubated patient. One recent article addressed this topic.
Bonomo and colleagues hypothesized that patients who have undergone RSI in the ED do not receive sufficient assistance with anxiety relief or adequate analgesia prior to being transported to the critical care unit (CCU).24 Retrospective analysis showed that of 117 patients, 74% received inadequate or no anxiety relief and 75% received inadequate analgesia or no analgesia at all.24 The findings were delivered at a conference for emergency physician-educators. The authors appropriately conclude that greater care is required when intubated patients remain in the ED for extended periods.24 These data are important for anyone who secures an airway with RSI outside the CCU. If you intubate the patient, you have accepted a critical level of care until an appropriate handoff can be made.
CONCLUSION
The ability to utilize rapid-acting sedatives and paralytics is an important skill set for any clinician who may need to secure control of an airway in an emergent setting. Although the Manual of Emergency Airway Management by Walls and colleagues is an excellent resource,7 several recent papers also contain relevant information. Pretreatment with lidocaine is currently being questioned. Etomidate provides short-term hemodynamic stability compared with midazolam but may cause adrenal suppression. Clinicians should therefore consider avoiding etomidate in the setting of septic shock. When not contraindicated, succinylcholine remains the paralytic of choice at a dose of 1.5 mg/kg. Cricoid pressure may not always be helpful during RSI, but when applied, the bimanual technique is probably superior to other approaches. JAAPA
Scott Light is a member of a hospitalist service in Aberdeen, Washington, and a retired US Air Force pararescueman. The author has indicated no relationships to disclose relating to the content of this article.
DRUGS MENTIONED
Albuterol
Atropine
Esmolol (Brevibloc, generics)
Etomidate (Amidate, generics)
Ketamine (Ketalar, generics)
Lignocaine/lidocaine (Xylocaine, generics)
Midazolam (generics)
Propofol (Diprivan, generics)
Rocuronium (Zemuron, generics)
Succinylcholine (Anectine, Quelicin)
Vecuronium (generics)
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