Pretreatment in rapid sequence intubation: Indicated or contraindicated?

Letters

CJEM 2006;8(4):243-244

To the Editors: In response to Kuzak and associates' Original Research article on the use of lidocaine and fentanyl premedication for neuroprotective rapid sequence intubation (RSI) in the emergency department (ED),1 it is well known that laryngoscopy and intubation is very stimulating and can lead to significant activation of the sympathetic nervous system and a resultant rise in intracranial pressure. This knowledge has resulted in the common use of pretreatment agents to blunt this "pressor" response.

It is, however, important to realize that the majority of these data have been gathered in the setting of "stable" patients in the non-emergent setting.2 Many, if not most, emergency patients requiring intubation have borderline physiologic reserve and are often compensating through catecholamine release. Although lidocaine has not been shown to threaten hemodynamics, it has also not been shown to provide clinical benefit.3 Other pretreatment agents are sympatholytic and have the potential to cause premature homodynamic decompensation even before the induction agent is given. Rapid sequence induction (an anesthesiology term) describes intubation for the purpose of providing an anesthetic and has to be differentiated from rapid sequence intubation, where an anesthetic is being given to facilitate intubation.4 Both terms describe a core procedure that use an induction agent followed by a neuromuscular blocking agent. However, the indications for use and patient population are very different.

The 2 most common potentially life-threatening complications related to ED intubation are hypoxia and hypotension. Transient hypertension is of unknown clinical significance and would often be welcome in the ED patient population requiring acute airway management. In contrast, hypotension during the resuscitation phase can be devastating in the acute head or heart patient.5 Unfortunately, post-RSI hypotension is still occurring with alarming frequency.6 This may be a marker of a "sick" ED patient population, but also may represent dosing inexperience. The AIME (Airway Interventions & Managament in Emergencies) program instructor group was relieved to read that these pretreatment agents are not being routinely used. The message in our program is clear: keep it simple, facilitate intubation and avoid hypoxia and hypotension.

George Kovacs, MD, MHPE
Department of Emergency Medicine

Kirk MacQuarrie, MD
Department of Anesthesiology

Sam Campbell, MD
Department of Emergency Medicine

And the AIME Instructors
Dalhousie University, Halifax, NS

References

1. Kuzak N, Harrison DW, Zed PJ. Use of lidocaine and fentanyl premedication for neuroprotective rapid sequence intubation in the emergency department. Can J Emerg Med 2006;8(2):80-4.
2. Helfman SM, Gold MI, DeLisser E, et al. Which drug prevents tachycardia and hypertension associated with tracheal intubation: lidocaine, fentanyl, or esmolol. Anesth Analg 1991;74(4):482-6.
3. Robinson N, Clancy M. In patients with head injury undergoing rapid sequence intubation, does pretreatment with intravenous lignocaine/lidocaine lead to an improved neurological outcome? A review of the literature. Emerg Med J 2001; 18:453-7.
4. Dronen S. Rapid-sequence intubation: a safe but ill-defined procedure. Acad Emerg Med 1999;6:1-2.
5. Brain Trauma Foundation. American Association of Neurological Surgeons. Joint Section on Neurotrauma and Critical Care. Initial management. J Neurotrauma 2000;17:463-9.
6. Reid C, Chan L, Tweeddale M. The who, where, and what of rapid sequence intubation: prospective observational study of emergency RSI outside the operating theatre. Emerg Med J 2004; 21:296-301.