Neuro Intubation Highlights

Author: Josh Bucher (EM Chief Resident, Rutgers – RWJMS) // Editors: Alex Koyfman, MD (@EMHighAK) and Manpreet Singh, MD (@MPrizzleER)

You are working a busy shift when you receive a phone call from EMS that they are bringing in a “sick trauma patient.” As you prepare the trauma bay, the patient arrives. He is the victim of an assault and in clear need of intubation. He is unconscious with a GCS of 5, HR 125, BP 180/11, Sp02 88% on NRB 15 lpm, RR 22.

As you prepare your medications, what are the best options for this scenario? 

Lidocaine

Tradition has taught that intravenous lidocaine should be given prior to intubation in order to prevent a sympathomimetic syndrome. However, recent data does not support this widespread medical myth. Two papers, one an RCT and one a literature review, found no change in vital signs or intracranial pressure.^1,2 Despite the mantra behind using lidocaine, this medication has never been proven to be beneficial and exposes the patient to potential adverse effects and likely should be avoided.

Fentanyl

Opioids, such as fentanyl, have also been taught as a go-to prior to performing RSI in patients who are neurologically injured. The physiology makes sense – they have the ability to blunt the hemodynamic and sympathomimetic response to laryngeal manipulation. But has this been studied?

Fentanyl and its other synthetic derivatives have been studied in several different papers. Fentanyl has been found to decrease the cardiovascular effects of airway manipulation, in addition to preventing the release of norepinephrine.^3,4,5-9 The dose of fentanyl is possibly somewhat higher than we normally use, and the studies used doses from 2 – 5 ucg/kg. Based on the available data, it is reasonable to use fentanyl prior to RSI in these patients, especially if they are already tachycardic and hypertensive.

Esmolol

Esmolol has recently been studied for the intubation of neurologically injured patients. Esmolol is a beta blocker that can be rapidly titrated.¹⁰ Esmolol has been investigated in studies and compared to other “standard” drugs used for intubation. In a small study of patients in elective surgery, esmolol was found to control the blood pressure and heart rate better than lidocaine or nitroglycerin.¹¹ Likewise, in a large study of patients undergoing general anesthesia, Ugur found that patients receiving esmolol 1.5 mg/kg bolus prior to initiation of airway management had better control of hemodynamics.¹²  Although the studies were not done in the setting of managing airways in critically ill patients, it can be extrapolated that the physiologic response to airway management is the same and that esmolol can be used to prevent further sympathomimetic responses to intubation. However, more studies needed to determine if it changes important outcomes.

Ketamine

Recently, ketamine has been of increasing use for RSI due to its hemodynamically neutral profile. The theoretical concern that it could increase ICP in patients with CSF outflow obstruction was based on case series without control groups being monitored.  The KETASED study group performed an RCT of etomidate vs. ketamine for RSI of critically ill patients. 104 of the 469 were due to trauma, and there were no outcome differences noted.¹³

In Annals of EM in 2014, a systematic review was published on the use of ketamine for patients with traumatic brain injury. There were no differences in outcome reported in any of the studies included.¹⁴ Furthermore, despite prior teaching, ketamine has a hemodynamically neutral property. There have been multiple studies that have examined ketamine and found it maintains hemodynamic neutrality without causing severe hypertensive and tachycardic responses.^15,16 It is reasonable to use ketamine as an ideal induction agent.

Succinylcholine

Along with prior myths, it has been preached that intubation with succinylcholine requires a “defasciculating” dose of a non-depolarizing agent prior to its use. This was taught to “prevent” the increase in ICP due to muscle defasciculations. A literature review conducted in 2001 found no studies that addressed this issue.¹⁷

A small study in the ICU on intubated patients suffering intracranial hemorrhage investigated the use of succinylcholine vs. placebo with each patient serving as their own control by giving saline first as a placebo, measuring ICP and then giving succinylcholine. There was no change in ICP or CPP in either group.¹⁸ Based on the available data, it cannot be recommended that a defasciculating dose be given routinely in intubation.

FOAMed Resources

• EMCrit – Scott Weingart (@EMCrit)
  • Podcast 129 – LAMW: The Neurocritical Care Intubation

References // Further Reading:

1. Lin CC, Yu JH, Lin CC, Li WC, Weng YM, Chen SY. Postintubation hemodynamic effects of intravenous lidocaine in severe traumatic brain injury. The American journal of emergency medicine. Nov 2012;30(9):1782-1787.
2. 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. Emergency medicine journal : EMJ. Nov 2001;18(6):453-457.
3. Dahlgren N, Messeter K. Treatment of stress response to laryngoscopy and intubation with fentanyl. Anaesthesia. Nov 1981;36(11):1022-1026.
4. Cork RC, Weiss JL, Hameroff SR, Bentley J. Fentanyl preloading for rapid-sequence induction of anesthesia. Anesthesia and analgesia. Jan 1984;63(1):60-64.
5. Adachi YU, Satomoto M, Higuchi H, Watanabe K. Fentanyl attenuates the hemodynamic response to endotracheal intubation more than the response to laryngoscopy. Anesthesia and analgesia. Jul 2002;95(1):233-237, table of contents.
6. Pouraghaei M, Moharamzadeh P, Soleimanpour H, et al. Comparison between the effects of alfentanil, fentanyl and sufentanil on hemodynamic indices during rapid sequence intubation in the emergency department. Anesthesiology and pain medicine. Feb 2014;4(1):e14618.
7. Hassani V, Movassaghi G, Goodarzi V, Safari S. Comparison of fentanyl and fentanyl plus lidocaine on attenuation of hemodynamic responses to tracheal intubation in controlled hypertensive patients undergoing general anesthesia. Anesthesiology and pain medicine. Winter 2013;2(3):115-118.
8. Gurulingappa, Aleem MA, Awati MN, Adarsh S. Attenuation of Cardiovascular Responses to Direct Laryngoscopy and Intubation-A Comparative Study Between iv Bolus Fentanyl, Lignocaine and Placebo(NS). Journal of clinical and diagnostic research : JCDR. Dec 2012;6(10):1749-1752.
9. Zhang GH, Sun L. Peri-intubation hemodynamic changes during low dose fentanyl, remifentanil and sufentanil combined with etomidate for anesthetic induction. Chinese medical journal. Oct 5 2009;122(19):2330-2334.
10. Moon YE, Lee SH, Lee J. The optimal dose of esmolol and nicardipine for maintaining cardiovascular stability during rapid-sequence induction. Journal of clinical anesthesia. Feb 2012;24(1):8-13.
11. Singh H, Vichitvejpaisal P, Gaines GY, White PF. Comparative effects of lidocaine, esmolol, and nitroglycerin in modifying the hemodynamic response to laryngoscopy and intubation. Journal of clinical anesthesia. Feb 1995;7(1):5-8.
12. Ugur B, Ogurlu M, Gezer E, Nuri Aydin O, Gursoy F. Effects of esmolol, lidocaine and fentanyl on haemodynamic responses to endotracheal intubation: a comparative study. Clinical drug investigation. 2007;27(4):269-277.
13. Jabre P, Combes X, Lapostolle F, et al. Etomidate versus ketamine for rapid sequence intubation in acutely ill patients: a multicentre randomised controlled trial. Lancet. Jul 25 2009;374(9686):293-300.
14. Cohen L, Athaide V, Wickham ME, Doyle-Waters MM, Rose NG, Hohl CM. The Effect of Ketamine on Intracranial and Cerebral Perfusion Pressure and Health Outcomes: A Systematic Review. Annals of emergency medicine. Jul 16 2014.
15. Habibi MR, Baradari AG, Soleimani A, et al. Hemodynamic responses to etomidate versus ketamine-thiopental sodium combination for anesthetic induction in coronary artery bypass graft surgery patients with low ejection fraction: a double-blind, randomized, clinical trial. Journal of clinical and diagnostic research : JCDR. Oct 2014;8(10):GC01-05.
16. Price B, Arthur AO, Brunko M, et al. Hemodynamic consequences of ketamine vs etomidate for endotracheal intubation in the air medical setting. The American journal of emergency medicine. Jul 2013;31(7):1124-1132.
17. Clancy M, Halford S, Walls R, Murphy M. In patients with head injuries who undergo rapid sequence intubation using succinylcholine, does pretreatment with a competitive neuromuscular blocking agent improve outcome? A literature review. Emergency medicine journal : EMJ. Sep 2001;18(5):373-375.
18. Kovarik WD, Mayberg TS, Lam AM, Mathisen TL, Winn HR. Succinylcholine does not change intracranial pressure, cerebral blood flow velocity, or the electroencephalogram in patients with neurologic injury. Anesthesia and analgesia. Mar 1994;78(3):469-473.
19. Brown MM, Parr MJ, Manara AR. The effect of suxamethonium on intracranial pressure and cerebral perfusion pressure in patients with severe head injuries following blunt trauma. European journal of anaesthesiology. Sep 1996;13(5):474-477.