Intubation of the Neurocritical Care Patient

Revised and reviewed 29 March 2017

OVERVIEW

The semi-elective intubation of neurocritical care patients requires a modified technique to avoid the harmful consequences of intubation, which include:

  • an exaggerated reflex sympathetic response to laryngoscopy
  • hypotension due to induction agents
  • exacerbation of raised intracranial pressure

USE OF THIS APPROACH

This approach is suitable for patients with:

  • unsecured aneurysmal subarachnoid haemorrhage (SAH)
  • traumatic brain injury (TBI)
  • stroke

It is not suitable for ‘crashing’ patients:

  • e.g. significant hypoxia and/or hypotension
  • these patients typically require emergency rapid sequence intubation +/- inopressor support (i.e. no time for premedication or optimising BP and ICP management)

KEY ASPECTS OF THE INTUBATION PROCEDURE

Pre-intubation optimisation

  • ensure adequate preoxygenation and use apnoeic oxygenation
  • attach ETCO2 to the BVM device; target an ETCO2 that correlates to a PaCO2 of 35-40 mmHg
  • control hypertension prior to intubation using a rapid acting, titratable antihypertensive agent
    • options include labetolol or esmolol
    • nicardipine and clavidipine are not available in Australia
    • remember to provide analgesia first if the patient is in pain as this may be the cause of hypertension, e.g. fentanyl 25-50 mcg IV q5-10min
  • consider treatment for intracranial hypertension (if TBI)
    • if raised ICP is present or strongly suspected, consider osmotherapy (e.g. hypertonic saline bolus)
    • provide analgesia (see above)
    • keep head in neutral position and avoid neck constrictions (e.g. remove c-spine collar and use midline in-line stabilisation)

Prevent reflex sympathetic response to intubation

  • prevent reflex sympathetic response to intubation using non-pharmacological measures
    • ensure first pass success
      • best possible intubator
      • ear-to-sternal notch postioning
      • head up 30-45 degrees
    • gentle laryngoscopy
      • e.g. use video laryngoscopy to reduce the force required to achieve glottic exposure
  • prevent reflex sympathetic response to intubation using pharmacological measures; options include:
    • fentanyl 3-5 mcg/kg IV is most commonly used outside of the operating theatres
      • cardiostable sympatholytic agent
      • may lead to respiratory depression, chest rigidity
      • Allow at least 3 minutes for onset prior to performing laryngoscopy (peak effect at ~5 minutes)
    • remifentanil 1-3 mcg/kg IV is an alternative to fentanyl
      • it has rapid onset and is rapidly titratable but is less available
    • lignocaine 1.5 mg/kg IV is an alternative option for sympatholysis
      •  evidence is weak and may cause hypotension
    • topical lignocaine (e.g. 5 ml of 4% lidocaine spray) effectively attenuates cardiovascular responses to intubation
    • esmolol 1.5-2 mg/kg IV could be used as a sympatholytic agent, but this is not widely practised and few clinicians have sufficient familiarity with the agent

Induction and neuromuscular blockade

  • Induction agent
    • minimal or no induction dose may be required if high dose fentanyl is used for sympatholysis (see above) in an obtunded patient
    • options include:
      • propofol or thiopentone
        • must decrease dose to avoid hypotension
        • increases cerebral metabolic rate (CMRO2) and cerebral blood flow
      • ketamine
        • no longer considered contra-indicated in most patients with raised ICP
        • indirect sympathetic effects may increase blood pressure
        • increases cerebral metabolic rate (CMRO2) and cerebral blood flow
      • etomidate is not available in Australia
  • Neuromuscular blocker
    • rocuronium 1.2 mg/kg IV is the agent of choice; rapid onset, does not increase ICP
    • suxamethonium may increase ICP and fasciculations may cause increased oxygen consumption; avoid in patients with stroke due to risk of hyperkalaemia

Post-intubation

  • adjust patient’s respiratory rate to target ETCO2 35mmHg until an ABG is obtained to confirm PaCO2 35-40 mmHg
  • target SaO2 95% (avoid hypoxia or extreme hyperoxia)
  • use the minimum PEEP necessary to avoid hypoxia

ADDITIONAL INFORMATION

TBI

  • sympatholytic premedication with fentanyl is still important in obtunded TBI patients
    • these patients typically have more severe neurological injuries
    • degree of obtundation poorly correlates with the degree of exaggerated reflex sympathetic response that will occur during laryngoscopy
    • The retrospective case series by Perkins et al, 2013 found that a hypertensive response to laryngoscopy and tracheal intubation occurred in 80% of TBI patients and in 11% of patients blood pressure increased by ≥100%.
  • hypoxia and hypotension are associated with markedly increased mortality in TBI, great care must be taken to avoid these complications during intubation

A similar approach can be used for intubation of patients with aortic dissection and/or myocardial ischaemia (though therapies specific to management of intracranial hypertension are not required)

References and links

LITFL

Journal articles

  • Chung KS, Sinatra RS, Halevy JD, Paige D, Silverman DG. A comparison of fentanyl, esmolol, and their combination for blunting the haemodynamic responses during rapid-sequence induction. Can J Anaesth. 1992 Oct;39(8):774-9. PubMed PMID: 1363221.
  • Curran MP, Robinson DM, Keating GM. Intravenous nicardipine: its use in the short-term treatment of hypertension and various other indications. Drugs. 2006;66(13):1755-82. Review. PubMed PMID: 16978041. [Full Text]
  • Dahlgren N, Messeter K. Treatment of stress response to laryngoscopy and intubation with fentanyl. Anaesthesia. 1981 Nov;36(11):1022-6. PubMed PMID: 7032347.
  • Helfman SM, Gold MI, DeLisser EA, Herrington CA. Which drug prevents tachycardia and hypertension associated with tracheal intubation: lidocaine, fentanyl, or esmolol? Anesth Analg. 1991 Apr;72(4):482-6. PubMed PMID: 1672488.
  • Horak J, Weiss S. Emergent management of the airway. New pharmacology and the control of comorbidities in cardiac disease, ischemia, and valvular heart disease. Crit Care Clin. 2000 Jul;16(3):411-27. Review. PubMed PMID: 10941581. [Full Text]
  • Feng CK, Chan KH, Liu KN, Or CH, Lee TY. A comparison of lidocaine, fentanyl, and esmolol for attenuation of cardiovascular response to laryngoscopy and tracheal intubation. Acta Anaesthesiol Sin. 1996 Jun;34(2):61-7. Erratum in: Acta Anaesthesiol Sin 1996 Sep;34(3):172. PubMed PMID: 9084524.
  • Korpinen R, Saarnivaara L, Siren K, Sarna S. Modification of the haemodynamic responses to induction of anaesthesia and tracheal intubation with alfentanil, esmolol and their combination. Can J Anaesth. 1995 Apr;42(4):298-304. PubMed PMID: 7788827.
  • Hamaya Y, Dohi S. Differences in cardiovascular response to airway stimulation at different sites and blockade of the responses by lidocaine. Anesthesiology. 2000 Jul;93(1):95-103. PubMed PMID: 10861151.
  • Hancı V, Yurtlu S, Karabağ T, Okyay D, Hakimoğlu S, Kayhan G, Büyükuysal Ç, Ayoğlu H, Özkoçak Turan I. Effects of esmolol, lidocaine and fentanyl on P wave dispersion, QT, QTc intervals and hemodynamic responses to endotracheal intubation during propofol induction: a comparative study. Braz J Anesthesiol. 2013 May-Jun;63(3):235-44. doi: 10.1016/S0034-7094(13)70223-X. English, Portuguese, Spanish. PubMed PMID: 23683444. [Free Full Text pdf]
  • Lin CC, Yu JH, Lin CC, Li WC, Weng YM, Chen SY. Postintubation hemodynamic effects of intravenous lidocaine in severe traumatic brain injury. Am J Emerg Med. 2012 Nov;30(9):1782-7. doi: 10.1016/j.ajem.2012.02.013. Epub 2012 May 23. PubMed PMID: 22633717.
  • Moon YE, Lee SH, Lee J. The optimal dose of esmolol and nicardipine for maintaining cardiovascular stability during rapid-sequence induction. J Clin Anesth. 2012 Feb;24(1):8-13. doi: 10.1016/j.jclinane.2010.12.010. Epub 2011 Jun 22. PubMed PMID: 21696933.
  • Perkins ZB, Wittenberg MD, Nevin D, Lockey DJ, O’Brien B. The relationship between head injury severity and hemodynamic response to tracheal intubation. J Trauma Acute Care Surg. 2013 Apr;74(4):1074-80. doi: 10.1097/TA.0b013e3182827305. PubMed PMID: 23511147.
  • 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 Nov;18(6):453-7. Review. PubMed PMID: 11696494; PubMed Central PMCID: PMC1725712.
  • Singh H, Vichitvejpaisal P, Gaines GY, White PF. Comparative effects of lidocaine, esmolol, and nitroglycerin in modifying the hemodynamic response to laryngoscopy and intubation. J Clin Anesth. 1995 Feb;7(1):5-8. PubMed PMID: 7772359.
  • Ugur B, Ogurlu M, Gezer E, Nuri Aydin O, Gürsoy F. Effects of esmolol, lidocaine and fentanyl on haemodynamic responses to endotracheal intubation: a comparative study. Clin Drug Investig. 2007;27(4):269-77. PubMed PMID: 17358099.

FOAM and web resources


CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

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