A Ketamine Protocol and Intubation Rates for Psychiatric Air Medical Retrieval

my approach

Show notes:

  1. Management of the acutely agitated patient in a remote location

  2. Management of patients with Acute Severe Behavioural Disturbance in Emergency Departments
  3. A Prospective Study of Ketamine versus Haloperidol for Severe Prehospital Agitaiton (7)
  4. The Use of Ketamine for Agitated Patients in the Prehospital Setting: A Systematic Review of the Literature (38)
  5. Use of Intranasal Ketamine for the Severely Agitated or Violent ED Patient

Now, onto the PODCAST!

Table 1: Mental Health Patients Requiring Intubation Pre and Post Implementation of Ketamine Sedation Protocol. Table 1: Mental Health Patients Requiring Intubation Pre and Post Implementation of Ketamine Sedation Protocol.[/caption]


To our knowledge, this is the largest review of ketamine sedation and tracheal intubation in mental health aeromedical retrievals to date.

Prior to implementation of the ketamine sedation protocol, the Cairns Base intubated 6 of 164 patients, and post 2007 (implementation), intubation for safe transfer was required in 4 of 332 retrievals, reflecting a reduction from 3.6 % to 1.2 %. This trend was noted in other bases staffed by RFDS doctors (Mount Isa, Charleville) after the 2010 rollout of the ketamine package. Cairns, Mount Isa and Charleville intubated 11 (or 2.7%) of 411 patients transferred pre- 2010.
Post 2010, 419 patients were retrieved, with intubation rates reduced to 4 of 419 patients (or 0.95%).

Intubation rates have not changed in the bases without any resident RFDS doctors. , 18 of 414 patients transferred (or 4.3%) pre-protocol were intubated, while post-protocol, this actually rose to 11 intubations in 234 patients (4.7%). These bases are staffed with flight doctors from Careflight Medical Services, and adoption of the ketamine protocol was the slowest to be implemented in these bases.

The other significant aspect of this study is for the first time ever to our knowledge, a statistical benchmark key performance indicator for psychiatric aeromedical retrieval care can be extrapolated from this data. Tracheal intubation as a means of patient restraint has no known published data regarding the aeromedical setting, although it is a frequently utilized method anecdotally. The data suggests that a benchmark percentage of 5% of all aeromedical patients with a primary mental health diagnosis, be considered as the threshold for flagging inappropriate or excessive use of such a restrictive means of patient care. This study also suggests that it is feasible to achieve a performance of less than 3% reliance upon tracheal intubation, using a standardized ketamine sedation protocol.

Limitations of Study

This electronic database required accurate coding of entries. It is possible that not all cases were coded correctly. We cannot establish causality from this type of study i.e. other reasons for reduction in intubation rates post protocol. For example, increased awareness and focus on improving sedation care may have resulted in higher rates of adequate preflight oral sedation, leading to reduced arousal prior to air transfer and hence reduced requirement for deep sedation and tracheal intubation.

Recommendation and Implications for Emergency Medicine

Ketamine sedation has been successfully implemented in a large aeromedical patient population, reducing the need for intubation by half in those managed by RFDS medical staff. Inter-hospital Emergency department transfer of acutely agitated patients using a ketamine sedation protocol should be considered.


This study has demonstrated that in our setting, the implementation of clear guidelines and a protocol-based approach can reduce the number of intubations required for aeromedical retrieval of the acutely agitated mental health patient.

Further work

Future study could examine complication rates over this same study period

No competing interests are declared.

This study has in part been funded by the Flying Doctor Retrieval Sedation Registry by RFDS QLD.

Lahti AC, Warfel D, Michaelidis T, Weiler MA, Frey K, Tamminga CA. Long-term
outcome of patients who receive ketamine during research. Biol Psychiatry. 2001
May 15;49(10):869-75.

Murrough JW, Charney DS. Cracking the moody brain: lifting the mood with
ketamine. Nat Med. 2010 Dec;16(12):1384-5.

Ballard ED, Ionescu DF, Vande Voort JL, Niciu MJ, Richards EM, Luckenbaugh DA,
Brutsché NE, Ameli R, Furey ML, Zarate CA Jr. Improvement in suicidal ideation
after ketamine infusion: relationship to reductions in depression and anxiety. J
Psychiatr Res. 2014 Nov;58:161-6.

Covvey JR, Crawford AN, Lowe DK. Intravenous ketamine for treatment-resistant
major depressive disorder. Ann Pharmacother. 2012 Jan;46(1):117-23.

Scheppke KA, Braghiroli J, Shalaby M, Chait R. Prehospital use of im ketamine
for sedation of violent and agitated patients. West J Emerg Med. 2014

Jennings PA, Cameron P, Bernard S. Ketamine as an analgesic in the
pre-hospital setting: a systematic review. Acta Anaesthesiol Scand. 2011

Bredmose PP, Lockey DJ, Grier G, Watts B, Davies G. Pre-hospital use of
ketamine for analgesia and procedural sedation. Emerg Med J. 2009 Jan;26(1):62-4.

Sibley A, Mackenzie M, Bawden J, Anstett D, Villa-Roel C, Rowe BH. A
prospective review of the use of ketamine to facilitate endotracheal intubation
in the helicopter emergency medical services (HEMS) setting. Emerg Med J. 2011

Mental Health Act 2000, http://www.health.qld.gov.au/mha2000/
Pritchard A, Le Cong M. Ketamine sedation during air medical retrieval of an
agitated patient. Air Med J. 2014 Mar-Apr;33(2):76-7.

Lossius HM, Røislien J, Lockey DJ. Patient safety in pre-hospital emergency
tracheal intubation: a comprehensive meta-analysis of the intubation success
rates of EMS providers. Crit Care. 2012 Feb 11;16(1):R24.

von Vopelius-Feldt J, Benger JR. Prehospital anaesthesia by a physician and
paramedic critical care team in Southwest England. Eur J Emerg Med. 2013

Davis DP, Dunford JV, Poste JC, Ochs M, Holbrook T, Fortlage D, Size MJ,
Kennedy F, Hoyt DB. The impact of hypoxia and hyperventilation on outcome after
paramedic rapid sequence intubation of severely head-injured patients. J Trauma.
2004 Jul;57(1):1-8; discussion 8-10.

Bernard SA, Nguyen V, Cameron P, Masci K, Fitzgerald M, Cooper DJ, Walker T,
Std BP, Myles P, Murray L, David, Taylor, Smith K, Patrick I, Edington J, Bacon
A, Rosenfeld JV, Judson R. Prehospital rapid sequence intubation improves
functional outcome for patients with severe traumatic brain injury: a randomized
controlled trial. Ann Surg. 2010 Dec;252(6):959-65.

Le Cong M, Gynther B, Hunter E, Schuller P. Ketamine sedation for patients
with acute agitation and psychiatric illness requiring aeromedical retrieval.
Emerg Med J. 2012 Apr;29(4):335-7.