Case presentation

You arrive on the scene of a motorbike accident. The driver, a 50 years old male, at your arrival is in “Pain” state with eyes closed and you can hear just a “snoring” sound coming from his mouth. His vitals are: NIMBP 80 over 50, HR 110, A quick primary survey reveal a low level of consciousness (eyes closed no finalised arms movement) with restored airway patency that after basic airway manoeuvres and O2 therapy (SaO2 goes to 95%) no signs of tension pneumo. A quick look to the pelvis and legs reveal a suspected “open book” lesion and a bilateral femoral fracture. No PMH is available at the moment.

Physiological response to shock

From the primary survey and vitals you can understand the patient is compensating a state of profound (hypovolemic) shock and consequent organ low perfusion with a sympathetic activation. Endogenous adrenergic mediators are trying to restore organ perfusion by vasoconstriction and increase in cardiac output.

First do not harm

Can we kill a patient destroying the physiologic response to shock?

The answer is YES! The need to protect airway performing a rapid pharmacological assisted airway management (RSI), can lead to bad consequences, destroying the physiological response to a state of profound shock.

All sedative, analgesic and anaesthetic drugs in fact antagonise and depress the sympathetic adrenergic response physiologically targeted to restore perfusion to vital organs.

First do not harm and choose minimal emodynamic impact type and dose of drugs to perform sedation. As we know (till now) the better choice are Ketamine and Etomidate with no clear evidences on which one is preferable. We for sure know that Ketamine can be dangerous in cathecolamine depleted patients and that this effect is dose dependent. So consider using a lower dose to reach dissociative threshold being conscious that can lead to a non ideal intubation condition.

Reanimate first intubate later (aka DSI)

After a dissociative dose of Ketamine, our next clinical target is to reanimate the patient form an oxygenation and/or an organ perfusion point of view.

So we shift from a concept of Rapid Sequence Intubation to a more comprehensive plan of Delayed Sequence Airway Management. Delayed (Ketamine/Etomidate induced) to get time and reanimate, Airway Management intended as any plan (tracheal intubation, supraglottic airway) we can apply in that specific patient in the middle of the road or in other prehospital scenarios.

A properly performed pre-oxygenation with the adjunct of apneic oxygenation can restore O2 levels giving us also a good reserve for following apnea times.

Cautelative fluid administration (avoid fluids in trauma, use BLOOD) and, push dose (Epinephrine, Phenilephrine) or continuous infusion (Norepinephrine) vasopressors, can restore perfusion to abdominal and extra abdominal organs by increasing circulating volume and cardiac performance (Alfa and Beta agonist ).

Delayed paralytic administration give us the time to perform a proper reanimation reanimation and to check the effects of our interventions.

If everything goes well and the patient’s oxygenation and emodynamic state is compensated, we can administer paralytic, and go straight to perform tracheal intubation.

But if the patient remains uncompensated despite all our efforts to correct the potentially lethal cause, our last weapon can be to preserve spontaneous breathing.

Don’t live me breathless

WHY? During inspiratory phase of respiratory cycle the negative intrathoracic pressure favourites venous return and increase the telediastolic volume of the left ventricle. The augmented left ventricle end diastolic pressure (LVEDP) according to Frank-Starling law improves myocardial performance increasing stroke volume and consequently cardiac output.

The refractory shocked patient is heavily preload dependent and suppressing the inspiratory drive risk to worsen the already dramatic emodynamic state taking him on the irreversible part of the shock curve.

We’ve got a plan

We need to have a plan for high difficult physiological airways. This is just a small residual percentage of the airways we manage in our clinical practice, but can be dramatically catastrophic when we deal with those patients without a precise plan.

We’ve got a backup plan

But when intubation fails we need to have a backup plan!

Case conclusion

You understand the need to protect patient’s airways but also the extreme physiologic difficulty of this airway.

After administering a dissociative dose of Ketamine, due to the failure of any try to restore perfusion, you decide to perform a DISSOCIATIVE INTUBATION using a videolaryngoscope with a hyperangulated blade and a bougie, AVOIDING PARALYSIS.

Then you put the patient on ACV mechanical ventilation targeting a TV of 6 ml/kg and considering a “zero PEEP” strategy.

Special Thanks to Scott Weingart and Jim DuCanto for the kindness and fundamental mentorship on inspiring and peer reviewing the algorithm

References

Brian E. Driver, Matthew E. Prekker, Robert F. Reardon, Benjamin J. Sandefur, Michael D. April, Ron M. Walls, Calvin A. Brown,
Success and Complications of the Ketamine-Only Intubation Method in the Emergency Department,
The Journal of Emergency Medicine

Weingart SD, Trueger NS, Wong N, Scofi J, Singh N, Rudolph SS. Delayed sequence intubation: a prospective observational study. Ann Emerg Med. 2015 Apr;65(4):349-55. doi: 10.1016/j.annemergmed.2014.09.025. Epub 2014 Oct 23. PMID: 25447559.

Merelman AH, Perlmutter MC, Strayer RJ. Alternatives to Rapid Sequence Intubation: Contemporary Airway Management with Ketamine. West J Emerg Med. 2019 May;20(3):466-471. doi: 10.5811/westjem.2019.4.42753. Epub 2019 Apr 26. PMID: 31123547; PMCID: PMC6526883.

Ko BS, Ahn R, Ryoo SM, et al. Prevalence and outcomes of endotracheal intubation–related cardiac arrest in the ED. Am J Emerg Med. 2015;33(11):1642-5.

Mort TC. Complications of emergency tracheal intubation: hemodynamic alterations – part I. J Intensive Care Med. 2007;22(3):157-65.

Jarvis JL, Gonzales J, Johns D, et al. Implementation of a clinical bundle to reduce out-of-pospital peri-intubation hypoxia. Ann Emerg Med.2018;72(3):272-279.e1.

Roantree RAG, Goldstein S. (2018). EMS, Facilitated Intubation Without 36.Paralytics. Treasure Island, Florida: StatPearls Publishing.

Braude D, Palomo O, Beamsley A. Sedation only intubation. EM:RAP. 39.2013.

Miller M, Kruit N, Heldreich C, et al. Hemodynamic response afterrapid sequence induction with ketamine in out-of-hospital patients 50. at risk of shock as defined by the shock index. Ann Emerg Med. 2016;68(2):181-8.e2.

Prehospital professionals dealing with acute agitated patients are always challenging all their clinical and non clinical skills at maximum levels. You need to deal with the patient, the bystanders and the law enforcement people trying to manage in the best way possible a social and clinical emergency.

Understanding if the patient is acutely intoxicated, psychiatrically decompensated (or both) is the first quick challenge we face. Clinical history, physical examination are not always possible so mostly of the times we have to guess based on our gestalt, clinical and non clinical experience.

What kind of patient I expect to find? Basically there is the sociopath agitated but collaborative, the agitated non collaborative but not dangerous (for himself and the others) the agitated non collaborative and highly dangerous. This is not a schematic and alway applicable definition but can help to understand how to gradually approach those kind of emergencies.

Alternative diagnosis

Consider alternative diagnosis:

Infections

• Lung 
• Urinary
• Brain
• Sepsi

Metabolic/toxic

• Ipoglicemia
• Alcol
• Drugs psychoactive substances
• Electrolytes

Neurologic

• Stroke or Tia
• Seizure or post critical state
• SAH
• Intracranial
• Brain tumor
• Subdural emorrhage

Cardipulmonary

• Cardiac
• Ischemia
• PE

Drug abuse

• Anticholinergic
• Sedatives
• Opioids

Risk Score and patient assessment.

Grade and scale the level of agitation

Patient Category Risk Score

Consider the risk to administer a sedative to a morbid agitated patient

Mental Risk Assessment and Patient Risk Score

Consider the level of agitation and the sedative/anaesthetic administration risk

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Agitated and collaborative

Use your non clinical skills, use humanity. Mostly of the times talking and trying to understand what is the problem is already a solution. Cigarettes and coffe helps more than police and drugs.

Agitated non collaborative non dangerous

You have time to de-escalate, it’s not an emergency. Try to enter behind the patients psychological self-defences. Here some tips on de-escalation techniques:

• RESPECT PERSONAL SPACE
• DO NOT BE PROVOCATIVE
• ESTABILISH VERBAL CONTACT
• BE CONCISE
• IDENTIFY WANTS AND FEELINGS
• LISTEN CLOSELY TO WHAT PATIENT SAYNG
• AGREE OR AGREE TO DISAGREE
• LAY DOWN THE LAW AND SET CLEAR LIMITS
• OFFER CHOICES AND OPTIMISM
• DEBRIEF THE PATIENT AND STAFF

Is not an emergency but you are an emergency medical service! Your time is precious and is non endless. When words and non clinical skills are not enough you need to use your pharmacological weapons.

IM (intramuscular) is the favourite route to administer drugs cause is fast, effective easily and widely accessible .

IN (intranasal) is fast effective but most of the times is not reliable and widely accessible.

Last chance is IV (intravenous) that need more time to be placed and put at great danger the rescuers and the patient himself.

My receipt is a combination of Benzodiazepines and Antipsychotics to reach all the possible receptors in assuefatte patients and to minimise the doses of each one to reduce possible side effects.

Agitated non collaborative and dangerous

Is a social and medical emergency! You need to act fast to protect patient and others and most of the time law enforcement need to apply a strong contention.

Highly agitated patients are physically and psychologically stressed and mostly of the times present a strong metabolic acidosis. When restraining them applying hypoxic measures (supine position, chest ore neck pressure, airway closure) we add respiratory acidosis and highly elevates the risk of mortality.

10-36% mortality

Learn how to restrain safely!

• Avoid prone position
• Avoid pressure on the chest
• Avoid covering the agitated patient’s mouth and/or nose with a gloved hand

• Lay the patient down in supine position
• Immobilise one arm above the head and the other below the waist.
• Use an oxygen mask to prevent the patient from spitting on staff

Favourite drug for this kind of patient is the one that doesn’t impact hemodinamyc and respiratory drive

Associating Ketamine with low dose Midazolam (0,03 mg/Kg) is a viable option.

Special conditions

Elderly agitated patients

• Avoid Benzo for increased risk of respiratory depression and delirium
• Best choice is Haloperidol (0,5 mg IM stating dose)
• Start without low doses, tritrate (slowly) to desired effect

Alcohol intoxication

• Alcohol intoxication is a high risk sedation.
• Avoid Midazolam
• Haloperidol or Droperidol are safest options but work slow for emergency situations.
• In emergency give half dose IM ketamine ( 2mg/kg) then Haloperidol or Droperidol if needed.

RSI in agitated patients

• Avoid succinylcholine because of potential side effects such as hyperkalemia, hyperthermia and acidemia.

Take Home Points

1. Consider alternative diagnosis
2. Grade and scale the level of agitation
3. Consider the risk to administer a sedative
4. Cross match risk and level of agitation

• What kind of patient you are dealing with?
  • Agitated collaborative
  • Agitated non collaborative non dangerous
  • Agitated non collaborative dangerous

• Agitated collaborative
  • Understand patients needs
  • Be nice
• Agitated non collaborative non dangerous
  • Take your time
  • De-escalate
  • If still agitated sedate
  • Choose the most reliable administration route
    1. IM
    2. IV
    3. IN route is most of the times unreliable in emergent agitated patient
  • Combine drugs for best result
    • Midazolam
    • Haloperidol/Droperidol
• Agitated non collaborative dangerous
  • Act fast
  • Protect patient during physical restraining
  • Avoid asfittic stimuluses
  • Sedate
    • Ketamine IM
    • Midazolam IM

Treat and Think

References

1. American College of Emergency Physicians White Paper Report on Excited Delirium Syndrome September 2009
2. Gill JR. The syndrome of excited delirium. Forensic Sci Med Pathol 2014; 10:223-228.
3. Vilke GM, Bozeman WP, Dawes DM et al. Excited Delirium Syndrome (EXDS); Treatment Options and Considerations. Journal of Forensic and Legal Medicine 2012; 19:117-121.
4. Vilke GM, Payne-James J, Karch SB. “Excited delirium (ExDS): Redefining an old diagnosis. Journal of Forensic and Legal Medicine 2012; 19:7-11
5. Hick JL, Smith S, Lynch MT. Metabolic acidosis in restraint-associated cardiac arrest: a case series. Academic Emergency Medicine 1999; 6(3):239-243.
6. Dimsdale JE, Hartley LH, Guiney T et al. Post exercise peril – plasma catecholamines and exercise. JAMA 1984; 251(5): 630-632.
7. Green SM, Roback MG, Kennedy RM, Krauss B. Clinical practice guideline for emergency department ketamine dissociative sedation: 2011 update. Annals of Emergency Medicine 2011; 57(5): 449-461.
8. Vilke GM, DEBard ML, Chan TC et al. Excited Delirium Syndrome (EXDS): Defining based on a review of the literature. Journal of Emergency Medicine 2012; 43(5): 897-905.
9. Chan EW, Taylor DM, Knott JC et al. Intravenous droperidol or olanzapine as an adjunct to midazolam for the acutely agitated patient: a multicenter, randomised, double blind, placebo controlled clinical trial. Ann Emerg Med 2013; 61:72-81.
10. Ibister GK, Calver LA, Page CB et al. Randomised controlled trial of intramuscular droperidol versus midazolam for violence and acute behavioral disturbance: The DORM study. Ann Emerg Med 2010; 56:392 – 401.