Ketamine is an N-methyl-D-aspartate receptor antagonist, providing rapid sedation and analgesia. Of the available options, its time to sedation is the fastest, usually less than five minutes with appropriate dosing. Current evidence for the effectiveness and safety of ketamine in calming the severely agitated patient is promising but not definitive.^11–13

Step 5: Treating Immediate Life Threats and Pursuing Underlying Diagnosis as Soon as Calming Medications Take Effect

For the mildly to moderately agitated patient, corroborating the history with a head-to-toe physical exam with the patient completely disrobed is essential. Consider a broad differential diagnosis, including space-occupying central nervous system lesions as well as toxicological, psychiatric, traumatic, and metabolic causes.

For the severely agitated patient, it is important to be organized in your approach, which can be divided into the first few minutes, the next few minutes, and the next hour.

In the first few minutes, place the patient in a resuscitation room and apply cardiorespiratory monitoring, capnography, and oximetry. Initiate one to two large-bore peripheral IVs and assess for and start to treat the four Hs: hypoxia, hyperthermia, hypovolemia, and hypoglycemia. If a definitive airway is required, consider delayed sequence rather than rapid sequence intubation, including hyperventilation and sodium bicarbonate in the peri-intubation period as the patient may be severely acidotic.^14,15 In the next few minutes, obtain electrolytes and blood gas and treat for hyperkalemia and acidemia. Consider a head CT scan. In the next hour, consider primary diagnoses such as sepsis, neuroleptic malignant syndrome, thyrotoxicosis, and meningitis/encephalitis. In addition, it is important to assess for consequences of agitation (eg, rhabdomyolysis and traumatic injuries).

Having a simple approach to the agitated patient in the emergency department will not only buffer your cortisol levels but also give you the tools you need to safely and efficiently uncover and manage a life-threatening diagnosis.

Special thanks to Dr. Margaret Thompson and Dr. Reuben Strayer, the guest experts on the podcast from which this column was inspired.

References

1. Gonin P, Beysard N, Yersin B, et al. Excited delirium: a systematic review. Acad Emerg Med. 2018;25(5):552-565.
2. Richmond JS, Berlin JS, Fishkind AB, et al. Verbal de-escalation of the agitated patient: consensus statement of the American Association for Emergency Psychiatry Project BETA De-escalation Workgroup. West J Emerg Med. 2012;13(1):17-25.
3. Windover AK, Boissy A, Rice TW, et al. The REDE model of healthcare communication: optimizing relationship as a therapeutic agent. J Patient Exp. 2014;1(1):8-13.
4. Annas GJ. The last resort—the use of physical restraints in medical emergencies. N Engl J Med. 1999;341(18):1408-1412.
5. Zun LS. A prospective study of the complication rate of use of patient restraint in the emergency department. J Emerg Med. 2003;24(2):119-124.
6. Berzlanovich AM, Schöpfer J, Keil W. Deaths due to physical restraint. Dtsch Arztebl Int. 2012;109(3):27-32.
7. Nobay F, Simon BC, Levitt MA, et al. A prospective, double-blind, randomized trial of midazolam versus haloperidol versus lorazepam in the chemical restraint of violent and severely agitated patients. Acad Emerg Med. 2004;11(7):744-749.
8. Isenberg DL, Jacobs D. Prehospital Agitation and Sedation Trial (PhAST): a randomized control trial of intramuscular haloperidol versus intramuscular midazolam for the sedation of the agitated or violent patient in the prehospital environment. Prehosp Disaster Med. 2015;30(5):491-495.
9. Kroczak V, Kirby A, Gunja N. Chemical agents for the sedation of agitated patients in the ED: a systematic review. Am J Emerg Med. 2016;34(12):2426-2431.
10. Battaglia J, Moss S, Rush J, et al. Haloperidol, lorazepam, or both for psychotic agitation? A multicenter, prospective, double-blind, emergency department study. Am J Emerg Med. 1997;15(4):335-340.
11. Cole JB, Moore JC, Nystrom PC, et al. A prospective study of ketamine versus haloperidol for severe prehospital agitation. Clin Toxicol (Phila). 2016;54(7):556-562.
12. Riddell J, Tran A, Bengiamin R, et al. Ketamine as a first-line treatment for severely agitated emergency department patients. Am J Emerg Med. 2017;35(7):1000-1004.
13. Isbister GK, Calver LA, Downes MA, et al. Ketamine as rescue treatment for difficult-to-sedate severe acute behavioral disturbance in the emergency department. Ann Emerg Med. 2016;67(5):581-587.
14. Weingart SD, Trueger NS, Wong N, et al. Delayed sequence intubation: a prospective observational study. Ann Emerg Med. 2015;65(4):349-355.
15. Forsythe SM, Schmidt GA. Sodium bicarbonate for the treatment of lactic acidosis. Chest. 2000;117(1):260-267.
16. Currier GW, Chou JC, Feifel D, et al. Acute treatment of psychotic agitation: a randomized comparison of oral treatment with risperidone and lorazepam versus intramuscular treatment with haloperidol and lorazepam. J Clin Psychiatry. 2004;65(3):386‐394.