January 26, 2024

Welcome once again to UH EMS Institute’s Pharmacy Phriday.  In this installment, we continue to review changes made to the protocols as of January 1, 2024, with the focus today being Ketamine and a few minor changes made in its use.

Ketamine is in a class of medications that are referred to as dissociative anesthetics.  It is used in the prehospital setting for sedation and pain management.  The medication can cause a state of sedation along with an amnestic effect.  At lower doses, Ketamine can provide an analgesic effect without the dissociative state.  These doses are referred to as the sub-dissociative dose of Ketamine. 

A dissociative state is described as a state where the patient is separated from conscious awareness and their environment.  It is thought to be caused by an interruption of neural transmission to parts of the brain and, therefore, produces anesthesia characterized by loss of short-term memory (amnesia), inability to feel pain (analgesia), and a decreased sensitivity to pain (catalepsy).  The goal of the dissociative state when administering the high dose of Ketamine is sedation, where a patient will often stare off as if the “lights are on, but no one is home,” who does not react to any stimuli but still maintains or preserves spontaneous respirations, airway reflexes, and remains hemodynamically stable.

In the past, Ketamine could be found within the UH protocols for pain management, airway procedures, rapid sequence intubation (RSI), and behavioral/psychiatric emergencies.  In 2023, its use in situations of CPR-induced consciousness, or CPRIC, was included in the protocol.  Changes in the 2024 protocols regarding Ketamine’s use include its use for additional or ongoing sedation as required after placing an advanced airway and clarification of its use in severe agitation or combativeness, not necessarily psychiatric in nature.

The specific changes include the addition of Ketamine as a possible agent for sedation following the placement of an advanced airway in the “Airway” and “Rapid Sequence Intubation (RSI)” algorithms.  In the case of the agitated or combative patient, the specific protocol title was changed from “Behavioral/Psychiatric Emergencies” in the 2023 version to “Behavioral/Agitation/Combative” in the 2024 version to address the wider use in the protocol.  

Under UH protocols, Ketamine’s use in the pediatric patient is limited to behavioral emergencies and then only for those 16 years of age and over 50 kg in weight.  AEMTs can administer Ketamine for pain and CPRIC, and in cases of the agitated or combative patient with prior approval and training.

For specific dosing ranges of Ketamine, see the chart below. 

Ketamine can have many side effects that may include:

• hallucinations 

• vivid dreams

• hypertension

• tachycardia

• increased cardiac output

• salivation

• tonic-clonic movements (not seizures)

• myocardial depression

• laryngospasm

• apnea

These and other possible side effects require monitoring the patient’s vitals, respiratory rate and effort, EKG, capnography, etc. 

Ketamine can also cause what is called an emergence reaction.  It is a syndrome of confusion, excitement, irrational behavior, and hallucinations that a patient may experience after getting Ketamine and may occur as the patient is starting to wake up (usually about 30 minutes after administration).  In most areas, this would typically be seen in the ER setting.  It occurs as the patient begins to metabolize the Ketamine and enters a partial dissociative state, becoming more aware of their surroundings and that something is not right. Treatment for such reactions includes the use of a benzodiazepine. 

When using Ketamine be sure to document the reasoning for its use, the dosing used, the effectiveness of the medication, and the reassessments of your patient. 

Some additional precautions and points to remember when administering Ketamine include:

• Rapid IV injection can result in transient apnea. Ketamine should be administered slowly over at least a 1-minute period.

• To administer low-dose Ketamine for pain, the provider must dilute the 100mg/ml concentration to that of 10mg/ml.  This can be accomplished by using a 10 ml syringe, drawing 9 ml of NS and 1ml of the 100mg/ml Ketamine, and mixing the new solution. 

• Providers administering Ketamine should be prepared to provide supplemental oxygen and secure the airway.

• The risk of Ketamine use during pregnancy is documented, and it is often recommended the provider consult medical direction prior to administration.

Until next week’s Pharmacy Phriday, stay safe!!

Sincerely,



The UH EMS-I Team

University Hospitals

January 20, 2023

Dear Colleagues,

Welcome once again to UH EMS Institute’s Pharmacy Phriday.  In this edition, we continue to review changes made to the protocols as of January 1, 2023.  In this past week’s Monday Morning Medical Director’s Message (January 16, 2023), Ketamine was referred to as a medication with multiple uses and dosing throughout the UH protocols.  In this CE article, we will review an additional use of Ketamine highlighted in the 2023 protocols for CPR-induced consciousness (CPRIC).

CPRIC is a very rare occurrence (one study suggested 0.9% of cardiac arrests) that has been receiving increased attention and discussion in the prehospital setting.  A case of CPRIC was reported locally in the UH region! In that case, CPR was started manually by the arriving squad, and the patient was quickly transitioned to a mechanical device.  While the device was operating, the patient became conscious.  The machine was then paused, but the patient immediately became unconscious again and lost any pulses.  After this occurred several times, the squad crew called medical direction for approval to use a sedative to keep the patient calm.  Other similar cases have been documented in literature and can be found by searching the internet.

CPRIC is defined as the consciousness of the patient during CPR despite having no return of spontaneous circulation.  Various levels of consciousness have been documented, including eye-opening, localizing painful stimuli, purposeful arm movements, verbal and nonverbal communication with the resuscitation team, and following instructions.  The most common manifestations of CPRIC in one study were body movement (87.5%), speech (29.5%), eye-opening (20.5%), jaw tone (20.5%), and combativeness (19.6%). [1] It is associated with early, high-quality CPR, either done manually or by a mechanical device.   It is reported that the use of mechanical devices can generate 20–30% of the prearrest cardiac output that is sufficient to maintain cerebral perfusion pressure and allow consciousness.

Such occurrences can obviously be distressing to providers, family, and the patient, to say the least, but can also complicate resuscitation efforts for patients that often have improved survival profiles.  In cases where the patient may be combative, CPRIC can interfere with the resuscitation by grabbing at the rescuer, withdrawing from compressions, and pulling on endotracheal tubes and mechanical devices, just to name a few.  Another issue is CPR being interrupted more frequently for pulse checks. 

The question is how to manage such an event and continue treatments in these cases. As more and more cases are documented, there is an increase in guidelines being written. A major point to consider is that once CPRIC is identified, the priority in the management should be the continuation of high-quality CPR with minimal interruptions. Restraints, instructing the patient, and sedation have been suggested as options. Medications that have been considered for sedation in CPRIC include Ketamine, midazolam, and fentanyl.  One study suggested Ketamine might be safer than other medications in CPRIC owing to its lower risk of inducing hypotension.  This is the preferred agent within the UH protocols due to this factor, as well as Ketamine being an agent that provides analgesia, sedation, and amnesia.  Within the UH protocols, fentanyl and benzodiazepines are recommended when Ketamine is not available.

Ketamine is also approved within the UH protocols for pain management, airway procedures and RSI, and behavioral/psychiatric emergencies.  Under our UH protocols, use in the pediatric patient is limited to behavioral emergencies and then only for those 16 years of age and over >50 kg in weight.  AEMTs can administer Ketamine for pain and in cases of behavioral emergencies with prior approval. Low dose Ketamine is used for pain management, intermediate dosing for procedural sedation and now CPRIC, and higher dose Ketamine for behavioral emergencies. For specific dosing ranges, see the chart below. 

Remember that Ketamine has many side effects that require monitoring of the patient, which should include complete vitals, respiratory rate and effort, EKG, and capnography.  Be sure to document the reasoning for Its use, the dosing used, the effectiveness of the medication, and the reassessments of your patient

As always, stay safe!

Sincerely,



The UH EMS-I Team

University Hospitals