What are the recommended uses and precautions for ketamine (anesthesia induction) in medical settings?

From the Guidelines

Ketamine is recommended for anesthesia induction in various medical settings, particularly when hemodynamic stability is desired or in patients with reactive airway disease, with a typical induction dose ranging from 1-2 mg/kg IV or 4-10 mg/kg IM, as supported by the most recent study from 2023 1.

Key Points to Consider

• The use of ketamine for anesthesia induction has been studied extensively, with recent guidelines suggesting its use in critically ill adults undergoing rapid sequence intubation, as it preserves respiratory drive and maintains or increases blood pressure and heart rate 1.
• Ketamine produces dissociative anesthesia while maintaining hemodynamic stability, making it valuable for trauma patients or those with hypovolemia, as noted in a study from 2017 1.
• However, several precautions must be observed, including contraindications in patients with severe hypertension, pre-eclampsia, increased intracranial pressure, or psychiatric disorders like schizophrenia, as highlighted in a study from 2007 1.
• Ketamine can cause emergence phenomena, such as hallucinations and vivid dreams, which can be mitigated by administering benzodiazepines like midazolam before or during ketamine use, as suggested in a study from 2012 1.
• The drug should be used cautiously in patients with coronary artery disease due to its sympathomimetic effects, and patients should be monitored throughout for vital signs and emergence reactions, as recommended in the most recent study from 2023 1.

Important Considerations

• The most recent study from 2023 1 suggests that ketamine may be a reasonable option for rapid sequence intubation in critically ill adults, due to its quick onset and short duration of action, as well as its preservation of respiratory drive and sympathomimetic properties.
• However, the study also notes that the use of ketamine in critically ill patients with depleted catecholamine stores may be associated with hypotension and cardiac arrest, highlighting the need for careful patient selection and monitoring.
• Overall, the use of ketamine for anesthesia induction should be guided by the most recent and highest-quality evidence, with careful consideration of the patient's individual needs and medical history, as supported by the studies from 2007 1, 2012 1, 2017 1, and 2023 1.

From the FDA Drug Label

Ketamine hydrochloride is a general anesthetic indicated: as the sole anesthetic agent for diagnostic and surgical procedures that do not require skeletal muscle relaxation (1) for the induction of anesthesia prior to the administration of other general anesthetic agents (1) as a supplement to other anesthetic agents (1)

The recommended uses for ketamine in medical settings include:

• Induction of anesthesia: Ketamine can be used as the sole anesthetic agent or prior to the administration of other general anesthetic agents.
• Supplement to other anesthetic agents: Ketamine can be used to produce balanced anesthesia when combined with other anesthetic agents. Precautions for ketamine use include:
• Hemodynamic instability: Monitor vital signs and cardiac function during ketamine administration.
• Emergence reactions: Minimize verbal, tactile, and visual stimulation of the patient to reduce postoperative confusional states.
• Risk of respiratory depression: Maintain adequate oxygenation and ventilation, especially with overdosage or rapid administration.
• Risks for procedures of the pharynx, larynx, or bronchial tree: Avoid using ketamine as a sole anesthetic agent in these procedures, as pharyngeal and laryngeal reflexes are not suppressed.
• Pediatric neurotoxicity: Avoid using ketamine for longer than 3 hours in children ≤ 3 years due to the risk of long-term cognitive deficits. 2

From the Research

Recommended Uses of Ketamine

• Ketamine is beneficial in clinical settings ranging from procedural sedation to the treatment of chronic pain 3
• It is used for acute pain management and sedation of patients undergoing mechanical ventilation 3
• Ketamine has been used for decades to treat acute pain, and its usage has become a mainstay of treatment in emergency departments, in the perioperative period in individuals with refractory pain, and in opioid-tolerant patients 4
• It is also used for pediatric pain control in emergency departments, with its anti-hyperalgesic and anti-inflammatory effects being revealed in acute and chronic pain management 5

Precautions for Ketamine Use

• Ketamine causes analgesic and amnestic effects by noncompetitive inhibition of the N-methyl-D-aspartate receptor and activation of the opioid μ and κ receptors 3
• Unlike other sedatives, ketamine provides analgesia and amnesia without causing hypotension or respiratory depression 3
• However, ketamine can cause respiratory adverse events, and the rate of these events can be higher when combined with propofol (ketofol) compared to etomidate and fentanyl (etofen) 6
• The use of ketamine requires monitoring of vital signs, hemodynamic parameters, and pain scores, as well as careful selection of patients and treatment parameters 4

Administration Considerations

• Ketamine can be administered through various routes, including intravenous, intranasal, and oral 4
• The subanesthetic dosage range of ketamine is recommended for acute pain management, and the evidence supports the use of ketamine as an adjunct to opioid-based therapy 4
• Patient-controlled ketamine analgesia is also an option, and nonparenteral forms of ketamine, such as intranasal formulations, are being explored 4
• The combination of ketamine and propofol (ketofol) has been shown to have less respiratory adverse effects than propofol alone in emergency department procedural sedation 7