What are the new studies on the administration of ketamine (Ketamine) in patients with suspected or confirmed head injury and those with hypertensive emergency?

From the Guidelines

Ketamine administration in patients with suspected or confirmed head injury is now considered acceptable for rapid sequence intubation and sedation, with a recommended dose of 1-2 mg/kg IV, as it maintains or may even improve cerebral perfusion pressure while providing analgesia and sedation 1. For patients with hypertensive emergencies, ketamine is generally not recommended as a first-line agent due to its sympathomimetic effects that can potentially worsen hypertension. However, in specific scenarios like agitated patients with hypertensive emergency requiring sedation, low-dose ketamine (0.1-0.3 mg/kg IV) may be used with careful blood pressure monitoring. The management of hypertensive emergencies is driven by the type of hypertensive organ damage, and the treatment goal is to prevent or limit further hypertensive damage by a controlled BP reduction, with labetalol or nicardipine being commonly used for this purpose 1. Key considerations in the administration of ketamine in these contexts include:

• The potential for ketamine to increase intracranial pressure, although current evidence suggests it may be safe in TBI patients with appropriate monitoring and blood pressure management 1
• The need for careful blood pressure monitoring, especially in patients with severe hypertension, due to ketamine's sympathomimetic effects
• The importance of considering individual risk factors before administration, such as the presence of acute organ damage or the need for rapid sequence intubation. In terms of new clinical practices or guidelines, the 2023 Society of Critical Care Medicine clinical practice guidelines for rapid sequence intubation in the critically ill adult patient suggest that ketamine may be a reasonable option for RSI due to its quick onset and short duration of action, its preservation of respiratory drive, and its sympathomimetic properties 1. However, the guidelines also note that the selection of a sedative-hypnotic agent should be based on the individual patient's needs and risk factors, and that etomidate may be a preferable option in some cases due to its favorable hemodynamic profile. Overall, the administration of ketamine in patients with suspected or confirmed head injury and hypertensive emergencies requires careful consideration of the individual patient's needs and risk factors, as well as close monitoring of blood pressure and other vital signs.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

New Studies on Ketamine Administration

• Recent studies have investigated the use of ketamine in patients with suspected or confirmed head injury, as well as those in hypertensive emergency 2, 3.
• The evidence suggests that ketamine may not have deleterious effects on cerebral circulation and perfusion, as previously thought, and may even be beneficial in certain cases 2, 3.

Clinical Practice and Guidelines

• The use of ketamine in patients with acute brain injury is still a topic of debate, but recent studies suggest that it may be a viable option for sedation and analgesia 2, 3.
• Clinical guidelines for the use of ketamine in patients with head injury and hypertensive emergency are not well established, but studies suggest that it may be considered as a first-line treatment in certain cases 3.
• The selection of drugs for analgosedation in patients with head injury should be based on their effects on cerebral metabolism, cerebral blood flow, and intracranial pressure, as well as their haemodynamic effects 4.

Adverse Effects of Ketamine

• The adverse effects of ketamine, such as hypertension, vomiting, and delusion, are relatively common, especially in younger adults 5.
• However, these side effects are generally mild and do not necessitate admission 5.
• The use of ketamine in patients with head injury and hypertensive emergency requires careful consideration of the potential benefits and risks, as well as close monitoring of the patient's condition 2, 3.

Comparison of Ketamine with Other Drugs

• Ketamine has been compared to other drugs, such as midazolam and fentanyl, in terms of its effects on intracranial pressure, cerebral perfusion pressure, and neurological outcome 6.
• The results of these studies suggest that ketamine may have advantages over other drugs in certain cases, such as its ability to increase cerebral perfusion pressure and improve enteral food intake 6.