Ketamine Mitigates Neurobehavioral Deficits in a Canine Model of Hypothermic Circulatory Arrest

The Role of Intravenous Anesthetics for Neuro: Protection or Toxicity?

The primary intravenous anesthetics employed in clinical practice encompass dexmedetomidine (Dex), propofol, ketamine, etomidate, midazolam, and remimazolam. Apart from their established sedative, analgesic, and anxiolytic properties, an increasing body of research has uncovered neuroprotective effects of intravenous anesthetics in various animal and cellular models, as well as in clinical studies. However, there also exists conflicting evidence pointing to the potential neurotoxic effects of these intravenous anesthetics. The role of intravenous anesthetics for neuro on both sides of protection or toxicity has been rarely summarized. Considering the mentioned above, this work aims to offer a comprehensive understanding of the underlying mechanisms involved both in the central nerve system (CNS) and the peripheral nerve system (PNS) and provide valuable insights into the potential safety and risk associated with the clinical use of intravenous anesthetics.

Post Cardiac Arrest Care in the Cardiac Intensive Care Unit

PURPOSE OF REVIEW

Cardiac arrests constitute a leading cause of mortality in the adult population and cardiologists are often tasked with the management of patients following cardiac arrest either as a consultant or primary provider in the cardiac intensive care unit. Familiarity with evidence-based practice for post-cardiac arrest care is a requisite for optimizing outcomes in this highly morbid group. This review will highlight important concepts necessary to managing these patients.

RECENT FINDINGS

Emerging evidence has further elucidated optimal care of post-arrest patients including timing for routine coronary angiography, utility of therapeutic hypothermia, permissive hypercapnia, and empiric aspiration pneumonia treatment. The complicated state of multi-organ failure following cardiac arrest needs to be carefully optimized by the clinician to prevent further neurologic injury and promote systemic recovery. Future studies should be aimed at understanding if these findings extend to specific patient populations, especially those at the highest risk for poor outcomes.

The use of ketamine as a neuroprotective agent following cardiac arrest: A scoping review of current literature

AIMS

The objective of this article is to summarize the state of the literature surrounding the use of ketamine as a neuroprotective agent following cardiac arrest.

METHODS

Five electronic databases were used to search for studies related to the use of ketamine for neuroprotection following cardiac arrest. This search was performed once in May 2020, and an updated search was conducted in May 2021 and March 2022.

RESULTS

All searches combined retrieved 181 results; no clinical trials were identified. As such, the authors were limited to writing a scoping review of the literature rather than a systematic review.

CONCLUSIONS

The current state of the literature describes the mechanism of action of ketamine as a neuroprotective agent through its action as an NMDA antagonist. There is evidence of its efficacy as a neuroprotective agent in preclinical models of cardiac arrest. Current published clinical work supports the use of ketamine ameliorating neurologic outcomes in other conditions such as epilepsy, traumatic brain injury, and depression. The current state of the literature is reflective of the notion that the use of ketamine following cardiac arrest may result in improved neurologic outcomes. Future research directions should focus on the use of ketamine as a possible clinical intervention following cardiac arrest.

Ketamine; history and role in anesthetic pharmacology

Ketamine (Ket) was developed in 1962 as a less hallucinogenic and shorter acting agent than phencyclidine. It was given to humans for the first time in 1964. However, Ket produces several adverse reactions such as raised intracranial and blood pressures along with seizures, and patients still show low acceptance due to hallucinations. As new volatile and intravenous anesthetic agents with good emergence and favorable side effect profiles were developed, Ket use markedly decreased. In the 1990s, as the ultrashort-acting opioid remifentanil was developed, high dose opioid could be used to reduce surgical stress in highly invasive procedures. However, high dose opioids can produce hyperalgesia and acute tolerance. As Ket can exert anti-hyperalgesic actions, the clinical use of low dose Ket has been reconsidered. Other beneficial effects of Ket such as; analgesia, anti-shock in hemorrhagic and septic insults, anti-inflammatory effects, anti-tumor effects, brain and spinal cord neuroprotection, and bronchodilation, have all been reported. Moreover, this anesthetic agent at low dose has been recently recognized to possess anti-depressive actions. This diverse profile extends Ket far beyond anesthesia practice and the operating room.