Anesthesia and analgesia
October 1, 2024
Xinglong Xiong, Yi Shao, Dongxu Chen et al.
41 citations
A single intravenous dose of esketamine (0.25 mg/kg) given before anesthesia induction lowers the risk of postoperative delirium in adults undergoing on-pump cardiac valve surgery. In a randomized controlled trial of 112 patients (average age 52 years, 53.6% female), delirium occurred in 23.2% of those given esketamine versus 44.6% in the placebo group, a relative risk reduction of about half. Esketamine also reduced the number of patients with multiple delirium episodes and the hyperactive subtype. The results suggest esketamine is an effective preventive intervention for delirium in this surgical population.
Anesthesia and analgesia
February 5, 2025
Nuanprae Kitisin, Nattaya Raykateeraroj, Nattachai Hemtanon et al.
11 citations
A low-dose ketamine infusion in the intensive care unit (ICU) after surgery reduced fentanyl consumption by 15% (68 µg over 24 hours) compared with placebo, a small but statistically significant opioid-sparing effect. The effect appeared stronger in patients who had intraabdominal surgery. Pain and sedation scores did not differ between groups, and no acute adverse effects were observed. However, a secondary follow-up (average 43 months later) of 45 patients found that those who received ketamine reported a higher incidence of frightening and delusional memories of their ICU stay (65% vs 41%). Low-dose ketamine modestly reduces opioid use but may increase the risk of traumatic memories after critical illness.
Anesthesia and analgesia
September 1, 2023
Trent Emerick, Thomas J Martin, Douglas G Ririe
7 citations
Psychostimulants like amphetamines, cocaine, and entactogens pose challenges for anesthesia providers because each subclass has unique receptor activity and effects. These substances alter how anesthetic agents, adjuvants, and pain medications work, complicating perioperative care. The article reviews the epidemiology, pharmacology, and clinical implications of acute or chronic psychostimulant exposure, providing a foundation for safe management during surgery.
Anesthesia and analgesia
November 1, 2022
Yali Chen, Siyang Li, Xia Liang et al.
Ketamine anesthesia increased glucose metabolism across most brain regions in rats, but reduced metabolic connectivity and network efficiency in the cortex while increasing them in subcortical regions. The study used FDG-PET imaging on 20 adult rats given saline (awake), low-dose ketamine (subanesthesia), and high-dose ketamine (anesthesia). Graph-theory analysis showed that during ketamine anesthesia, global efficiency decreased in the cortex and increased in the subcortex compared to the awake state. These changes in cortical metabolic networks may help explain how general anesthesia induces loss of consciousness.
Anesthesia and analgesia
June 1, 2022
Michael A. Brito, Duan Li, Christopher W Fields et al.
Cortical acetylcholine levels correlate with neurophysiologic complexity and frontoparietal connectivity during altered states of consciousness. In rats under isoflurane anesthesia, subanesthetic ketamine (10 mg/kg/h) produced sustained increases in brain complexity and high gamma connectivity, accompanied by progressive rises in prefrontal (104%) and parietal (159%) acetylcholine. Nitrous oxide caused a transient increase in complexity and connectivity with smaller acetylcholine increases (prefrontal 56%, parietal 43%), followed by a later phase of decreased acetylcholine, reduced complexity, and weaker connectivity. These findings link cortical acetylcholine to changes in consciousness level.