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JAP Volume 7 Issue 1
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editor@japractice.com Numb with nightmares
was used to investigate the metabolic consequences of general anaesthesia in the brains of rodents. Findings revealed inhalant gas anaesthetic was characterised with higher concentrations of lactate, glutamate and glucose in the brains compared to propofol. Next, researchers analysed 59 children, ages two to seven years, who underwent magnetic resonance imaging under anaesthesia with either sevoflurane or propofol. 1HMRS scans were acquired in the parietal cortex after approximately 60 minutes of anaesthesia. Upon consciousness, children were assessed using the paediatric anaesthesia emergence delirium scale. The research discovered that sevoflurane was associated
“Higher levels of lactate in the brain could lead to anxiety or delirium”
Some types of anaesthetics cause an increase in the level of lactate production in unconscious children’s brains, causing delirium. Two commonly used anaesthetics produce different metabolic
patterns in the brains of children, according to a study from Anesthesiology. Researchers from Stony Brook University, New York, found the inhalant gas anaesthetic sevoflurane produced more lactate, a marker for enhanced or changed brain metabolism, compared to the intravenous anaesthetic propofol. While past paediatric literature has reported that sevoflurane may be associated with emergence delirium, a state of consciousness in which a child is inconsolable, irritable or uncooperative, the study explored the potential association between emergence delirium and specific brain metabolites like lactate.
Applied proton magnetic resonance spectroscopy (1HMRS) Shock to the system
Electric stimulation on the brain of a patient with chronic, severe facial pain released an opiate-like substance that’s considered one of the body’s most powerful painkillers, according to new research. Alexandre DaSilva, assistant professor of biologic and materials
sciences at the U-M School of Dentistry and director of the school’s Headache & Orofacial Pain Effort Lab and colleagues intravenously administered a radiotracer that reached important brain areas in a patient with trigeminal neuropathic pain (TNP). They applied the electrodes and electrically stimulated the skull right above the motor cortex of the patient for 20 minutes during a PET scan (positron emission tomography). The stimulation is called transcranial direct current stimulation (tDCS). The radiotracer was specifically designed to measure, indirectly,
the local brain release of m-opioid, a natural substance that alters pain perception. In order for opiate to function, it needs to bind to the m-opioid receptor (the study assessed levels of this receptor). “This is arguably the main resource in the brain to reduce pain,” DaSilva said. “We’re stimulating the release of our [body’s] own
resources to provide analgesia. Instead of giving more pharmaceutical opiates, we are directly targeting and activating the same areas in the brain on which they work. [Therefore], we can increase the power of this pain-killing effect and even decrease the use of opiates in general, and consequently avoid their side effects, including addiction.” Most pharmaceutical opiates, especially morphine, target the m
opioid receptors in the brain, DaSilva said. Just one session immediately improved the patient’s threshold
for cold pain by 36 percent, but not the patient’s clinical, TNP/facial pain. This suggests that repetitive electrical stimulation over several sessions are required to have a lasting effect on clinical pain as shown in their previous migraine study, DaSilva says. Next, researchers will investigate long-term effects of electric
stimulation on the brain, even though the dose of electricity used is very small, and find specific targets in the brain that may be more effective depending on the pain condition and patients’ status. For example, the frontal areas may be more helpful for chronic pain patients with depression symptoms.
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with higher concentrations of lactate and glucose, compared to children who were anaesthetised with propofol. Exploratory analysis of the data showed children who emerged from anaesthesia with more agitation and dissociative behavior had the highest levels of brain lactate. “Higher levels of lactate in the brain could lead to anxiety and/or delirium during emergence from anaesthesia and in the immediate post-operative period,” said lead study authors Helene Benveniste, M.D., Ph.D. and Zvi Jacob, M.D. “As an increasingly young patient population continues to have a growing need for general anaesthesia, it is important to determine the impact inhalant and intravenous anaesthetics have on children.” While millions of children safely undergo anaesthesia without
any evidence of harm, the researchers hope the study will provide understanding as to why some children have delirium after anaesthesia. For more information, visit the Anesthesiology website at
www.anesthesiology.org.
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