Anesthesiology

Research published this week in Pediatrics takes a newly rigorous approach to investigating whether anesthesia exposure harms young children’s developing brains. The results suggest that even a single anesthesia exposure before age 3 could hurt kids’ language skills and abstract reasoning abilities.

Earlier studies, including those in animals, had suggested that anesthesia drugs harm young brains, but none had taken such a direct approach to the question as the new paper. In the latest study, Columbia University’s Caleb Ing, MD, and colleagues studied a group of 2,608 Australian children, 321 of whom received anesthesia at least once before age 3. At age 10, the children’s cognitive function was rigorously tested. Scores for skill in expressive language (the ability to form words and sentences) and receptive language (understanding what others say) were both lower in children who had been exposed to anesthesia than those never exposed, as were abstract-reasoning scores. Motor skills, behavior, and visual tracking and attention were not different between the groups.

In a Healthland entry on the research, Ing cautioned that more work is needed to clarify the new findings:

While the exposed children showed deficits in language and reasoning, the researchers were not able to determine whether that effect was due to the anesthesia or to the underlying medical condition that required surgery in the first place. But Ing notes that anesthesia was the likely influence on brain development, since most of the infants who were exposed had had relatively minor procedures, including tonsillectomy, insertion of ear tubes to drain infections and circumcision; only a small percentage needed operations for more serious heart problems or neurological conditions.

Still, says Ing, “At this point there is not enough evidence to show a causal link between anesthesia and deficits. It’s concerning in the sense that we should continue to pursue research to answer this question. I don’t think we should change our practice; we still need to do a lot more research before causing too much alarm.”

Although many uses of anesthesia can’t be avoided, the research could help scientists and physicians figure out what cognitive problems to watch for in children who have had anesthesia, as well as how to remedy them, the Healthland post concludes.

Previously: Researchers gain new insights into state of anesthesia

In a recent KevinMD.com entry, Kelly McQueen, MD, discusses the critical shortage of anesthesiologists in developing nations. I know that anesthetics and equipment are in short supply in various parts of the world, but I had no idea how bad the situation could be in low-income nations:

Many are unaware of the global anesthesia crisis in low-income countries around the world. Some countries have less than one physician per 10,000 people and even less than one anesthesiologist per 100,000 people. The ability to provide safe anesthesia for surgery, labor and delivery, and other procedures, as well as for acute and chronic pain, is nearly absent in many countries.

She later writes:

According to a 2010 Lancet article, 2 billion people are without access to emergency and essential surgery worldwide, and 34 million anesthetics are delivered annually in low-income countries without the standard safety equipment needed or a trained provider.

Those are absolutely shocking numbers.

Today Letters of Note is featuring a fascinating letter from Lucy Thurston, a 60-year-old missionary living in 1855 Hawaii, in which she recounts undergoing a mastectomy without anesthesia. Writing to her daughter, she describes how the procedure began:

Thus instructed, and everything in readiness. Dr. Ford looked me full in the face, and with great firmness asked: “Have you made up your mind to have it cut out?” “Yes, sir.” “Are you ready now?” “Yes, sir; but let me know when you begin, that I may be able to bear it. Have you your knife in that hand now?” He opened his hand that I might see it, saying, “I am going to begin now.”

The rest of the letter isn’t for squeamish readers, but it does provide a fascinating look at 19th-century medicine. Reading it will make you very thankful for modern anesthesiology.

Happily, Thurston lived for many years after her mastectomy: “And here is again your mother, engaged in life’s duties, and life’s warfare.”

Photo of Lucy Thurston is in the public domain

In an effort to reduce the pain felt after eye surgery, scientists at multiple institutions are working to create contact lenses capable of supplying anesthetic medication at a consistent rate. As CNET reports, a team of researchers at University of Florida have made a notable advancement in the area and have identified a way to extend the time of release of anesthetics delivered by the lenses. Elizabeth Armstrong Moore writes:

The trick, chemist Anuj Chauhan and colleagues report in the journal Langmuir, is vitamin E.

By adding “highly hydrophobic” vitamin E aggregates to silicone hydrogel lenses for distribution of three commonly used anesthetics post-surgery, they found that the aggregates acted as barriers; by not interacting so readily with water on the surface of the eye, this barrier was able to extend the release time of the anesthetics from just a few hours to multiple days.

This isn’t the first time contact lenses have been used to distribute drugs, or even that vitamin E has been used to slow the release of drugs in lenses. But it is an early sign of success for the specific anesthetics used following laser eye surgery.

Photo by eyesogreen

Thanks to an entry over at Boing Boing, I’ve just finished watching this great video offering an anesthesiologist’s view of the heart. It was produced by The Guardian as part of its video series about heart health and cardiovascular medicine. The video centers on Bruce Martin, who talks about how he anesthetizes patients for heart surgery. (One other minor point: The video shows a Final Cut “media offline” message for a few seconds around 2:55, but the rest of the video is fine.)

Via Boing Boing

By conducting imaging studies on volunteers under general anesthesia, researchers are developing a deeper understanding of how different areas of the brain are affected as individuals lose and regain consciousness. NPR’s Fresh Air program, reports on the ongoing research:

So far, researchers have learned that different drugs create different patterns in the brain, says [Emery Brown, MD, PhD, co-author of a previous study describing what researchers know and don't know about anesthesia.] For example, propofol - one of the most widely-used anesthetics - is a very potent drug and initially puts the brain into a state of excitation.

“It doesn’t really cause a state of sedation or anesthesia [initially,]” says Brown. “Then what actually see next is the brain start to slow. [So first you see] a period where the brain is active and then [when you give] a higher dose, the brain starts to slow.”

In contrast, the drug ketamine - which is used in conjunction with anesthesia to make certain drugs work better - puts the brain into a state of excitation even at higher doses.

Researchers say that better understanding the complex behavioral state of anesthesia could lead to improved treatments for pain, depression and sleep disorders.

Yesterday, Sean Mackey, MD, PhD, and his collaborator, Jarred Younger, PhD, announced findings, published in PLoS One, showing that intense, passionate feelings of love can block pain in ways similar to painkillers or drugs like cocaine. They also found that stronger love produced stronger analgesic effects.

For your afternoon viewing pleasure, we present this CBS San Francisco segment in which Mackey discusses his findings. One warning before you watch: This video contains explicit scenes of kissing and rodeo looping.

Previously: Stanford study shows love blocks pain: Analgesic moments in movie history and Love blocks pain, Stanford study shows

On Tuesday the Stanford Anesthesia Informatics and Media Lab (AIM) released a new iPad application designed to be used as an educational tool in the critical care student clerkship at the School of Medicine. According to the app description:

StanMed is an iPad app designed to be used by Stanford medical students, residents, fellows and faculty. We intend StanMed to be used in the classroom and at the bedside. StanMed will provide clinically useful educational modules, tutorials, videos, podcasts and cognitive aids to help facilitate learning at the point of care.

The application is free, but is currently open only to Stanford University affiliates with valid SUNet IDs. AIM is directed by Larry Chu, MD.

The Medpedia Project has expanded its offerings to include hundreds of medical and health videos from a number of sources including the Center for Disease Control and Prevention, National Institute of Health and online expert forum Big Think.

The video topics range from diabetes and H1N1 education to medical procedures and health care reform. The above video, as an example, appears on Medpedia’s general anesthesia page and features anesthesia resident Jesse Hill, MD, on a typical day at Stanford.

Medpedia is a worldwide project to evolve a new model for sharing and advancing knowledge about health, medicine and the body among medical professionals and the general public. Stanford’s medical school is part of a consortium of academic medical centers and global health organizations contributing to Medpedia.

Previously: Medpedia goes public

Today is Doctors’ Day, a day honoring physicians of all specialties. According to the American Society of Anesthesiologists, however, Doctors’ Day also has a special tie to anesthesiology:

Doctors Day marks the date that Crawford W. Long, M.D., of Jefferson, GA, administered the first ether anesthetic for surgery on March 30, 1842. On that day, Dr. Long administered ether anesthesia to a patient and then operated to remove a tumor from the man’s neck. Later, the patient would swear that he felt nothing during the surgery and wasn’t aware the surgery was over until he awoke.

So, from all of us at Scope to all of our physician readers, we wish you a happy and pain-free (wink, wink) Doctors’ Day.