Posts tagged medecine

Earlier this year, the center announced that it was conducting a trial of a procedure that may revolutionize trauma care by buying patients and their doctors even more time. Known as E.P.R., for “emergency preservation and resuscitation,” it is the result of nearly thirty years of work. The procedure has long been proved successful in animal experiments, but overcoming the institutional, logistical, and ethical obstacles to performing it on a human being has taken more than a decade. When this patient loses his pulse, the attending surgeon will, as usual, crack his chest open and clamp the descending aorta. But then, instead of trying to coax the heart back into activity, the surgeon will start pumping the body full of ice-cold saline at a rate of at least a gallon a minute. Within twenty minutes (depending on the size of the patient, the number of wounds, and the amount of blood lost), the patient’s brain temperature, measured using a probe in the ear or nose, will sink to somewhere in the low fifties Fahrenheit. At this point, the patient, his circulatory system filled with icy salt water, will have no blood, no pulse, and no brain activity. He will remain in this state of suspended animation for up to an hour, while surgeons locate the bullet holes or stab wounds and sew them up. Then, after as much as sixty minutes without a heartbeat or a breath, the patient will be resuscitated. A cardiac surgeon will attach a heart-lung bypass machine and start pumping the patient full of blood again, cold, at first, but gradually warming, one degree at a time, over the course of a couple of hours. As soon as the heartbeat returns, perhaps jump-started with the help of a gentle electric shock, and as long as the lungs seem capable of functioning, at least with the help of a ventilator, the patient will be taken off bypass.

via http://www.newyorker.com/magazine/2016/11/28/can-hypothermia-save-gunshot-victims

“As clinicians and scientists who study noninvasive brain stimulation, we share a common interest with do-it-yourself (DIY) users, namely administering transcranial direct current stimulation (tDCS) to improve brain function. Evidence suggests that DIY users reference the scientific literature to guide their use of tDCS, including published ethical and safety standards. However, as discussed at a recent Institute of Medicine Workshop, there is much about noninvasive brain stimulation in general, and tDCS in particular, that remains unknown. Whereas some risks, such as burns to the skin and complications resulting from electrical equipment failures, are well recognized, other problematic issues may not be immediately apparent. We perceive an ethical obligation to draw the attention of both professionals and DIY users to some of these issues”

• Stimulation affects more of the brain than a user may think
• Stimulation interacts with ongoing brain activity, so what a user does during tDCS changes tDCS effects
• Enhancement of some cognitive abilities may come at the cost of others
• Changes in brain activity (intended or not) may last longer than a user may think
• Small differences in tDCS parameters can have a big effect
• tDCS effects are highly variable across different people
• The risk/benefit ratio is different for treating diseases versus enhancing function

http://onlinelibrary.wiley.com/doi/10.1002/ana.24689/pdf

The central, unifying theme of the institute was time. Not physical time, but biological and psychological time. How does our brain perceive physical time? What is the structure of perceived time? What regulates biological oscillations in humans, animals and even algae? Can environmental cues modify temporal perception? The close proximity of so many disciplines made for fascinating coffee-break discussions, forcing us to re-evaluate our own research findings in the light of the discoveries made in neighboring labs and inspired us to become more creative in our experimental design.

http://www.3quarksdaily.com/3quarksdaily/2013/07/three-seconds-poems-cubes-and-the-brain.html#more