We all get by better with a little help from our tunes. iStockphoto hide caption

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iStockphoto

A nurse anesthetist practices using the Universal Anesthesia Machine on an uncomplaining patient. John Sampson/JHMI hide caption

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No anesthesia here: A patient watches his colonoscopy as it happens at Memorial Sloan-Kettering Hospital in New York. Ted Thai/Time & Life Pictures/Getty Image hide caption

itoggle caption Ted Thai/Time & Life Pictures/Getty Image