Dr Michelle Dickinson: nanotechnologist on whether blocking out noise during surgery can reduce sickness

Could blocking out noise during surgery stop you from feeling sick afterwards?  If you've ever had surgery under general anaesthetic, you might remember waking up feeling nauseous, dizzy or desperately wanting to vomit.  It's a surprisingly common side effect of anaesthesia, and despite doctors routinely giving patients medications to prevent it, many people still experience it.  A new clinical trial suggests that simply covering patients' ears during surgery could significantly reduce their chances of feeling sick afterwards.  The research, presented at the ANESTHESIOLOGY 2026 annual conference in San Diego, raises an intriguing question about how much information our brains continue to process when we're under general anaesthetic.  The researchers recruited 192 adults aged between 18 and 65 who were undergoing keyhole surgery and randomly divided them into two groups.  The first group underwent surgery as normal, receiving standard general anaesthesia and medications to help prevent nausea.  The second group received exactly the same treatment, but from the moment they were anaesthetised until their surgery was completed, they wore noise-blocking ear defenders.  They recorded whether participants experienced nausea, retching or vomiting while recovering from their anaesthetic and during the following two days.  The results found that only 35 percent of the ear defender wearing patients experienced nausea or vomiting within 48 hours compared to 52 percent without ear defenders (32 percent reduction).  They also found that patients whose hearing had been protected experienced less severe symptoms during the first 24 hours after surgery.  So why would blocking sound make a difference when someone is unconscious?  It's tempting to think of general anaesthesia as switching the brain off, but that's not really what happens.  The researchers suspect that sound exposure during surgery might activate stress-related responses even when patients aren't consciously aware of the noise.  Those responses could potentially interact with the brainstem circuits involved in triggering nausea and vomiting.  Perhaps blocking sound reduces physiological stress, or changes how the nervous system processes pain.  The fascinating part to this study is that it challenges our assumptions about what it means to be unconscious.  The study raises the question that if our brains can still respond to the world when we are unconscious, perhaps a quieter operating theatre could help us wake up feeling better.  **LISTEN ABOVE** See omnystudio.com/listener for privacy information.