This is a high-stakes scenario for any surgeon: a 65-year-old male patient with a high BMI and a heart condition undergoes emergency surgery for a perforated appendix.
An internal bleed is detected, an anesthesia monitor malfunctions and several beeps sound – before an urgent call about an ectopic pregnancy comes in on another ward.
This kind of drama often plays out in operating theatres, but in this case trainee surgeon Mary Goble is joined by a team of researchers Imperial College in London which studies what goes on in the brains of surgeons as they perform life-or-death procedures.
Goble looks cool and composed as she laparoscopically excises the silicon appendix, fending off a barrage of distractions. But her brain activity, monitored through a cap covered with optical probes, may tell a different story.
The researchers, led by Daniel Leff, a senior researcher and consultant thoracic surgeon at Imperial College Healthcare NHS Trust, are working to detect clear signs of cognitive overload based on brain activity. In the future, they say, it could help flag warning signs during surgery.
“The operating theater can be a very chaotic environment and as a surgeon you have to keep your head and stay calm when everyone is losing theirs,” Leff said. “As the cognitive load increases, this has major implications for patient safety. There is no tool we can use to know that the surgeon is handling the cognitive demands of that environment. What happens if the surgeon is exhausted?”
In the future, Leff envisions a system that can read brain activity in real time in the operating room and trigger an intervention if a surgeon is at risk of overload.
“If you really like listening to Whitney Houston, you can automatically play calming music. Or it could alert the lead theater nurse so she can deal with the inevitable nonsense that happens in a theater room,” Leff said. “It’s like Minority Report for surgery.”
More controversially, it may also be possible to use brain stimulation to improve a surgeon’s performance if they lose concentration.
The cap worn by Goble uses functional near-infrared spectroscopy (fNIRS), a non-invasive technique to measure changes in blood oxygenation in the brain – a proxy for the underlying neural activity. Previously, the team showed that novices had greater pre-frontal brain activity than experienced doctors when performing surgery. They too found that pre-frontal activity is more easily disrupted in doctors whose performance has decreased during stressful situations.
The latest work seeks to map the fNIRS signatures of cognitive overload when a doctor’s performance begins to decline because they can no longer cope with the influx of information and demands placed on them. The study, using trainee surgeons, will monitor brain activity and surgical performance as progressively more demands are introduced. The simulated environment means that every movement of the laparoscopic instruments can be tracked, and copper wires embedded in the silicon appendix detect whether incisions are on target.
“You often don’t really see any external signs from people,” Leff said, adding that doctors stereotypically have a “don’t hesitate to treat” mentality.
After the walkthrough, Dr Goble, a surgical trainee at Kings College NHS trust and study participant, said her stress levels soared even though it was a simulation. “Surgery is a stressful environment,” she said. “On a night shift, when you’re alone and you have to deal with competing clinical priorities, it’s really easy to get really overwhelmed. I work on my breathing as a kind of concentration method.”
Simulated surgery is increasingly used in teaching at medical schools and so this type of monitoring can be integrated into training to identify trainees who need more support and to track progress, according to Leff. Future patient safety policies could also be informed by better evidence about how operating theater environments affect performance, similar to how findings about fatigue led to new rules about safe work patterns for doctors.
“I think if it’s framed in a way that’s about helping people become the best doctors they can be and that it’s about patient safety, the acceptance is greater,” Leff said. “The moment you try to use these things to say that someone is capable or not capable, you start having problems.”
It is not yet possible to read out brain activity in real time while surgeons operate – and this application is likely to be more than a decade away. But rapid advances are underway in brain-computer interface technologies, including non-invasive helmets designed to measure brain activity in healthy individuals.
The Imperial team is also investigating the possibility of using a non-invasive technique called transcranial direct current stimulation (tDCS) to improve performance. It involves passing a weak electric current between two sponge electrodes placed on the scalp – just enough to feel a slight tingling sensation. Previously, they found that trainee surgeons learning to suture laparoscopically improved faster and achieved a higher level of performance if they received tDBS while training. However, experienced surgeons did not see the same gains.
“When it comes to neuro-augmentation, it’s definitely more challenging terrain and people are becoming more skeptical,” Leff said. “It’s an area that’s going to struggle to get a lot of support because you’re talking about sending signals to someone’s brain. fNIRS is harmless monitoring of what is happening and we have seen that it is much more acceptable to people.”
