An Italian study shows having clowns in the operating room can ease anxiety - at least among child patients.
Clown antics are an acquired taste for some
Clowns successfully distracted children aged five to 12 years while they were put under anaesthesia for surgery.
But their clowning around annoyed most medical staff - who were concerned it interfered with normal working protocols, says a report in Pediatrics.
A charity that provides "clown doctors" said it had found hospital staff were positive about such schemes.
Clowns from the Theodora Foundation are active in 89 hospitals around the world, including eight in the UK.
In the study, Laura Vagnoli and colleagues from the Anna Meyer Children's Hospital in Florence assessed the stress levels of 40 children who about to undergo a planned minor operation.
Half of the children interacted with two clowns before entering the operating room and stayed with them and their parent while they were given a general anaesthetic, which took about 15 minutes.
The clowns used magic tricks, gags, puppets and soap bubbles to entertain the children.
The other children were only accompanied by a parent with no other distractions before the operation.
Anxiety of the child was measured by staff who looked out for recognised signs of stress. The parents were asked to fill out a survey about their own anxiety during the process.
After the operation, the researchers also asked the operating room staff for their opinions about the experience.
Overall, the children in the clown group appeared to be far less stressed and anxious than the other children. Similarly, their parents were also less anxious.
The medical personnel also noted that the presence of the clowns helped reduce anxiety among the children and parents.
However, few of the staff said they would continue to use clowns in their operating theatres because they were concerned that their presence interfered with the routine of the preoperative room.
The doctors and nurses said they thought that the clowns delayed procedures and interfered with the relationship between medical personnel and the child.
The researchers did not measure whether these concerns were supported by longer operating times, but they said it would be worth investigating.
They said: "We would encourage the promotion of this form of distraction therapy for children requiring surgery.
"The resistance of medical personnel to this kind of therapy could be dealt with better by providing information regarding the benefit of the therapy to children and by investigating whether the presence of clowns during anaesthesia induction slows the process in a significant manner."
Sue Hind-Woodward, executive director of the Theodora Foundation, said: "In the UK, our clown doctors do not go into the preoperative room where the anaesthetic is being administered, but some are there when children are given their premeds before surgery.
"The clowns are excellent. They do help children relax, particularly when they are having procedures that they do not like."
She said UK medical staff had been "very receptive and supportive" of such schemes.
However, she said they had heard about some anecdotal reports from Italy where staff were less receptive.
"A lot of it is about making absolutely sure that you do get the medical team onside.
"We make sure we fall in with the medical, ethical and hygiene guidelines and conform."