A fresh look at past research suggests voice and throat problems are common in patients who've had a breathing tube placed during general anaesthesia.
Researchers pooled a dozen studies that looked at complications following the use of an endotracheal tube or laryngeal mask, two popular techniques that allow patients to breathe while being put under for surgery.
While the complication rates varied, one study found as many as seven out of 10 patients suffered a vocal cord injury, such as swelling or internal bleeding.
"In general, it's a very safe thing to do – having general anaesthesia with a breathing tube in place," said Dr Norman Hogikyan, an ear, nose and throat physician at the University of Michigan in Ann Arbor.
Vocal cords injuries vary
But Hogikyan, who was not involved with the new research, added that the devices are put past soft and delicate tissue in a person's throat, so it's not surprising that temporary hoarseness would occur.
For the new study, Dr Elodie Mendels and colleagues from the Maastricht University Medical Centre in the Netherlands combed through over 5,000 scientific articles from various databases.
They selected studies that described vocal cord injuries or hoarseness after a patient had been under general anaesthesia for less than five hours, and those that had before-and-after measurements of vocal cord function.
Results of the 13 studies they ended up with were hard to compare. For example, vocal cord injuries varied from none out of six patients to seven out of 10 in studies involving endotracheal tubes, which are passed through the mouth and into the windpipe.
Nothing to be alarmed over
Hoarseness was found in four out of 10 patients immediately after the operation and three out of ten within the first week.
There were also some complications after using laryngeal masks, which sit on top of the voice box instead of passing through it. In one study, one patient out of 21 had a vocal cord injury after their operation, and one in 28 patients was hoarse.
According to the researchers, whose findings are published in the Archives of Otolaryngology—Head & Neck Surgery, some people with hoarseness and injuries recovered quickly
And one expert said it wasn't anything to be alarmed over.
People have hoarse voice for a while
"We've always seen this," said Dr John F. Dombrowski, a spokesman for the American Society of Anaesthesiologists. "People have a scratchy throat or a hoarse voice for a while."
And the complications that occur are treatable, he said.
Hogikyan said that the hoarseness should clear up by itself, but if it doesn't people should see their physician, because it could be a sign of something more serious.
"If you have persistent hoarseness following a procedure, then being examined by an ear, nose and throat physician would be important," he said.
The new study's lead researcher serves on the advisory board of Ambu, a maker of laryngeal masks, and has received free samples of equipment from several companies. But she reported no financial ties to any company.
(Andrew M. Seaman, Reuters Health, March 2012)