Muscle relaxants given to millions of patients during general anaesthesia are associated with an increased risk of serious breathing problems after surgery, research suggests.
The drugs that are used to reverse the muscle relaxants after surgery may also increase the risk according to a team of US researchers.
The drugs, known as neuromuscular blocking agents, paralyse the muscles and enable surgeons to perform intricate operations without fearing that the patient will move.
The research, published on bmj.com, examined 18,579 patients who received at least one intermediate acting neuromuscular blocking agent during surgery with the same number of patients who did not.
They found that respiratory complications, such as the need for reintubation after surgery and deteriorating blood oxygen levels were more common if a muscle relaxant and a reversal agent had been given.
There was a 36% increased risk of deteriorating blood oxygen levels for patients who were given the muscle relaxants.
Researchers also found that 151 patients who received the neuromuscular blocking agents needed reintubation compared to 108 who did not.
“The use of intermediate acting neuromuscular blocking agents during anaesthesia was associated with an increased risk of clinically meaningful respiratory complications,” the authors conclude.
“Our data suggest that the strategies used in our trial to prevent residual postoperative neuromuscular blockade should be revisited.”
But an accompanying editorial argues that it would be a mistake to change clinical practice on the basis of this one study.
Jennifer Hunter, emeritus professor of anaesthesia at the University of Liverpool, said: “It would be a mistake to conclude that current recommended clinical practice should change on the basis of the findings of this one study, however large and well executed.
“It is difficult to accurately define the incidence of rare but serious complications associated with widely practised techniques.”