After five years of reviewing the latest research findings, a panel of experts led by a Duke University Medical Center anesthesiologist has developed new guidelines to help physicians reduce the occurrence of nausea and vomiting in patients after surgery.
Despite decades of advances in surgical techniques and improved anesthetic agents, one out of three patients still experiences postoperative nausea and vomiting, said Duke anesthesiologist Tong J. Gan, M.D., leader of the panel that developed the guidelines. Such conditions not only can lead to patient dissatisfaction, but also can lengthen hospital stays and prolong recovery, he said.
Gan presented the new guidelines, one set for adults and one for children, on Monday, Oct. 16, at the annual scientific meeting of the American Society of Anesthesiologists, in Chicago. The panel, which included anesthesiologists, surgeons, pharmacists, nurse anesthetists and biostatisticians, was commissioned and supported by the Society of Ambulatory Anesthesia.
The guidelines incorporate the use of new drugs, known as antiemetics, which patients receive prior to surgery to prevent nausea and vomiting. The researchers also found that combining different classes of antiemetics added to their effectiveness.
The guidelines also provide new information that should help physicians identify which patients are at the greatest risk for nausea and vomiting and therefore should receive antiemetics prior to surgery.
"The results of more than 250 trials of antiemetics have been published since the last guidelines were developed five years ago," Gan said. "The new guidelines incorporate much of this new information and provide physicians with up-to-date strategies for preventing and treating postoperative nausea and vomiting."
Children are twice as likely as adults to develop postoperative nausea and vomiting, Gan said, and the panel developed a simple four-point scoring system for identifying those children at highest risk. The four factors are: when a surgical procedure lasts more than 30 minutes; when children are three years of age or older; when there is a family history of postoperative nausea and vomiting; and when the surgery is to correct strabismus, or crossed eyes.
"If one of these risk factors is present, then there is a 10 percent chance of postoperative nausea and vomiting," Gan said. "Each additional factor adds another 20 percent chance, meaning that a child with all four would be at a 70 percent risk. Since the previous guidelines were developed, there have been a number of effective antiemetics approved for use in children, and we would recommend that children identified as being at high risk should be given a combination of these drugs."
For adults, the factors that elevate risk include being female, being a nonsmoker and having a family history of motion sickness or postoperative nausea and vomiting. Also, long surgeries, or those that use nitrous oxide as an agent of general anesthesia, increase risk, Gan said, as does the use of opioids to control pain after surgery.