Reducing Postoperative Nausea and Vomiting
DURHAM, N.C. -- A Duke University Medical Center
anesthesiologist who analyzed studies of postoperative nausea
and vomiting (PONV) believes that better communication between
physicians and patients would significantly reduce nausea and
vomiting as a side effect of surgery.
He advocates that physicians work with each patient to
develop a plan to reduce PONV that might include treatments
ranging from anti-emetic drugs to stress reduction to
acupuncture. Not only would the use of such plans return
patients to their everyday lives sooner, he said, it could also
significantly reduce health care costs.
Despite decades of advances in surgical technique and
improved anesthetic agents, one out of three patients will
still experience nausea and vomiting after surgery. Such a
condition not only influences patient satisfaction, but can
also prolong recovery, lengthen hospital stays and negatively
impact the surgery itself.
"There are more than 35 million surgical procedures
performed each year in the U.S., so PONV is an extremely
important health care issue," said Duke anesthesiologist Dr.
Tong J. Gan, whose analysis was published in the March 13, 2002
issue of the Journal of the American Medical Association. "It
is also an issue that most physicians do not take seriously
enough; they see it as a short-term nuisance that will soon
pass. However, studies have shown that nausea and vomiting
after surgery is the major factor influencing whether or not
patients are satisfied with their surgery.
"We already know a lot about PONV and new drugs are being
developed all the time. It is just a matter of putting it all
together," Gan continued. "To do better, physicians need to ask
the right questions of their patients in order to develop
strategies to reduce the chances of it occurring."
The challenge, according to Gan, is identifying all relevant
the risk factors ? whether they be patient characteristics,
type of surgery, and method of anesthesia ? that place the
patient at higher risk for PONV. With this knowledge, steps can
then be taken to make a postoperative recovery as painless and
event-free as possible.
According to Gan, four main patient characteristics appear
to predispose patients to PONV: being female, being young,
being a non-smoker and having a history of PONV or motion
sickness. Additionally, the chance of PONV increases
significantly if opioids are used for postoperative pain
"Women are at a three times higher risk of PONV when
compared to men," Gan explained. "There have been studies
looking at hormonal links or where a woman may be in her
menstrual cycle at the time of surgery. But nothing to date is
In general terms, the likelihood of developing PONV
decreases with age, and studies during the past five years have
shown that smokers have a lower risk for PONV, though the
mechanism of this protection is not well understood, Gan
According to Gan, patients with none of the above patient
risk factors have a 10 percent chance of PONV, while patients
with all risk factors have a 79 percent chance.
On the surgical side, there are certain procedures that are
known for producing a high incidence of PONV, including certain
neurosurgical procedures, major breast procedures, certain eye
surgeries, otolaryngologic (ear, nose, throat) operations,
laparoscopy and laparotomy.
Interestingly, he said, the minimally invasive procedures
such as laparoscopy have high rates of PONV. This could be due
to the gas, which is used to "inflate" the abdomen to create a
workspace for the instruments, putting pressure on the vagus
nerve, which has a connection to the brain's nausea and
"By assessing all these potential risk factors ? both from
the patient and the surgical sides ? we can tailor a plan to
reduce the incidence of PONV," Gan said. "It takes input from
the patient and all members of the medical team."
According to Gan's analysis, patients with one or two of the
combined risk factors are considered at mid- to moderate-risk,
and a single dose of an anti-emetic drug (anti-nausea) such as
droperidol, scopolamine or dexamethasone can be effective.
Those with more than four factors should be considered at high
risk and should receive a combination of anti-emetics and
should probably receive total intravenous anesthesia for their
In addition to these approaches to preventing PONV, Gan said
there are additional options that should be considered, ranging
from the delivery of additional oxygen during surgery to
maintaining proper hydration during surgery to reducing stress
before surgery through the use of medication.
Another complimentary approach includes the use of
acupuncture before and during surgery. A recent study conducted
by Gan demonstrated that this ancient Chinese practice was just
as effective in controlling PONV for women undergoing major
breast surgery as anti-emetics. These procedures cause PONV in
about 70 percent of the cases.
"Anesthesia is very safe now and we need to move beyond the
surgery itself to improving the quality of recovery," Gan said.
"The aim is not just to ensure our patients survive a surgical
procedure, but to get our patients back to their normal
everyday lives quicker."