WEDNESDAY, Feb. 27, 2008 (HealthDay News) -- The artery-tightening medication vasopressin holds no overall advantage over an older drug, norepinephrine, in the treatment of severe septic shock, a new study finds.
But vasopressin did appear to be better for less severe cases in the study, said Dr. James. A Russell, a professor of medicine at the University of British Columbia and lead author of a report in the Feb. 28 issue of the New England Journal of Medicine.
Septic shock occurs when an infection, usually bacterial, overwhelms the body's natural defenses, causing drastic drops in blood pressure and blood flow. Quick treatment to raise blood pressure can reduce the death rate, which is high. In this study, more than 35 percent of those treated with either drug died in the first four weeks.
"Vasopressin has been widely used for the treatment of septic shock because of studies showing an improvement in blood pressure and function," Russell said. "There has never been a large study examining the effect on mortality. Our study showed that basically, vasopressin and norepinephrine are safe and equally effective overall."
The study included 778 people treated for septic shock in a number of hospitals in Canada, Australia and the United States. In the first 28 days, 35.4 percent of those given vasopressin and 39.3 percent of those treated with norepinephrine died -- a difference that was not statistically significant.
But there was a statistically significant difference among those with less severe septic shock, defined by the dose of norepinephrine needed to raise blood pressure the desired amount, Russell said. In that group -- about half the people in the study -- 26.5 percent of those given vasopressin died, compared to 35.7 percent of those given norepinephrine. The death rate for more severe cases was 44 percent with vasopressin treatment, 42.5 percent with norepinephrine treatment.
"In our hospital, patients with less severe septic shock are being treated with vasopressin," Russell said.
But perhaps the most important factor in treatment is time, said Dr. Joseph E. Parrillo, a professor of medicine at Robert Wood Johnson Medical School in Camden, N.J.
"Two previous papers suggest that the support you give to the patient, fluids and a vasopressor, are only effective if instituted within the first few hours after the onset of septic shock," Parrillo said. "One paper also suggested that giving an antibiotic early made a difference, with a 20 percent death rate if an antibiotic was given in the first hour, and 60 percent if given by hour six."
The choice of antibiotic to treat the infection underlying the condition is also important, he said. "It makes a difference if you use antibiotics to which the infectious organism is sensitive," Parrillo said. A broad-spectrum antibiotic is adequate in most cases, he added.
Recent guidelines issued in a joint effort by 11 medical organizations, led by the Society of Critical Care Medicine, stress the need for early antibiotic treatment, Parrillo said. The guidelines do not stress the use of one artery-tightening medication over another, but, "the feeling is that there is no reason to use vasopressin," he said.
Causes and treatment of septic shock are described by the U.S. National Library of Medicine.