Procalcitonin helps predict prognosis among those with peritonitis

Monitoring blood levels of a compound known as procalcitonin in patients with peritonitis (a serious intra-abdominal infection) could help identify patients at increased risk of organ failure and death, according to a report in the February issue of Archives of Surgery.

Organ failure related to blood stream infection (sepsis) is the leading cause of death in surgical intensive care units, accounting for up to 60 percent of deaths, according to background information in the article. Peritonitis, infection of the layer of tissue lining the abdominal wall, is one of the most important sources of abdominal sepsis. Secondary peritonitis occurs as a consequence of another condition, such as a puncture in the gastrointestinal tract that allows the spread of bacteria, and generally this underlying condition must be treated surgically. However, continuing or new-onset abdominal sepsis continues to be a major problem for these patients following surgery, placing them at risk of multi-organ dysfunction syndrome (failure of two or more organ systems) and death.

"Facing this clinical dilemma, there is major interest in the search for an optimum diagnostic tool for an early, noninvasive and reliable diagnosis of abdominal infections and sepsis," the authors write. Currently, these conditions are diagnosed with imaging procedures and guided aspiration (suction) techniques. "An accurate and readily available biochemical marker for identifying patients at risk for abdominal infections would definitely contribute to easier and safer diagnosis."

Bettina M. Rau, M.D., University of the Saarland, Homber/Saar, Germany, and colleagues enrolled 82 patients with secondary peritonitis between 1999 and 2004 in a study to determine whether procalcitonin could be such a marker. Procalcitonin, an inactive precursor to a hormone known as calcitonin, has been shown to be more prevalent in patients with bacterial and fungal infections and sepsis. Bacterial specimens were obtained from the abdomens of all participants, as were other tissue cultures when sepsis was suspected. The patients were monitored from within 96 hours of their first symptoms to a maximum of 21 days for levels of procalcitonin and another marker of inflammation, C-reactive protein, and for signs of lung or kidney failure.

Over the follow-up period, 42 patients developed lung failure, 25 developed kidney failure, 35 had multiorgan dysfunction syndrome (31 cases of which were related to sepsis) and nine died. "Procalcitonin concentrations were most closely correlated with the development of septic multi-organ dysfunction syndrome, with peak levels occurring early after symptom onset or during the immediate post-operative course," the authors write. "No such correlation was observed for C-reactive protein."

It was possible to predict multi-organ dysfunction syndrome by assessing procalcitonin levels on the first two days following surgery; those with values of 10 nanograms per milliliter on two consecutive days were at higher risk. "Persisting procalcitonin levels greater than 1 nanogram per milliliter beyond the first week after disease onset strongly indicated non-survival and were significantly better than C-reactive protein in assessing overall prognosis," they continue.

"In summary, the present prospective, international multi-center study shows that monitoring of procalcitonin levels is a fast and reliable approach to assessing severe septic complications and overall prognosis in patients with secondary peritonitis," the authors conclude. "This single-test marker improves stratification of patients who will develop clinically relevant complications."