Results of a multicenter randomized controlled trial published in the September issue of the Journal of the American Medical Association (JAMA) indicate that including procalcitonin (PCT) levels in the diagnostic algorithm may reduce the frequency of prescribing antibiotics for lower respiratory tract infections.

It is generally recognized that unjustified prescription of antibiotics leads to the emergence and spread of antibiotic resistance from microorganisms, and also increases the cost of treatment and the risk of adverse drug reactions (NLR).

The most common indications for prescribing antibiotics in European countries are lower respiratory tract infections (LDS). At the same time, the severity of acute respiratory infections can range from cases of acute bronchitis without treatment to severe exacerbations of life-threatening chronic obstructive pulmonary disease (COPD) and severe community-acquired pneumonia (CAP). In general, about 75% of SARS patients receive antibiotics, although most infections are caused by viruses. It is assumed that determining the level of PCT in blood serum will adequately differentiate between viral and bacterial infections and reduce the frequency of unjustified prescription of antibiotics.

The objective of the Swiss study was to determine the possibility of reducing the frequency of prescription of antibiotics in patients with LID due to the inclusion of a PCT test in the diagnostic algorithm, without increasing the risk of unwanted LUT results.

During the period from October 2006 to March 2008, 1359 patients, mainly those with severe LDP, who referred to the emergency services of 6 large hospitals in Switzerland, were randomized into 2 groups. In patients in the study group (n = 687), the level of PCT was included in the diagnostic algorithm; in the control group (n = 694), they were limited to a list of routine examinations.

In the patients in the study group, the decision on the necessity of prescribing and on the possibility of stopping the antibiotics was made on the basis of predetermined values of the level of PCT. In particular, antibiotics were considered absolutely indicated for PCT values greater than 0.5 μg / L, indicated for PCT values greater than 0.25 to 0.5 μg / L, not shown for PCT levels of 0, 1 to 0.25 μg / l and absolutely not indicated for PCT less than 0.1 μg / l. Repeated PCT determinations were performed on the 3rd, 5th, 7th day of treatment and upon discharge. Antibiotic treatment was stopped with a decrease in PCT levels of 80% or more. In patients in the control group, antibiotic therapy was carried out in accordance with the standards adopted by the establishment.

Unfavorable treatment outcomes included death, hospitalization in the intensive care unit and intensive care unit (ICU), complications of LDP or recurrence of infection requiring antibiotics within 30 days of first treatment. The other parameters studied were the frequency and duration of the prescription of antibiotics, as well as the recorded HLR antibiotic therapy.

Two groups of patients were comparable, the average age of the patients was 73 years, 59% were men, 40% had COPD, 20% had coronary artery disease and 22% had chronic kidney disease. At admission, 68% were diagnosed with CAP, 17% had an exacerbation of COPD, 11% had acute bronchitis and 4% had other LIDs.

A similar frequency of undesirable results was observed in the two groups of patients: in the group with PCT determination, 15.4% [n = 103], in the control group, 18.9% [n = 130]; the difference is -3.5%; 95% confidence interval (CI) from -7.6% to 0.4%. The odds ratio (OR) for an adverse treatment outcome was 0.76 in all subgroups of patients with PCT; in the OS pneumonia subgroup, it was also 0.76.

The frequency of prescription of antibiotics in the study group increased from 87.7% to 75.4% for all IDPs in general, which represents 25.7-38.5% in different research centers. In community-acquired pneumonia, the frequency of prescribing antibiotics increased from 99.1% to 90.7%, with exacerbations of COPD - from 69.9% to 48.7%, and in bronchitis acute - from 50% to 23.2%.

The mean duration of antibiotic therapy was lower in all of the following subgroups of patients who underwent PCT determination, compared to similar subgroups in the control group:

The average duration of IV antibacterial therapy decreased overall from 3.8 to 3.2 days, with CAP - from 4.8 to 4.1 days, with exacerbations of COPD - from 1.9 to 1.3 days and 1.0-0.6 days for acute bronchitis. The average duration of taking oral antibiotics overall decreased from 4.9 to 2.5 days, with the CAP - from 5.9 to 3.1 days, with exacerbations of COPD - from 3.2 to 1, 3 days and 1.8 to 0.4 days with acute bronchitis.

Compared with the control group, in the group of patients who underwent a PCT determination, a lower incidence of antibiotic-induced NLR was observed: 19.8% (n = 133) vs 28, 1% (n = 193); the difference is 8.2%; 95% CI from -12.7% to -3.7%. Note that the maximum reduction in the risk of developing NLR has been noted in patients with community-acquired pneumonia. The length of hospital stay was similar in the two groups of patients.

Thus, administration of antibiotics to patients with lower respiratory tract infections based on the results of determining the level of PCT in blood serum does not increase the risk of adverse treatment results in patients for which antibiotic therapy is not performed. At the same time, the use of such tactics for the management of patients with LID reduces the frequency of prescription of antibiotics and reduces the risk of adverse drug reactions associated with their use. In addition, it is expected that reducing the frequency of unjustified use of antibiotics will help reduce the likelihood of the development and spread of antibiotic resistance.