Procalcitonin Versus C-reactive Protein to Guide Therapy in Community Acquired Pneumonia

In this study the investigators aim to test if C-reactive protein (CRP) or procalcitonin(PCT) - guided strategy allows to reduce the antibiotic use in patients wiht community-acquired pneumonia. Therefore, the safety of this intervention will be carefully measured.

Methods

• Patients and settings:

All adult (\> 18 years old) patients with diagnosis community-acquired pneumonia will receive initial antibiotic therapy based on local guidelines and susceptibility patterns, according to the decision of the treating physician.Patients will be randomly assigned to one of two groups, which respectively include PCR and PCT clinical procedure protocol. Randomization will be done using a table of random numbers generated by computer. For practical reasons the doctors treating the patients in question have science group in which the patient was included.

Patients included in the two groups will have baseline assessment during the first day of study:

* Clinical evaluation of basic
* Start of antibiotic therapy
* Inclusion in the study
* Randomization (after signing the Informed Consent)
* Interventions:

They will have circulating PCT and CRP levels measured at baseline and days 1,2,3 e 5 in both groups.

Group 1 - CRP group: the duration of antibiotic therapy will be based on circulating CRP levels.

Group 2 - PCT group: the duration of antibiotic therapy will be based on circulating PCT levels.

Patients enrolled in the study will undergo daily measurements of plasma CRP (Dry Chemistry - Johnsons \& Johnsons) and PCT (BRAHMS PCT VIDAS) levels up to day 5, and then, every 48hr in patients remaining in the ICU, and every 5 days in those transferred to the ward. Patients will be followed up 28 days, or until death or hospital transference, which comes first. PCT and CRP results will be released in sealed envelopes. During the study period, only the results corresponding to the patient randomization group will be open; i.e., CRP for CRP group patients and PCT for PCT group patients.

Criteria for antibiotic interruption:

The investigators will propose the interruption of antibiotics if:

1. The patients is clinically stable, without signs of active infection
2. CRP group: a relative reduction of 50% in baseline CRP levels, or a value lower than 25mg/dl is reached.
3. PCT group: a relative reduction of 90% in baseline PCT levels, or if a absolute value lower than 0.1 ng/ml is reached.

The final decision regarding antibiotic therapy will be always let to the discretion of the treating physician.

Eligibility Criteria:
Inclusion Criteria:

1. Age ≥ 18 years
2. Signed informed consent
3. Suspected or confirmed community-acquired pneumonia

Exclusion Criteria:

1. Nosocomial pneumonia: development of symptoms after 48 hours of admission to the Emergency Department, or within 14 days after hospital discharge
2. Patients with lung cancer confirmed strongly suspected.
3. Patients with severe immunosuppression, such as severe neutropenia (\<500 neutrófilos/mm3), use of corticosteroids in doses above 0.5 mg / kg / day of prednisone or equivalent for at least 2 weeks, transplantation of solid organs or cells hematopoietic, use of immunosuppressants for any other reason (eg. azathioprine or cyclosporine), hipogamagloulinemia
4. Patients with asplenia in any order
5. Pregnant
6. Patients with known HIV infection
7. Stay indicated only for social reasons
8. Patients on antibiotics for any other reason
9. Patients with multiple trauma, burns or surgery grid size in the last 5 days