C-reactive protein as a prognostic marker and guidance for use of antibiotic therapy in patients presenting with lower respiratory tract manifestations in intensive care unit in tertiary care centre

Nisha ., Uday G


Introduction: C-reactive protein is a acute phase reactant protein synthesized in the liver and in response to various stimuli. It is a simple blood test to distinguish between viral and bacterial pneumonia. It is a cheap and easily available useful adjunctive test to limit the use of antibiotics in patients presenting with lower respiratory tract manifestations.
Materials and Methods: It is a prospective study of 60 patients admitted with lower respiratory signs and symptoms in Intensive Care Unit of Mallareddy institute of medical sciences, Hyderabad, Telangana. Serum CRP level measured by latex agglutination method and other markers of infection like Complete blood count, Sputum microscopy culture and sensitivity and chest X-ray were done on presentation. CRP concentration of more than 20mg/l taken as positive. Number of CRP positive patients were correlated with patients of increased WBC count and positive sputum routine culture and sensitivity and results were compared using chi -square test.
Result: Total 60 patients were taken for study out of which 38 were male and 22 were female. Out of which 24(40%) were diagnosed with pneumonia, 6(10%) with pulmonary Koch’s, 7(11.6%) with acute exacerbation of asthma, 11(18.3%) were COPD,4(6%) with congestive cardiac failure, 5(8.3%) with autoimmune disorder and 3(5%) with interstitial lung disease. Among them 29(48.3%) patients were found to have CRP value of more than 20mg/dl which is considered as positive, out of these 29 patients, 16(55.17%) were having pneumonia which was confirmed on imaging and sputum culture and sensitivity.
Out of these 29 patients with CRP positive 21(72.4%) were found to have sputum culture and sensitivity as positive for bacteria in which 4(19%) were diagnosed as autoimmune disorder,2(9%) with bronchial asthma, 10(47.6%) with pneumonia, 3(14.2%) with COPD, 2(9.5%) with pulmonary Koch’s. Among 29 patients with positive CRP, 18(62%) patients have the WBC count of >11,000cells/mm3. Patients with CRP positivity having positive culture sensitivity {21patients (72.4%)} were started on antibiotic therapy. Out of total 24 pneumonia cases, 10(41.6%) were sputum culture positive as well as CRP positive pneumonia. As according to the result of our study the patient of pneumonia had higher CRP in comparison with patients with COPD, bronchial asthma, Congestive cardiac failure, Autoimmune disorders, interstitial lung disease. Correlation of number of raised CRP positivity, sputum positivity and raised WBC count were statistically significant with p value of <0.005 by using chi -square test. No significant difference of CRP found in the age and sex distribution of the patients and no significant mortality found. Patients with positive CRP, positive sputum culture and sensitivity were started on specific antibiotic therapy.
Conclusion: Serum CRP levels is a useful marker for establishing the diagnosis of Community Acquired Pneumonia in adult patients presenting with lower respiratory tract manifestations. Higher CRP values are suggestive of severity of the disease which may help in deciding the appropriateness of use of antibiotics
in the line of management.

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