Description

Subjects and Methods

Study Design:

This cross-sectional descriptive study will be conducted on admitted patients in Cardiovascular Unit at the Tertiary Care Hospital in Port Said hospitals.

Subjects

From each patient the following data will be collected: full medical history, symptoms and signs, lab investigations including serum electrolytes, procalcitonin, liver and kidney function tests, receipt of antibiotics and its response.

Inclusion criteria:

• Patients diagnosed with sepsis based on medical history, lab investigations and clinical picture.
• Both sex, and all age-groups.

Exclusion criteria:

• Patients diagnosed with sepsis proved by medical history, lab investigations and clinical picture who received non-beta lactam antibiotics for the past 24 hours.
• Samples proved contaminated by microbial flora will be rejected.

  Methods

Study design This study will be conducted at the tertiary care hospital which offers a medical and surgery ICU and also has a cardiovascular Unit.

Epidemiologic and clinical information of patients and classification of the bacteremia as Primary Bloodstream Infections (PBI), and Secondary Bloodstream Infections (SBI), based on CDC criteria (5) and its National Healthcare Safety Network (NHSN) yearly update.

Sample collection

1. Venous blood samples from cases with suspected sepsis, or bacteremia will be incubated with a medium which encourages promotes bacterial growth.
2. We will take samples of 2 or more sets of aerobic and anaerobic blood cultures (3or 8 mL per small or large bottle)
3. Two blood cultures drawn from different areas are frequently enough to diagnose bacteremia. Two out of 2 cultures growing identical type of bacteria often represents a real bacteremia, in particular if the organism which grows isn't a frequent contaminant.
4. Bacterial isolates from blood will be analysed by utilizing an automatic blood culture system (Bact/Alert).
5. Positive samples will be cultured on different selective media. Primary organism recognition will be done with matrix assisted laser desorption ionization time of flight MS on a Vitek MS system (BioMerieux, Inc. France).
6. Calibration will be performed using standard strains to validate the run.
7. Minimum Inhibitory Concentration (MIC) outcomes will be interpreted based on the Clinical and Laboratory Standards Institute (CLSI) protocols.
8. Biochemical tests which include CRP of Procalcitonin is most of time increased among cases with BSI.

Sample size:

Number of Samples is calculated according to the next equation:

N= (Z α\2)²×P(1-P)\d² (Daniel, 2009) In which; N= the required sample size (Z α\2) = A normal deviation reflect the type 1 error = 1.96 P = the prevalence of atypical bacteria in sputum samples = (46%) (13). D = the accuracy of estimate (how close to the true population) = 0.1

Thus; N= 60 blood samples.

Data Management and Statistical Analysis The results of the collected data will entered into SPSS-19 program for statistical analysis.

Descriptive data will be managed based on its type; mean, SD and range will summarize continuous data. While qualitative data will be summarized by frequencies.

With regard to analytic data, chi square test will be utilized to determine the difference between qualitative data, while T test and ANOVA will be utilized to determine the difference between quantitative data.

Ethical considerations

• The samples will be collected from patients after taking written informed consent.
• The study will be conducted after taking the permission from chairman of each department.
• The results of the patient will be confidential.
• The patient will be informed of the results and will be treated accordingly.
• The patient has the right to leave the study without compromising the patient's treatment or the patient's relationship with the care provider.