Antibiotic sensitivity testing: Antibiotic sensitivity test of bacterial strain separation on 23 frequently used antibiotics were applied on MullerHinton agar medium by disk diffusion technique according to National Committee for Clinical Laboratory Standards (NCCLS) as mentioned by (10) utilizing Disc of antibiotics such as Erythromycin (15μg), Cephalexin(30μg), Ceftriaxone(30μg), Chloramphenicol (30μg Piperacillin (100μg), Colistin(50μg), Streptomycin (25μg), Cefotaxime (30μg), Gentamycin (10μg), Amikacin (30μg), Neomycin(30μg), Vancomycin(30μg), Azithromycin (30μg), Tetracycline (30μg), Amoxicillin(30μg), Penicillin ( 10μg), Ceftazidime (30μg) , Cloxacillin (1μg), Nalidixic acid (30μg), Ciprofloxacin(5μg), Cotrimoxazole (25μg) Levofloxacin (5μg), and Imipenem (10μg) were placed on each isolated bacteria respectively and incubated at 37°C. Later, after 24 hours of incubation, the diameter of zone of inhibition that encircles the antibiotics was quantified as suggested by the Clinical Laboratory Standard Institute (11).The procedure of data collection The patients were contacted by the researchers to explain the steps of the CVP insertion and withdrawing sample for blood culture. Later the written permissions were taken from the patients to engage in the study. Next, the patients’ demographic data and clinical profile were fulfilled by the researchers from the medical records including age, sex, body mass index, pre-morbid disease, length of hospital stay. This stage consumed half an hour for each patient. Later, the nurse researchers attended the procedure of insertion of central venous catheters for each patient. Central venous CVCs were supplied as an available kit and inserted using a Seldinger technique by intensive care physician. Insertion was carried out under strict aseptic techniques (gowns, gloves, and masks). The insertion site ( jugular or subclavian ) was cleaned with 10% povidone-iodine solution for at least 1-2 min and a sterile field protected with long wraps . After sterilization of the insertion site, the physician underwent the insertion process. During this invasive intervention, the researchers observed the procedural steps and recorded the CVCs related data including the site of insertion, duration of insertion, the use of guide wire, the number of lumens, and duration of Cather in situ. . Following completion of CVC insertion, the critical care nurses withdrew the venous blood culture. The site of insertion was covered by sterile gauze and a transparent adhesive tape. This phase took 30-45 minutes for each patient. Later, the withdrawn samples were aseptically transferred to the laboratory to be cultured. Dressings were replaced if the gauze became soiled. CVCs were not routinely replaced unless they were suspected of being contaminated. The blood culture was repeated again on the seventh of insertion. After 72 hours, the researcher got the patients’ blood culture reports and recorded them. If blood culture was positive , the bacterial isolates and sensitivity test were carried out and documented . The overall data collection took 16 months starting from May 2015 to September 2016. Ethical consideration This study was agreed by the ethical committee of faculty of nursing, Cairo University. As well, written permission was obtained from the head of the critical care unit at Al-Haram Hospital in Egypt. Each patient was contacted by the researchers to clarify the nature of the study. In addition, formal consent was taken from all studied patients before enrollment in the study. Anonymity and confidentiality of patients’ data were ensured throughout the study. Content validity and reliability Content validity of study tools such as an observational checklist of central venous catheter-related data and patients’ clinical profile were reviewed by nine experts in the critical care nursing and microbiology specialties . Based on experts’ recommendations, the researchers employed the content validity index (CVI) to investigate the quantitative content validity of the established data collection tools utilizing a 4-point likert scale (12). The critical threshold value for CVI was adopted at 0.79 (Polit et al., 2007). Items that showed a CVI of 0.79 or more were incorporated in the final form of both tools . Regarding content validity ratio (CVR,) the experts were asked to quantify each item on a 3-point Likert scale–important (graded 1), Useful but not important (graded 2) and not important (graded 3). Regarding the number of experts and the significant values of CVR as proposed by (13). Elements that revealed a CVR of 0.5 or more were adopted . Reliability for both checklists were tested utilizing the Cronbach Alpha (r=0.83) in a pilot study of 12 patients. Data AnalysisStudy data were analyzed utilizing the statistical package for social sciences (SPSS) version 21. Continuous data was calculated such as mean and standard deviation (SD), while the qualitative data were illustrated as frequencies and percentages. Moreover, Chi-square was tested for correlates qualitative data. The level of significance was adopted at 0.05.